WO2018186055A1

WO2018186055A1 - Liquid crystal alignment agent, liquid crystal alignment film and method for manufacturing same, liquid crystal element, polymer and compound

Info

Publication number: WO2018186055A1
Application number: PCT/JP2018/007185
Authority: WO
Inventors: 拓也村上; 伸夫安池; 遼須原
Original assignee: Jsr株式会社
Priority date: 2017-04-04
Filing date: 2018-02-27
Publication date: 2018-10-11
Also published as: JP7028241B2; KR102269265B1; CN110383156B; TWI805573B; CN110383156A; JPWO2018186055A1; TW201837085A; KR20190103397A

Abstract

According to the present invention, when a liquid crystal alignment film is obtained by an optical alignment method, a liquid crystal element having an excellent AC afterimage characteristics and long-term heat resistance is achieved. This liquid crystal alignment agent contains a polymer (P) having at least one selected from the group consisting of a partial structure represented by formula (1) and a partial structure represented by formula (2). In the formula, X1 is a tetra-valent organic group having a cyclobutane ring structure and has at least one substituent at a ring portion of the cyclobutane ring, X2 a divalent organic group having a specific structure having at least any one among a chain hydrocarbon structure and a cycloaliphatic hydrocarbon structure, and R5 and R6 are each independently a hydrogen atom or a monovalent organic group having 1-6 carbon atoms.

Description

Liquid crystal aligning agent, liquid crystal aligning film and production method thereof, liquid crystal element, polymer, and compound

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2017-74659 filed on April 4, 2017, the contents of which are incorporated herein by reference.

The present disclosure relates to a liquid crystal aligning agent, a liquid crystal aligning film and a manufacturing method thereof, a liquid crystal element, a polymer, and a compound.

Liquid crystal elements are widely used in TVs, mobile devices, various monitors, and so on. In the liquid crystal element, a liquid crystal alignment film is used to control the alignment of liquid crystal molecules in the liquid crystal cell. Conventional methods for obtaining an organic film having a liquid crystal alignment regulating force include a method of rubbing an organic film, a method of obliquely depositing silicon oxide, a method of forming a monomolecular film having a long chain alkyl group, and a photosensitive organic film. A method of irradiating a film with light (photo-alignment method) is known.

In recent years, the photo-alignment method can impart uniform liquid crystal alignment to a photosensitive organic film while suppressing generation of static electricity and dust, and also enables precise control of the liquid crystal alignment direction. Investigations are underway (see, for example, Patent Document 1). Patent Document 1 discloses forming a liquid crystal alignment film by irradiating a film obtained by applying and baking a liquid crystal aligning agent containing a polyamic acid having a cyclobutane ring structure in the main chain on a substrate and baking it. Has been.

International Publication No. 2012/176822

When a liquid crystal alignment film is obtained by a photo-alignment process, the alignment regulating force of liquid crystal molecules is not sufficient as compared with a rubbing process, and image sticking called an AC afterimage tends to occur. The AC afterimage is an afterimage that is generated due to the initial alignment direction deviating from the original direction of the liquid crystal device due to the liquid crystal device being driven for a long time. In order to reduce the AC afterimage in the liquid crystal element, improving the degree of alignment of the liquid crystal alignment film is one effective means. As a liquid crystal element, it is desired that the AC afterimage is sufficiently reduced in order to satisfy the recent demand for higher performance.

In recent years, liquid crystal elements have been applied to a wide range of devices and applications from large-screen liquid crystal televisions to small display devices such as smartphones and tablet PCs. With such versatility, liquid crystal elements are placed or installed in places where they can be hot, such as in the car or outdoors, or they can be driven for a longer time than before, and are used under more severe temperature conditions. It is assumed that Therefore, the liquid crystal element is required to have high reliability with respect to heat resistance. However, when a liquid crystal alignment film is obtained by photo-alignment treatment using a liquid crystal aligning agent containing a polyimide polymer having a cyclobutane ring structure in the main chain, it can be obtained due to decomposition products generated by light irradiation on the coating film. When a liquid crystal element is exposed to a high temperature environment for a long time, a fine bright spot is likely to be generated, and there is a concern that the heat resistance (particularly long-term heat resistance) is inferior in reliability.

The present disclosure has been made in view of the above circumstances, and provides a liquid crystal aligning agent capable of obtaining a liquid crystal element excellent in AC afterimage characteristics and long-term heat resistance when a liquid crystal alignment film is obtained by a photo-alignment method. One purpose.

This disclosure employs the following means in order to solve the above problems.

<1> A liquid crystal aligning agent containing a polymer (P) having at least one selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In the formula (1) and (2), X ¹ is a tetravalent organic group having a cyclobutane ring structure, .X ² having at least one substituent in the ring portion of the cyclobutane ring, the following formula (4) or a divalent organic group represented by the following formula (5): R ⁵ and R ⁶ are each independently a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms. )

(In Formula (4) and Formula (5), A ¹ and A ² are divalent aromatic ring groups, which may have a substituent in the ring portion. However, A ¹ and A ² are the same. Y ¹ and Y ² are each independently a single bond, an oxygen atom, a sulfur atom, or “—NR ⁷ —” (R ⁷ is a hydrogen atom or a monovalent organic group). However, Y ¹ and Y ² are different from each other, B ¹ is a divalent heterocyclic group represented by the following formula (7) or formula (8), Y ³ is an oxygen atom or “− NR ⁹ — ”(R ⁹ is a hydrogen atom or a monovalent organic group). Z ¹ has 1 to 15 carbon atoms having at least ^one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure. a divalent organic group, Z ² is a single bond, or a linear C 1 - having at least one hydrocarbon structures and alicyclic hydrocarbon structure 5 is a divalent organic group. However, when one of Y ¹ and Y ² is a sulfur atom and the other is a single bond, the carbon number of Z ¹ is 2 or more. "*" Indicates a bond.)

(In Formula (7) and Formula (8), R ⁸ is a substituent, r is an integer of 0 to 3, m is an integer of 0 to (r + 2), and “*” represents a bond. .)
<2> A liquid crystal alignment film formed using the liquid crystal aligning agent of <1> above.
<3> A method for producing a liquid crystal alignment film, comprising a photo-alignment step of forming a coating film using the liquid crystal aligning agent of <1> and applying a light irradiation treatment to the coating film to impart liquid crystal alignment ability.
<4> A liquid crystal element comprising the liquid crystal alignment film of <2> above.
<5> A polymer having at least one selected from the group consisting of a partial structure represented by the above formula (1) and a partial structure represented by the above formula (2).
<6> A compound represented by the following formula (16).

(In Formula (16), A ³ and A ⁴ are divalent groups in which two hydrogen atoms have been removed from the ring part of the benzene ring, pyridine ring or pyrimidine ring, and have a substituent in the ring part. Provided that A ³ and A ⁴ are the same, R ¹³ is a hydrogen atom or a monovalent organic group, Y ⁸ is an oxygen atom or a sulfur atom, and n is 1-5. (It is an integer.)

According to the liquid crystal aligning agent of the present disclosure, when a liquid crystal alignment film is obtained by a photo-alignment method, a liquid crystal element having excellent long-term heat resistance and reduced AC afterimage can be obtained.

FIG. 1 is a ¹ H-NMR spectrum of diamine (DA-1). FIG. 2 is a ¹ H-NMR spectrum of diamine (DA-4). FIG. 3 is a ¹ H-NMR spectrum of diamine (DA-10).

Hereinafter, components blended in the liquid crystal aligning agent of the present disclosure and other components arbitrarily blended as necessary will be described.

≪Polymer (P) ≫
The liquid crystal aligning agent of this indication contains the polymer (P) which has at least 1 type chosen from the group which consists of the partial structure represented by the said Formula (1), and the partial structure represented by the said Formula (2). In the above formulas (1) and (2), X ¹ is a tetravalent organic group having a cyclobutane ring structure, and has at least one substituent in the ring portion of the cyclobutane ring. Examples of the substituent that the cyclobutane ring has include a halogen atom, an alkyl group, a halogenated alkyl group, an alkoxy group, an alkenyl group, and an alkynyl group. The number of substituents is not particularly limited, but 1 to 4 is preferable.

X ¹ is preferably a group represented by the following formula (3).

(In the formula (3), R ¹ to R ³ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, or 1 to 6 carbon atoms. An alkoxy group, a thioalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or “—COR ²⁰ ” (where R ²⁰ is an alkyl having 1 to 6 carbon atoms) R ⁴ is a halogen atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, or a carbon number, and a fluorine-containing alkyl group, an alkoxy group, or a fluorine-containing alkoxy group. An alkoxy group having 1 to 6 carbon atoms, a thioalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or “—COR ²⁰ ”, provided that R ¹ to R ⁴ Adjacent groups of Te If R ²⁰ in may also be. Formula which form a ring structure there is a plurality, the plurality of R ²⁰ may be the same or different from each other. "*" Indicates a bond.)

When X ^{1 in} the above formula (1) is a group represented by the above formula (3), the above formula (1) is represented by the following formula (1-A) or (1-B) The above formula (2) is represented by the following formula (2-A).

(In the formula (1-A) and formula ^{(1-B), X 2} , R 5 and ^{R 6} are each synonymous with ^X 2, ^{R 5} and ^{R 6} in the formula (1) ^.R 1 ~ R ⁴ has the same meaning as R ¹ to R ⁴ in the above formula (3).)

(In the formula (2-A), ^{X 2} is ^.R 1 ~ ^{R 4} are the same meaning as ^{X 2} in the formula (1) are synonymous with ^R 1 ~ ^{R 4} in each of the above formula (3) is there.)

