CN107338058B

CN107338058B - Liquid crystal aligning agent, liquid crystal alignment film and method for producing same, liquid crystal element, polymer and compound

Info

Publication number: CN107338058B
Application number: CN201710260108.8A
Authority: CN
Inventors: 村上拓也; 村主拓弥; 须原辽; 安池伸夫; 樫下幸志; 冈田敬
Original assignee: JSR Corp
Current assignee: JSR Corp
Priority date: 2016-04-28
Filing date: 2017-04-19
Publication date: 2022-01-25
Anticipated expiration: 2037-04-19
Also published as: JP6841069B2; KR102236019B1; KR20170123234A; TW201807067A; TWI750165B; CN107338058A; JP2017200991A

Abstract

The invention provides a liquid crystal aligning agent, a liquid crystal alignment film and a manufacturing method thereof, a liquid crystal element, a polymer and a compound, wherein the liquid crystal aligning agent can obtain a liquid crystal element which has good heat resistance and shows good liquid crystal alignment property and image retention property even if the film is not subjected to special treatment after being irradiated by light when a photo-alignment method is applied. The liquid crystal aligning agent contains a polymer (P) having a partial structure represented by formula (1).

(in the formula (1), R¹A tetravalent organic group having a cyclobutane ring structure which may have a substituent, R²Is a divalent organic radical; x¹And X²Each independently a hydroxyl group or a monovalent organic group having 1 to 40 carbon atoms; wherein, X¹And X²At least any one of (a) is a monovalent organic group having a reactive group).

Description

Liquid crystal aligning agent, liquid crystal alignment film and method for producing same, liquid crystal element, polymer and compound

Technical Field

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

Background

Liquid crystal elements are widely used in televisions, mobile devices, various monitors (monitors), and the like. In addition, in a liquid crystal element, a liquid crystal alignment film is used for controlling alignment of liquid crystal molecules in a liquid crystal cell. Conventionally, as a method for obtaining an organic film having a liquid crystal alignment regulating force, there have been known: 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, a method of irradiating a photosensitive organic film with light (photo-alignment method), and the like.

Since the photo-alignment method can provide a photosensitive organic film with uniform liquid crystal alignment properties while suppressing generation of static electricity or dust and can also realize precise control of the liquid crystal alignment direction, various studies have been made in recent years (for example, see patent document 1). Patent document 1 discloses the following: a liquid crystal alignment film is obtained by applying a liquid crystal alignment agent containing a polyimide precursor or a polyimide having a cyclobutane ring structure in the main chain thereof onto a substrate, calcining the applied liquid crystal alignment agent, irradiating the obtained film with polarized radiation, bringing an organic solvent having a boiling point of 110 to 180 ℃ into contact with the film, bringing the film into contact with water or a water-soluble organic solvent having a boiling point of 50 to 105 ℃, and then heating the film at 150 ℃ or higher. And the following are disclosed: when the film is subjected to the cleaning treatment and the heating treatment, and the film is provided with the alignment ability by the photo-alignment method, the liquid crystal display element of the In-Plane Switching (IPS) driving method or the Fringe Field Switching (FFS) driving method suppresses the image sticking caused by the generated ac driving.

[ Prior art documents ]

[ patent document ]

[ patent document 1] International publication No. 2014/084362

Disclosure of Invention

[ problems to be solved by the invention ]

However, in the method described in patent document 1, since the steps of cleaning and heating the film are required, the number of steps is increased, the cost is increased, or the manufacturing process becomes complicated when manufacturing the liquid crystal element. In recent years, liquid crystal televisions having a large screen and high definition have become the main body, and small display terminals such as smart phones (smartphones) and tablet Personal Computers (PCs) have been spreading, and demands for high definition and low cost of liquid crystal panels have been further increased. Therefore, it is more important than ever to develop a technology capable of producing a liquid crystal element having excellent various characteristics relating to the display quality of the liquid crystal element, such as liquid crystal alignment properties and image sticking characteristics, at the lowest possible cost.

At present, liquid crystal elements are used in a wide range of devices and applications from liquid crystal televisions with large screens to small display devices such as smart phones and tablet PCs. In addition, with the increase in the use of liquid crystal elements, the liquid crystal elements are assumed to be used in a severer high-temperature environment by being placed or installed in a place where a high temperature is likely to occur, such as in a vehicle or outdoors, or being driven for a longer period of time than before. Therefore, the liquid crystal element is required to have high reliability against heat resistance. However, when a liquid crystal alignment film is produced by photo-alignment treatment using a liquid crystal alignment agent containing a polyimide polymer having a cyclobutane ring structure in its main chain, there is a concern that: due to decomposition products generated by light irradiation to the coating film, minute bright spots are likely to be generated when the obtained liquid crystal element is exposed to the sun for a long time in a high-temperature environment, and reliability to heat resistance is deteriorated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal aligning agent for a liquid crystal device, which can obtain a liquid crystal alignment layer having good heat resistance and exhibiting good liquid crystal alignment properties and image sticking characteristics, even when a photo-alignment method is applied, without performing a special treatment after a film is irradiated with light.

[ means for solving problems ]

The present inventors have made intensive studies to achieve the above-described problems of the prior art, and as a result, have found that the above-described problems can be solved by using a polymer having a specific partial structure in an alignment film material, and have completed the present invention. Specifically, the following means are provided.

<1> a liquid crystal aligning agent comprising a polymer (P) having a partial structure represented by the following formula (1);

[ solution 1]

<2> a method for producing a liquid crystal alignment film, which comprises forming a coating film using the liquid crystal aligning agent <1> and irradiating the coating film with light to impart a liquid crystal alignment ability.

<3> a liquid crystal alignment film formed using the liquid crystal aligning agent <1 >.

<4> a liquid crystal cell comprising the liquid crystal alignment film according to <3 >.

<5> a polymer having a partial structure represented by the formula (1).

<6> a compound represented by the following formula (1-1) or the following formula (1-2) or a salt thereof;

[ solution 2]

(in the formulae (1-1) and (1-2), X¹¹And X¹²Each independently represents a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms; wherein, X¹¹And X¹²At least any one of (a) is a monovalent organic group having a reactive group; r³Each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or a monovalent aliphatic group having 1 to 10 carbon atoms and having a substituent; x is one selected from the group consisting of a hydroxyl group, a chlorine atom, a bromine atom, and structures represented by the following formulae (4-1) to (4-6)

[ solution 3]

(in formulae (4-1) to (4-6), "+" represents a bond).

[ Effect of the invention ]

According to the liquid crystal aligning agent of the present disclosure, a liquid crystal element having high heat resistance and exhibiting good liquid crystal alignment properties and image sticking properties can be obtained without performing special treatment such as cleaning or heating of a film after irradiation with radiation. That is, when the film is provided with the alignment ability by the photo-alignment method, a liquid crystal device having high heat resistance, less image sticking, and good liquid crystal alignment properties can be obtained in as few steps as possible.

Detailed Description

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

Polymer (P)

The liquid crystal aligning agent of the present disclosure contains a polymer (P) having a partial structure represented by the formula (1). In the formula (1), R¹The tetravalent group derived from a tetracarboxylic acid derivative having a cyclobutane ring structure is preferably a partial structure represented by the following formula (r-1). That is, the polymer (P) preferably has at least one of a partial structure represented by the following formula (1-A) and a partial structure represented by the following formula (1-B).

[ solution 4]

(in the formula (R-1), R³Each independently is hydrogen atomA monovalent aliphatic group having 1 to 10 carbon atoms and optionally having a substituent(s)

[ solution 5]

(in the formulae (1-A) and (1-B), R²、X¹And X²Are each as defined for R in said formula (1)²、X¹And X²The same is true. R³With R in said formula (R-1)³Same)

In the formula (R-1), R³The monovalent aliphatic group having 1 to 10 carbon atoms which may have a substituent is preferably an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group, an alkoxy group, a fluoroalkoxy group, or "-COOR²⁰"(wherein, R is²⁰An alkyl group, a fluoroalkyl group, an alkoxy group or a fluoroalkoxy group having 1 to 10 carbon atoms). Furthermore, 4R in the formula³May be the same or different.

R²Examples of the divalent group derived from the diamine compound include divalent groups obtained by removing two primary amino groups from a conventionally known diamine compound.

As X¹And X²Examples of the monovalent organic group having 1 to 40 carbon atoms include: C1-C40 monovalent hydrocarbon group, methylene group of the hydrocarbon group-O-, -S-, -CO-, -COO-, -COS-, -NR-, -³-、-CO-NR³-、-Si(R³)₂- (wherein, R)³Hydrogen atom or C1-12 monovalent hydrocarbon group), -N ═ N-, -SO)₂And monovalent groups such as monovalent groups A, monovalent hydrocarbon groups, monovalent groups obtained by substituting at least one of hydrogen atoms bonded to carbon atoms of monovalent group A with a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), a hydroxyl group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfinic acid group, a phosphino group, a carboxyl group, a cyano group, a sulfo group, an acyl group, and the like, and monovalent groups having a heterocycle. Wherein, X¹And X²At least any one of (a) is a monovalent organic compound having a reactive groupAnd (4) a base.

Here, the term "hydrocarbon group" as used herein includes chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. The "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group having only a chain structure, which do not include a cyclic structure in the main chain. The polymer may be saturated or unsaturated. The "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. The alicyclic hydrocarbon structure does not need to be included, and a part thereof may have a chain structure. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. In addition, the aromatic ring structure does not need to be included, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure. The "aliphatic group" refers to a chain hydrocarbon group and an alicyclic hydrocarbon group.

X¹And X²The at least one reactive group of (a) is preferably a group which forms a covalent bond between the reactive groups and each other and/or the maleimide compound in the presence of at least one of heat, light, an acid, a base and a radical. The reactive group is preferably a group that reacts by at least one of heat and light. Specific examples of the reactive group include: (meth) acryloyloxy group, styryl group, vinylphenyl group, (meth) acrylamido group, vinyloxy group (CH) represented by each of the following formulae (5-1) to (5-10)₂CH — O-), a group represented by each of the following formulae (p-1) and (p-2), and the like. The vinylphenyl group and the vinyloxy group are examples of the structure represented by the following formula (5-1).

[ solution 6]

(formula (5-1) to (5-10) wherein R⁴¹A divalent aliphatic group having 1 to 6 carbon atoms which may have a substituent, R⁵Each independently represents a hydrogen atom or a monovalent aliphatic group having 1 to 6 carbon atoms and optionally having a substituent. Wherein R is⁴¹And R⁵Any two of the aliphatic groups in (a) may be bonded to each other to form a ring structure. Formula (5-1) and formulaPlural R in (5-9)⁵May be the same or different from each other. "+" indicates a bond)

[ solution 7]

(in the formula (p-1), X⁵Is an oxygen atom or-NH-. "+" indicates a bond)

In the formula (5-1), R⁴¹The divalent aliphatic group having 1 to 6 carbon atoms is preferably an alkanediyl group or an alkenediyl group. As R⁴¹Examples of the substituent which may be present include a halogen atom and an alkoxy group. R⁵The monovalent aliphatic group having 1 to 6 carbon atoms is preferably an alkyl group or an alkenyl group.

