JPWO2018159733A1 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Abstract

The present invention provides a liquid crystal aligning agent capable of obtaining a liquid crystal aligning film that does not decrease in its ability to vertically align liquid crystals even when exposed to excessive heating, and that the film may be damaged by contact with any foreign matter. The present invention also provides a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film in which the ability to vertically align liquid crystals does not decrease. The present invention relates to a diamine represented by the formula [1] (in the formula [1], X represents a single bond or a divalent group such as -O-, and Y represents a group represented by the formula [1-1]. Y1 to Y6 each represent a specific group described in the specification) and at least one selected from a polyimide precursor which is a reaction product of a tetracarboxylic acid component and a polyimide which is an imidated product thereof. A liquid crystal aligning agent containing a kind of polymer is provided. [Chemical 1] [Selection diagram] None

Description

  TECHNICAL FIELD The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device having excellent ability to vertically align liquid crystals.

  A liquid crystal display element of a type in which liquid crystal molecules vertically aligned with respect to a substrate responds by an electric field (also referred to as a vertical alignment (VA) type) is irradiated with ultraviolet rays while applying a voltage to the liquid crystal molecules in a manufacturing process. Some steps include the step of performing

  In such a vertical alignment type liquid crystal display device, a photopolymerizable compound is added to a liquid crystal composition in advance, and ultraviolet rays are applied while applying a voltage to the liquid crystal cell using a vertical alignment film such as a polyimide. Thus, a technique for increasing the response speed of a liquid crystal (PSA (Polymer Sustained Alignment) type element, for example, see Patent Document 1 and Non-Patent Document 1) is known.

  As a liquid crystal aligning agent used in such a PSA type device, a liquid crystal aligning agent using a side chain having a specific ring structure has been proposed (see Patent Document 2). This specific ring structure has a high ability to vertically align liquid crystals, and a liquid crystal display device of a vertical alignment system using this liquid crystal aligning agent had good display characteristics.

JP 2003-307720 A WO2006 / 070819

K.Hanaoka, SID 04 DIGEST, P.1200-1202

However, in recent vertical alignment type liquid crystal display devices, due to the effect of thinning and increasing the size of the substrate used, a temperature difference is generated between different portions of the same substrate during firing, and the liquid crystal in an excessively heated portion is generated. The alignment film has a reduced ability to vertically align the liquid crystal, and as a result, there is a problem that the resulting liquid crystal display element partially causes display failure.
Another problem is that in the liquid crystal panel manufacturing process, the liquid crystal alignment film and the column spacer come into contact with each other and the liquid crystal alignment film is damaged, thereby causing an alignment defect (bright spot) at that portion.

It is an object of the present invention to provide a liquid crystal aligning agent capable of obtaining a liquid crystal aligning film which does not decrease in ability to vertically align liquid crystals even when subjected to excessive heating.
Another object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film in which the ability to vertically align liquid crystals does not decrease even when some foreign matter comes into contact with the film and is damaged.

The inventors have found that the object can be achieved by the liquid crystal aligning agent having the following constitution, and have completed the present invention.
That is, the configuration of the present invention is as follows.
1. Liquid crystal containing at least one polymer selected from a polyimide precursor which is a reaction product of a diamine component containing a diamine represented by the following formula [1] and a tetracarboxylic acid component, and a polyimide which is an imidized product thereof. Alignment agent.

Wherein [1], X is a single _{bond, -O -, - C (CH} 3) 2 -, - NH -, - CO -, - NHCO -, - COO -, - (CH 2) m -, - Represents a divalent organic group composed of SO ₂ — and an arbitrary combination thereof, and m represents an integer of 1 to 8.
Y each independently represents a structure of the following formula [1-1].

In the formula [1-1], Y ¹ and Y ³ are each independently a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CH ₂ O— , -CONH-, -NHCO-, -COO- and -OCO-.
Y ² represents a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 15) (provided that when Y ¹ or Y ³ is a single bond or — (CH ₂ ) _a —, ² is a single bond, and Y ¹ is at least one selected from the group consisting of —O—, —CH ₂ O—, —CONH—, —NHCO—, —COO—, and —OCO—, and / or Or when Y ³ is at least one selected from the group consisting of —O—, —CH ₂ O—, —CONH—, —NHCO—, —COO—, and —OCO—, Y ² is a single bond or — ( CH ₂ ) _b — (however, when Y ¹ is —CONH—, it is a single bond of Y ² and Y ³ )).
Y ⁴ represents a benzene ring, at least one divalent cyclic group selected from the group consisting of a cyclohexane ring and a heterocyclic ring, or a divalent organic group having 17 to 51 carbon atoms having a steroid skeleton and a tocophenol skeleton; An arbitrary hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, and a fluorine-containing alkoxy group having 1 to 3 carbon atoms. Or it may be substituted by a fluorine atom.
Y ⁵ represents at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, To 3 alkoxy groups, a C 1-3 fluorine-containing alkyl group, a C 1-3 fluorine-containing alkoxy group or a fluorine atom.
Y ⁶ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and an alkoxy group having 1 to 18 carbon atoms. At least one selected from the group consisting of fluorine-containing alkoxy groups. n shows the integer of 0-4.

According to the present invention, it is possible to provide a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film in which the ability to vertically align liquid crystals does not decrease even when exposed to excessive heating.
Further, according to the present invention, in addition to or in addition to the above-mentioned effects, a liquid crystal alignment agent capable of obtaining a liquid crystal alignment film in which the ability to vertically align liquid crystals does not decrease even when some foreign matter contacts the film and is damaged. Can be provided.
Further, according to the present invention, it is possible to provide a liquid crystal alignment film obtained from the liquid crystal alignment agent and a method for obtaining a liquid crystal alignment film using the liquid crystal alignment agent.

  The liquid crystal aligning agent of the present invention includes a diamine component containing a diamine represented by the above formula [1] (hereinafter, the “diamine represented by the above formula [1]” may be abbreviated as “specific diamine”). And at least one polymer selected from a polyimide precursor that is a reaction product with a tetracarboxylic acid component and a polyimide that is an imidized product thereof (hereinafter, may be abbreviated as “specific polymer”).

The specific polymer contains a specific diamine, but may have a diamine other than the specific diamine.
The amount of the specific diamine and the other diamine in the specific polymer has the specific diamine in an amount of 5 mol% to 70 mol%, preferably 10 mol% to 50 mol%, more preferably 10 mol% to 40 mol%. Is good.
Further, the liquid crystal aligning agent of the present invention may contain "polyimide which is a polyimide precursor and / or an imidized product thereof" other than the specific polymer.
Hereinafter, the “specific diamine” will be described, and then diamines other than the “specific diamine” will be described.

<Specific diamine>
The specific diamine used in the liquid crystal alignment agent of the present invention is represented by the following formula [1].

Wherein [1], X is a single _{bond, -O -, - C (CH} 3) 2 -, - NH -, - CO -, - NHCO -, - COO -, - (CH 2) m -, - Represents a divalent organic group composed of SO ₂ — and an arbitrary combination thereof, and m represents an integer of 1 to 8.
As "any combination _{thereof", -O- (CH 2) m -O} -, - O-C (CH 3) 2 -, - CO- (CH 2) m -, - NH- (CH 2) m _{-, - SO 2 - (CH} 2) m -, - CONH- (CH 2) m -, - CONH- (CH 2) m -NHCO -, - COO- (CH 2) m -OCO- , and the like However, the present invention is not limited to these.
X is preferably a single bond, -O -, - NH -, - O- (CH 2) is good is an m -O-.