X ² in the above formulas (1) and (2) is a divalent organic group represented by the above formula (4) or formula (5). In the above formulas (4) and (5), A ¹ and A ² are groups in which two hydrogen atoms have been removed from the ring portion of the aromatic ring, and the ring portion may have a substituent. Examples of the aromatic ring include aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring and biphenyl ring; nitrogen-containing heterocycles such as pyridine ring, pyrazine ring, pyrimidine ring and pyridazine ring. Examples of the substituent that the aromatic ring may have include an alkyl group having 1 to 6 carbon atoms. However, it is identical to ^{A 1} and ^{A 2.} When A ¹ and A ² are the same, the monomer used in obtaining the polymer (P) can be easily synthesized, but has a high effect of reducing AC afterimage and improving long-term heat resistance. This is preferable.
A ¹ and A ² are benzene rings, biphenyl rings, pyridine rings or pyrimidines which may have a substituent among them because a liquid crystal element excellent in liquid crystal alignment and AC afterimage characteristics can be obtained. A group obtained by removing two hydrogen atoms from the ring portion of the ring is preferable.

Y ¹ and Y ² in the formula (4) are each independently a single bond, an oxygen atom, a sulfur atom, or “—NR ⁷ —” (R ⁷ is a hydrogen atom or a monovalent organic group. .) However, Y ¹ and Y ² are different from each other. Among these, the sensitivity of the polymer (P) to light can be enhanced, and the effect of improving the liquid crystal orientation and AC afterimage characteristics of the obtained liquid crystal element is higher. Among these, an oxygen atom, a sulfur atom, or “—NR ⁷ — Is preferable, and an oxygen atom or “—NR ⁷ —” is more preferable. Since Y ¹ and Y ² are different from each other, X ² in the above formula (1) has an asymmetric structure, so that the solubility of the polymer can be improved and the crystallinity of the photodegradation product is lowered. Therefore, it is considered that the generation of minute bright spots can be reduced.
Examples of the monovalent organic group for R ⁷ include an alkyl group having 1 to 6 carbon atoms and a protecting group. The protecting group is preferably a group capable of leaving by heat, and examples thereof include a carbamate protecting group, an amide protecting group, an imide protecting group, and a sulfonamide protecting group. Of these, the tert-butoxycarbonyl group is preferred because of its high ability to leave by heat and to reduce the remaining amount of the deprotected portion in the film.
R ⁷ is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a protecting group. From the viewpoint that generation of fine luminescent spots can be further reduced and transparency of the liquid crystal alignment film can be increased, R ⁷ has 1 to 3 carbon atoms. The alkyl group is more preferable.
Y ³ in the above formula (5) is an oxygen atom or “—NR ⁹ —”. For the specific examples and preferred examples of R ⁹ , the description of R ⁷ in “—NR ⁷ —” described above applies.

Z ¹ is a divalent organic group having 1 to 15 carbon atoms having at least ^one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure, and Z ² is a single bond or a chain hydrocarbon structure and A divalent organic group having 1 to 15 carbon atoms and having at least one of alicyclic hydrocarbon structures. However, when ^one of Y ¹ and Y ² is a sulfur atom and the other is a single bond, the carbon number of Z ¹ is an integer of 2 to 15. Here, in the present specification, the “chain hydrocarbon structure” means a linear hydrocarbon structure and a branched hydrocarbon structure composed of only a chain structure without including a cyclic structure. However, the chain hydrocarbon structure may be saturated or unsaturated. The “alicyclic hydrocarbon structure” means a hydrocarbon structure that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, the alicyclic hydrocarbon structure does not need to be constituted only by the structure of the alicyclic hydrocarbon, and includes a part having a chain structure. Z ¹ represents a divalent chain hydrocarbon group or a carbon-carbon bond between the chain hydrocarbon group, an oxygen atom, a sulfur atom or “—NR ¹² —” (R ¹² represents a hydrogen atom or a monovalent organic group). It is preferably a group having a group. Z ² may be a single bond, a divalent chain hydrocarbon group, or a group having an oxygen atom, a sulfur atom or “—NR ¹² —” between carbon-carbon bonds of the chain hydrocarbon group. preferable.

The divalent organic group of Z ¹ and Z ² is preferably a divalent organic group represented by the following formula (6) from the viewpoint that the generation of fine bright spots caused by the photodecomposed product can be further reduced. .

(In Formula (6), R ¹⁰ and R ¹¹ are each independently an alkanediyl group, and the total carbon number of R ¹⁰ and R ¹¹ is 1 to 15. Y ⁴ represents an oxygen atom, a sulfur atom Or “—NR ¹² —” (R ¹² is a hydrogen atom or a monovalent organic group.) P is an integer of 0 to 4. When p is 2 or more, a plurality of R ¹⁰ , Y ⁴ may be the same as or different from each other, provided that when one of Y ¹ and Y ^{2 in} the formula (4) is a sulfur atom and the other is a single bond, R ¹⁰ and R ¹¹ The total number of carbon atoms is 2 or more.)

In the above formula (6), R ¹⁰ and R ¹¹ may be linear or branched, but are preferably linear in that the effect of suppressing the formation of fine luminescent spots in the liquid crystal element can be enhanced. . Specifically, the group represented by the above formula (6) (that is, Z ¹ and Z ² ) is an alkanediyl group or an oxygen atom, a sulfur atom, or a carbon-carbon bond of the alkanediyl group. A group having “—NR ⁸ —” is preferable, and an alkanediyl group or a group having an oxygen atom between carbon-carbon bonds of the alkanediyl group is more preferable, and an alkanediyl group is preferable. Further preferred. The description of R ⁷ in “—NR ⁷ —” described above applies to specific examples and preferred examples of R ¹² . p is preferably 0-2.

When Z ¹ in the above formula (4) is a divalent group represented by the above formula (6), the total number of carbon atoms of R ¹⁰ and R ¹¹ (when p is 2 or more, a plurality of R ¹⁰ And the total number of carbon atoms of R ¹¹ ) is that the number of carbon atoms is 2 or more in terms of accelerating realignment of molecular chains by heating in the production of a liquid crystal alignment film and reducing the occurrence of minute bright spots in a liquid crystal element. Preferably, it has 3 or more carbon atoms. Y ⁴ is preferably an oxygen atom or a sulfur atom, and more preferably an oxygen atom.
When Z ² in the above formula (5) is a divalent group represented by the above formula (6), R ¹¹ is a methylene group and p = 0 is preferred. Z ² is preferably a single bond or a methylene group.

B ^{1 in the} above formula (5) is a nitrogen-containing heterocyclic group represented by the above formula (7) or formula (8). In the above formulas (7) and (8), examples of the substituent for R ⁸ include an alkyl group having 1 to 6 carbon atoms. From the viewpoint of liquid crystal alignment, r is preferably 1 or 2, and more preferably 2. Among these, B ¹ is a substituted or unsubstituted piperidine-1,4-diyl group, or a substituted or unsubstituted piperazine-1,4-diyl group. From the viewpoint of liquid crystal alignment and AC afterimage characteristics The substituted or unsubstituted piperidine-1,4-diyl group is particularly preferable.

The above formula (4) is particularly preferably a group represented by the following formula (4A) in that the effect of improving liquid crystal orientation, AC afterimage characteristics and long-term heat resistance is high.

(In Formula (4A), A ³ and A ⁴ are divalent groups obtained by removing two hydrogen atoms from the ring part of the benzene ring, pyridine ring or pyrimidine ring, and have a substituent in the ring part. Provided that A ³ and A ⁴ are the same, Y ⁵ and Y ⁶ each independently represent a single bond, an oxygen atom, a sulfur atom, or “—NR ¹³ —” (R ¹³ is A hydrogen atom or a monovalent organic group, provided that Y ⁵ and Y ⁶ are different from each other, n is an integer of 1 to 5, provided that one of Y ⁵ and Y ⁶ is a sulfur atom. When the other is a single bond, n is 2 or more. “*” Indicates a bond.)

Examples of the substituent that A ³ and A ⁴ may have include an alkyl group having 1 to 6 carbon atoms. With respect to specific examples and preferred examples of the monovalent organic group of R ¹³ , the description of R ⁷ described above is applied. When Y ⁵ and Y ^{6 of the} group represented by the above formula (4A) are a single bond, an oxygen atom or a sulfur atom (however, Y ⁵ and Y ⁶ are different from each other), they are highly sensitive to light. However, it is preferable in that the yield can be increased in the synthesis of the polyamic acid ester. In this case, ^{X 2} is represented by the following formula (4C). In the following formula (4C), it is particularly preferable that one of Y ⁵¹ and Y ⁶¹ is an oxygen atom and the other is a single bond.

(In Formula (4C), Y ⁵¹ and Y ⁶¹ are each independently a single bond, an oxygen atom, or a sulfur atom, provided that Y ⁵¹ and Y ⁶¹ are different from each other, n is an integer of 1 to 5) However, when one of Y ⁵¹ and Y ⁶¹ is a sulfur atom and the other is a single bond, n is 2 or more, and A ³ and A ⁴ have the same meanings as in the above formula (4A). ("*" Indicates a bond)

From the viewpoint of liquid crystal orientation and AC afterimage characteristics, the bonding site on the benzene ring, pyridine ring or pyrimidine ring of A ³ and A ⁴ in Y ⁵ and Y ⁶ in the above formula (4A) is the above formula (1). and is preferably para to the nitrogen atom attached to X ² in the formula (2). The group represented by the above formula (4A) is particularly preferably a group represented by the following formula (4A-1).

(In Formula (4A-1), Q ¹ and Q ² are each independently “CH” or a nitrogen atom. R ¹³ , Y ⁵ , Y ⁶ and n have the same meanings as in Formula (4A) above). “*” Indicates a bond.)

The above formula (5) is preferably a divalent organic group represented by the following formula (5A). K in the formula (5) is preferably 0 to 3, more preferably 0 or 1.