In the formulae (5-2) to (5-10), R⁴¹The divalent aliphatic group having 1 to 6 carbon atoms is preferably an alkanediyl group. With respect to R⁴¹The description of said formula (5-1) can be applied to substituents which may be present. R⁵The monovalent aliphatic group having 1 to 6 carbon atoms is preferably an alkyl group. From the viewpoint of reactivity, R in the formula (5-5)⁵Particularly preferred is a hydrogen atom or a methyl group.

From the viewpoint of obtaining a liquid crystal element having more excellent liquid crystal alignment properties, Alternating Current (AC) residual image characteristics, and heat resistance, the reactive group is preferably at least one selected from the group consisting of the structures represented by the above formulae (5-1) to (5-10) and the (meth) acryloyloxy group, and more preferably at least one selected from the group consisting of the structures represented by the formulae (5-1), (5-2), the formulae (5-4) to (5-6) and the (meth) acryloyloxy group. In the present specification, "(meth) acrylic group" means an acrylic group and a methacrylic group.

The exemplary reactive groups may be directly bonded to the carbonyl group in formula (1) or may be bonded via a divalent linking group. Examples of the divalent linking group include: an oxygen atom, an alkanediyl group having 1 to 20 carbon atoms, a divalent group having-O-, -CO-, -COO-, and the like, between carbon-carbon bonds of the alkanediyl group, and the like.

X¹And X²ToAt least one of them is preferably one selected from the group consisting of the structures represented by the following formulae (2-1) to (2-10) and (meth) acryloyloxy groups, and more preferably one selected from the group consisting of the structures represented by the following formulae (2-1), (2-2), and (2-4) to (2-6) and (meth) acryloyloxy groups. Furthermore, R in the following formulae (2-1) to (2-10)⁴And R⁵As an explanation therefor, R in the above-mentioned formulae (5-1) to (5-10) can be applied respectively⁴¹And R⁵And (4) description.

[ solution 8]

In (formulae (2-1) to (2-10), R⁴A divalent aliphatic group having 1 to 6 carbon atoms which may have a substituent, R⁵Each independently represents a hydrogen atom or a monovalent aliphatic group having 1 to 6 carbon atoms and optionally having a substituent. Wherein R is⁴And R⁵Any two of the aliphatic groups in (a) may be bonded to each other to form a ring structure. A plurality of R in the formula (2-1) or the formula (2-9)⁵May be the same or different from each other. "+" indicates a bond)

[ Synthesis of Polymer (P) ]

The method for synthesizing the polymer (P) is not particularly limited, and preferable methods include: a method of reacting a tetracarboxylic acid derivative containing at least one of the compounds represented by the formulae (1-1) and (1-2) (hereinafter, also referred to as "specific acid derivative") with a diamine compound.

In the present specification, the term "tetracarboxylic acid derivative" includes a tetracarboxylic dianhydride obtained by dehydration condensation of four carboxyl groups of a tetracarboxylic acid, and a tetracarboxylic acid derivative obtained by subjecting at least one of four carboxyl groups of a tetracarboxylic acid to "-COX reaction³"(wherein, X³A halogen atom or a C1-40 monovalent organic group). Specifically, examples of the tetracarboxylic acid dianhydride include: one or two of the four carboxyl groups of the tetracarboxylic acid are esterified and the remainder is a carboxyl group, one or two of the four carboxyl groups of the tetracarboxylic acidAnd compounds or salts thereof in which one is esterified and a leaving group (e.g., a halogen atom, a structure represented by each of the formulae (4-1) to (4-6), etc.) is introduced into the remaining carboxyl group.

With respect to the formula (1-1), formula (1-2), R³The description of said formula (r-1) can be applied to the preferred examples. X¹¹And X¹²Is preferably at least one selected from the group consisting of structures represented by the formulae (2-1) to (2-10) and (meth) acryloyloxy groups. In addition, in X¹¹、X¹²In the case of a group having no reactive group, X¹1、X¹²Preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

X is preferably a hydroxyl group or a chlorine atom. In addition, when X is a hydroxyl group, the specific acid dianhydride is a tetracarboxylic acid diester, and when X is a chlorine atom or a bromine atom, the specific acid dianhydride is a tetracarboxylic acid diester dihalide.

[ tetracarboxylic acid derivatives ]

(specific acid derivative)

The specific acid derivative can be obtained, for example, by the following method or the like: [1] a method in which a tetracarboxylic dianhydride comprising a tetracarboxylic dianhydride having a cyclobutane ring structure (hereinafter, also referred to as "specific tetracarboxylic dianhydride") is reacted with a compound having a reactive group (hereinafter, also referred to as "reactive group-containing compound (E)"); [2] a method in which a tetracarboxylic dianhydride comprising a specific tetracarboxylic dianhydride is reacted with a reactive group-containing compound (E) to obtain a tetracarboxylic diester, and then reacted with a compound having the leaving group (e.g., a halogenating agent).

Specific tetracarboxylic dianhydride

The specific tetracarboxylic dianhydride is not particularly limited as long as it has a cyclobutane ring structure, and is specifically represented by the following formula (4).

[ solution 9]

(in the formula (4), A¹Being a tetravalent organic radical having a cyclobutane ring structure)

In the formula (4), A¹The structure represented by the formula (r-1) is preferred. Specific examples of the specific tetracarboxylic dianhydride include: 1,2,3, 4-cyclobutanetetracarboxylic dianhydride, 1-methyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1,2, 3-trimethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1,2,3, 4-tetramethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1-ethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1, 3-diethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1-ethyl-3-methyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, compounds represented by the following formulae (T-1-1) to (T-1-16), and the like.

[ solution 10]

The specific tetracarboxylic acid dianhydride is preferably 1,2,3, 4-cyclobutanetetracarboxylic acid dianhydride and 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid dianhydride among these tetracarboxylic acid dianhydrides, and particularly preferably 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid dianhydride. Further, as the specific tetracarboxylic dianhydride, one species may be used alone or two or more species may be used in combination.

Compound (E) having a reactive group

The reactive group-containing compound (E) is not particularly limited as long as it has a reactive group and a functional group that reacts with an acid dianhydride group, and is preferably a compound represented by the following formula (3-1).

[ solution 11]

(in the formula (3-1), A²Is a reactive group, R¹¹Is a single bond or a (k +1) -valent hydrocarbon group. k is an integer of 1 to 3)

In the formula (3-1), as R¹¹Examples of the (k +1) -valent hydrocarbon group of (A) include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon groupAn aromatic hydrocarbon group. k is preferably 1, R in this case¹¹Specific examples of the divalent chain hydrocarbon group include: methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene and the like, and these may be straight or branched. In addition, as R¹¹The divalent alicyclic hydrocarbon group of (2) includes: cyclohexylidene radical, -R^c-(CH₂)_n- (wherein, R)^cCyclohexylene group, n is an integer of 1 to 5), and the like, and examples of the divalent aromatic hydrocarbon group include: phenylene, biphenylene, -Ph- (CH)₂)_n- (wherein Ph is phenylene and n is an integer of 1 to 5), and the like.

A²The description of the reactive group of the formula (1) and the description of preferred embodiments can be applied.

Specific examples of the compound represented by the above formula (3-1) include compounds represented by the following formulae (3-1-1) to (3-1-16), respectively. Further, the reactive group-containing compound (E) may be used singly or in combination of two or more.

[ solution 12]

Reaction of tetracarboxylic dianhydride with reactive group-containing Compound (E)

The reaction of the tetracarboxylic dianhydride with the reactive group-containing compound (E) may be carried out in an organic solvent as required. The organic solvent used is not particularly limited as long as it is inactive with respect to the tetracarboxylic dianhydride and the reactive group-containing compound (E), and examples thereof include: ketones such as acetone and methyl ethyl ketone; hydrocarbons such as hexane, heptane, toluene and the like; halogen hydrocarbons such as chloroform and 1, 2-dichloroethane; ethers such as tetrahydrofuran, diethyl ether, and 1, 4-dioxane; nitrile compounds such as acetonitrile and propionitrile. These organic solvents may be used alone or in combination of two or more.

The proportion of the reactive group-containing compound (E) to be used is usually 2 to 100 moles, preferably 2 to 40 moles, based on 1 mole of the tetracarboxylic dianhydride. The reaction temperature in this case may be suitably set depending on the kind of the reactive group-containing compound (E) to be used, and is preferably-20 to 150 ℃ and more preferably 0 to 100 ℃. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. In addition, reprecipitation may be carried out after the reaction, if necessary. Then, the obtained precipitate is washed and dried as necessary to obtain a target compound (tetracarboxylic acid diester).

In the above method [2], when the tetracarboxylic acid diester obtained by the above reaction is reacted with an appropriate halogenating agent such as thionyl chloride, it is preferably carried out in an organic solvent. The reaction conditions of the tetracarboxylic dianhydride and the reactive group-containing compound (E) can be applied to the conditions such as the organic solvent, the reaction temperature, and the reaction time.

Other acid derivatives

When the polymer (P) is synthesized, only the specific acid derivative may be used as the tetracarboxylic acid derivative, or the specific acid derivative and a tetracarboxylic acid derivative different from the specific acid derivative (hereinafter, also referred to as "other acid derivative") may be used in combination. Examples of other acid derivatives include: a tetracarboxylic acid diester having no reactive group, a tetracarboxylic acid diester dihalide having no reactive group, a reaction product of a tetracarboxylic acid dianhydride having no cyclobutane ring structure (hereinafter, also referred to as "other tetracarboxylic acid dianhydride") and a compound (E) having a reactive group, a tetracarboxylic acid dianhydride, and the like.

The other tetracarboxylic dianhydrides are not particularly limited. Specific examples of the aliphatic tetracarboxylic dianhydride include: ethylenediaminetetraacetic dianhydride, and the like;

examples of the alicyclic tetracarboxylic dianhydride include: 2,3, 5-tricarboxycyclopentylacetic acid dianhydride, 5- (2, 5-dioxotetrahydrofuran-3-yl) -3a, 4, 5, 9 b-tetrahydronaphtho [1, 2-c ] furan-1, 3-dione, 5- (2, 5-dioxotetrahydrofuran-3-yl) -8-methyl-3 a, 4, 5, 9 b-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-tricarboxyl-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2, 4, 6, 8-tetracarboxylic bicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, etc.; examples of the aromatic tetracarboxylic dianhydride include: pyromellitic dianhydride, 4' - (hexafluoroisopropylidene) diphthalic anhydride, p-phenylene bis (trimellitic acid monoester anhydride), ethylene glycol bis (anhydrotrimellitate), 1, 3-propanediol bis (anhydrotrimellitate), and the like; in addition, tetracarboxylic dianhydrides described in Japanese patent application laid-open No. 2010-97188 can be used. Further, when the polymer (P) is synthesized, other tetracarboxylic dianhydrides may be used singly or in combination of two or more.