  In the formula [1], Y may be a meta position or an ortho position from the position of X, but is preferably an ortho position. That is, the formula [1] is preferably the following formula [1 '].

The position of “—NH ₂ ” in the above formula [1] may be any position as shown in the formula [1], but preferably the following formulas [1] -a1, [1] -a2, [1] The position is preferably represented by [1] -a3, more preferably [1] -a1.

  From the formulas [1] -a1 to [1] -a3 and the formula [1 ′], the formula [1] may be any structure selected from the following formulas, and preferably the formula [1] ] -A1-1.

  Y each independently represents a structure of the following formula [1-1].

In the formula [1-1], Y ¹ and Y ³ are each independently a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CH ₂ O— , -CONH-, -NHCO-, -COO- and -OCO-.
Y ² represents a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 15) (provided that when Y ¹ or Y ³ is a single bond or — (CH ₂ ) _a —, ² is a single bond, and Y ¹ is at least one selected from the group consisting of —O—, —CH ₂ O—, —CONH—, —NHCO—, —COO—, and —OCO—, and / or Or when Y ³ is at least one selected from the group consisting of —O—, —CH ₂ O—, —CONH—, —NHCO—, —COO—, and —OCO—, Y ² is a single bond or — ( CH ₂ ) _b — (however, when Y ¹ is —CONH—, it is a single bond of Y ² and Y ³ )).
Y ⁴ represents a benzene ring, at least one divalent cyclic group selected from the group consisting of a cyclohexane ring and a heterocyclic ring, or a divalent organic group having 17 to 51 carbon atoms having a steroid skeleton and a tocophenol skeleton; An arbitrary hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, and a fluorine-containing alkoxy group having 1 to 3 carbon atoms. Or it may be substituted by a fluorine atom.
Y ⁵ represents at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, To 3 alkoxy groups, a C 1-3 fluorine-containing alkyl group, a C 1-3 fluorine-containing alkoxy group or a fluorine atom.
Y ⁶ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and an alkoxy group having 1 to 18 carbon atoms. At least one selected from the group consisting of fluorine-containing alkoxy groups. n shows the integer of 0-4.

  Examples of the group represented by the formula [1-1] include the following groups [1-1] -1 to [1-1] -22, but are not limited thereto. Among these, [1-1] -1 to [1-1] -4, [1-1] -8, and [1-1] -10 are preferable. In addition, * shows the position couple | bonded with the phenyl group in said Formula [1], said Formula [1 '], said Formula [1] -a1-said Formula [1] -a3. m represents an integer of 1 to 15, and n represents an integer of 0 to 18.

<Photoreactive side chain>
The polymer contained in the liquid crystal alignment agent of the present invention may have a photoreactive side chain.
Even if the photoreactive side chain is contained in the “specific polymer”, it is contained in the “polyimide precursor and / or imidized polyimide” which is a polymer other than the “specific polymer”. May be.
<Diamine containing photoreactive side chain>
In order to introduce a photoreactive side chain into a “specific polymer” and / or a polymer other than the “specific polymer”, it is necessary to use a diamine having a photoreactive side chain as a part of the diamine component. Good. Examples of the diamine having a photoreactive side chain include, but are not limited to, a diamine having a side chain represented by the formula [VIII] or [IX].

The bonding positions of the two amino groups (—NH ₂ ) in the formulas [VIII] and [IX] are not limited. Specifically, with respect to the bonding group in the side chain, the positions of 2, 3 on the benzene ring, the positions of 2, 4, the positions of 2, 5, the positions of 2, 6, the positions of 3, 4, and 3, 5 positions. Among them, the 2,4 position, the 2,5 position, or the 3,5 position is preferred from the viewpoint of reactivity when synthesizing the polyamic acid. Taking into account the ease of synthesizing the diamine, the positions of 2, 4 or 3, 5 are more preferable.

The definitions of R ⁸ , R ⁹ and R ^{10 in} the formula [VIII] are as follows.
That, ^{R 8} represents a single _{bond, -CH 2 -, - O -} , - COO -, - OCO -, - NHCO -, - CONH -, - NH -, - CH 2 O -, - N (CH 3) _{-, - CON (CH 3)} -, or an -N _(CH 3) CO-. In particular, R ⁸ is preferably a single bond, —O—, —COO—, —NHCO—, or —CONH—.
R ⁹ represents a single bond or an alkylene group having 1 to 20 carbon atoms which may be substituted with a fluorine atom, wherein -CH _2-in the alkylene group is optionally substituted with -CF ₂ -or -CH = CH-. And when any of the following groups are not adjacent to each other, they may be substituted with these groups; -O-, -COO-, -OCO-, -NHCO-, -CONH-,- NH-, a divalent carbocyclic or heterocyclic ring.
Specific examples of the divalent carbon ring or heterocyclic ring include the following, but are not limited thereto.

R ⁹ can be formed by a usual organic synthetic technique, but is preferably a single bond or an alkylene group having 1 to 12 carbon atoms from the viewpoint of ease of synthesis.
R ¹⁰ represents a photoreactive group selected from the following formula.

R ¹⁰ is preferably a methacryl group, an acryl group or a vinyl group from the viewpoint of photoreactivity.

The definitions of Y ₁ , Y ₂ , Y ₃ , Y ₄ , Y ₅ , and Y _{6 in} the formula [IX] are as follows.
_That, Y ₁ is -CH 2 -, - O -, - CONH -, - NHCO -, - COO -, - OCO -, - NH-, or represent a -CO-.
Y ₂ is an alkylene group having 1 to 30 carbon atoms, a divalent carbocyclic or heterocyclic ring, and one or more hydrogen atoms of the alkylene group, the divalent carbon ring or the heterocyclic ring are a fluorine atom or an organic May be substituted with a group. Y ₂ is, when the following groups are not adjacent to each other, —CH ₂ — may be substituted by these groups; —O—, —NHCO—, —CONH—, —COO—, —OCO—, -NH-, -NHCONH-, -CO-.
Y ₃ represents —CH ₂ —, —O—, —CONH—, —NHCO—, —COO—, —OCO—, —NH—, —CO—, or a single bond.
Y ₄ represents a cinnamoyl group. Y ₅ is a single bond, an alkylene group having 1 to 30 carbon atoms, a divalent carbon ring or a heterocyclic ring, and one or more hydrogen atoms of the alkylene group, the divalent carbon ring or the heterocyclic ring are a fluorine atom Alternatively, it may be substituted with an organic group.
Y ₅ is, when the following groups are not adjacent to each other, —CH ₂ — may be substituted by these groups; —O—, —NHCO—, —CONH—, —COO—, —OCO—, -NH-, -NHCONH-, -CO-.
Y ₆ represents a photopolymerizable group that is an acryl group or a methacryl group.

Specific examples of the diamine having a photoreactive side chain include, but are not limited to, the following. In the following formula, X ⁹ and X ¹⁰ are each independently a single bond, a bonding group that is —O—, —COO—, —NHCO—, or —NH—, and Y may be substituted with a fluorine atom. Represents an alkylene group having 1 to 20 carbon atoms.

  Examples of the diamine having a photoreactive side chain include a diamine having a group that causes a photodimerization reaction represented by the following formula and a group that causes a photopolymerization reaction in the side chain.

In the above formula, Y _{1 to} Y ₆ are the same as defined above.
The above-mentioned diamine having a photoreactive side chain depends on the liquid crystal alignment property when forming a liquid crystal alignment film, the pretilt angle, the voltage holding property, the characteristics such as accumulated charge, and the response speed of the liquid crystal when forming a liquid crystal display element. In addition, one kind or a mixture of two or more kinds can be used.