(In Formula (5A), A ⁵ and A ⁶ are divalent groups in which two hydrogen atoms have been removed from the ring part of the benzene ring, pyridine ring or pyrimidine ring, and have a substituent in the ring part. However, A ⁵ and A ⁶ are the same, and B ² is a substituted or unsubstituted piperidine-1,4-diyl group, or a substituted or unsubstituted piperazine-1,4-diyl group. Y ⁷ is an oxygen atom or “—NR ⁹ —” (R ⁹ is a hydrogen atom or a monovalent organic group), k is an integer of 0 to 5. “*” is a bond Showing hand.)

The polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide. The polymer (P) has a partial structure derived from a tetracarboxylic acid derivative having a cyclobutane ring structure having at least one substituent in the ring portion, and a divalent compound represented by the above formula (4) or formula (5). And a partial structure derived from a diamine compound having an organic group. The synthesis method of such a polymer (P) is not particularly limited, and can be obtained by appropriately combining organic chemistry methods. In this specification, “tetracarboxylic acid derivative” is meant to include tetracarboxylic dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dihalide.

(Polyamic acid)
When the polymer (P) is a polyamic acid, the polyamic acid (hereinafter also referred to as “polyamic acid (P)”) is, for example, a tetrabutane having a cyclobutane ring structure having at least one substituent in the ring portion. A tetracarboxylic dianhydride including a carboxylic dianhydride (hereinafter also referred to as “specific acid dianhydride”), and a divalent organic group represented by the above formula (4) or formula (5). It can be obtained by reacting a diamine compound containing a diamine compound (hereinafter also referred to as “specific diamine”).

(Specific acid dianhydride)
Specific acid dianhydrides include tetracarboxylic dianhydrides having a partial structure represented by the above formula (3). Specific examples of the specific acid dianhydride include compounds represented by the following formulas (TA-1-1) to (TA-1-15).

Among these, the specific acid dianhydride is preferably a compound represented by any of the above formulas (TA-1-1) to (TA-1-12), and 1,3-dimethyl-1,2, 3,4-cyclobutanetetracarboxylic dianhydride (a compound represented by the above formula (TA-1-2)) is particularly preferred. In addition, specific acid dianhydride can be used individually by 1 type or in combination of 2 or more types.

In the synthesis of the polyamic acid (P), other tetracarboxylic dianhydrides other than the specific acid dianhydride may be used as the tetracarboxylic dianhydride together with the specific acid dianhydride. Other tetracarboxylic dianhydrides are not particularly limited as long as they do not have a cyclobutane ring structure having at least one substituent in the ring portion. Specific examples of other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides such as ethylenediaminetetraacetic acid dianhydride;

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-di Oxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8 -Methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3- Cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo 3.3.0] octane-2: 4,6: 8-dianhydride, cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, etc .; as aromatic tetracarboxylic dianhydride, for example Pyromellitic dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, p-phenylenebis (trimellitic acid monoester anhydride), ethylene glycol bis (anhydrotrimellitate), 1, 3-propylene glycol bis (anhydrotrimellitate), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and the like can be mentioned, respectively, as described in JP 2010-97188 A Tetracarboxylic dianhydride can be used.

Other tetracarboxylic dianhydrides include ethylenediaminetetraacetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, among them, in terms of increasing the effect of reducing the fine bright spot. , 2,3,5-tricarboxycyclopentylacetic dianhydride, pyromellitic dianhydride and at least one selected from the group consisting of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride It can be preferably used as a component. In addition, in the synthesis | combination of a polymer (P), as another tetracarboxylic dianhydride, 1 type can be used individually or in combination of 2 or more types.

In the synthesis of the polyamic acid (P), the use ratio of the specific acid dianhydride is 30 mol% with respect to the total amount of tetracarboxylic dianhydrides used for the synthesis from the viewpoint of sufficiently obtaining the effects of the present disclosure. The above is preferable. More preferably, it is 50 mol% or more, More preferably, it is 80 mol% or more. When other tetracarboxylic dianhydrides are used, the proportions used are preferably 5 to 70 mol% with respect to the total amount of tetracarboxylic dianhydrides used in the synthesis, and 10 to 50 mol. % Is more preferable.

(Specific diamine)
The specific diamine is a compound represented by the following formula (14) or the following formula (15).

(In the formula (14) and Equation ^{^{^{(15), A 1, A}}} 2, B 1, Y 1, Y 2, Y 3, Z 1 and ^{Z 1} are the above formula (4), with defined for formula (5) is there.)

In the above formula (14) and formula (15), A ¹ , A ² , B ¹ , Y ¹ , Y ² , Y ³ , Z ¹ and Z ¹ are explained in the above formula (4) and formula (5). Respectively applies. Among these, the compound represented by the above formula (14) is preferably a compound represented by the following formula (4B), and the compound represented by the above formula (15) is represented by the following formula (5B). It is preferable that it is a compound represented.

(In the formula ^{^{(4B), A 3, A}} 4, Y 5, Y 6 and n, ^A 3 in the above formula ^{^{(4A), A 4, Y}} 5, the same meanings as ^{Y 6} and n.)

(In the formula ^{^{(5B), A 5, A}} 6, B 2, Y 7 and k have the same meanings as ^{^{^{A 5, A 6, B 2}}} , Y 7 and k in the formula (5A).)

The primary amino group in the above formula (4B) and formula (5B) is relative to other groups bonded to the ring of A ³ , A ⁴ , A ⁵ and A ⁶ (benzene ring, pyridine ring or pyrimidine ring). The para position is preferred. Specific examples and preferred examples of A ³ , A ⁴ , Y ⁵ , Y ⁶ and n in the above formula (4B) and A ⁵ , A ⁶ , B ² , Y ⁷ and k in the above formula (5B) The above description applies.

Specific examples of the specific diamine include, for example, compounds represented by the following formulas (d-1) to (d-54). The specific diamine can be synthesized by appropriately combining organic chemistry methods. In addition, a specific diamine may be used individually by 1 type, or may be used in combination of 2 or more type. “Boc” in the following formula represents a tert-butoxycarbonyl group.

In the synthesis of polyamic acid (P), only a specific diamine may be used as the diamine compound, but other diamines other than the specific diamine may be used together with the specific diamine. Other diamines are not particularly limited as long as they do not correspond to specific diamines, and examples thereof include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples thereof include aliphatic diamines such as metaxylylenediamine, ethylenediamine, 1,3-propanediamine, tetramethylenediamine, hexamethylenediamine and the like; alicyclic diamines such as p-cyclohexanediamine, 4 , 4'-methylenebis (cyclohexylamine) and the like;

Examples of aromatic diamines include dodecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene, cholesteryl diaminobenzoate, cholesteryl diaminobenzoate, and diaminobenzoic acid. Lanostanyl, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butyl Cyclohexane, 2,5-diamino-N, N-diallylaniline, the following formula (E-1)

(In the formula (E-1), X ^I and X ^II are each independently a single bond, —O—, —COO— or —OCO—, and R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1. However, a and b are not 0 at the same time.)
Side-chain diamines such as compounds represented by:
Paraphenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-ethylenedianiline, 4,4′-diaminodiphenylamine, 4,4′-diaminodiphenyl sulfide, 4-aminophenyl-4′-aminobenzoate, 4 , 4′-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,2-bis (4-aminophenoxy) ethane, 1,5-bis (4-aminophenoxy) pentane, N, N′-di (4- Aminophenyl) -N, N′-dimethylethylenediamine, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, bis (4-aminophenyl) amine, N, N-bis (4-aminophenyl) methylamine 1,4-bis (4-aminophenyl) -piperazine, N, N′-bis (4-aminophenyl) -benzidine, 2,2′-dimethyl Til-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-amino Phenoxy) phenyl] propane, 4,4 ′-(phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) Non-side chain diamines such as piperidine, 4,4 ′-[4,4′-propane-1,3-diylbis (piperidine-1,4-diyl)] dianiline;
As the diaminoorganosiloxane, for example, 1,3-bis (3-aminopropyl) -tetramethyldisiloxane and the like can be mentioned, respectively, and the diamine compound described in JP 2010-97188 A can be used. .

Other diamines used for the synthesis of the polyamic acid (P) include O, O′-di (4-aminophenyl) -ethylene glycol, and N, because they have a high effect of reducing the fine bright spots generated in the liquid crystal element. , N′-di (4-aminophenyl) -N, N′-dimethylethylenediamine is preferable, and a liquid crystal element having favorable liquid crystal alignment and AC afterimage characteristics can be obtained. In addition, it preferably contains at least one selected from the group consisting of paraphenylenediamine, 1,4-bis (4-aminophenyl) -piperazine, and 2,2′-dimethyl-4,4′-diaminobiphenyl. In the synthesis of polyamic acid (P), other diamines can be used alone or in combination of two or more.

The proportion of the specific diamine used is preferably 20 mol% or more based on the total amount of diamine compounds used in the synthesis of the polyamic acid (P) from the viewpoint of sufficiently obtaining the effects of the present disclosure. More preferably, it is 40 mol% or more, More preferably, it is 60 mol% or more. When other diamines are used, the proportions used are preferably 5 to 80 mol%, more preferably 10 to 60 mol%, based on the total amount of diamine compounds used in the synthesis.

(Synthesis of polyamic acid)
The polyamic acid (P) is obtained by reacting the tetracarboxylic dianhydride and the diamine compound as described above with a molecular weight adjusting agent (for example, acid monoanhydride, monoamine compound, monoisocyanate compound, etc.) as necessary. Obtainable. The ratio of the tetracarboxylic dianhydride and the diamine compound used in the polyamic acid (P) synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is equivalent to 1 equivalent of the amino group of the diamine compound. A ratio of 0.2 to 2 equivalents is preferred.