In synthesizing the polymer (P), the ratio of the specific acid derivative to be used is preferably 10 mol% or more relative to the total amount of the tetracarboxylic acid derivatives used in the synthesis, from the viewpoint of sufficiently obtaining the effects of the present disclosure. More preferably 30 mol% or more, and still more preferably 50 mol% or more. In addition, the specific acid derivative and the other acid derivatives may be used alone or in combination of two or more.

[ diamine Compound ]

The diamine compound used for the synthesis of the polymer (P) is not particularly limited, and various diamine compounds can be used. Specific examples thereof include the aliphatic diamines: m-xylylenediamine, 1, 3-propylenediamine, tetramethylenediamine, hexamethylenediamine, etc.; examples of the alicyclic diamine include: 1, 4-diaminocyclohexane, 4' -methylenebis (cyclohexylamine), and the like;

examples of the aromatic diamine include: dodecyloxydiaminobenzene, hexadecyloxydiaminobenzene, octadecyloxydiaminobenzene, cholestanoxydiaminobenzene, cholestenyloxydiaminobenzene, cholestyryl diaminobenzoate, cholestidyl diaminobenzoate, lanostanyl diaminobenzoate, 3, 6-bis (4-aminobenzoyloxy) cholestane, 3, 6-bis (4-aminophenoxy) cholestane, 1-bis (4- ((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 2, 5-diamino-N, N-diallylaniline, the following formula (E-1).

[ solution 13]

(in the formula (E-1), X^IAnd X^IIEach independently is a single bond, -O-, -COO-or-OCO-, R^IIs C1-3 alkanediyl, R^IIIs a single bond or C1-3 alkanediyl, a is 0 or 1, b is an integer of 0-2, c is an integer of 1-20, and d is 0 or 1. Wherein a and b do not become 0 at the same time)

Side chain type diamines such as the compounds represented by:

p-phenylenediamine, 4 ' -diaminodiphenylmethane, 4 ' -diaminodiphenylethane, 4 ' -diaminodiphenylsulfide, 4-aminophenyl-4 ' -aminobenzoate, 4 ' -diaminoazobenzene, 3, 5-diaminobenzoic acid, 1, 5-bis (4-aminophenoxy) pentane, bis [2- (4-aminophenyl) ethyl ] hexanedioic acid, bis (4-aminophenyl) amine, N-bis (4-aminophenyl) methylamine, 2, 6-diaminopyridine, 1, 4-bis- (4-aminophenyl) -piperazine, N ' -bis (4-aminophenyl) -benzidine, 2 ' -dimethyl-4, non-side-chain diamines such as 4 ' -diaminobiphenyl, 2 ' -bis (trifluoromethyl) -4, 4 ' -diaminobiphenyl, 4 ' -diaminodiphenyl ether, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 4 ' - (phenylenediisopropylidene) dianiline, 1, 4-bis (4-aminophenoxy) benzene, 4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine, and 4, 4 ' - [4, 4 ' -propane-1, 3-diylbis (piperidine-1, 4-diyl) ] diphenylamine;

examples of the diaminoorganosiloxanes include: 1, 3-bis (3-aminopropyl) -tetramethyldisiloxane and the like; in addition, diamines described in Japanese patent application laid-open No. 2010-97188 can be used. In addition, the diamine compound used in the synthesis of the polymer (P) may have the group having a reactive group as a substituent.

The diamine compound used for synthesizing the polymer (P) preferably contains at least one of P-phenylenediamine, 4 '-diaminodiphenylmethane, and 4, 4' -diaminodiphenylethane. Further, when the polymer (P) is synthesized, the diamine compound may be used alone or in combination of two or more.

[ reaction of tetracarboxylic acid derivative with diamine Compound ]

The reaction of the tetracarboxylic acid derivative with the diamine compound can be carried out by appropriately combining the conventional methods of organic chemistry depending on the tetracarboxylic acid derivative used.

For example, in the case where the tetracarboxylic acid derivative is a tetracarboxylic acid diester, a method of reacting the tetracarboxylic acid diester with a diamine compound, preferably in an organic solvent, in the presence of an appropriate dehydration catalyst can be used. Examples of the dehydration catalyst used in the reaction include: halogenated 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholine, carbonylimidazole, dicyclohexylcarbodiimide, phosphorus-based condensing agents, and the like. The proportion of the dehydration catalyst used is preferably 2 to 3 moles, more preferably 2 to 2.5 moles, based on 1 mole of the tetracarboxylic acid diester.

In addition, in the case where the tetracarboxylic acid derivative is a tetracarboxylic acid diester dihalide, a method of reacting the tetracarboxylic acid diester dihalide with a diamine compound, preferably in an organic solvent, in the presence of an appropriate base can be used. Examples of the base used in the reaction include: tertiary amines such as pyridine and triethylamine; alkali metals such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium and potassium, and the like. The ratio of the base to be used is preferably 2 to 4 moles, more preferably 2 to 3 moles, based on 1 mole of the diamine compound. Further, the reaction of the tetracarboxylic acid diester dihalide with the diamine compound may be carried out in the presence of a lewis acid for the purpose of promoting the reaction. Examples of the lewis acid include lithium halides such as lithium chloride.

In the reaction of the tetracarboxylic acid derivative and the diamine compound, the ratio of the tetracarboxylic acid derivative and the diamine compound to be used in the reaction is preferably 1 equivalent of the group (-COX) related to the reaction, which the tetracarboxylic acid derivative has, relative to the amino group of the diamine compound⁴(X⁴Hydroxyl group or leaving group) "is contained in a proportion of 0.2 to 2 equivalents. The reaction temperature is preferably-30-150 ℃, and the reaction time is preferably 0.1-48 hoursThen (c) is performed.

Examples of the organic solvent used in the reaction include: aprotic polar solvents, ketones, esters, ethers, halogenated hydrocarbons, and the like. Among these organic solvents, it is preferable to use one or more selected from the group consisting of aprotic polar solvents (organic solvents of the first group), or a mixture of one or more selected from the group consisting of organic solvents of the first group and one or more selected from the group consisting of ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (organic solvents of the second group). In the latter case, the ratio of the organic solvent in the second group to the total amount of the organic solvents in the first group and the organic solvents in the second group is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less.

Particularly preferred as the organic solvent is one or more selected from the group consisting of N-methyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, γ -butyrolactone, tetramethylurea, hexamethylphosphoric triamide, m-cresol, xylenol, and a halogenated phenol, or a mixture of one or more of these organic solvents and another organic solvent in the above ratio. The amount (a) of the organic solvent used is preferably such that the total amount (b) of the monomers used in the reaction is 0.1 to 50% by mass relative to the total amount (a + b) of the reaction solution.

(end-modifying agent)

When the polymer (P) is synthesized, a polymer having a partial structure represented by the above formula (1) and a functional group at a polymer terminal can be obtained by using a tetracarboxylic acid derivative and a diamine compound together with a terminal modifier having a functional group as the polymer (P). In this case, when the polymer (Q) and the polymer (P) described later are contained in the liquid crystal aligning agent, the coating property of the liquid crystal aligning agent can be further improved, and this is preferable in view of the above.

Examples of the terminal modifier include: monoanhydrides, monocarbochlorides, monoamine compounds, monoisocyanate compounds, and the like. Examples of the functional group of the terminal modifier include: the reactive group, thiol group, protected amino group, and the like.

Specific examples of such a terminal modifier include: (meth) acryloyl chloride, 2-furancarbonyl chloride, furfuryl amine, 2-aminoethanethiol, 3-aminopropanethiol, N- (tert-butoxycarbonyl) -1, 2-diaminoethane, N- (tert-butoxycarbonyl) -1, 3-diaminopropane, and the like. Further, the terminal-modifying agent may be used singly or in combination of two or more.

In the above synthesis, the terminal-modifying agent is used in a proportion of preferably 20 parts by mole or less, more preferably 0.001 to 10 parts by mole, based on 100 parts by mole of the total of the diamine compounds used.

The polymer (P) is a reaction product of a tetracarboxylic acid derivative containing at least one of the compounds represented by the formulae (1-1) and (1-2) and a diamine compound. The reaction product may be a polymer having only a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine compound, and may further have another partial structure different from the structural unit derived from the tetracarboxylic acid derivative and the structural unit derived from the diamine compound. Examples of the other partial structure include a partial structure derived from the terminal-modifying agent.

As described above, a reaction solution in which the polymer (P) as the polyamic acid ester is dissolved can be obtained. The reaction solution can be directly used for preparing the liquid crystal aligning agent, and also can be used for preparing the liquid crystal aligning agent after the polyamic acid ester contained in the reaction solution is separated. The polyamic acid ester may have only the amic acid ester structure or may be a partially esterified product in which the amic acid structure and the amic acid ester structure coexist. The method for synthesizing polyamic acid ester is not limited to the above method, and for example, polyamic acid ester can be obtained by a method of reacting polyamic acid with alcohol having a reactive group or halogenated alkyl group.

The polymer (P) obtained in this manner is preferably one having a solution viscosity of from 20 mPas to 1,800 mPas, more preferably from 50 mPas to 1,500 mPas, when it is made into a solution having a concentration of 15% by mass. The solution viscosity (mPa · s) of the polymer (P) is a value measured at 25 ℃ using an E-type rotational viscometer on a polymer solution having a concentration of 15 mass% prepared using a good solvent for the polymer (P) (e.g., γ -butyrolactone, N-methyl-2-pyrrolidone, etc.).

The weight average molecular weight (Mw) of the polymer (P) in terms of polystyrene, as measured by Gel Permeation Chromatography (GPC), is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 7 or less, and more preferably 5 or less. By setting the molecular weight in such a range, good alignment properties and stability of the liquid crystal element can be ensured.

By comparing the case of forming a film using a liquid crystal aligning agent containing the polymer (P) with the case of using a liquid crystal aligning agent containing only a polymer not having a partial structure represented by the formula (1) as a polymer component, there is an advantage that generation of decomposition products due to photo-alignment treatment can be suppressed. The reason is presumed to be: it is considered that when anisotropy is imparted to the film by decomposing the cyclobutane ring in the main chain by the reverse reaction of [2+2] and lowering the molecular weight, the decomposition product substantially generated by the reaction of the reactive group can be bonded to the component in the film, and the generation of the decomposition product can be reduced. The above description is merely an estimation and does not limit the disclosure in any way.

Other ingredients

< Polymer (Q) >

The liquid crystal aligning agent of the present disclosure may contain only the polymer (P) as a polymer component, or may contain the polymer (P) and at least one polymer (Q) selected from the group consisting of polyamic acid and polyimide. It is presumed that when a coating film is formed on a substrate by using a liquid crystal aligning agent containing a polymer (P) and a polymer (Q), the polymer (P) is biased to exist in an outer layer of the coating film due to a difference in surface energy, and thus, the liquid crystal alignment property and the AC image sticking property can be further improved.

(Polyamic acid)

The polyamic acid as the polymer (Q) can be obtained by, for example, reacting tetracarboxylic dianhydride with a diamine compound. Examples of the tetracarboxylic dianhydride and the diamine compound used in the reaction include those exemplified in the description of the polymer (P).