Further, as the diamine having a photoreactive side chain, it is preferable to use 10 to 70 mol% of the diamine component used for the synthesis of the polyamic acid, more preferably 20 to 60 mol%, and particularly preferably 30 to 50 mol%. It is.
Examples of the diamine having a photoreactive side chain also include a diamine having a site having a radical generating structure in which a radical is generated by being decomposed by irradiation with ultraviolet light.

Ar, R ₁ , R ₂ , T ₁ , T ₂ , S and Q in the above formula (1) have the following definitions.
That is, Ar represents an aromatic hydrocarbon group selected from phenylene, naphthylene, and biphenylene, which may be substituted with an organic group, and a hydrogen atom may be substituted with a halogen atom.
R ₁ and R ₂ are each independently an alkyl group or an alkoxy group having 1 to 10 carbon atoms.
T1, T2 are each independently a single bond or -O -, - COO -, - OCO -, - NHCO -, - CONH -, - NH -, - CH 2 O -, - N (CH 3) -, —CON (CH ₃ ) — and —N (CH ₃ ) CO—.
S is a single bond or an unsubstituted or substituted alkylene group having 1 to 20 carbon atoms. However, -CH ₂ -or -CF _{2-of the} alkylene group may be arbitrarily replaced by -CH = CH-, and when any of the following groups is not adjacent to each other, it is replaced by these groups. -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, a divalent carbocycle, a divalent heterocycle.
Q is a structure selected from the following (in the structural formula, R represents water, an elemental atom or an alkyl group having 1 to 4 carbon atoms, and R ₃ represents —CH ₂ —, —NR—, —O—, or —S Represents-).

  In the above formula (I), Ar having a carbonyl bonded thereto is involved in the absorption wavelength of ultraviolet light. Therefore, when the wavelength is increased, a structure having a long conjugate length such as naphthylene or biphenylene is preferable. Ar may be substituted with a substituent, and such a substituent is preferably an electron-donating organic group such as an alkyl group, a hydroxyl group, an alkoxy group, and an amino group.

  In the formula (I), when Ar has a structure such as naphthylene or biphenylene, the solubility is deteriorated and the difficulty of the synthesis is increased. If the wavelength of the ultraviolet light is in the range of 250 nm to 380 nm, a phenyl group is most preferable because sufficient characteristics can be obtained even with a phenyl group.

R ₁ and R ₂ are each independently an alkyl group having 1 to 10 carbon atoms, an alkoxy group, a benzyl group, or a phenethyl group. In the case of an alkyl group or an alkoxy group, R ₁ and R _{2 represent} a ring. May be formed.

In the formula (I), Q is preferably an electron-donating organic group, and more preferably the above groups.
When Q is an amino derivative, a carboxylic acid group and an amino group generated during the polymerization of a polyamic acid which is a precursor of polyimide may cause a problem such as formation of a salt. Or an alkoxyl group.

  The diaminobenzene in the formula (1) may have any structure of o-phenylenediamine, m-phenylenediamine, or p-phenylenediamine, but from the viewpoint of reactivity with an acid dianhydride, m-phenylenediamine or P-phenylenediamine is preferred.

  Specifically, a structure represented by the following formula is most preferable in terms of ease of synthesis, high versatility, characteristics, and the like. In the formula, n is an integer of 2 to 8.

<Other diamines>
As the other diamine component for obtaining the specific polymer, a diamine other than the specific diamine represented by the above formula [1] (hereinafter, also referred to as other diamine) may be contained. Such a diamine is represented by the following general formula [2]. In addition, one or more diamines can be used in combination.

In the above formula [2], A ₁ and A ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms. It is. From the viewpoint of monomer reactivity, A ₁ and A ₂ are preferably a hydrogen atom or a methyl group. To illustrate the structure of Y _1, it is as follows.

  In the formula, n is an integer of 1 to 6, unless otherwise specified. In the following formula, Boc represents a tert-butoxycarbonyl group.

  Other diamine components used in the liquid crystal alignment agent of the present invention are not particularly limited, but from the viewpoints of applicability, voltage holding characteristics, residual DC voltage characteristics, and the like, (Y-7), (Y-8), (Y-16), (Y-17), (Y-21), (Y-22), (Y-28), (Y-37), (Y-38), (Y-60), (Y -67), (Y-68), (Y-71) to (Y-73) and (Y-160) to (Y-180).

(Tetracarboxylic acid component)
Examples of the tetracarboxylic acid component for obtaining the specific polymer include tetracarboxylic acid, tetracarboxylic dianhydride, tetracarboxylic dihalide, tetracarboxylic dialkyl ester, or tetracarboxylic dialkyl ester dihalide. Then, these are also collectively referred to as a tetracarboxylic acid component.
As the tetracarboxylic acid component, tetracarboxylic dianhydride, a derivative thereof, tetracarboxylic acid, tetracarboxylic dihalide, tetracarboxylic dialkyl ester, or tetracarboxylic dialkyl ester dihalide (collectively, 1 tetracarboxylic acid component).

<Tetracarboxylic dianhydride>
Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples thereof include those of the following groups [1] to [5].

[1] As an aliphatic tetracarboxylic dianhydride, for example, 1,2,3,4-butanetetracarboxylic dianhydride;

[2] As the alicyclic tetracarboxylic dianhydride, for example, acid dianhydrides of the following formulas (X1-1) to (X1-13),

In the formulas (X1-1) to (X1-4), R ₃ to R ₂₃ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, An alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, which may be the same or different,
In the above formula, _RM is a hydrogen atom or a methyl group,
Xa is a tetravalent organic group represented by the following formulas (Xa-1) to (Xa-7).

  [3] 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 3,5,6-tricarboxy- 2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.02,6] undecane-3,5,8,10-tetraone and the like;

  [4] As the aromatic tetracarboxylic dianhydride, for example, pyromellitic anhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid Acid dianhydride, acid dianhydride represented by the following formulas (Xb-1) to (Xb-10), and

[5] Further, acid dianhydrides represented by the formulas (X1-44) to (X1-52) and tetracarboxylic dianhydrides described in JP-A-2010-97188 can be exemplified.

In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.
The tetracarboxylic dianhydride component used in the liquid crystal aligning agent of the present invention is not particularly limited. However, from the viewpoints of coatability, voltage holding characteristics, residual DC voltage characteristics, and the like, (X1-1), (X1- 2), (X1-3), (X1-6), (X1-7), (X1-8), (X1-9), (Xa-2), pyromellitic anhydride, 3,3 ′, It is preferable to select and use a tetracarboxylic dianhydride selected from 4,4′-diphenylsulfonetetracarboxylic dianhydride, (Xb-6) and (Xb-9).

<Method for producing polymer>
The method for producing these polymers is usually obtained by reacting a diamine component with a tetracarboxylic acid component. A polyamic acid is obtained by reacting at least one tetracarboxylic acid component selected from the group consisting of tetracarboxylic dianhydride and a derivative of the tetracarboxylic acid with a diamine component composed of one or more diamines. Method. Specifically, a method of polycondensing a tetracarboxylic dianhydride with a primary or secondary diamine to obtain a polyamic acid is used.

In order to obtain a polyamic acid alkyl ester, a method of polycondensing a tetracarboxylic acid in which a carboxylic acid group is dialkylesterified with a primary or secondary diamine, a method in which a tetracarboxylic acid dihalide in which a carboxylic acid group is halogenated and a primary Alternatively, a method of polycondensing with a secondary diamine, or a method of converting a carboxy group of a polyamic acid into an ester is used.
In order to obtain a polyimide, a method is used in which the above-mentioned polyamic acid or polyamic acid alkyl ester is closed to form a polyimide.