The synthesis reaction of polyamic acid (P) is preferably performed in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., and the reaction time is preferably 0.1 to 24 hours. Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons and the like. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. And one or more selected from the group consisting of halogenated phenols, or a mixture of one or more of these and another organic solvent (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount of the organic solvent used is preferably such that the total amount of tetracarboxylic dianhydride and diamine compound is 0.1 to 50% by mass relative to the total amount of the reaction solution. The reaction solution obtained by dissolving the polyamic acid (P) may be used as it is for the preparation of the liquid crystal aligning agent, and the polyamic acid (P) contained in the reaction solution is isolated and then used for the preparation of the liquid crystal aligning agent. May be.

(Polyamic acid ester)
The polyamic acid ester as the polymer (P) has a structural unit in which at least one of R ⁵ and R ^{6 is} a monovalent organic group having 1 to 6 carbon atoms in the partial structure represented by the above formula (1). It is a polymer having. Specific examples of R ⁵ and R ⁶ include, for example, a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkenyl group having 2 to 6 carbon atoms, a cyclohexyl group, a phenyl group, and the like. Is mentioned. The polyamic acid ester is, for example, [I] a method of reacting the polyamic acid (P) obtained above with an esterifying agent (for example, methanol, ethanol, N, N-dimethylformamide diethyl acetal, etc.), [II] A tetracarboxylic acid diester containing a tetracarboxylic acid diester having a partial structure represented by the above formula (3) and a diamine compound containing a specific diamine are preferably mixed in a suitable dehydration catalyst (for example, 4- (4 , 6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium halide, carbonylimidazole, phosphorus condensing agent, etc.], [III] the above formula (3 Tetracarboxylic acid diester dihalogen containing a tetracarboxylic acid diester dihalide having a partial structure represented by And a diamine compound containing a specific diamine, preferably in an organic solvent, a suitable base (eg, tertiary amine such as pyridine and triethylamine, sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium , Alkali metals such as potassium), and the like.

The tetracarboxylic acid diester used in the above [II] can be obtained by ring-opening a specific acid dianhydride or other tetracarboxylic acid dianhydride with an alcohol or the like. The tetracarboxylic acid diester dihalide used in the above [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride.
The polyamic acid ester may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. When the polyamic acid ester is obtained as a solution by the above reaction, the solution may be used as it is for the preparation of the liquid crystal aligning agent. After the polyamic acid ester contained in the reaction solution is isolated, the liquid crystal aligning agent is prepared. May be provided.

(Polyimide)
The polyimide as the polymer (P) is a polymer having a partial structure represented by the above formula (2). The polyimide can be obtained, for example, by dehydrating and ring-closing and imidizing the polyamic acid (P) synthesized as described above. The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure of the polyamic acid (P) that is a precursor thereof, and only a part of the amic acid structure is dehydrated and cyclized. A partially imidized product in which a structure and an imide ring structure coexist may be used. The polyimide preferably has an imidation ratio of 40 to 100%, more preferably 60 to 90%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of the polyamic acid (P) is preferably carried out by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution, and heating as necessary. As the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol with respect to 1 mol of the amic acid structure of the polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. As an organic solvent to be used, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid (P) can be mentioned. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C., and the reaction time is preferably 1.0 to 120 hours. The reaction solution containing the polyimide thus obtained may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after the polyimide is isolated. In addition, a polyimide can also be obtained by imidation by the dehydration ring closure reaction of polyamic acid ester.

The solution viscosity of the polymer (P) preferably has a solution viscosity of 10 to 800 mPa · s, and a solution viscosity of 15 to 500 mPa · s when the solution is 10% by mass. It is more preferable. The solution viscosity (mPa · s) is E for a polymer solution having a concentration of 10% by mass prepared using a good solvent for the polymer (P) (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.
The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the polymer (P) is preferably 1,000 to 500,000, more preferably 5,000 to 100,000. It is. The molecular weight distribution (Mw / Mn) represented by the ratio between Mw and the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. In addition, the polymer (P) contained in a liquid crystal aligning agent may be only 1 type, or may combine 2 or more types.

≪Other ingredients≫
The liquid crystal aligning agent of this indication may contain other components other than a polymer (P). Examples of the other component include a polymer having neither the partial structure represented by the above formula (1) nor the partial structure represented by the above formula (2) (hereinafter referred to as “other polymer”). ), Compounds having at least one epoxy group in the molecule, functional silane compounds, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers, acid generators Agents, base generators, radical generators and the like. These compounding ratios can be appropriately selected according to each compound within a range not impairing the effects of the present disclosure.

The liquid crystal aligning agent is preferable in that it can enhance the effect of suppressing the formation of minute bright spots by containing other polymer. The main skeleton of the other polymer is not particularly limited. For example, polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane, polyester, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meta ) A polymer having an acrylate or the like as a main skeleton. Among these, it is preferable that the other polymer is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide from the viewpoint that generation of fine bright spots can be suitably suppressed. When other polymers are blended in the liquid crystal aligning agent, the blending ratio is preferably 1 to 90% by weight, more preferably 10 to 80% by weight, more preferably 20 to 20% by weight based on the total amount of the polymer in the liquid crystal aligning agent. 70 mass% is still more preferable.

The liquid crystal aligning agent of the present disclosure is prepared as a liquid composition in which the polymer (P) and components used as necessary are preferably dispersed or dissolved in an appropriate solvent.
Examples of the organic solvent used include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-butyrolactam, and N, N-dimethylformamide. N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, Ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether Ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, A propylene carbonate etc. can be mentioned. These can be used alone or in admixture of two or more.

The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc. It is in the range of 1 to 10% by mass. That is, the liquid crystal aligning agent is applied to the substrate surface as will be described later, and preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. At this time, when the solid content concentration is less than 1% by mass, the film thickness of the coating film is too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency.

The content ratio of the polymer (P) in the liquid crystal aligning agent is preferably 10 parts by mass or more, more preferably 20 parts by mass with respect to a total of 100 parts by mass of the solid components (components other than the solvent) in the liquid crystal aligning agent. As mentioned above, More preferably, it is 30 mass parts or more.

≪Liquid crystal alignment film and liquid crystal element≫
The liquid crystal alignment film of the present disclosure is formed by the liquid crystal aligning agent prepared as described above. In particular, the liquid crystal alignment film of the present disclosure can be manufactured by a method including a photo-alignment step of forming a coating film using the liquid crystal aligning agent and applying a light irradiation treatment to the coating film to impart liquid crystal alignment ability. preferable.
Moreover, the liquid crystal element of this indication comprises the liquid crystal aligning film formed using the liquid crystal aligning agent demonstrated above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and includes, for example, a TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA (Vertical Alignment) type (VA-MVA type, VA-PVA type, etc.). It can be applied to various modes such as an IPS (In-Plane Switching) type, an FFS (Fringe Field Switching) type, and an OCB (Optically Compensated Bend) type. The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. In step 1, the substrate to be used varies depending on the desired operation mode. Step 2 and step 3 are common to each operation mode.

(Step 1: Formation of coating film)
First, a liquid crystal aligning agent is apply | coated on a board | substrate, Preferably a coating surface is formed on a board | substrate by heating an application surface. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) Etc. can be used. In the case of manufacturing a TN type, STN type, or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film are used. On the other hand, when manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and a counter substrate provided with no electrode Is used. As the metal film, for example, a film made of a metal such as chromium can be used. Application of the liquid crystal aligning agent to the substrate is preferably performed on the electrode forming surface by an offset printing method, a flexographic printing method, a spin coating method, a roll coater method or an ink jet method.

After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-bake temperature is preferably 30 to 200 ° C., and the pre-bake time is preferably 0.25 to 10 minutes. Thereafter, the solvent is completely removed, and if necessary, a baking (post-baking) step 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., and the post-bake time is preferably 5 to 200 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm. After applying the liquid crystal aligning agent on the substrate, the organic solvent is removed to form a liquid crystal aligning film or a coating film that becomes the liquid crystal aligning film.

(Step 2: Orientation treatment)
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal element, a treatment (orientation treatment) for imparting liquid crystal alignment ability to the coating film formed in Step 1 is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. As the alignment treatment, a rubbing treatment in which a roll wound with a cloth is rubbed in a certain direction may be used. However, the polymer (P) has high photosensitivity, and can develop anisotropy in the coating film even with a small exposure amount. In view of this, a photo-alignment treatment in which the coating film formed on the substrate is irradiated with light to impart liquid crystal alignment ability to the coating film can be preferably used. On the other hand, when manufacturing a vertical alignment type liquid crystal element, the coating film formed in the above step 1 can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to an alignment treatment.

The light irradiation in the photo-alignment treatment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, at least the pre-baking process and the post-baking process. In any case, it can be performed by a method of irradiating the coating film while the coating film is heated. In the photo-alignment treatment, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as radiation applied to the coating film, for example. Preferably, it is an ultraviolet ray containing light having a wavelength of 200 to 400 nm. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When non-polarized radiation is irradiated, the irradiation direction is an oblique direction.

As a 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. The radiation dose is preferably 400 to 20,000 J / m ² , more preferably 1,000 to 5,000 J / m ² . You may perform light irradiation with respect to a coating film, heating a coating film, in order to improve the reactivity.

In the production of the liquid crystal alignment film, it may further include a contact step of bringing the coating film that has been subjected to the light irradiation treatment into contact with water, a water-soluble organic solvent, or a mixed solvent of water and a water-soluble organic solvent. By performing such a contact step, the decomposition product generated by the photo-alignment treatment can be removed from the film, which is preferable in that generation of minute bright spots can be further suppressed in the obtained liquid crystal element. Here, examples of the water-soluble organic solvent include methanol, ethanol, 1-propanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone. Of these, the solvent used in the contacting step is preferably water, isopropanol, or a mixture thereof.