The ratio of the tetracarboxylic dianhydride to the diamine compound used in the synthesis reaction of the polyamic acid is preferably a ratio of 0.2 to 2 equivalents, more preferably a ratio of 0.3 to 1.2 equivalents, of the acid anhydride group of the tetracarboxylic dianhydride to 1 equivalent of the amino group of the diamine compound. The synthesis reaction of the polyamic acid is preferably carried out in an organic solvent. The reaction temperature in this case is preferably-20 ℃ to 150 ℃ and the reaction time is preferably 0.1 hour to 24 hours. When the polymer (Q) contains a polyamic acid, the effect of the polymer (P) can be obtained, and the printability can be further improved, which is preferable.

(polyimide)

The polyimide as the polymer (Q) can be obtained, for example, by subjecting a polyamic acid synthesized as described above to dehydrative ring closure and imidization. The polyimide may be a complete imide compound obtained by dehydration ring closure of all the amic acid structures of the polyamic acid as a precursor thereof, or may be a partial imide compound obtained by dehydration ring closure of only a part of the amic acid structures so that the amic acid structure and the imide ring structure coexist. The imidization ratio of the polyimide used for the preparation of the liquid crystal aligning agent is preferably 20% or more, more preferably 30% to 99%, and still more preferably 40% to 99%. The imidization ratio is a percentage representing the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of the polyimide. Here, a part of the imide ring may be an imide ring.

The dehydration and ring-closure of the polyamic acid are preferably carried out by a method of heating the polyamic acid, or a method of dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration and ring-closure catalyst to the solution, and optionally heating the solution. Among these, the method described later is preferably used.

In the method of adding a dehydrating agent and a dehydration ring-closure catalyst to a solution of polyamic acid, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride may be used as the dehydrating agent. The amount of the dehydrating agent to be used is preferably 0.01 to 20 moles based on 1 mole of the amic acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, there can be used: tertiary amines such as pyridine, collidine, lutidine and triethylamine. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 mol based on 1 mol of the dehydrating agent to be used. Examples of the organic solvent used in the dehydration ring-closure reaction include organic solvents exemplified as compounds used in the reaction of a tetracarboxylic acid diester and a diamine. The reaction temperature of the dehydration ring-closing reaction is preferably 0 ℃ to 180 ℃, and the reaction time is preferably 1.0 hour to 120 hours. In the case where polyimide is contained as the polymer (Q), the effect of the polymer (P) can be obtained, and the electrical characteristics can be further improved, which is preferable in this respect.

The polymer (Q) is preferably one having a solution viscosity of 20 mPas to 1,800 mPas, more preferably 50 mPas to 1,500 mPas when it is prepared into a 15 mass% solution. The solution viscosity (mPa · s) of the polymer (Q) is a value measured at 25 ℃ using an E-type rotational viscometer on a polymer solution having a concentration of 15 mass% prepared using a good solvent for the polymer (Q) (e.g., γ -butyrolactone, N-methyl-2-pyrrolidone, etc.).

The weight average molecular weight (Mw) of the polymer (Q) in terms of polystyrene measured by GPC is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 7 or less, and more preferably 5 or less.

When the liquid crystal aligning agent of the present disclosure contains the polymer (Q), the content of the polymer (P) is preferably 3 parts by mass or more, more preferably 5 parts by mass to 95 parts by mass, even more preferably 10 parts by mass to 90 parts by mass, and particularly preferably 15 parts by mass to 85 parts by mass, based on 100 parts by mass of the total of the polymer (P) and the polymer (Q). The polymer (P) and the polymer (Q) may be used alone or in combination of two or more.

The liquid crystal aligning agent of the present disclosure may contain a component other than the polymer (Q) as another component. Examples of the other components include: the polymer (P) and the polymer (Q) other than the polymer (P) and the polymer (Q) (hereinafter referred to as "other polymer"), a compound having at least one epoxy group in the molecule (hereinafter referred to as "epoxy group-containing compound"), a functional silane compound, a photopolymerizable compound, an antioxidant, a metal complex compound, a curing accelerator, a crosslinking agent, an imidization accelerator, a surfactant, a filler, a dispersant, a photosensitizing agent, an acid generator, a base generator, a radical generator, and the like. The liquid crystal aligning agent of the present disclosure preferably contains a polymer (P) and at least one selected from the group consisting of a functional silane compound, an acid generator, a base generator and a radical generator.

(other Polymer)

Other polymers may be used to improve solution properties or electrical properties. Examples of the other polymers include: and polymers having a main skeleton such as polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, and poly (meth) acrylate. The blending ratio of the other polymer is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 20 parts by mass or less, with respect to 100 parts by mass of the total of the polymers blended in the liquid crystal aligning agent.

(epoxy group-containing Compound)

The epoxy group-containing compound can be used to improve the adhesion of the liquid crystal alignment film to the substrate surface or the electrical characteristics. Examples of such epoxy group-containing compounds include: ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N '-tetraglycidyl-m-xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N' -tetraglycidyl-4, 4 '-diaminodiphenylmethane, N' -tetrakis (2-hydroxyethyl) ethylenediamine, N-diglycidylcenzylamine, N-diglycidylaminomethylcyclohexane, N-diglycidylcyclohexylamine and the like. In addition, as an example of the epoxy group-containing compound, an epoxy group-containing polyorganosiloxane described in international publication No. 2009/096598 can be used. When the epoxy group-containing compound is added to the liquid crystal aligning agent, the blending ratio is preferably 50 parts by mass or less, and more preferably 0.1 to 30 parts by mass, relative to 100 parts by mass of the total of the polymers contained in the liquid crystal aligning agent.

(functional silane Compound)

The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, 10-trimethoxysilyl-1, 4, 7-triazadecane, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and the like. When the functional silane compound is added to the liquid crystal aligning agent, the blending ratio is preferably 5 parts by mass or less, more preferably 0.02 to 3 parts by mass, and still more preferably 0.1 to 2 parts by mass, relative to 100 parts by mass of the total of the polymers.

(acid generator)

The acid generator may be suitably selected from compounds known to generate an acid by heat or light. Specifically, examples of the thermal acid generator include: iodine salts such as diphenyliodotrifluoromethanesulfonate and bis (4-tert-butylphenyl) iodotrifluoromethanesulfonate, and examples of the photoacid generator include: sulfonium salts such as triphenylsulfonium trifluoromethanesulfonate; tetrahydrothiophenium salts such as 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate; n-sulfonyloxyimide compounds such as N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2, 3-dicarboximide, and the like. When the acid generator is added to the liquid crystal aligning agent, the blending ratio is preferably 50 parts by mass or less, and more preferably 0.1 to 30 parts by mass, relative to 100 parts by mass of the total of the polymers.

(alkali generating agent)

The base generator can be suitably selected from compounds known to generate a base by heat or light, and used. Specifically, for example, an imidazole thermal base generator; photobase generators of the o-nitrobenzylcarbamate, α -dimethyl-3, 5-dimethoxybenzylcarbamate, acyloxyimino group, and the like. When the alkali generator is added to the liquid crystal aligning agent, the blending ratio is preferably 50 parts by mass or less, and more preferably 0.1 to 30 parts by mass, relative to 100 parts by mass of the total of the polymers.

(free radical generators)

The radical generator may be suitably selected from compounds known to generate radicals by heat or light, and used. Specifically, examples of the thermal radical generator include: peroxides such as t-butyl hydroperoxide and t-butyl peroxyacetate; azo compounds such as Azobisisobutyronitrile (AIBN) and 2, 2' -azobis (isobutyronitrile); redox initiators and the like; examples of the photo radical generator include: acetophenone, 1-hydroxycyclohexyl phenyl ketone, fluorene, triphenylamine, 3-methylacetophenone, 4' -dimethoxybenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, and the like. When the radical generator is added to the liquid crystal aligning agent, the blending ratio is preferably 50 parts by mass or less, and more preferably 0.1 to 30 parts by mass, relative to 100 parts by mass of the total of the polymers.

< solvent >

The liquid crystal aligning agent of the present disclosure is prepared in the form of a liquid composition in which the polymer (P) and other components used as needed are preferably dispersed or dissolved in an appropriate solvent.

Examples of the organic solvent to be used include: n-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1, 2-dimethyl-2-imidazolidinone, butyl-butyrolactone, gamma-butyrolactam, N-dimethylformamide, 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 isopropyl ether, ethylene glycol N-butyl ether (butylcellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl 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 monomethyl ether, Diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, and the like. These may be used alone or in combination of two or more.

The concentration of the solid component in the liquid crystal aligning agent (the ratio of the total mass of the 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, and the like, and is preferably in the range of 1 to 10 mass%. That is, as described below, a coating film as a liquid crystal alignment film or a coating film to be a liquid crystal alignment film is formed by applying a liquid crystal alignment agent to a surface of a substrate, preferably heating the liquid crystal alignment agent. In this case, when the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10 mass%, the film thickness of the coating film becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent tends to increase to lower the coatability.

The content of the polymer (P) in the liquid crystal aligning agent of the present disclosure is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more, based on 100 parts by mass of the total of the solid components (components other than the solvent) in the liquid crystal aligning agent.

Liquid crystal alignment film and liquid crystal element

The liquid crystal alignment film of the present disclosure is formed using the liquid crystal aligning agent prepared as described. The liquid crystal element of the present disclosure includes a liquid crystal alignment film formed using the liquid crystal aligning agent described above. The mode of operation of the liquid crystal In the liquid crystal element is not particularly limited, and can be applied to various modes such as a Twisted Nematic (TN) type, a Super Twisted Nematic (STN) type, a Vertical Alignment (VA) type (including a Vertical Alignment-Multi-domain Vertical Alignment (VA-MVA) type, a Vertical Alignment-Patterned Vertical Alignment (VA-PVA) type, etc.), an In-Plane Switching (IPS) type, an edge field Switching (FFS) type, an Optically Compensated Bend (OCB) type, and the like. The liquid crystal element can be manufactured by a method including, for example, the following steps 1 to 3. Step 1 uses different substrates depending on the desired mode of operation. Step 2 and step 3 are common in each operation mode.

(step 1: formation of coating film)

First, a liquid crystal aligning agent is applied to a substrate, and preferably, the coated surface is heated, thereby forming a coating film on the substrate. As the substrate, for example: glass such as float glass (float glass) and soda glass (soda glass); transparent substrates comprising plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin). As the transparent conductive film provided on one surface of the substrate, a transparent conductive film containing tin oxide (SnO) can be used₂) A film of (Nesa) (registered trademark of PPG Corp., USA) containing indium oxide-tin oxide (In)₂O₃-SnO₂) Indium Tin Oxide (ITO) film, and the like. In the case of manufacturing a TN-type, STN-type, or VA-type liquid crystal cell, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the manufacture of IPS-type or FFS-type liquidsIn the case of a wafer element, a substrate provided with an electrode including a transparent conductive film or a metal film patterned into a comb-tooth shape and a counter substrate provided with no electrode are used. As the metal film, for example, a film containing a metal such as chromium can be used. The liquid crystal aligning agent is preferably applied to the substrate by a lithographic method, a spin coating method, a roll coater method or an ink jet printing method on the electrode-forming surface.