The reaction between the diamine component and the tetracarboxylic acid component is usually performed in a solvent. The solvent used at this time is not particularly limited as long as the produced polyimide precursor is dissolved. Specific examples of the solvent used in the reaction are shown below, but are not limited to these examples.
For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide or 1,3-dimethyl-imidazolidinone. Can be When the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the following formulas [D-1] to [D-3] are used. The solvent used can be used.

In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms; in the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms; In the formula, D ³ represents an alkyl group having 1 to 4 carbon atoms.

  These solvents may be used alone or as a mixture. Furthermore, even if the solvent does not dissolve the polyimide precursor, the solvent may be mixed with the solvent as long as the generated polyimide precursor does not precipitate. Further, since water in the solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyimide precursor, it is preferable to use a solvent that has been dehydrated and dried.

  When reacting a diamine component and a tetracarboxylic acid component in a solvent, a solution in which the diamine component is dispersed or dissolved in the solvent is stirred, and the tetracarboxylic acid component is added as it is or dispersed or dissolved in the solvent. A method of adding a diamine component to a solution in which a tetracarboxylic acid component is dispersed or dissolved in a solvent, or a method of alternately adding a diamine component and a tetracarboxylic acid component, and the like. May be used. When a plurality of diamine components or tetracarboxylic acid components are used for the reaction, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. May be mixed to form a polymer.

The temperature at which the diamine component and the tetracarboxylic acid component are polycondensed can be selected from any temperature in the range of -20 to 150 ° C, but is preferably in the range of -5 to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it is difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult. . Therefore, it is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction is performed at a high concentration, after which the solvent can be added.
In the polymerization reaction of the polyimide precursor, the ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component is preferably 0.8 to 1.2. As in the ordinary polycondensation reaction, the molecular weight of the generated polyimide precursor increases as the molar ratio approaches 1.0.

Polyimide is a polyimide obtained by ring-closing the above-mentioned polyimide precursor, and in this polyimide, the ring-closing rate of amic acid groups (also referred to as imidation rate) does not necessarily need to be 100%, It can be adjusted as needed.
Examples of the method for imidizing the polyimide precursor include thermal imidization in which the polyimide precursor solution is heated as it is, and catalytic imidization in which a catalyst is added to the polyimide precursor solution.

  The temperature at which the polyimide precursor is thermally imidized in the solution is 100 to 400 ° C., preferably 120 to 250 ° C., and a method in which water generated by the imidization reaction is removed outside the system is preferable. Catalytic imidation of the polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to the solution of the polyimide precursor and stirring at -20 to 250C, preferably 0 to 180C.

The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amide acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to mol time of the amide acid group. It is 30 mole times.
Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferable since it has an appropriate basicity for causing the reaction to proceed.
Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. In particular, it is preferable to use acetic anhydride because purification after the reaction is easy.
The imidization rate by the catalytic imidization can be controlled by adjusting the amount of the catalyst, the reaction temperature, and the reaction time.

  When recovering the produced polyimide precursor or polyimide from the polyimide precursor or polyimide reaction solution, the reaction solution may be put into a solvent to precipitate. Examples of the solvent used for the precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water and the like. The polymer that has been put into the solvent and precipitated can be collected by filtration and then dried at normal temperature or under reduced pressure at normal temperature or under normal pressure. Further, by repeating the operation of re-dissolving the polymer recovered by precipitation in a solvent and recovering the recovered precipitate by 2 to 10 times, impurities in the polymer can be reduced. Examples of the solvent at this time include alcohols, ketones, and hydrocarbons. It is preferable to use three or more solvents selected from these, because the purification efficiency is further increased.

More specific methods for producing the polyamic acid alkyl esters of the present invention are shown in the following (1) to (3).
(1) Method for Producing Polyamic Acid by Esterification Reaction A polyamic acid is produced from a diamine component and a tetracarboxylic acid component, and a carboxy group (COOH group) is subjected to a chemical reaction, that is, an esterification reaction, to produce a polyamic acid. This is a method for producing an alkyl ester.
The esterification reaction is a method of reacting a polyamic acid and an esterifying agent in the presence of a solvent at −20 to 150 ° C. (preferably 0 to 50 ° C.) for 30 minutes to 24 hours (preferably 1 to 4 hours). is there.

  As the esterification agent, those which can be easily removed after the esterification reaction are preferable, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N N-dimethylformamide dineopentyl butyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl -3-p-tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like. The amount of the esterifying agent to be used is preferably 2 to 6 molar equivalents per 1 mol of the repeating unit of the polyamic acid. Especially, 2-4 molar equivalent is preferable.

Examples of the solvent used for the esterification reaction include solvents used for the reaction between the diamine component and the tetracarboxylic acid component from the viewpoint of solubility of the polyamic acid in the solvent. Among them, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. These solvents may be used alone or in combination of two or more.
The concentration of the polyamic acid in the solvent in the esterification reaction is preferably from 1 to 30% by mass from the viewpoint that precipitation of the polyamic acid hardly occurs. Especially, 5-20 mass% is preferable.

(2) Method for producing by reacting a diamine component with a tetracarboxylic diester dichloride Specifically, a diamine component and a tetracarboxylic diester dichloride are prepared in the presence of a base and a solvent at -20 to 150 ° C (preferably (0 to 50 ° C) for 30 minutes to 24 hours (preferably 1 to 4 hours).
As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used. Among them, pyridine is preferred because the reaction proceeds gently. The amount of the base used is preferably an amount that can be easily removed after the reaction, and is preferably 2 to 4 times the molar amount of the tetracarboxylic diester dichloride. Above all, a 2- to 3-fold molar amount is more preferable.

The solvent includes a solvent used in the reaction between the diamine component and the tetracarboxylic acid component in view of the solubility of the obtained polymer, that is, the polyamic acid alkyl ester in the solvent. Among them, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. These solvents may be used alone or in combination of two or more.
The concentration of the polyamic acid alkyl ester in the solvent in the reaction is preferably 1 to 30% by mass from the viewpoint that precipitation of the polyamic acid alkyl ester hardly occurs. Especially, 5-20 mass% is preferable. In order to prevent hydrolysis of the tetracarboxylic diester dichloride, it is preferable that the solvent used for preparing the polyamic acid alkyl ester is as dehydrated as possible. Furthermore, the reaction is preferably performed in a nitrogen atmosphere to prevent outside air from being mixed.

(3) Method for producing by reacting a diamine component with a tetracarboxylic diester Specifically, a diamine component and a tetracarboxylic diester are prepared at 0 to 150 ° C. (preferably in the presence of a condensing agent, a base and a solvent). (0 to 100 ° C.) for 30 minutes to 24 hours (preferably 3 to 15 hours).

  Condensing agents include triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinyl Methylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluronium hexafluorophosphate, diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate and the like can be used. The amount of the condensing agent to be used is preferably 2 to 3 moles, more preferably 2 to 2.5 moles, per mole of the tetracarboxylic acid diester.

Tertiary amines such as pyridine and triethylamine can be used as the base. The amount of the base used is preferably an amount that can be easily removed after the polycondensation reaction, and is preferably 2 to 4 times, more preferably 2 to 3 times the mol of the diamine component.
The solvent used for the polycondensation reaction includes the solvent used for the reaction between the diamine component and the tetracarboxylic acid component in view of the solubility of the obtained polymer, that is, the polyamic acid alkyl ester in the solvent. Among them, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. One or more of these solvents may be used.