Examples of the contact method between the coating film and the solvent include, but are not limited to, spraying, showering, dipping, and liquid filling. The contact time between the coating film and the solvent is not particularly limited, but is, for example, 5 seconds to 15 minutes.

In the production of the liquid crystal alignment film, a heating step of heating the coating film subjected to the light irradiation treatment within a temperature range of 120 ° C. or higher and 280 ° C. or lower before at least one of the contact step and after the contact step. May be further performed. By performing such a heating step, it is preferable in that a liquid crystal element in which the liquid crystal orientation is further improved and the AC afterimage is further reduced can be obtained.
In the heating step, the heating temperature is preferably 140 ° C. or higher, and more preferably 150 ° C. to 250 ° C., from the viewpoint of promoting reorientation of molecular chains by heating. The heating time is preferably 5 minutes to 200 minutes, more preferably 10 minutes to 60 minutes.

(Process 3: Construction of liquid crystal cell)
Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates disposed to face each other. In order to manufacture a liquid crystal cell, for example, (1) two substrates are arranged to face each other with a gap (spacer) so that the liquid crystal alignment films are opposed to each other, and a peripheral part of the two substrates is used with a sealant. A method of sealing the injection hole after injecting and filling liquid crystal into the cell gap defined by bonding, the substrate surface and the sealing agent, and (2) sealing at a predetermined place on one substrate on which the liquid crystal alignment film is formed A method of applying an agent and dropping liquid crystal to a predetermined number of locations on the surface of the liquid crystal alignment film, and then bonding the other substrate so that the liquid crystal alignment film faces each other and spreading the liquid crystal over the entire surface of the substrate (ODF method) ) And the like. The manufactured liquid crystal cell is preferably heated to a temperature at which the used liquid crystal takes an isotropic phase, and then slowly cooled to room temperature to remove the flow alignment at the time of filling the liquid crystal.

As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. As the spacer, a photo spacer, a bead spacer, or the like can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl. Cyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, for example, a cholesteric liquid crystal, a chiral agent, or a ferroelectric liquid crystal may be added to these liquid crystals.

Subsequently, a polarizing plate is bonded to the outer surface of the liquid crystal cell as necessary. Examples of the polarizing plate include a polarizing plate comprising a polarizing film called an “H film” in which iodine is absorbed while stretching and orientation of polyvinyl alcohol is sandwiched between cellulose acetate protective films, or a polarizing plate made of the H film itself. Thereby, a liquid crystal element is obtained.

The reason why the liquid crystal alignment agent containing the polymer (P) can provide a liquid crystal element excellent in AC afterimage characteristics and long-term heat resistance is not clear, but the following may be considered. The polymer (P) has a structural unit having an asymmetric structure as a structural unit derived from diamine. For this reason, it is surmised that the crystallinity of the photodegradation product generated when the coating film containing the polymer (P) is irradiated with light is low, and the generation of fine bright spots is suppressed. In addition, the crystallinity of the photodegradation product is lowered due to the chain hydrocarbon structure and alicyclic hydrocarbon structure of X ² , which is one reason why a liquid crystal element with few generation of fine bright spots was obtained. It is guessed. Furthermore, in the structural portion derived from diamine, photo-induced electron transfer (electron transfer sensitization reaction) from the diamine skeleton to the substituted cyclobutane ring is promoted by the polymerization bond group (amino group) and the electron donating group, It is presumed that the degree of alignment order of the liquid crystal was improved and the AC afterimage could be reduced as a result of the promotion of the photolysis by the retro [2 + 2] reaction of the cyclobutane ring.

The liquid crystal element of the present disclosure can be effectively applied to various applications, for example, watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors. It can be used for various display devices such as liquid crystal televisions and information displays, and light control films. Moreover, the liquid crystal element formed using the liquid crystal aligning agent of this indication can also be applied to retardation film.

Hereinafter, the present disclosure will be described more specifically by way of examples. However, the present disclosure is not limited to these examples.

The structures and abbreviations of main compounds used in the following examples are as follows.
(Tetracarboxylic acid derivative)
TA-1; (1R, 2R, 3S, 4S) -1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride TB-2; 1,2,3,4-cyclobutanetetracarboxylic Acid dianhydride TB-3; 2,3,5-tricarboxycyclopentyl acetic acid dianhydride TC-4; dimethallyl (2r, 4r) -2,4-bis (chlorocarbonyl) -2,4-dimethylcyclobutane-1 , 3-Dicarboxylate

(Specific diamine)
DA-1, N, O-di (4-aminophenyl) -N-methylethanolamine DA-2; N, O-di (4-aminophenyl) -N-tert-butoxycarbonylethanolamine DA-3; N , O-di (4-aminophenyl) -ethanolamine DA-4; N, O-di (4-aminophenyl) -4-hydroxypiperidine DA-5; N, O-di (4-aminophenyl) -4 -Piperidinemethanol DA-6; N, N'-di (4-aminophenyl) -N-methyl-4-aminopiperidine DA-7; N, S-di (4-aminophenyl) -2-aminoethanethiol DA -8; N, O-di (5-amino-2-pyridyl) -N-methylethanolamine DA-9; N, O-di (5-amino-2-pyridyl) -4-hydroxypiperidine DA-10; 4 , 4'-Diaminobenzyl phenyl ether

(Other diamines)
DB-1, O, O′-di (4-aminophenyl) -ethylene glycol DB-2; N, N′-di (4-aminophenyl) -N, N′-dimethylethylenediamine DB-3; '-Ethylenedianiline DB-4; N, N'-di (4-aminophenyl) -piperazine DB-5; N, N'-di (5-amino-2-pyridyl) -piperazine DB-6; paraphenylene Diamine DB-7; 2,2'-dimethyl-4,4'-diaminobiphenyl

(solvent)
NMP; N-methyl-2-pyrrolidone γBL; γ-butyrolactone BC; butyl cellosolve

<Compound Synthesis 1>
[Synthesis Example 1]
A three-necked flask equipped with a reflux tube and a nitrogen introduction tube was charged with potassium carbonate (34.55 g, 0.25 mol) and purged with nitrogen, and N-methylethanolamine (7.51 g, 0.10 mol), NMP ( 150 mL). While the reaction solution was stirred under nitrogen, 4-fluoronitrobenzene (28.22 g, 0.20 mol) was added dropwise. The reaction solution was stirred at 150 ° C. for 6 hours to complete the reaction. After cooling, the reaction solution was poured into 300 mL of water and stirred to solidify the product. 150 mL of a mixed solvent of hexane: ethyl acetate = 4: 1 (volume ratio) was added to this water coagulation dispersion, and the mixture was stirred at room temperature for 1 hour. The resulting dispersion was filtered and washed with water and ethyl acetate, respectively. The obtained precipitate was washed by heating and stirring in 150 mL of ethyl acetate, cooled, filtered and dried under vacuum to obtain a yellow powder nitro intermediate product (29.51 g, yield 93%). Obtained.
Subsequently, 2.4 g of palladium carbon was put into a three-necked flask equipped with a reflux tube and a nitrogen introduction tube, and the atmosphere was replaced with nitrogen. Thereto were added 120 mL of tetrahydrofuran degassed by nitrogen bubbling and 30 mL of ethanol, and after adding a nitro intermediate product (9.41 g, 0.03 mol), the mixture was stirred to obtain a suspension solution. To the reaction solution, 10 mL of hydrazine monohydrate was slowly added dropwise at room temperature. After the dropping, the temperature was gradually raised to 60 ° C. and stirred for 4 hours. The reaction solution was diluted with 200 mL of ethyl acetate, filtered through Celite, and then separated and washed with 200 mL of water three times. The obtained organic layer was concentrated and vacuum-dried to obtain a light brown liquid diamine (DA-1) (4.94 g, yield 64%). FIG. 1 shows the measurement result of ¹ H-NMR spectrum (DMSO-d ⁶ , 400 MHz) of diamine (DA-1).

[Synthesis Example 2]
A nitro intermediate product was obtained in the same manner as in Synthesis Example 1 except that N-methylethanolamine was changed to ethanolamine.
Subsequently, a nitro intermediate product (3.03 g, 0.010 mol), N, N-dimethyl-4-aminopyridine (0.24 g, 0.03 mol) was added to a three-necked flask equipped with a reflux tube and a nitrogen introduction tube. 002 mol) was substituted with nitrogen, and tetrahydrofuran (60 mL) was added. The reaction solution was heated to 50 ° C., and a mixed solution of di-tert-butyl dicarbonate (5.24 g, 0.024 mol) and tetrahydrofuran (5 mL) was added dropwise and reacted for 24 hours. The reaction solution was concentrated under reduced pressure, and the resulting precipitate was recrystallized from toluene and vacuum dried to obtain a Boc protected nitro intermediate product (3.43 g, yield 85%) as a yellow powder. The obtained Boc-protected nitro intermediate product was subjected to a reduction reaction in the same manner as in Synthesis Example 1 to obtain a light brown powdered diamine (DA-2).
[Synthesis Example 3]
A diamine (DA-3) was obtained in the same manner as in Synthesis Example 1 except that N-methylethanolamine was changed to ethanolamine.