After the liquid crystal aligning agent is applied, preheating (prebaking) is preferably performed for the purpose of preventing sagging of the applied liquid crystal aligning agent and the like. The pre-baking temperature is preferably 30-200 ℃, and the pre-baking time is preferably 0.25-10 minutes. Then, the solvent is completely removed, and a calcination (post-baking) step is carried out as necessary for the purpose of thermal imidization of the amic acid structure present in the polymer. The calcination temperature (post-baking temperature) in this case is preferably 80 to 300 ℃, and the post-baking time is preferably 5 to 200 minutes. The film thickness of the film formed in this manner is preferably 0.001 to 1 μm. After a liquid crystal aligning agent is applied to a substrate, an organic solvent is removed to form a liquid crystal alignment film or a coating film to be the liquid crystal alignment film.

(step 2: orientation treatment)

In the case of producing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal cell, the coating film formed in step 1 is subjected to a treatment (alignment treatment) for imparting liquid crystal alignment ability. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As the orientation treatment, there can be mentioned: rubbing the coating film in a fixed direction by a roller around which a cloth containing fibers such as nylon, rayon, and cotton is wound, thereby imparting liquid crystal alignment ability to the coating film; and photo-alignment treatment for applying a liquid crystal alignment capability to a coating film formed on a substrate by irradiating the coating film with light. In particular, the polymer (P) has high photosensitivity, and can exhibit anisotropy of a coating film even with a small exposure amount, and therefore, the photoalignment method can be preferably applied. On the other hand, in the case of producing a vertical alignment type liquid crystal element, the coating film formed in the above-mentioned step 1 may be used as it is as a liquid crystal alignment film, but the coating film may be subjected to an alignment treatment.

Light irradiation in the photo-alignment treatment can be performed by the following method: a method of irradiating the coating film after the post-baking step; a method of irradiating the coating film after the pre-baking step and before the post-baking step; a method of irradiating the coating film during the heating of the coating film in at least one of the pre-baking step and the post-baking step. In the photo-alignment treatment, as the radiation to irradiate the coating film, for example, ultraviolet rays and visible rays including light having a wavelength of 150nm to 800nm can be used. Preferably ultraviolet light including light having a wavelength of 200nm to 400 nm. When the radiation is polarized light, the radiation may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, the substrate surface may be irradiated from the vertical direction, may be irradiated from the oblique direction, or may be irradiated in combination. When unpolarized radiation is irradiated, the irradiation direction is set to be an oblique direction.

As the light source used, for example, there can be used: low pressure mercury lamps, high pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, excimer lasers, and the like. The irradiation dose of the radiation is preferably 400J/m²～50,000J/m²More preferably 1,000J/m²～20,000J/m². In order to improve the reactivity, the coating film may be irradiated with light while being heated.

After the light irradiation for imparting alignment ability, for example, a treatment of cleaning the surface of the substrate with water, an organic solvent (e.g., methanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.), or a mixture thereof, or a treatment of heating the substrate may be performed. In the case of forming a coating film using the liquid crystal aligning agent of the present disclosure, a liquid crystal element having excellent display performance can be obtained without performing such cleaning treatment or heating treatment, and cost reduction can be achieved, which is preferable in view of the above.

(step 3: construction of liquid Crystal cell)

A liquid crystal cell is manufactured by preparing two substrates on which liquid crystal alignment films are formed in this manner, and disposing liquid crystal between the two substrates disposed in opposition to each other. When a liquid crystal cell is manufactured, for example, the following methods can be cited: (1) a method of arranging two substrates in an opposing manner with a gap (spacer) therebetween so that the liquid crystal alignment films face each other, bonding peripheral portions of the two substrates with a sealant, injecting a filling liquid crystal into a cell gap defined by a surface of the substrate and the sealant, and then sealing the injection hole; (2) a method (One Drop Fill (ODF) method) in which a sealant is applied to a predetermined portion of One of the substrates on which the liquid crystal alignment film is formed, liquid crystal is dropped onto a predetermined plurality of portions on the surface of the liquid crystal alignment film, and then the other substrate is bonded so that the liquid crystal alignment film faces the other substrate, and the liquid crystal is spread over the entire surface of the substrate. It is desirable that the liquid crystal cell to be manufactured is further heated to a temperature at which the liquid crystal to be used takes an isotropic phase, and then gradually cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal.

As the sealant, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used. As the spacer, a photo spacer (photospacer), a bead spacer (beads spacer), or the like can be used. Examples of the liquid crystal include nematic liquid crystal (nematic liquid crystal) and smectic liquid crystal (smectic liquid crystal), and among them, nematic liquid crystal is preferable, and for example: schiff base (Schiffbase) liquid crystals, azoxy (azoxy) liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl (terphenyl) liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane (cubane) liquid crystals, and the like. For example, a cholesteric liquid crystal (cholesteric liquid crystal), a chiral agent, a ferroelectric liquid crystal (ferroelectric liquid crystal), or the like may be added to the liquid crystal.

Then, a polarizing plate is bonded to the outer surface of the liquid crystal cell as necessary to produce a liquid crystal element. Examples of the polarizing plate include: a polarizing plate formed by sandwiching a polarizing film called "H film" which is a film obtained by absorbing iodine while stretching and orienting polyvinyl alcohol, or a polarizing plate including the H film itself, with a cellulose acetate protective film.

The liquid crystal element of the present disclosure can be effectively applied to various uses, for example, can be used for: various display devices such as a clock, a portable game machine, a word processor (word processor), a notebook Personal computer (note type Personal computer), a car navigation system (car navigation system), a camcorder (camrecorder), a Personal Digital Assistant (PDA), a Digital camera (Digital camera), a mobile phone, a smart phone, various monitors, a liquid crystal television, an information display (information display), a light adjusting film, and the like. In addition, a liquid crystal element formed using the liquid crystal aligning agent of the present disclosure can also be applied to a retardation film.

[ examples ]

The present invention will be further specifically described below with reference to examples, but the present invention is not limited to these examples.

In the following examples, the molecular weight of the polymer was measured by the following method.

[ molecular weight of Polymer ]

The number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene were measured by Gel Permeation Chromatography (GPC) under the following conditions, and the molecular weight distribution (Mw/Mn) was determined.

A measuring device: manufactured by Tosoh (Strand), HLC-8020

Pipe column: manufactured by Tosoh corporation, TSK guardcolum alpha, TSK gel alpha-M, and TSK gel alpha-2500 were used in series

Developing solvent: a solution containing 9.4g of lithium bromide monohydrate and 1.7g of phosphoric acid in 3L of dimethylformamide

Temperature: 35 deg.C

Flow rate: 1.0mL/min

The structures and abbreviations of the main compounds used in the following examples are as follows.

(tetracarboxylic dianhydride)

TA-1: 1,2,3, 4-butanetetracarboxylic dianhydride

TA-2: 1,2,3, 4-cyclobutanetetracarboxylic dianhydride

TA-3: (1R, 2R, 3S, 4S) -1, 3-dimethylcyclobutane-1, 2,3, 4-tetracarboxylic dianhydride

TA-4: trans-1, 2,3, 4-cyclopentanetetracarboxylic dianhydride

TA-5: 2,3, 5-tricarboxylic cyclopentyl acetic dianhydride

TA-6: pyromellitic dianhydride

[ solution 14]

(diamine)

DA-1: p-phenylenediamine

DA-2: 4, 4' -diaminodiphenylmethane

DA-3: 4, 4' -Ethyl diphenylamine

DA-4: 2, 2 '-dimethyl-4, 4' -diaminobiphenyl

DA-5: n- (tert-butoxycarbonyl) -2, 5-diaminobenzylamine

DA-6: 4-amino-N- (4-aminophenyl) -N- (tert-butoxycarbonyl) benzamide

DA-7: 4, 4' -diaminodiphenylamine

DA-8: 4, 4 ' -diamino-N4, N4 ' -bis (4-aminophenyl) -N4, N4 ' -dimethylbiphenyl

DA-9: n-2- (4-aminophenylethyl) -N-methylamines

DA-10: 6, 6' - (piperazine-1, 4-diyl) -bis (pyridin-3-amine)

DA-11: 1, 4-Phenoxy-bis (4-aminobenzoate)

DA-12: 4-aminophenyl-3- (4-aminophenyl) -2-methacrylate

[ solution 15]

(end-modifying agent)

EC-1: methacryloyl chloride

EC-2: 2-Furanocarbonyl chloride

EC-3: furfuryl amine

EC-4: 2-aminoethanethiol

EC-5: n- (tert-butoxycarbonyl) -1, 2-diaminoethane

[ solution 16]

(imidization accelerators)

I-1: 3- (2-hydroxyphenyl) -N- (pyridin-3-ylmethyl) propionamide

I-2: n-alpha- (9-fluorenylmethoxycarbonyl) -N- (tert-butoxycarbonyl) -L-histidine

(functional silane Compound)

s-1: 3-glycidoxypropylmethyldiethoxysilane

(epoxy group-containing Compound)

CL-1: n, N, N ', N ' -tetraglycidyl-4, 4 ' -diaminodiphenylmethane

CL-2: n, N, N ', N' -tetrakis (2-hydroxyethyl) ethylenediamine

(dehydration catalyst)

DMT-MM: 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholine chloride

(solvent)

NMP: n-methyl-2-pyrrolidone

γ BL: gamma-butyrolactone

BC: butyl cellosolve

[ example 1a ]

In a 200mL three-necked flask equipped with a nitrogen inlet, a reflux condenser and a thermometer, 22.42g (100mmol) of TA-3, 100mL of tetrahydrofuran and 0.79g (10.0mmol) of pyridine were placed, and the mixture was stirred under a nitrogen stream to be suspended. To the suspension was added 15.14g (210mmol) of β -methylallyl alcohol, and the mixture was stirred at room temperature for 2 hours. Further reacted at 60 ℃ for 8 hours to obtain a colorless transparent solution. The reaction solution was concentrated under reduced pressure at 60 ℃ and further dried under vacuum, whereby 36.84g of a mixture of the compound represented by the following formula (DE-1a) and the compound represented by the following formula (DE-1b) (hereinafter, referred to as DE-1a/b) was obtained.

[ solution 17]

[ example 2a ]

18.42g (50.0mmol) of DE-1a/b and 100mL of toluene were placed in a 100mL round bottom flask equipped with a nitrogen inlet tube and a reflux condenser tube, and stirred at 80 ℃ for 30 minutes. Then, the mixture was cooled to room temperature while stirring, and further stirred at room temperature for 30 minutes. The resulting suspension was filtered and washed 2 times with 5mL of toluene. The obtained solid was dried under vacuum at 60 ℃ to obtain 15.47g (42.0mmol, yield 84%) of DE-1a as a white powder.