  In addition, in the polycondensation reaction, the reaction proceeds efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The amount of the Lewis acid used is preferably 0.1 to 10 times the mol of the diamine component. Above all, a 2.0- to 3.0-fold molar amount is preferable.

When recovering the polyamic acid alkyl ester from the solution of the polyamic acid alkyl ester obtained by the above-mentioned methods (1) to (3), the reaction solution may be poured into a solvent to cause precipitation. Examples of the solvent used for the precipitation include water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, and toluene. It is preferable to carry out a washing operation with the above-mentioned solvent a plurality of times for the purpose of removing the additives and catalysts used in the polymer that has been put into the solvent and precipitated. After washing, filtration and recovery, the polymer can be dried at normal pressure or reduced pressure at normal temperature or by heating. In addition, by repeating the operation of re-dissolving the precipitated and recovered polymer in a solvent and re-precipitating and recovering it 2 to 10 times, impurities in the polymer can be reduced.
For the polyamic acid alkyl ester, the production method of (2) or (3) is preferable.

<Liquid crystal aligning agent>
The liquid crystal alignment agent of the present invention contains the above-mentioned specific polymer, and is preferably a solution for forming a liquid crystal alignment film. The content of the polymer in the liquid crystal aligning agent is preferably 2 to 10% by mass, more preferably 3 to 8% by mass in the liquid crystal aligning agent.

  All the polymer components in the liquid crystal aligning agent of the present invention may be all the specific polymer of the present invention, or may be mixed with other polymers. Other polymers include cellulose-based polymers, acrylic polymers, methacrylic polymers, polystyrene, polyamides, polysiloxanes, and the like, in addition to polyimide and polyimide precursors. The content of the other polymer is preferably from 1 to 90% by mass, more preferably from 30 to 80% by mass, of the resin components contained in the liquid crystal aligning agent.

The good solvent used for the liquid crystal aligning agent of the present invention is not particularly limited as long as the specific polymer of the present invention can be dissolved. Specific examples of the solvent used for the liquid crystal aligning agent are described below, but the present invention is not limited to these examples.
For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide or 1,3-dimethyl-imidazolidinone. Can be
When the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or a compound represented by the above formulas [D-1] to [D-3] is used. Solvents used can also be used.
The above-mentioned good solvent may be used alone, or may be used in a more suitable combination and ratio according to a coating method or the like.
The good solvent in the liquid crystal aligning agent of the present invention is preferably 20 to 99% by mass of the entire solvent contained in the liquid crystal aligning agent. Especially, 20 to 90 mass% is preferable. More preferably, the content is 30 to 80% by mass.

As the liquid crystal aligning agent of the present invention, a solvent (also referred to as a poor solvent) that improves the coatability and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied can be used. Specific examples are given below.
For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol , 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6- Dimethyl 4-heptanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3- Butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diisopropyl ether, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether , Ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl Tyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxybutyl Acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (methoxymethoxy) ethanol, ethylene Glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, Propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol Propylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether Acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, Ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl ethyl 3-ethoxypropionate, 3-methoxypropionic acid Ethyl, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, milk Ethyl ester, lactic acid n- propyl ester, lactate n- butyl ester, lactic acid isoamyl ester, the formula [D-1] ~ can be exemplified solvents represented by [D-3].

  Among them, preferred combinations of solvents include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ- Butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N- Methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone, γ-butyrolactone, and propylene glycol Monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, And the like. The content of the poor solvent is preferably from 1 to 80% by mass, more preferably from 10 to 80% by mass, and particularly preferably from 20 to 70% by mass of the entire solvent contained in the liquid crystal aligning agent. The type and content of such a solvent are appropriately selected according to the application device, application conditions, application environment, and the like of the liquid crystal aligning agent.

  The liquid crystal alignment agent of the present invention, in addition to the above, a polymer other than the polymer according to the present invention, a dielectric for the purpose of changing the electrical properties of the liquid crystal alignment film such as the dielectric constant and conductivity, a liquid crystal alignment film and A silane coupling agent for the purpose of improving the adhesion to the substrate, a crosslinkable compound for the purpose of increasing the hardness and denseness of the liquid crystal alignment film, and heating of the polyimide precursor when the coating film is baked And an imidization accelerator or the like for the purpose of promoting the imidization by the compound efficiently.

  Examples of the compound that improves the adhesiveness between the liquid crystal alignment film and the substrate include a functional silane-containing compound and an epoxy group-containing compound, such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-aminopropyltriethoxysilane. Glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2- (Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl- 3-aminopropyltrimethoxy Silane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10 -Triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-amino Propyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3 -Aminopropyltrimethoxysilane, N Bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl Ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N , N ', N',-Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane or N, N, N ', N',-tetraglycidyl Etc. Le-4,4'-diaminodiphenylmethane and the like.

  Further, the following additives may be added to the liquid crystal alignment agent of the present invention in order to increase the mechanical strength of the liquid crystal alignment film.

  The amount of the additive is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. If the amount is less than 0.1 part by mass, no effect can be expected. If the amount exceeds 30 parts by mass, the orientation of the liquid crystal is reduced.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film of the present invention can be formed by applying the liquid crystal aligning agent of the present invention on a substrate and baking it.
For example, a cured film obtained by applying the liquid crystal aligning agent of the present invention to a substrate, followed by drying and baking as necessary can be used as a liquid crystal alignment film as it is. The cured film was rubbed, irradiated with polarized light or light of a specific wavelength, treated with an ion beam, or the like, and a voltage was applied to the liquid crystal display element after filling the liquid crystal as a PSA alignment film. UV irradiation is also possible. In particular, it is useful to use it as an alignment film for PSA.

  At this time, the substrate to be used is not particularly limited as long as it is a substrate having high transparency, and is a glass plate, polycarbonate, poly (meth) acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone. And a plastic substrate such as trimethylpentene, polyolefin, polyethylene terephthalate, (meth) acrylonitrile, triacetylcellulose, diacetylcellulose and acetate butyratecellulose. It is preferable to use a substrate on which an ITO electrode or the like for driving a liquid crystal is formed from the viewpoint of simplifying the process. In the case of a reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used if only one substrate is used. In this case, a material that reflects light such as aluminum can be used.

  The method for applying the liquid crystal aligning agent is not particularly limited, and examples thereof include printing methods such as screen printing, offset printing, and flexographic printing, inkjet methods, spray methods, roll coating methods, dips, roll coaters, slit coaters, and spinners. From the viewpoint of productivity, the transfer printing method is widely used industrially, and is preferably used in the present invention.

  The coating film formed by applying the liquid crystal aligning agent by the above method can be fired to form a cured film. The drying step after applying the liquid crystal aligning agent is not necessarily required, but when the time from application to baking is not constant for each substrate, or when baking is not performed immediately after application, a drying step is performed. Is preferred. This drying may be performed as long as the solvent is removed to such an extent that the shape of the coating film is not deformed by the transfer of the substrate or the like, and the drying means is not particularly limited. For example, a method of drying on a hot plate at a temperature of 40 ° C. to 150 ° C., preferably 60 ° C. to 100 ° C. for 0.5 to 30 minutes, preferably 1 to 5 minutes, may be mentioned.

  The baking temperature of the coating film formed by applying the liquid crystal alignment agent is not limited, and is, for example, 100 to 350 ° C, preferably 120 to 350 ° C, and more preferably 150 to 330 ° C. The firing time is 5 minutes to 240 minutes, preferably 10 minutes to 90 minutes, and more preferably 10 minutes to 30 minutes. Heating can be performed by a generally known method, for example, a hot plate, a hot air circulation furnace, an infrared furnace, or the like.