[Synthesis Example 4]
A three-necked flask equipped with a reflux tube and a nitrogen introduction tube was charged with potassium carbonate (34.55 g, 0.25 mol) and purged with nitrogen, and 4-hydroxypiperidine (10.12 g, 0.10 mol), NMP (150 mL) ) While the reaction solution was stirred under nitrogen, 4-fluoronitrobenzene (28.22 g, 0.20 mol) was added dropwise. The reaction solution was stirred at 150 ° C. for 6 hours to complete the reaction. After cooling, the reaction solution was poured into 300 mL of water and stirred to solidify the product. 150 mL of a mixed solvent of hexane: ethyl acetate = 4: 1 (volume ratio) was added to this water coagulation dispersion, and the mixture was stirred at room temperature for 1 hour. The resulting dispersion was filtered and washed with water and ethyl acetate, respectively. The obtained precipitate was washed by heating and stirring in 150 mL of ethyl acetate, cooled, filtered and dried in vacuo to give a nitro intermediate product of ocherous powder (29.87 g, yield 87%). Got.
Subsequently, 2.4 g of palladium carbon was put into a three-necked flask equipped with a reflux tube and a nitrogen introduction tube, and the atmosphere was replaced with nitrogen. Thereto were added 120 mL of tetrahydrofuran degassed by nitrogen bubbling and 30 mL of ethanol, and after adding a nitro intermediate product (10.30 g, 0.03 mol), the mixture was stirred to obtain a suspension solution. To the reaction solution, 10 mL of hydrazine monohydrate was slowly added dropwise at room temperature. After the dropping, the temperature was gradually raised to 60 ° C. and stirred for 4 hours. The reaction solution was diluted with 200 mL of ethyl acetate, filtered through Celite, and then separated and washed with 200 mL of water three times. The obtained organic layer was concentrated and recrystallized with 100 mL of ethyl acetate. The obtained solid was filtered and vacuum-dried to obtain a light pink solid diamine (DA-4) (5.19 g, yield 61%). FIG. 2 shows the measurement result of ¹ H-NMR spectrum (DMSO-d ⁶ , 400 MHz) of diamine (DA-4).

[Synthesis Example 5]
Synthesis was performed in the same manner as in Synthesis Example 4 except that 4-hydroxypiperidine was changed to 4-piperidinemethanol to obtain diamine (DA-5).
[Synthesis Example 6]
A nitro intermediate product was obtained in the same manner as in Synthesis Example 4 except that 4-hydroxypiperidine was changed to 4-aminopiperidine.
Subsequently, a nitro compound intermediate product (3.42 g, 0.010 mol) and potassium-tert-butoxide (1.68 g, 0.015 mol) were placed in a three-necked flask equipped with a reflux tube and a nitrogen introduction tube. The atmosphere was replaced with nitrogen, and tetrahydrofuran (100 mL) was added. Methyl iodide (2.84 g, 0.020 mol) was added dropwise while stirring the reaction solution under nitrogen. The reaction solution was stirred at 40 ° C. for 24 hours to complete the reaction. After cooling, the reaction solution was poured into 300 mL of water and stirred to solidify the product. The resulting dispersion was filtered and washed with water. The resulting precipitate was recrystallized from tetrahydrofuran and vacuum-dried to obtain a yellow powder N-methylated nitro intermediate product (3.10 g, yield 87%). The obtained N-methylated nitro intermediate product was subjected to a reduction reaction in the same manner as in Synthesis Example 4 to obtain a pink powder of diamine (DA-6).

[Synthesis Example 7]
A diamine (DA-7) was obtained in the same manner as in Synthesis Example 1 except that N-methylethanolamine was changed to 2-aminoethanethiol.
[Synthesis Example 8]
A diamine (DA-8) was obtained in the same manner as in Synthesis Example 1 except that 4-fluoronitrobenzene was changed to 2-fluoro-5-nitropyridine.
[Synthesis Example 9]
A diamine (DA-9) was obtained in the same manner as in Synthesis Example 4 except that 4-fluoronitrobenzene was changed to 2-fluoro-5-nitropyridine.

<Synthesis of polymer 1>
[Synthesis Example 10]
Diamine (DA-1) is dissolved in NMP, 0.95 equivalent of tetracarboxylic dianhydride (TA-1) is added, and the reaction is performed at room temperature for 6 hours. The diamine (DA-1) is represented by the following formula (PA-1). A 15% by mass solution of polyamic acid (PA-1) having a structural unit was obtained.

[Synthesis Examples 11 to 26]
Polyamic acids (PA-2 to PA-17) were obtained in the same manner as in Synthesis Example 10 except that the types and molar ratios of tetracarboxylic dianhydride and diamine compound were changed as shown in Table 1 below. . In addition, the numerical value of Table 1 represents the usage rate (mole part) of each compound with respect to 100 mol part of total amount of the tetracarboxylic dianhydride used for the synthesis about tetracarboxylic dianhydride. Represents the use ratio (mole part) of each compound with respect to 100 mol parts of the total amount of diamine compounds used in the synthesis (the same applies to Table 3).

[Synthesis Example 27]
A 15% by mass solution of polyamic acid (PA-1) obtained in Synthesis Example 10 was diluted to 10% by mass with NMP, 0.8 equivalents of 1-methylpiperidine and acetic anhydride were added, and the mixture was heated at 60 ° C. for 3 hours. Heat with stirring. The obtained solution was repeatedly concentrated under reduced pressure and diluted with NMP to obtain a 15% by mass solution of polyimide (PI-1) having a structural unit represented by the following formula (PI-1). A ¹ H-NMR spectrum (DMSO-d ⁶ , 400 MHz) of polyimide (PI-1) was measured, and aromatic protons (δ 6.0 to 9.0 ppm) and main chain amide protons (δ 9.8 to 10.3 ppm) When the imidization rate was calculated from the integral ratio of acetyl-terminated amide protons (δ 9.6 to 9.8 ppm), the imidation rate was 78%.

[Synthesis Example 28]
A polyimide (PI-2) was obtained in the same manner as in Synthesis Example 27 except that the polyamic acid (PA-1) was changed to the polyamic acid (PA-10).

[Example 1: Photo-alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent The solution of polyamic acid (PA-1) obtained in Synthesis Example 10 was diluted with NMP and BC, and the solid content concentration was 4.0% by mass, and the solvent composition ratio was NMP. : A solution with BC = 80: 20 (mass ratio) was obtained. A liquid crystal aligning agent (R-1) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.

(2) Formation of liquid crystal alignment film by photo-alignment method On each surface of a glass substrate in which a flat plate electrode, an insulating layer and a comb-like electrode are laminated in this order on one side, and a counter glass substrate on which no electrode is provided Then, the liquid crystal aligning agent (R-1) prepared in the above (1) was applied using a spinner, heated for 1 minute on a hot plate at 80 ° C. (prebaked), and then the oven at 230 ° C. in which the inside of the chamber was replaced with nitrogen Were dried (post-baked) for 30 minutes to form a coating film having an average film thickness of 0.1 μm. Using a Hg—Xe lamp, the surface of the coating film was irradiated with ultraviolet rays of 3,000 J / m ² containing a linearly polarized 254 nm emission line from the normal direction of the substrate to perform photo-alignment treatment. The coating film that had been subjected to the photo-alignment treatment was heated in a clean oven at 230 ° C. for 30 minutes for heat treatment to form a liquid crystal alignment film.

(3) Manufacture of liquid crystal display element About the pair of substrates having the liquid crystal alignment film prepared in (2) above, containing aluminum oxide spheres having a diameter of 5.5 μm leaving the liquid crystal injection port at the edge of the surface on which the liquid crystal alignment film is formed After the epoxy resin adhesive is screen-printed and applied, the substrates are stacked and pressure-bonded so that the projection direction of the polarization axis on the substrate surface during light irradiation is antiparallel, and the adhesive is heated at 150 ° C. for 1 hour. Cured. Next, a nematic liquid crystal (MLC-7028, manufactured by Merck & Co., Inc.) was filled between the pair of substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment during liquid crystal injection, this was heated at 120 ° C. and then gradually cooled to room temperature. Next, a polarizing plate was bonded to both sides of the substrate to manufacture an FFS type liquid crystal display element.

(4) Evaluation of liquid crystal orientation In the liquid crystal display device manufactured in (3) above, the presence or absence of an abnormal domain in the change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is observed at a magnification of 50 times using a microscope. Observed. In the evaluation, when the abnormal domain was not observed, the liquid crystal orientation was “good”, and when the abnormal domain was observed, “bad”. As a result, in this example, the evaluation was “good”.

(5) Evaluation of AC afterimage characteristics An FFS type liquid crystal cell was prepared by performing the same operation as in the above (3) except that the polarizing plate was not bonded to both the outer surfaces of the substrate. About this FFS type liquid crystal cell, after driving for 30 hours at an AC voltage of 10 V, using a device in which a polarizer and an analyzer are arranged between a light source and a light quantity detector, the minimum relative value expressed by the following formula (2) is used. The transmittance (%) was measured.
Minimum relative transmittance (%) = ((β−B ₀ ) / (B ₁₀₀ −B ₀ )) × 100 (2)
(In Formula (2), B ₀ is the transmission amount of light under a blank and crossed Nicols. B ₁₀₀ is the transmission amount of light under a blank and paranicols. Β is a polarizer under crossed Nicols. (This is the minimum light transmission amount with the liquid crystal cell sandwiched between the analyzers.)
The black level in the dark state is represented by the minimum relative transmittance of the liquid crystal cell. In the FFS type liquid crystal cell, the smaller the black level in the dark state, the better the contrast. “Excellent” if the minimum relative transmittance is less than 0.2%, “Good” if the minimum relative transmittance is 0.2% or more and less than 0.5%, 1.0% or more was regarded as “bad”. As a result, this example was evaluated as “excellent”.

(6) Evaluation of long-term heat resistance (defect of fine luminescent spot) The liquid crystal cell manufactured by performing the same operation as in (3) above except that the polarizing plate was not bonded to both outer surfaces of the substrate. Was stored in a constant temperature bath at 100 ° C. for 21 days, and then the presence or absence of minute bright spots in the liquid crystal cell was observed with a microscope. When decomposition products generated by light irradiation for photo-alignment treatment remain in the film, the decomposition products bleed out to the film surface by exposing the liquid crystal display element to a high temperature environment for a long time, and gradually in the liquid crystal. It is known that it is crystallized and observed as a fine bright spot. The observation area was 680 μm × 680 μm, and the microscope magnification was 100 times. The evaluation is “excellent” when no fine luminescent spots are observed, “good” when the number of fine luminescent spots is 1 or more and 5 or less, and the number of fine luminescent spots is 6 or more and 10 or less. The case was “OK”, and the case where the number of fine luminescent spots was 11 points or more was “bad”. As a result, in this example, the evaluation was “good”.