[ example 3a ]

A500 mL three-necked flask equipped with a nitrogen inlet, a reflux condenser and a thermometer was charged with 14.74g (40.0mmol) of DE-1a, 80mL of heptane and 0.032g (0.40mmol) of pyridine, and the mixture was stirred at 75 ℃ under a nitrogen stream. It took 20 minutes to slowly add thionyl chloride 14.28g (120mmol) dropwise, and bubbling accompanied by the reaction was confirmed. After completion of the dropwise addition, the reaction mixture was allowed to react at 75 ℃ for 2 hours to obtain a colorless transparent solution. The reaction solution was concentrated under reduced pressure at 60 ℃ and excess thionyl chloride was distilled off. To the obtained liquid, 80mL of heptane was added and stirred at room temperature, and the precipitated insoluble matter was removed by filtration. The filtrate was concentrated under reduced pressure at 60 ℃ and dried under vacuum at 60 ℃ for 4 hours, whereby 15.89g (39.2mmol, yield 98%) of a compound represented by the following formula (DC-1a) was obtained as a colorless transparent liquid.

[ solution 18]

[ example 4a ]

A mixture of a compound represented by the following formula (DE-2a) and a compound represented by the following formula (DE-2b) (hereinafter, referred to as DE-2a/b)42.04g was obtained in the same manner as in example 1a except that 15.14g (210mmol) of β -methylallyl alcohol was changed to 20.60g (210mmol) of furfuryl alcohol.

[ solution 19]

[ example 5a ]

In a 100mL three-necked flask equipped with a nitrogen inlet, a reflux condenser and a thermometer, 9.81g (50mmol) of TA-2, 50mL of tetrahydrofuran and 0.40g (5.0mmol) of pyridine were placed, and the mixture was suspended by stirring under a nitrogen stream. To the suspension was added 13.66g (105mmol) of 2-hydroxyethyl methacrylate, and the mixture was stirred at room temperature for 2 hours. Further reacted at 40 ℃ for 24 hours to obtain a colorless transparent solution. The reaction solution was concentrated under reduced pressure at 40 ℃ and further dried under vacuum, whereby 22.82g of a mixture of the compound represented by the following formula (DE-3a) and the compound represented by the following formula (DE-3b) (hereinafter, referred to as DE-3a/b) was obtained.

[ solution 20]

[ example 6a ]

A mixture of the compound represented by the following formula (DE-4a) and the compound represented by the following formula (DE-4b) (hereinafter, referred to as DE-4a/b) was obtained in 33.63g in the same manner as in example 1a except that 15.14g (210mmol) of β -methylallyl alcohol was changed to 11.77g (210mmol) of propargyl alcohol.

[ solution 21]

[ example 7a ]

A mixture (hereinafter, referred to as DE-5a/b) of the compound represented by the following formula (DE-5a) and the compound represented by the following formula (DE-5b) was obtained in 37.23g in the same manner as in example 1a except that 15.14g (210mmol) of β -methylallyl alcohol was changed to 15.56g (210mmol) of hydroxyacetone.

[ solution 22]

[ example 8a ]

A mixture of a compound represented by the following formula (DE-6a) and a compound represented by the following formula (DE-6b) (hereinafter, referred to as DE-6a/b) was obtained in the same manner as in example 5a except that 13.66g (105mmol) of 2-hydroxyethyl methacrylate was changed to 12.40g (105mmol) of glycerol 1, 2-carbonate (DE-6 a/b), and 21.61g was obtained.

[ solution 23]

[ Synthesis example 9]

In a 100mL three-necked flask equipped with a nitrogen introduction tube, a reflux condenser and a thermometer, 9.81g (50mmol) of 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride, 50mL of tetrahydrofuran and 0.40g (5.0mmol) of pyridine were placed, and the mixture was stirred under a nitrogen flow to suspend the mixture. To the suspension was added 6.4g (200mmol) of methanol, and the mixture was stirred at room temperature for 24 hours to obtain a colorless transparent solution. The reaction solution was concentrated under reduced pressure at 60 ℃ and further dried under vacuum, whereby 14.41g of a mixture of the compound represented by the following formula (DE-7a) and the compound represented by the following formula (DE-7b) (hereinafter, referred to as DE-7a/b) was obtained.

[ solution 24]

[ Synthesis example 10]

A compound represented by the following formula (DE-8a) was synthesized according to the method described in example 4 of International publication No. 2010/092989. Further, a compound represented by the following formula (DC-8a) was synthesized according to the method described in example 47 of International publication No. 2010/092989.

[ solution 25]

[ Synthesis example 11]

A50 mL round bottom flask equipped with a nitrogen inlet, a reflux condenser and a thermometer was charged with 1.63g (11.0mmol) of 3, 4-dihydrocoumarin, 1.08g (10.0mmol) of 3- (aminomethyl) pyridine and 10mL of tetrahydrofuran, and the mixture was heated under reflux at 80 ℃ for 3 hours under a nitrogen stream. To the reaction solution, 40ml of heptane was added to precipitate a product, which was then filtered. The obtained solid was washed with heptane and dried under reduced pressure to obtain 2.51g (9.8mmol) of 3- (2-hydroxyphenyl) -N- (pyridin-3-ylmethyl) propionamide.

[ solution 26]

[ Synthesis example 12]

N- (tert-butoxycarbonyl) -2, 5-diaminobenzylamine was synthesized according to the method described in Synthesis example 7 of International publication No. 2011/115118.

[ example 1]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 3.54g (9.6mmol) of DE-1a/b, 1.08g (10.0mmol) of DA-1, 31.0g of NMP, and 0.51g (5.0mmol) of triethylamine, cooled to about 10 ℃ and added with 8.30g (30.0mmol) of DMT-MM as a triazine-based dehydration condensation agent, and reacted under a nitrogen stream at room temperature for 24 hours. The obtained polymerization solution was diluted with NMP, and gradually poured into methanol while being stirred to solidify the solution. The precipitated solid was recovered and washed with stirring in methanol twice and dried under vacuum at 60c to obtain polyamic acid ester (PAE-1) as a white powder. The number average molecular weight Mn of the polymer was 11,000, and the molecular weight distribution Mw/Mn was 3.0.

[ example 2]

A polyamic acid ester (PAE-2) was obtained in the same manner as in example 1, except that DE-1a/b was changed to DE-1a 3.54g (9.6 mmol). The number average molecular weight Mn of the polymer was 12,000, and the molecular weight distribution Mw/Mn was 4.1.

[ example 3]

A polyamic acid ester (PAE-3) was obtained in the same manner as in example 1, except that DE-1a/b was changed to DE-1a 2.83g (7.68mmol) and DE-7a/b 0.553g (1.92 mmol). The number average molecular weight Mn of the polymer was 21,000, and the molecular weight distribution Mw/Mn was 3.5.

[ example 4]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 1.03g (9.5mmol) of DA-1, 0.106g (0.50mmol) of DA-3, and 20.0g of NMP, and cooled to about 10 ℃ to prepare a diamine solution. To the solution was added an acid chloride solution prepared by dissolving DC-1a 3.89g (9.6mmol) in pyridine 1.90g (21.6mmol) and γ BL 20.0g in advance, and the mixture was reacted at room temperature for 4 hours under a nitrogen stream. To the polymerization solution was added 0.209g (2.0mmol) of EC-1, and the reaction was continued for 4 hours. The obtained polymerization solution was diluted with γ BL, and gradually poured into deionized water while stirring to solidify the solution. The precipitated solid was recovered and washed with stirring in isopropanol repeatedly twice, and vacuum-dried at 60 ℃ to obtain a polyamic acid ester (PAE-4) as a white powder. The number average molecular weight Mn of this polymer was 8,000, and the molecular weight distribution Mw/Mn was 2.1.

[ example 5]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 0.973g (9.0mmol) of DA-1, 0.327g (1.0mmol) of DA-6, and 20.0g of NMP, and cooled to about 10 ℃ to prepare a diamine solution. To the solution was added an acid chloride solution prepared by dissolving DC-1a 3.89g (9.6mmol) in pyridine 1.90g (21.6mmol) and γ BL 20.0g in advance, and the mixture was reacted at room temperature for 4 hours under a nitrogen stream. To the polymerization solution was added 0.261g (2.0mmol) of EC-2, and the reaction was continued for 4 hours. The obtained polymerization solution was diluted with γ BL, and gradually poured into deionized water while stirring to solidify the solution. The precipitated solid was recovered and washed with stirring in isopropanol repeatedly twice, and vacuum-dried at 60 ℃ to obtain a polyamic acid ester (PAE-5) as a white powder. The number average molecular weight Mn of this polymer was 25,000, and the molecular weight distribution Mw/Mn was 4.5.

[ example 6]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 4.04g (9.6mmol) of DE-2a/b, 0.995g (9.2mmol) of DA-1, 0.078g (0.8mmol) of EC-3, 31.0g of NMP, and 0.51g (5.0mmol) of triethylamine, cooled to about 10 ℃ and added with 8.30g (30.0mmol) of DMT-MM, and reacted under a nitrogen stream at room temperature for 24 hours. The obtained polymerization solution was diluted with NMP, and gradually poured into methanol while being stirred to solidify the solution. The precipitated solid was recovered and washed with stirring in methanol twice and dried under vacuum at 60c to obtain polyamic acid ester (PAE-6) as a white powder. The number average molecular weight Mn of the polymer was 15,000, and the molecular weight distribution Mw/Mn was 3.2.

[ example 7]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 2.19g (4.8mmol) of DE-3a/b, 1.38g (4.8mmol) of DE-8a, 1.08g (10.0mmol) of DA-1, 31.0g of NMP, and 0.51g (5.0mmol) of triethylamine, cooled to about 10 ℃ and added with 8.30g (30.0mmol) of DMT-MM, and reacted under a nitrogen stream at room temperature for 24 hours. The obtained polymerization solution was diluted with NMP, and gradually poured into methanol while being stirred to solidify the solution. The precipitated solid was recovered and washed with stirring in methanol twice and dried under vacuum at 60c to obtain a polyamic acid ester (PAE-7) as a white powder. The number average molecular weight Mn of this polymer was 18,000, and the molecular weight distribution Mw/Mn was 1.8.

[ example 8]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 3.23g (9.6mmol) of DE-4a/b, 0.995g (9.2mmol) of DA-1, 0.062g (0.8mmol) of EC-4, 31.0g of NMP, and 0.51g (5.0mmol) of triethylamine, cooled to about 10 ℃ and added with 8.30g (30.0mmol) of DMT-MM, and reacted under a nitrogen stream at room temperature for 24 hours. The obtained polymerization solution was diluted with NMP, and gradually poured into methanol while being stirred to solidify the solution. The precipitated solid was recovered and washed with stirring in methanol twice and dried under vacuum at 60c to obtain polyamic acid ester (PAE-8) as a white powder. The number average molecular weight Mn of the polymer was 12,000, and the molecular weight distribution Mw/Mn was 3.3.

[ example 9]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 3.57g (9.6mmol) of DE-5a/b, 0.796g (7.36mmol) of DA-1, 0.437g (1.84mmol) of DA-5, 0.128g (0.80mmol) of EC-5, 31.0g of NMP, and 0.51g (5.0mmol) of triethylamine, cooled to about 10 ℃ and charged with 8.30g (30.0mmol) of DMT-MM, and reacted at room temperature under a nitrogen stream for 24 hours. The obtained polymerization solution was diluted with NMP, and gradually poured into methanol while being stirred to solidify the solution. The precipitated solid was recovered and washed with stirring in methanol twice and dried under vacuum at 60c to obtain a polyamic acid ester (PAE-9) as a white powder. The number average molecular weight Mn of the polymer was 12,000, and the molecular weight distribution Mw/Mn was 3.5.