  The thickness of the liquid crystal alignment film obtained by firing is not particularly limited, but is preferably 5 to 300 nm, more preferably 20 to 200 nm.

  In the liquid crystal display element, a liquid crystal cell can be manufactured by a known method after forming a liquid crystal alignment film on a substrate by the above method. Specific examples of the liquid crystal display element include two substrates disposed so as to face each other, a liquid crystal layer provided between the substrates, and a liquid crystal alignment agent provided between the substrates and the liquid crystal layer and formed by a liquid crystal alignment agent. This is a vertical alignment type liquid crystal display device including a liquid crystal cell having a liquid crystal alignment film. Specifically, a liquid crystal alignment agent is applied on two substrates and baked to form a liquid crystal alignment film, and the two substrates are arranged so that the liquid crystal alignment films face each other. A vertical alignment type liquid crystal display device including a liquid crystal cell manufactured by sandwiching a liquid crystal layer formed of liquid crystal between substrates.

  Using a liquid crystal alignment film formed of a liquid crystal alignment agent containing the specific polymer of the present invention, a liquid crystal alignment film and a liquid crystal layer are irradiated with ultraviolet rays while applying a voltage to react a polymerizable compound contained in the liquid crystal. As a result, a PSA mode liquid crystal display device having a remarkably excellent vertical alignment ability can be obtained.

  The substrate of the liquid crystal display element is not particularly limited as long as it is a substrate having high transparency, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed. As a specific example, the same substrate as the substrate described for the liquid crystal alignment film can be used. A substrate provided with a conventional electrode pattern or projection pattern may be used.However, in the PSA mode liquid crystal display element, since the liquid crystal alignment agent containing the polyimide polymer of the present invention is used, for example, A line / slit electrode pattern of 1 to 10 μm is formed, and it can operate even in a structure in which a slit pattern or a protrusion pattern is not formed on the opposing substrate. The liquid crystal display element of this structure simplifies the manufacturing process. And high transmittance can be obtained.

In the case of a high-performance element such as a TFT element, an element such as a transistor formed between an electrode for driving liquid crystal and a substrate is used.
In the case of a transmissive liquid crystal display device, it is common to use the above-described substrate, but in the case of a reflective liquid crystal display device, an opaque substrate such as a silicon wafer may be used if only one substrate is used. It is possible. At this time, a material such as aluminum which reflects light can be used for the electrode formed on the substrate.

  The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element is not particularly limited, and liquid crystal materials used in a conventional vertical alignment system, for example, negative type such as MLC-6608, MLC-6609, and MLC-3023 manufactured by Merck & Co. Liquid crystal can be used. In the PSA-type liquid crystal display device, for example, a liquid crystal containing a polymerizable compound represented by the following formula can be used.

  As a method of sandwiching the liquid crystal layer between two substrates, a known method can be used. For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared, and spacers such as beads are scattered on the liquid crystal alignment film of one of the substrates so that the surface on which the liquid crystal alignment film is formed is inside. Then, the other substrate is bonded, and a liquid crystal is injected under reduced pressure and sealed. In addition, a pair of substrates on which a liquid crystal alignment film is formed is prepared, a spacer such as beads is scattered on the liquid crystal alignment film of one of the substrates, and then liquid crystal is dropped, and then the surface on which the liquid crystal alignment film is formed is formed. The liquid crystal cell can also be manufactured by a method in which the other substrate is bonded and sealed so that the inside is inside. The thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

  The step of manufacturing a liquid crystal cell by irradiating ultraviolet rays while applying a voltage to the liquid crystal alignment film and the liquid crystal layer includes, for example, applying a voltage between electrodes provided on a substrate to apply an electric field to the liquid crystal alignment film and the liquid crystal layer. And irradiating ultraviolet rays while maintaining the electric field. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, preferably 5 to 20 Vp-p. The irradiation amount of the ultraviolet ray is, for example, 1 to 60 J, preferably 40 J or less. The smaller the irradiation amount of the ultraviolet ray, the more the reduction in reliability caused by the destruction of the members constituting the liquid crystal display element can be suppressed, and the shorter the irradiation time of the ultraviolet ray. This is preferable because the production efficiency increases.

  As described above, when ultraviolet rays are applied while applying a voltage to the liquid crystal alignment film and the liquid crystal layer, the polymerizable compound reacts to form a polymer, and the direction in which the liquid crystal molecules tilt is stored by the polymer. The response speed of the obtained liquid crystal display element can be increased. Further, when ultraviolet rays are applied to the liquid crystal alignment film and the liquid crystal layer while applying a voltage, a polyimide precursor having a side chain for vertically aligning the liquid crystal and a photoreactive side chain, and this polyimide precursor is an imide. Since the photoreactive side chains of at least one polymer selected from the polyimide obtained by the polymerization and the photoreactive side chains of the polymer react with the polymerizable compound, the resulting liquid crystal display element The response speed can be increased.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention should not be construed as being limited thereto. The abbreviations of the compounds used are as follows:
(liquid crystal)
MLC-3023 (Merck, negative type polymerizable compound-containing liquid crystal)

(Specific side chain type diamine component)
W-A1: Compound W-A2 represented by Formula [W-A1]: Compound W-A3 represented by Formula [W-A2]: Compound W-A4 represented by Formula [W-A3]: Formula Compound W-A5 represented by [W-A4]: Compound W-A6 represented by Formula [W-A5]: Compound WA-A7 represented by Formula [W-A6]: Formula [W-A7] Compound WA8 represented by the formula: Compound WA9 represented by the formula [W-A8]: Compound WA10 represented by the formula [W-A9]: Compound represented by the formula [W-A10]

(Other side chain type diamine compounds)
A1: Compound represented by formula [A1] A2: Compound represented by formula [A2] A3: Compound represented by formula [A3]

(Other diamine compounds)
C1: Compound represented by Formula [C1] C2: Compound represented by Formula [C2] C3: Compound represented by Formula [C3] C4: Compound represented by Formula [C4] C5: Formula [C5] C6: a compound represented by the formula [C6] C7: a compound represented by the formula [C7] C8: a compound represented by the formula [C8] C9: a compound represented by the formula [C9] C10 : Compound represented by formula [C10]

(Tetracarboxylic acid component)
D1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride D2: Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride D3: Pyromellitic dianhydride Compound D4: 2,3,5-tricarboxycyclopentylacetic acid dianhydride D5: 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride

(solvent)
NMP: N-methyl-2-pyrrolidone BCS: ethylene glycol monobutyl ether NEP: N-ethyl-2-pyrrolidone (crosslinking agent)
E1: Crosslinking agent (additive) represented by the following formula (E1)
E2: 3-picolylamine

(Molecular weight measurement)
The molecular weights of the polyimide precursor and the polyimide were determined using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko KK) and a column (KD-803, KD-805) (manufactured by Shodex) using the following methods. Was measured as follows.
Column temperature: 50 ° C
Eluent: N, N'as dimethylformamide (additive, lithium bromide - hydrate _(LiBr-H 2 O) is 30mmol / L (liter), phosphoric acid anhydride crystals (o-phosphoric acid) 30mmol / L, tetrahydrofuran (THF) is 10 ml / L)
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight; about 900,000, 150,000, 100,000 and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight; about 12,000, 4,000 and 1,000) (manufactured by Polymer Laboratory).