[Examples 2 to 12, Comparative Examples 1 to 6]
In Example 1 above, except that the polymer contained in the liquid crystal aligning agent was changed as shown in Table 2 below, a liquid crystal aligning agent was prepared to form a liquid crystal aligning film in the same manner as in Example 1, and FFS A liquid crystal display element and a liquid crystal cell were manufactured and various evaluations were performed. The evaluation results are shown in Table 2 below. In Examples 11 and 12, two types of polymers (Polymer 1 and Polymer 2) were mixed into a liquid crystal aligning agent at a blending ratio of Polymer 1: Polymer 2 = 40: 60 (solid content equivalent mass ratio). Contained.

[Example 13]
Example 1 in Example 1 except that “(1) Preparation of liquid crystal aligning agent” and “(2) Formation of liquid crystal alignment film by photo-alignment method” were changed as described in (1a) and (2a) below. In the same manner as described above, an FFS type liquid crystal display element and a liquid crystal cell were manufactured and various evaluations were performed. The evaluation results are shown in Table 2 below.

(1a) Preparation of liquid crystal aligning agent Using the polyimide (PI-1) solution obtained in Synthesis Example 27 as a polymer, it was diluted with NMP and BC, and the solid content concentration was 4.0% by mass. Was obtained as NMP: BC = 80: 20 (mass ratio). A liquid crystal aligning agent (R-13) was prepared by filtering this solution through a filter having a pore size of 0.2 μm.

(2a) Formation of liquid crystal alignment film by photo-alignment method On each surface of a glass substrate in which a flat plate electrode, an insulating layer and a comb-like electrode are laminated in this order on one side and a counter glass substrate on which no electrode is provided Then, apply the liquid crystal aligning agent (R-13) prepared in (1a) above using a spinner so that the film thickness becomes 0.1 μm, and dry (pre-bake) for 1 minute on an 80 ° C. hot plate. A film was formed. Using a Hg—Xe lamp, the surface of the coating film was irradiated with ultraviolet rays of 3,000 J / m ² containing a linearly polarized 254 nm emission line from the normal direction of the substrate to perform photo-alignment treatment. The coating film subjected to the photo-alignment treatment was heated for 30 minutes in an oven at 230 ° C. in which the inside of the chamber was replaced with nitrogen to perform heat treatment (post-bake), thereby forming a liquid crystal alignment film.

[Examples 14 to 16]
In Example 13, except that the polymer contained in the liquid crystal aligning agent was changed as shown in Table 2 below, a liquid crystal aligning agent was prepared in the same manner as in Example 13 to form a liquid crystal aligning film, and the FFS type A liquid crystal display element and a liquid crystal cell were manufactured and subjected to various evaluations. The evaluation results are shown in Table 2 below. In Examples 15 and 16, two types of polymers (Polymer 1 and Polymer 2) were mixed into a liquid crystal aligning agent at a blending ratio of Polymer 1: Polymer 2 = 40: 60 (solid content equivalent mass ratio). Contained.

The liquid crystal alignment was “good” in Examples 1 to 16. Further, the AC afterimage characteristics were “excellent” or “good” in Examples 1 to 16. These are considered due to the improvement of the photoreactivity of the liquid crystal alignment film. That is, the liquid crystal aligning agents of Examples 1 to 16 contain a polymer of substituted cyclobutanetetracarboxylic dianhydride and diamine. In addition, the diamine used for the synthesis of the polymer has an aromatic ring to which a polymerization bond group (—NH ₂ ) is bonded, an alkylamino group, a piperidinediyl group, an oxyalkylene group (—C _n H _2n —O—). Substituted with an electron donating group such as Although the mechanism for increasing the sensitivity to light is not clear, the photoinduced electron transfer (electron transfer sensitization reaction) from the diamine skeleton to the substituted cyclobutane ring by the electron donating group causes the light from the retro [2 + 2] reaction of the substituted cyclobutane ring. It is presumed that decomposition was promoted.

In addition, regarding long-term heat resistance (reduction of fine bright spot defects), all of Examples 1 to 16 were “excellent” or “good”. The liquid crystal aligning agents of Examples 1 to 16 contain a polymer having a structural unit derived from a diamine having an asymmetric structure as a polymer component. The mechanism of long-term heat resistance improvement is not clear, but in the case of diamines having an asymmetric structure, the photolysis product generated by the photo-alignment treatment process becomes an asymmetric structure, which lowers the crystallinity of the photolysis product and generates fine bright spots. Is presumed to be suppressed.

In addition, the polymer (P) contained in the liquid crystal aligning agents of Examples 8 to 10, 14, and 16 is composed of a compound of plural kinds of acid dianhydride components or diamine components. Therefore, it is presumed that the photodegradation product has various chemical structures, inhibits crystallization of the photodegradation product, and suppresses the generation of fine bright spots. Furthermore, in Examples 11, 12, 15, and 16 (blend system), since the content ratio of the polymer (polymer 1) that undergoes photodegradation is small, the amount of photodegradation product that is generated is small. It is presumed that generation was suppressed.

On the other hand, in Comparative Examples 1 to 5 using polymers having no partial structure derived from a substituted cyclobutane ring and a specific diamine, the long-term heat resistance of the liquid crystal cell was “poor”. These liquid crystal aligning agents of Comparative Examples 1 to 5 contain a polymer using only a diamine having a symmetric structure as a diamine component. In this case, it is presumed that the photolysis product generated by the photo-alignment treatment has a symmetric structure, and the crystallinity of the photolysis product becomes high, so that fine bright spots are easily generated. In Comparative Example 6, the liquid crystal orientation and AC afterimage characteristics of the liquid crystal cell were “bad”. The long-term heat resistance could not be evaluated because the liquid crystal alignment of the liquid crystal cell was “bad”.

<Compound Synthesis 2>
[Synthesis Example 29]
To a three-necked flask equipped with a reflux tube and a nitrogen introduction tube, 4-nitrophenol (13.91 g, 0.10 mol), 4-nitrobenzyl bromide (21.60 g, 0.10 mol), potassium carbonate (16.59 g) , 0.12 mol) and nitrogen substitution, and acetone (200 mL) was added. The reaction solution was stirred at 60 ° C. under nitrogen for 8 hours to complete the reaction. After cooling, the reaction solution was poured into 300 mL of water and stirred to solidify the product. The product was filtered, washed with water, and then vacuum-dried to obtain a colorless crystalline nitro intermediate product (26.70 g, 0.097 mol).
Subsequently, a nitro compound intermediate product (8.22 g, 0.030 mol), zinc (39.2 g, 0.60 mol), ammonium chloride (32.09 g) was added to a three-necked flask equipped with a reflux tube and a nitrogen introduction tube. , 0.60 mol) and nitrogen substitution. Tetrahydrofuran (120 mL) and ethanol (40 mL) deaerated by nitrogen bubbling were added thereto, and the mixture was stirred and cooled to 5 to 10 ° C. with an ice-water bath. After slowly dropping 16 mL of water into the reaction solution, the mixture was stirred at room temperature for 8 hours to complete the reaction. The reaction solution was diluted with 100 mL of water, insolubles were removed by Celite filtration, and Celite was further extracted and washed with 200 mL of ethyl acetate. The obtained filtrate was separated, and the organic layer was washed 5 times with water. The obtained organic layer was concentrated and recrystallized with 30 mL of a mixed solvent of ethyl acetate / ethanol = 1/10. The obtained solid was filtered and vacuum-dried to obtain a light yellow solid diamine (DA-10) (4.50 g, yield 70%). FIG. 3 shows the measurement result of ¹ H-NMR spectrum (DMSO-d ⁶ , 400 MHz) of diamine (DA-10).

<Polymer synthesis 2>
[Synthesis Example 30]
Diamine (DA-10) is dissolved in NMP, 0.95 equivalent of tetracarboxylic dianhydride (TA-1) is added, and the reaction is carried out at room temperature for 6 hours, which is represented by the following formula (PA-18). A 15% by mass solution of polyamic acid (PA-18) having a structural unit was obtained.

[Synthesis Examples 31 to 34]
Polyamic acids (PA-19 to PA-22) were obtained in the same manner as in Synthesis Example 30, except that the types and molar ratios of tetracarboxylic dianhydride and diamine compound were changed as shown in Table 3 below. . In addition, the numerical value in Table 3 represents the usage rate (mole part) of each compound with respect to 100 mol part of total amount of the tetracarboxylic dianhydride used for the synthesis about tetracarboxylic dianhydride. Represents the use ratio (mole parts) of each compound with respect to 100 mol parts of the total amount of diamine compounds used in the synthesis.

[Synthesis Example 35]
In a 50 mL three-necked flask equipped with a nitrogen inlet tube and a thermometer, a tetracarboxylic acid derivative (TC-4) (8.11 g, 20.0 mmol), pyridine (3.80 g, 48.0 mmol), γBL 20.4 g, and NMP13 .6 g was added and cooled to about 10 ° C. to prepare an acid chloride solution. To this was added a diamine solution prepared by previously dissolving diamine (DA-10) (3.86 g, 18.0 mmol) in 20.4 g of γBL, and allowed to react at 10 ° C. for 4 hours under a nitrogen stream. The obtained polymerization solution was diluted with 70 g of methanol, and slowly poured into a mixed solvent of water / isopropanol = 1/1 with stirring to solidify. The precipitated solid was collected, washed with stirring in water and isopropanol, and vacuum dried at 60 ° C. to obtain a white powder. The obtained powder was dissolved in γBL to obtain a 15% by mass solution of polyamic acid ester (PAE-1) having a structural unit represented by the following formula (PAE-1).