[ example 10]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 2.08g (4.8mmol) of DE-6a/b, 1.38g (4.8mmol) of DE-8a, 0.796g (7.36mmol) of DA-1, 0.437g (1.84mmol) of DA-5, 0.128g (0.80mmol) of EC-5, 31.0g of NMP, and 0.51g (5.0mmol) of triethylamine, cooled to about 10 ℃ and charged with 8.30g (30.0mmol) of DMT-MM, and reacted at room temperature under a nitrogen stream for 24 hours. The obtained polymerization solution was diluted with NMP, and gradually poured into methanol while being stirred to solidify the solution. The precipitated solid was recovered and washed with stirring in methanol twice and dried under vacuum at 60c to obtain polyamic acid ester (PAE-10) as a white powder. The number average molecular weight Mn of the polymer was 20,000, and the molecular weight distribution Mw/Mn was 3.0.

[ Synthesis example 13]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 1.08g (10.0mmol) of DA-1 and 16.0g of NMP, and cooled to about 10 ℃ to prepare a diamine solution. To the solution was added an acid chloride solution prepared by dissolving DC-8a 3.12g (9.6mmol) in pyridine 1.90g (21.6mmol) and γ BL 16.0g in advance, and the mixture was reacted at room temperature for 4 hours under a nitrogen stream. The obtained polymerization solution was diluted with γ BL, and gradually poured into deionized water while stirring to solidify the solution. The precipitated solid was recovered and washed with stirring in isopropanol repeatedly twice, and vacuum-dried at 60 ℃ to obtain a polyamic acid ester (PAE-11) as a white powder. The number average molecular weight Mn of this polymer was 19,000, and the molecular weight distribution Mw/Mn was 1.5.

[ Synthesis example 14]

100 parts by mole of TA-3 as tetracarboxylic dianhydride and 100 parts by mole of DA-1 as diamine were dissolved in NMP and reacted at room temperature for 6 hours to obtain a solution containing 20 mass% of polyamic acid (PAA-1).

[ Synthesis example 15]

100 parts by mole of TA-2 as tetracarboxylic dianhydride and 100 parts by mole of DA-4 as diamine were dissolved in NMP and reacted at room temperature for 6 hours to obtain a solution containing 20 mass% of polyamic acid (PAA-2).

[ Synthesis example 16]

100 parts by mole of TA-1 as tetracarboxylic dianhydride and 100 parts by mole of DA-7 as diamine were dissolved in NMP and reacted at room temperature for 6 hours to obtain a solution containing 20 mass% of polyamic acid (PAA-3).

[ Synthesis example 17]

100 parts by mole of TA-4 as tetracarboxylic dianhydride, 80 parts by mole of DA-2 as diamine, and 20 parts by mole of DA-8 were dissolved in NMP and reacted at room temperature for 6 hours to obtain a solution containing 20% by mass of polyamic acid (PAA-4).

The kinds and blending ratios of the compounds used for the synthesis of the polymer are shown in table 1 below. In table 1 below, "molar ratio" indicates the ratio of each compound used in the synthesis (molar ratio) (the same applies to table 3 below).

[ Table 1]

Example 11: light-oriented FFS type liquid crystal display element

(1) Preparation of liquid crystal aligning agent

The polymer (PAE-1) obtained in example 1 as a polymer was dissolved in a mixed solvent containing γ -butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) and Butyl Cellosolve (BC) (GBL: NMP: BC 80: 10 (mass ratio)) to prepare a solution having a solid content concentration of 4.0 mass%. The liquid crystal aligning agent (R-1) was prepared by filtering the solution with a filter having a pore size of 0.2 μm.

(2) Evaluation of coatability

The prepared liquid crystal aligning agent (R-1) was applied to a glass substrate using a spin coater, prebaked for 1 minute using a hot plate at 80 ℃ and then heated for 30 minutes using an oven at 230 ℃ in which nitrogen gas was substituted in the chamber (postbaking), thereby forming a coating film having an average film thickness of 0.1. mu.m. The coating film was observed with a microscope at a magnification of 100 times and 10 times to examine the presence or absence of film thickness unevenness and pinholes. For the evaluation, the case where both the film thickness unevenness and the pinholes were not observed even when observed with a microscope at a magnification of 100 times was evaluated as "good" coatability, the case where at least one of the film thickness unevenness and the pinholes was observed with a microscope at a magnification of 100 times but both the film thickness unevenness and the pinholes were not observed with a microscope at a magnification of 10 times was evaluated as "good" coatability, and the case where at least one of the film thickness unevenness and the pinholes was clearly observed with a microscope at a magnification of 10 times was evaluated as "bad" coatability. In this example, neither film thickness unevenness nor pinholes were observed with a microscope of 100 times, and the coatability was "good".

(3) Measurement of imidization ratio of Polymer component in coating film

With respect to the coating film obtained in the above (2), 1360cm in FT-IR measurement was measured^-1Nearby absorption (C-N stretching vibration absorption of imide group)Receive) absorbance of alpha 1 and 1500cm^-1The imidization ratio (%) was calculated by using the following numerical formula (4) with respect to the absorbance α 2 of the absorption in the vicinity (absorption of the aromatic ring due to C ═ C stretching vibration).

Imidization rate (%) { (α 1)_230℃/α2_230℃)/(α1_300℃/α2_300℃)}×100…(4)

(in the numerical formula (4),. alpha.1_230℃And alpha 2_230℃Alpha 1 is a measurement result of the coating film obtained in the above (2)_300℃And alpha 2_300℃The coating film was heated for 90 minutes in an oven at 300 ℃ in which nitrogen gas was replaced in the chamber, and the measurement results were obtained. Wherein the imidization rate of the coating film heated at 300 ℃ was 100%)

As a result, the imidization ratio of the coating film was 30%.

(4) Adhesion Property

The coating film produced in (2) above was used to evaluate the adhesion between the coating film formed from the liquid crystal aligning agent and the substrate. First, a coating film was cut with a cutter using an equally spaced spacer with a guide to form a 10 × 10 lattice pattern in a range of 1cm × 1 cm. The depth of each notch is formed to reach the middle of the coating film. Then, the transparent tape is closely adhered so as to cover the entire surface of the lattice pattern, and then the transparent tape is peeled off. The cut portions of the lattice pattern after peeling were observed by visual observation under crossed nicols to evaluate the adhesiveness. The evaluation was carried out as follows: the portion along the cut line and the intersection portion of the lattice pattern where no peeling was observed was evaluated as "excellent" in adhesion, the portion where peeling was observed was evaluated as "good" in adhesion when the number of lattice eyes was less than 15% of the number of the entire lattice pattern, the portion where peeling was observed was evaluated as "Δ" in adhesion when the number was 15% or more and less than 20%, and the portion where peeling was 20% or more was evaluated as "x". As a result, the adhesiveness of the coating film was "Δ".

(5) Manufacture of liquid crystal display element by optical alignment method

The prepared liquid crystal was aligned using a spin coater so that the film thickness became 0.1 μmThe agent (R-1) was applied to the surfaces of a glass substrate having a plate electrode, an insulating layer and a comb-shaped electrode laminated on one surface thereof in this order, and a counter glass substrate having no electrode, and dried for 1 minute on a hot plate at 80 ℃ and 1 hour in a clean oven at 200 ℃ to form a coating film. The surface of the coating film was irradiated with polarized ultraviolet light of 500mJ/cm containing a bright line of 254nm from the substrate normal direction using an Hg-Xe lamp²Thereby forming a liquid crystal alignment film. Next, with respect to the pair of substrates subjected to the light irradiation treatment, an epoxy resin adhesive containing alumina balls having a diameter of 5.5 μm was screen-printed on the edge of the surface on which the liquid crystal alignment film was formed, leaving a liquid crystal injection port, and then the substrates were superposed and pressure-bonded so that the projection direction of the polarization axis to the substrate surface at the time of light irradiation became antiparallel, and the adhesive was thermally cured at 150 ℃ for 1 hour. Then, after nematic liquid crystal (MLC-7028, manufactured by merck) was filled between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow alignment at the time of liquid crystal injection, the liquid crystal was heated to 150 ℃ and then gradually cooled to room temperature. Next, polarizing plates are bonded to both outer surfaces of the substrate to produce a liquid crystal display element of a lateral electric field (FFS) system.

(6) Evaluation of liquid Crystal alignment Properties

With respect to the liquid crystal display element manufactured in (5), the presence or absence of an abnormal region of a change in brightness when a voltage of 5V is turned ON/OFF (ON/OFF) (applied/released) is observed with a microscope at a magnification of 50 times. For the evaluation, the case where no abnormal region was observed was evaluated as "good" liquid crystal alignment, and the case where an abnormal region was observed was evaluated as "poor" liquid crystal alignment. As a result, the evaluation was "good" in this example.

(7) Evaluation of contrast after Driving stress (evaluation of AC afterimage characteristics)

An FFS type liquid crystal cell was produced by performing the same operation as in (5) above, except that no polarizing plate was bonded to both outer sides of the substrate. After the FFS type liquid crystal cell was driven at an ac voltage of 10V for 30 hours, the minimum relative transmittance (%) represented by the following expression (2) was measured using a device in which a polarizer and an analyzer were disposed between a light source and a light quantity detector.

Minimum relative transmittance (%) - (β -B0)/(B100-B0) × 100 … (2)

(in the equation (2), B0 represents the amount of light transmitted under crossed nicols using a blank, B100 represents the amount of light transmitted under parallel nicols using a blank, and β represents the minimum amount of light transmitted under crossed nicols with a liquid crystal display element interposed between a polarizer and an analyzer.)

The black level in the dark state is represented by the minimum relative transmittance of the liquid crystal display element, and in the FFS type liquid crystal display element, the smaller the black level in the dark state, the better the contrast. The sample having a minimum relative transmittance of less than 1.0% was evaluated as "very good" for the AC image retention property, 1.0% or more and less than 1.5% was evaluated as "good", 1.5% or more and less than 2.0% was evaluated as "Δ", and 2.0% or more was evaluated as "x". As a result, it was evaluated as "Δ" in this example.

(8) Observation of minute Brightness (Heat resistance reliability test)

Evaluation of the minute bright spots was carried out by storing the liquid crystal cell produced in the same manner as in (5) above in a thermostatic bath at 100 ℃ for 21 days, and observing the presence or absence of the minute bright spots in the liquid crystal cell with a microscope, except that the polarizing plates were not bonded to both outer sides of the substrate. And can know that: when the decomposed product generated by the light irradiation with the photo-alignment treatment remains in the film, the decomposed product oozes out to the film surface by exposing the liquid crystal display element to the high temperature environment for a long time, and is gradually crystallized in the liquid crystal and observed as a minute bright point. The observation region was 680. mu. m.times.680. mu.m, and the observation was carried out at a microscope magnification of 100 times. Regarding the evaluation, a case where no fine bright spots were observed was evaluated as "o", a case where the number of observed fine bright spots was 1 dot or 2 dots was evaluated as "Δ", a case where the number of observed fine bright spots was 3 dots or more and 5 dots or less was evaluated as "x", and a case where the number of observed fine bright spots was 6 dots or more was evaluated as "xxx". As a result, in this example, the evaluation was "o".