(Measurement of imidation ratio of polyimide)
20 mg of the polyimide powder is placed in an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Science)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05% by mass TMS (tetramethylsilane)) (Mixture) (0.53 ml) was added, and the mixture was completely dissolved by sonication. The solution was measured for proton NMR at 500 MHz using an NMR measuring device (JNW-ECA500) (manufactured by JEOL Datum). The imidation rate is determined by using a proton derived from a structure that does not change before and after imidation as a reference proton, and a peak integrated value of this proton and a proton peak derived from an NH group of amic acid appearing around 9.5 to 10.0 ppm. It was determined by the following equation using the integrated value.
Imidation ratio (%) = (1−α · x / y) × 100
In the above formula, x is the integrated value of the proton peak derived from the NH group of the amic acid, y is the integrated value of the peak of the reference proton, and α is one NH group proton of the amic acid in the case of polyamic acid (imidation ratio is 0%) Is the ratio of the number of reference protons to

(Viscosity measurement)
In the synthesis example or the comparative synthesis example, the viscosity of the polyimide-based polymer was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), the sample amount was 1.1 mL, and the cone rotor TE-1 (1 ° 34 ′, R24), measured at a temperature of 25 ° C.

W-A1 to W-A3 and W-A4 to W-A10 are novel compounds which have not been published yet in literatures, and the synthesis methods will be described in detail below.
The products described in Synthesis Examples 1 to 3 and 4 to 10 below were identified by ¹ H-NMR analysis (analysis conditions are as follows).
Apparatus: Varian NMR System 400 NB (400 MHz).
Measurement _{solvent: CDCl 3, DMSO-d 6} .
Reference substance: tetramethylsilane (TMS) (δ0.0 ppm for ¹ H).

<< Synthesis Example 1 Synthesis of W-A1 >>

<Synthesis of Compound [1] and Compound [2]>
In tetrahydrofuran (165.6 g), 4,4′-dinitro-1,1′-biphenyl-2,2′-dimethanol (41.1 g, 135 mmol) and triethylamine (31.5 g) were charged, and cooled in a nitrogen atmosphere under ice-cooling. Under the conditions, methanesulfonyl chloride (33.2 g) was added dropwise and allowed to react for 1 hour to obtain compound [1]. Subsequently, p- (trans-4-heptylcyclohexyl) phenol (77.8 g) dissolved in tetrahydrofuran (246.6 g) was added, and the mixture was stirred at 40 ° C. for 1 hour, and then dissolved in pure water (233 g). Potassium oxide (41.0 g) was added at the same temperature and reacted for 21 hours. After completion of the reaction, a 1.0 M aqueous hydrochloric acid solution (311 ml) and pure water (1050 g) were added to precipitate a crude product, and the crude product was recovered by filtration. The obtained crude product was heated and dissolved in tetrahydrofuran (574 g) at 50 ° C., and methanol (328 g) was added to precipitate crystals, which was filtered and dried to obtain compound [2] (yield: 97.9 g, yield). Rate: 89%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6H), 0.96-1.05 ppm (m, 4H), 1.9-1.39 ppm (m, 30H), 1.80-1.85 ppm (m, 8H), 2.33-2.40 ppm (m, 2H), 4.77 ppm (s, 4H), 6.66-6.70 ppm (m, 4H), 7. 02-7.06 ppm (m, 4H), 7.40 ppm (d, 2H, 8.4), 8.25 ppm (dd, 2H, J = 2.4 Hz, J = 8.4 Hz), 8.54 ppm (d , 2H, J = 2.4 Hz).

<Synthesis of W-A1>
Compound [2] (74.3 g, 90.9 mmol) and 3% platinum carbon (5.94 g) in tetrahydrofuran (1783 g) were charged and reacted under a hydrogen atmosphere at room temperature. After completion of the reaction, the reaction mixture was filtered, and the filtrate was concentrated under reduced pressure to a total internal weight of 145 g. Subsequently, methanol (297 g) was added to the concentrated solution, and the mixture was stirred under ice-cooling, filtered, and dried to obtain W-A1 (yield: 59.2 g, 86%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6H), 0.96-1.05 ppm (m, 4H), 1.19-1.40 ppm (m, 30H), 1.81-1.84 ppm (m, 8H), 2.32-2.38 ppm (m, 2H), 3.67 ppm (s, 4H), 4.69 ppm (d, 2H, J = 12.0 Hz), 4.74 ppm (d, 2H, J = 11.6 Hz), 6.62 ppm (dd, 2H, J = 2.4 Hz, J = 8.0 Hz), 6.70-6.75 ppm (m, 4H), 6 .91 ppm (d, 2H, J = 2.4 Hz), 6.97-7.03 ppm (m, 6H).

<< Synthesis Example 2 Synthesis of W-A2 >>

<Synthesis of Compound [3]>
4,4′-Dinitro-2,2′-diphenic acid (40.9 g, 123 mmol) and p- (trans-4-heptylcyclohexyl) phenol (72.1 g) in tetrahydrofuran (327.2 g), 4-dimethyl Aminopyridine (1.50 g) was charged, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (56.6 g) was charged under a nitrogen atmosphere at room temperature, and the mixture was reacted for 3 hours. After completion of the reaction, the reaction solution was poured into pure water (1226 g) to precipitate a crude product, which was collected by filtration. Subsequently, the crude material was slurry-washed with methanol (245 g) and then filtered, and the obtained crude material was dissolved in tetrahydrofuran (245 g) by heating at 60 ° C. After removing insoluble matter by filtration, the total internal weight was reduced to 232 g by concentration under reduced pressure, and methanol (163 g) was added to precipitate crystals. The mixture was stirred under ice-cooling conditions, filtered, and dried to obtain compound [3]. Was obtained (yield: 73.9 g, yield: 71%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6H), 0.98-1.06 ppm (m, 4H), 1.18-1.43 ppm (m, 30H), 1.83-1.86 ppm (m, 8H), 2.41-2.47 ppm (m, 2H), 6.89-6.92 ppm (m, 4H), 7.17-7.20 ppm (m, 4H) ), 7.48 ppm (d, 2H, 8.4), 8.49 ppm (dd, 2H, J = 2.4 Hz, J = 8.4 Hz), 9.11 ppm (d, 2H, J = 2.4 Hz) .

<Synthesis of W-A2>
Compound [3] (73.9 g, 87.4 mmol) and 5% palladium carbon (8.80 g) in tetrahydrofuran (443 g) and methanol (73.9 g) were charged and reacted under a hydrogen atmosphere at room temperature. After completion of the reaction, palladium carbon was removed by filtration, and the total internal weight was reduced to 171 g by concentration under reduced pressure. Subsequently, methanol (222 g) was added to the concentrated solution to precipitate crystals, which were stirred under ice-cooling, filtered and dried to obtain W-A2 (yield: 66.6 g, yield: 97%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6H), 0.96-1.05 ppm (m, 4H), 1.17-1.42 ppm (m, 30H), 1.82-1.85 ppm (m, 8H), 2.38-2.44 ppm (m, 2H), 3.77 ppm (s, 4H), 6.80-6.87 ppm (m, 6H), 7. 08-7.13 ppm (m, 6H), 7.41 ppm (d, 2H, J = 2.4 Hz).