[Synthesis Examples 36 to 37]
Polyamic acid esters (PAE-2 to PAE-3) were obtained in the same manner as in Synthesis Example 35 except that the type and molar ratio of the diamine compound were changed as shown in Table 3 below.

[Examples 17 to 24, Comparative Example 7]
In Example 1 above, the polarized UV light exposure amount of the photo-alignment treatment was changed from 3,000 J / m ² to 5,000 J / m ² , and the polymer contained in the liquid crystal aligning agent was changed as shown in Table 4 below. In the same manner as in Example 1, a liquid crystal aligning agent was prepared to form a liquid crystal alignment film, and an FFS type liquid crystal display element and a liquid crystal cell were manufactured and various evaluations were performed. The evaluation results are shown in Table 4 below. In Examples 20 and 24, two types of polymers (Polymer 1 and Polymer 2) were mixed into a liquid crystal aligning agent at a blending ratio of Polymer 1: Polymer 2 = 40: 60 (solid content equivalent mass ratio). Contained.

The liquid crystal orientation and AC afterimage characteristics were “excellent” or “good” in Examples 17 to 24. These results indicate that, as in Examples 1 to 16, the aromatic ring to which the polymerization bonding group (—NH ₂ ) is bonded is formed by the electron donating group (“—O—CH ₂ —” of the diamine (DA-10)). It is considered that the photoreactivity of the liquid crystal alignment film was improved by including a polymer having a structural unit derived from a substituted diamine. Further, in terms of long-term heat resistance (reduction of fine bright spot defects), all of Examples 17 to 24 were “excellent”. These results are also caused by the fact that the photolysis product generated by the photo-alignment treatment step has an asymmetric structure, so that the crystallinity is lowered and the generation of minute bright spots is suppressed, as in Examples 1 to 16. Conceivable.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the above-described embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

The liquid crystal aligning agent containing the polymer (P) which has at least 1 type chosen from the group which consists of the partial structure represented by following formula (1), and the partial structure represented by following formula (2).

(In the formula (1) and (2), X 1 is a tetravalent organic group having a cyclobutane ring structure, .X 2 having at least one substituent in the ring portion of the cyclobutane ring, the following formula (4) or a divalent organic group represented by the following formula (5): R 5 and R 6 are each independently a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms. )

(In Formula (4) and Formula (5), A 1 and A 2 are divalent aromatic ring groups, which may have a substituent in the ring portion. However, A 1 and A 2 are the same. Y 1 and Y 2 are each independently a single bond, an oxygen atom, a sulfur atom, or “—NR 7 —” (R 7 is a hydrogen atom or a monovalent organic group). However, Y 1 and Y 2 are different from each other, B 1 is a divalent heterocyclic group represented by the following formula (7) or formula (8), Y 3 is an oxygen atom or “− NR 9 — ”(R 9 is a hydrogen atom or a monovalent organic group). Z 1 has 1 to 15 carbon atoms having at least one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure. a divalent organic group, Z 2 is a single bond, or a linear C 1 - having at least one hydrocarbon structures and alicyclic hydrocarbon structure 5 is a divalent organic group. However, when one of Y 1 and Y 2 is a sulfur atom and the other is a single bond, the carbon number of Z 1 is 2 or more. "*" Indicates a bond.)

(In Formula (7) and Formula (8), R 8 is a substituent, r is an integer of 0 to 3, m is an integer of 0 to (r + 2), and “*” represents a bond. .)
Z 1 is a divalent organic group represented by the following formula (6),
2. The liquid crystal aligning agent according to claim 1, wherein Z 2 is a single bond or a divalent organic group represented by the following formula (6).

(In Formula (6), R 10 and R 11 are each independently an alkanediyl group, and the total carbon number of R 10 and R 11 is 1 to 15. Y 4 represents an oxygen atom, a sulfur atom Or “—NR 12 —” (R 12 is a hydrogen atom or a monovalent organic group.) P is an integer of 0 to 4. When p is 2 or more, a plurality of R 10 , Y 4 may be the same as or different from each other, provided that when one of Y 1 and Y 2 in the formula (4) is a sulfur atom and the other is a single bond, R 10 and R 11 The total number of carbon atoms is 2 or more.)
The liquid crystal aligning agent according to claim 1, wherein X 1 is a tetravalent organic group represented by the following formula (3).

(In the formula (3), R 1 to R 3 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, or 1 to 6 carbon atoms. An alkoxy group, a thioalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or “—COR 20 ” (R 20 is an alkyl group having 1 to 6 carbon atoms) R 4 is a halogen atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, or 1 carbon atom. An alkoxy group having 1 to 6 carbon atoms, a thioalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or “—COR 20 ”, provided that R 1 to R 4 Adjacent groups are bonded together to form a ring If R 20 in concrete and may form. Formula there are a plurality, the plurality of R 20 may be the same or different from each other. "*" Indicates a bond.)
The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the divalent organic group represented by the formula (4) is represented by the following formula (4A).

(In Formula (4A), A 3 and A 4 are divalent groups obtained by removing two hydrogen atoms from the ring part of the benzene ring, pyridine ring or pyrimidine ring, and have a substituent in the ring part. Provided that A 3 and A 4 are the same, Y 5 and Y 6 each independently represent a single bond, an oxygen atom, a sulfur atom, or “—NR 13 —” (R 13 is A hydrogen atom or a monovalent organic group, provided that Y 5 and Y 6 are different from each other, n is an integer of 1 to 5, provided that one of Y 5 and Y 6 is a sulfur atom. When the other is a single bond, n is 2 or more. “*” Indicates a bond.)
The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the divalent organic group represented by the formula (5) is represented by the following formula (5A).

(In Formula (5A), A 5 and A 6 are divalent groups in which two hydrogen atoms have been removed from the ring part of the benzene ring, pyridine ring or pyrimidine ring, and have a substituent in the ring part. However, A 5 and A 6 are the same, and B 2 is a substituted or unsubstituted piperidine-1,4-diyl group, or a substituted or unsubstituted piperazine-1,4-diyl group. Y 7 is an oxygen atom or “—NR 9 —” (R 9 is a hydrogen atom or a monovalent organic group), k is an integer of 0 to 5. “*” is a bond Showing hand.)
R 5 and R 6 are each independently a monovalent organic group having 1 to 6 carbon atoms;
The liquid crystal aligning agent according to any one of claims 1 to 3, wherein X 2 is a divalent organic group represented by the following formula (4C).

(In Formula (4C), A 3 and A 4 are divalent groups obtained by removing two hydrogen atoms from the ring part of the benzene ring, pyridine ring or pyrimidine ring, and have a substituent in the ring part. However, A 3 and A 4 are the same, Y 51 and Y 61 are each independently a single bond, an oxygen atom, or a sulfur atom, provided that Y 51 and Y 61 are N is an integer of 1 to 5. However, when one of Y 51 and Y 61 is a sulfur atom and the other is a single bond, n is 2 or more. (Shows the bond.)
A liquid crystal alignment film formed using the liquid crystal aligning agent according to any one of claims 1 to 6.
A liquid crystal alignment film comprising a photo-alignment step of forming a coating film using the liquid crystal aligning agent according to any one of claims 1 to 6 and subjecting the coating film to light irradiation treatment to impart liquid crystal alignment ability. Manufacturing method.
The liquid crystal alignment film according to claim 8, further comprising a contact step of bringing the coating film subjected to the light irradiation treatment into contact with water, a water-soluble organic solvent, or a mixed solvent of water and a water-soluble organic solvent. Method.
The heating process which heats the coating film in which the above-mentioned light irradiation treatment was performed within the temperature range of 120 ° C or more and 280 ° C or less at least one before the contact process and after the contact process is further included. The manufacturing method of the liquid crystal aligning film as described in 2.
A liquid crystal element comprising the liquid crystal alignment film according to claim 7.
A polymer having at least one selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In the formula (1) and (2), X 1 is a tetravalent organic group having a cyclobutane ring structure, .X 2 having at least one substituent in the ring portion of the cyclobutane ring, the following formula (4) or a divalent organic group represented by the following formula (5): R 5 and R 6 are each independently a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms. )

(In Formula (4) and Formula (5), A 1 and A 2 are divalent aromatic ring groups, which may have a substituent in the ring portion. However, A 1 and A 2 are the same. Y 1 and Y 2 are each independently a single bond, an oxygen atom, a sulfur atom, or “—NR 7 —” (R 7 is a hydrogen atom or a monovalent organic group). However, Y 1 and Y 2 are different from each other, B 1 is a divalent heterocyclic group represented by the following formula (7) or formula (8), Y 3 is an oxygen atom or “− NR 9 — ”(R 9 is a hydrogen atom or a monovalent organic group). Z 1 has 1 to 15 carbon atoms having at least one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure. a divalent organic group, Z 2 is a single bond, or a linear C 1 - having at least one hydrocarbon structures and alicyclic hydrocarbon structure 5 is a divalent organic group. However, when one of Y 1 and Y 2 is a sulfur atom and the other is a single bond, the carbon number of Z 1 is 2 or more. "*" Indicates a bond.)

(In Formula (7) and Formula (8), R 8 is a substituent, r is an integer of 0 to 3, m is an integer of 0 to (r + 2), and “*” represents a bond. .)
The compound represented by following formula (16).

(In Formula (16), A 3 and A 4 are divalent groups in which two hydrogen atoms have been removed from the ring part of the benzene ring, pyridine ring or pyrimidine ring, and have a substituent in the ring part. Provided that A 3 and A 4 are the same, R 13 is a hydrogen atom or a monovalent organic group, Y 8 is an oxygen atom or a sulfur atom, and n is 1-5. (It is an integer.)