Examples 12 to 22 and comparative examples 1 to 3

In the above-mentioned example 11, a liquid crystal aligning agent was prepared in the same manner as in example 11 except that the kinds and blending ratios of the polymer and the additive contained in the liquid crystal aligning agent were changed as shown in the following table 2, and an FFS type liquid crystal display element or a liquid crystal cell was manufactured to perform various evaluations. The evaluation results are shown in table 2 below. In table 2, the blending ratios of the polymer 1 and the polymer 2 in the liquid crystal aligning agent are expressed by parts by mass in terms of solid content, and the blending ratios of the additive 1 and the additive 2 are expressed by parts by mass when the total of the solid content masses of the polymer 1 and the polymer 2 is assumed to be 100 parts by mass.

[ Table 2]

In examples 11 to 22, the coating properties and adhesion properties of the liquid crystal aligning agent, and the liquid crystal alignment properties, AC image sticking characteristics, and heat resistance of the liquid crystal display element were balanced. In particular, in examples 14 to 18, 20, and 21, the results of "good", "excellent", or "o" in all of the above properties showed that the balance of the properties was excellent. In examples 19 and 22, the AC image sticking characteristics were evaluated as "o" and were slightly inferior, but the coatability, the liquid crystal alignment properties, and the heat resistance were good as in the other examples. In contrast, comparative examples 1 to 3 are inferior to the examples in a plurality of evaluation items.

In addition, when examples 12 to 22 and comparative example 1 were compared, the examples showed a high imidization rate and the AC image retention characteristics were good. The reason is considered to be that: it is possible that the interaction with the liquid crystal is improved by increasing the imidization ratio, thereby improving the liquid crystal alignment.

Further, from the results of comparative example 1, it was found that the polyamic acid had low photodecomposition and had poor liquid crystal alignment properties at the same exposure amount of polarized ultraviolet light.

Further, it is considered that in the liquid crystal aligning agent containing polyamic acid and polyamic acid ester whose ends have been modified, fine unevenness derived from phase separation of polyamic acid ester and polyamic acid is suppressed and the coatability is good by comparing examples 14 to 18, examples 20 to 22, and comparative example 3.

From the results of examples 11 to 22 and comparative examples 1 to 3, it is understood that the liquid crystal aligning agent containing a polyamic acid ester having a reactive group in a side chain has good heat resistance (particularly long-term heat resistance) even if the cleaning treatment for washing the decomposed product in the film is not performed after the photo-alignment treatment. Examples 14 to 18 teach that the long-term heat resistance is particularly excellent, and that the diffusion and/or crystallization of the photodecomposition substance, which is a causative substance of the fine bright point, is suppressed.

Synthesis examples 18 to 22

Polyamic acid solutions (PAA-5 to PAA-9) were obtained in the same manner as in synthesis example 14, except that the kinds and amounts of tetracarboxylic dianhydride and diamine compound were changed as shown in table 3.

[ example 23]

A50 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 1.08g (10.0mmol) of DA-1 and 20.0g of NMP, and cooled to about 10 ℃ to prepare a diamine solution. To the solution was added an acid chloride solution prepared by dissolving DC-1a 3.89g (9.6mmol) in pyridine 1.90g (21.6mmol) and γ BL 20.0g in advance, and the mixture was reacted at room temperature for 4 hours under a nitrogen stream. The obtained polymerization solution was diluted with γ BL, and gradually poured into deionized water while stirring to solidify the solution. The precipitated solid was recovered and washed with stirring in isopropanol repeatedly twice, and vacuum-dried at 60 ℃ to obtain a polyamic acid ester (PAE-12) as a white powder. The number average molecular weight Mn of the polymer was 20,000, and the molecular weight distribution Mw/Mn was 3.20.

[ examples 24 to 27]

Polyamide acid esters (PAE-13 to PAE-16) were obtained in the same manner as in example 23, except that the kinds and amounts of the tetracarboxylic acid derivative and the diamine compound were changed as shown in Table 3 below. The number average molecular weight Mn of the polymer (PAE-13) was 22,000, the molecular weight distribution Mw/Mn was 3.90, the number average molecular weight Mn of the polymer (PAE-14) was 30,000, and the molecular weight distribution Mw/Mn was 4.10. The number average molecular weight Mn of the polymer (PAE-15) was 11,000, the molecular weight distribution Mw/Mn was 3.00, the number average molecular weight Mn of the polymer (PAE-16) was 10,000, and the molecular weight distribution Mw/Mn was 2.90.

[ example 28]

A polyamic acid ester-polyamic acid copolymer (PAE-17) was synthesized by the following method with reference to the method described in synthetic example 4 of International publication No. 2015/152174.

A100 mL three-necked flask equipped with a nitrogen inlet and a thermometer was charged with 3.50g (9.5mmol) of DE-1a and 55.4g of NMP, and the mixture was dissolved by stirring. Then, 2.11g (20.9mmol) of triethylamine and 2.05g (19.0mmol) of DA-1 were added thereto and dissolved by stirring. The solution was cooled to about 10 ℃ and 7.28g (19.0mmol) diphenyl (2, 3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate was added, followed by 11.9g NMP, and reacted at room temperature under a stream of nitrogen for 12 hours. Then, 0.95g (3.80mmol) of diphenyl phosphate and 2.00g (8.93mmol) of TA-3 were added, and 11.9g of NMP was further added, followed by reaction at room temperature under a nitrogen stream for 12 hours. The obtained polymerization solution was gradually poured into methanol (600g) while stirring to solidify the solution. The precipitated solid was recovered and washed repeatedly with stirring in methanol twice, followed by vacuum drying at 60 ℃ to obtain a powder of polyamic acid ester-polyamic acid copolymer (PAE-17). The number average molecular weight Mn of the polymer was 20,000, and the molecular weight distribution Mw/Mn was 3.50.

[ Table 3]

[ examples 29 to 41]

In the above example 11, a liquid crystal aligning agent was prepared in the same manner as in example 11 except that the kinds of polymers and additives contained in the liquid crystal aligning agent were changed as shown in the following table 4, and an FFS type liquid crystal display element or a liquid crystal cell was manufactured and various evaluations were performed. The evaluation results are shown in table 4 below.

[ Table 4]

The results of examples 29 to 41 were "good", "excellent", and "o", and the balance of the characteristics was obtained with respect to the coating property and adhesion property of the liquid crystal aligning agent, and the liquid crystal alignment property, the AC image sticking property, and the heat resistance in the liquid crystal display element. Among them, the liquid crystal alignment property and the AC image sticking property in example 31 were particularly good, and the adhesiveness in example 41 was particularly good.

Examples 29 to 37 are particularly excellent in heat resistance, and exhibit good liquid crystal alignment properties and AC image retention properties even with a composition of 10 parts by weight with a small proportion of polymer 1. The reason is considered to be that: the polyamic acid ester of polymer 1 has high hydrophobicity, and promotes layer separation from the polyamic acid of polymer 2, so that polyimide derived from polymer 1 is likely to be present in the surface layer of the alignment film in a biased manner. Further, it is considered that when the ratio of the polymer 1 is small, the amount of the photodecomposition decreases, so that the contamination of the calcining furnace can be reduced, and the amount of the photodecomposition remaining in the alignment film decreases, so that the generation of the fine bright spots is reduced when the alignment film is exposed to a high-temperature environment, and the heat resistance is improved.

Claims

1. A liquid crystal aligning agent characterized in that: a polymer (P) having a partial structure represented by the following formula (1);

in the formula (1), R¹Is a tetravalent organic group containing a cyclobutane ring structure which may have a substituent, derived from 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride，R²Is a divalent organic radical; x¹And X²Each independently a hydroxyl group or a monovalent organic group having 1 to 40 carbon atoms; wherein, X¹And X²At least one of the above (a) and (b) is one selected from the group consisting of structures represented by the following formulae (2-1) to (2-10);

in the formulae (2-1) to (2-10), R⁴A divalent aliphatic group having 1 to 6 carbon atoms which may have a substituent, R⁵Each independently represents a hydrogen atom or a monovalent aliphatic group having 1 to 6 carbon atoms and having a substituent; wherein R is⁴And R⁵Any two of the aliphatic groups in (1) may be bonded to each other to form a ring structure; a plurality of R in the formula (2-1) or the formula (2-9)⁵May be the same or different from each other; "" indicates a bond.

2. The liquid crystal aligning agent according to claim 1, wherein: further comprising a polymer not having the partial structure represented by the formula (1).

3. The liquid crystal aligning agent according to claim 2, wherein: the polymer not having the partial structure represented by the formula (1) is at least one polymer selected from the group consisting of polyamic acids and polyimides.

4. The liquid crystal aligning agent according to claim 1, wherein: contains at least one selected from the group consisting of a functional silane compound, an acid generator, a base generator and a radical generator.

5. A liquid crystal alignment film characterized in that: formed using the liquid crystal aligning agent according to any one of claims 1 to 4.

6. A method for manufacturing a liquid crystal alignment film, comprising: a coating film formed by using the liquid crystal aligning agent according to any one of claims 1 to 4, wherein the coating film is irradiated with light to impart liquid crystal aligning ability.

7. A liquid crystal cell, characterized by: comprising the liquid crystal alignment film according to claim 5.

8. A polymer characterized by: has a partial structure represented by the following formula (1);

in the formula (1), R¹Is a tetravalent organic radical derived from 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride and containing a cyclobutane ring structure which may have substituents, R²Is a divalent organic radical; x¹And X²Each independently a hydroxyl group or a monovalent organic group having 1 to 40 carbon atoms; wherein, X¹And X²At least one of the above (a) and (b) is one selected from the group consisting of structures represented by the following formulae (2-1) to (2-10);

9. A compound or salt thereof, characterized in that: represented by the following formula (1-1) or the following formula (1-2);

in the formulae (1-1) and (1-2), X¹¹And X¹²Each independently represents a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms; wherein, X¹¹And X¹²At least one of the above (a) and (b) is one selected from the group consisting of structures represented by the following formulae (2-2) to (2-10);

in the formulae (2-2) to (2-10), R⁴A divalent aliphatic group having 1 to 6 carbon atoms which may have a substituent, R⁵Each independently represents a hydrogen atom or a monovalent aliphatic group having 1 to 6 carbon atoms and having a substituent; wherein R is⁴And R⁵Any two of the aliphatic groups in (1) may be bonded to each other to form a ring structure; plural R in the formula (2-9)⁵May be the same or different from each other; "+" indicates a bond;

R³each independently is a hydrogen atom or a methyl group, adjacent R³Are different from each other; x is one selected from the group consisting of a hydroxyl group, a chlorine atom, a bromine atom, and structures represented by the following formulae (4-1) to (4-6);

in formulae (4-1) to (4-6), "+" represents a bond.