<< Synthesis Example 3 Synthesis of W-A3 >>

<Synthesis of Compound [4] and Compound [5]>
In toluene (366 g), 4- (trans-4-heptylcyclohexyl) -benzoic acid (73.1 g, 242 mmol) and N, N-dimethylformamide (0.73 g) were charged, and thionyl chloride was placed under a nitrogen atmosphere at 50 ° C. (35.9 g) was added dropwise. After the dropwise addition, the mixture was reacted at the same temperature for 1 hour, and then the reaction solution was concentrated under reduced pressure to obtain compound [4]. Subsequently, 4,4′-dinitro-1,1′-biphenyl-2,2′-dimethanol (35.0 g, 115 mmol) and triethylamine (26.8 g) were charged in tetrahydrofuran (210 g), and the mixture was charged with ice in a nitrogen atmosphere. Under cold conditions, compound [4] dissolved in tetrahydrofuran (73.1 g) was added dropwise. After the completion of the dropwise addition, the reaction was carried out at room temperature for 18 hours. After completion of the reaction, triethylamine hydrochloride was removed by filtration, and then an oily compound was obtained by concentration under reduced pressure. Crystals were precipitated by adding the obtained oily compound to pure water (1015 g), and a crude product was recovered by filtration. Subsequently, the obtained crude product was washed with methanol (291 g) at room temperature, washed with ethyl acetate (175 g) at room temperature, filtered, and dried to obtain compound [5] (yield: 92.7 g, yield: 92.7 g). Rate: 92%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.89-0.91 ppm (m, 6H), 0.99-1.09 ppm (m, 4H), 1.20-1.47 ppm (m, 30H), 1.85-1.88 ppm (m, 8H), 2.46-2.52 ppm (m, 2H), 5.14 ppm (s, 4H), 7.23-7.26 ppm (m, 4H), 7. 45 ppm (d, 2H, J = 8.4 Hz), 7.83-7.86 ppm (m, 4H), 8.27 ppm (dd, 2H, J = 2.4 Hz, J = 8.4 Hz), 8.47 ppm (D, 2H, J = 2.4 Hz).

<Synthesis of W-A3>
Compound [5] (80.5 g, 92.2 mmol) and 3% platinum carbon (6.44 g) in tetrahydrofuran (484 g) and methanol (161 g) were charged and reacted under a hydrogen atmosphere at room temperature. After completion of the reaction, platinum carbon was removed by filtration, and the solvent was removed by concentration under reduced pressure to make the total internal weight 96.6 g. Subsequently, methanol (322 g) was added to the concentrated solution to precipitate crystals, which were stirred with ice cooling and filtered to obtain a crude product. Subsequently, the obtained crude product was dissolved by heating at 60 ° C. with ethyl acetate (322 g), methanol (700 g) was added, crystals were precipitated under ice-cooling conditions, and the crystals were filtered and dried to obtain W-A3. (Yield: 67.9 g, yield: 91%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87 to 0.91 ppm (m, 6H), 0.98 to 1.08 ppm (m, 4H), 1.19 to 1.47 ppm (m, 30H), 1.84-1.87 ppm (m, 8H), 2.44-2.51 ppm (m, 2H), 3.71 ppm (s, 4H), 5.02 ppm (d, 2H, J = 12.8 Hz), 5.09 ppm (d, 2H, J = 12.4 Hz), 6.66 ppm (dd, 2H, J = 2.4 Hz, J = 8.0 Hz), 6.84 ppm (d, 2H, J = 2.4 Hz) , 7.03 ppm (d, 2H, J = 8.0 Hz), 7.19-7.25 ppm (m, 4H), 7.89-7.92 ppm (m, 4H).

<< Synthesis Example 4 Synthesis of W-A4 >>

<Synthesis of Compound [6] and Compound [7]>
In toluene (134 g), trans, trans-4′-amylbicyclohexyl-4-carboxylic acid (26.7 g, 95.1 mmol) and N, N-dimethylformamide (0.401 g) were charged, and a nitrogen atmosphere at 50 ° C. was used. Thionyl chloride (13.6 g, 114 mmol) was added dropwise underneath. After the dropwise addition, the mixture was reacted at the same temperature for 1 hour, and then the reaction solution was concentrated under reduced pressure to obtain compound [6]. Subsequently, 4,4′-dinitro-1,1′-biphenyl-2,2′-dimethanol (12.6 g, 41.4 mmol) and triethylamine (10.9 g, 108 mmol) in tetrahydrofuran (63.0 g). The compound [6] dissolved in tetrahydrofuran (12.6 g) was added dropwise under a nitrogen atmosphere and ice-cooled conditions. After completion of the dropwise addition, the reaction was carried out at room temperature for 17 hours. After completion of the reaction, the reaction solution was added to pure water (731 g) to precipitate crystals, which were filtered, washed with pure water, and washed with methanol to collect a crude product. Subsequently, the obtained crude product was dissolved in toluene (56.0 g) by heating, and hexane (112 g) was added to precipitate crystals. The mixture was stirred at room temperature, filtered, and dried to give compound [7]. Was obtained (yield: 17.0 g, 20.6 mmol, yield: 50%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.82-1.38 ppm (m, 44H), 1.67-1.81 ppm (m, 12H), 1.90-1.98 ppm (m, 4H), 2.19-2.25 ppm (m, 2H), 4.82 ppm (d, 2H, J = 13.6 Hz), 4.88 ppm (d, 2H, J = 13.6 Hz), 7.39 ppm (d, 2H) , J = 8.4 Hz), 8.26 ppm (dd, 2H, J = 2.4 Hz, J = 8.4 Hz), 8.38 ppm (d, 2H, J = 2.0 Hz)

<Synthesis of W-A4>
Compound [7] (17.0 g, 20.6 mmol) and 3% platinum carbon (1.36 g) in tetrahydrofuran (136 g) and methanol (34.0 g) are charged and reacted under a hydrogen atmosphere at room temperature for about 41 hours. Was. After completion of the reaction, filtration and concentration under reduced pressure made the total internal weight 40 g. Subsequently, methanol (68.0 g) was added to precipitate crystals, which were filtered and dried to obtain W-A4 (yield: 15.2 g, 19.9 mmol, yield: 97%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.81-1.39 ppm (m, 44H), 1.67-1.78 ppm (m, 12H), 1.90-1.97 ppm (m, 4H), 2.14 to 2.20 ppm (m, 2H), 3.71 ppm (br, 4H), 4.73 ppm (d, 2H, J = 12.4 Hz), 4.78 ppm (d, 2H, J = 12.4 Hz) ), 6.62 ppm (dd, 2H, J = 2.4 Hz, J = 8.0 Hz), 6.73 ppm (d, 2H, J = 2.8 Hz), 6.94 ppm (d, 2H, J = 8.8 Hz). 0Hz)

<< Synthesis Example 5 Synthesis of W-A5 >>

<Synthesis of Compound [8]>
In toluene (227 g), trans-1-bromo-4- (4-heptylcyclohexyl) benzene (45.4 g, 135 mmol) and lithium bis (trimethylsilyl) amide (about 26% tetrahydrofuran solution, about 1.30 mol / L, 218 mL) ), Tri-tert-butylphosphonium tetrafluoroborate (1.58 g, 5.44 mmol) and bis (dibenzylideneacetone) palladium (0) (3.14 g, 5.46 mmol) were charged under a nitrogen atmosphere at room temperature. The reaction was performed for 17 hours. After completion of the reaction, a 5.7 mol / L aqueous hydrochloric acid solution (80.0 mL) was added to precipitate crystals, and the hydrochloride of compound [8] was recovered by filtration. The obtained hydrochloride was dispersed in a mixed solution of toluene (300 g), ethyl acetate (200 g), and tetrahydrofuran (100 g), separated with a 3.0 mol / L aqueous sodium hydroxide solution (200 g), and further saturated with an organic phase. Washed with saline. Subsequently, activated carbon (brand: specially made Shirasagi, 2.27 g) was added to the organic phase and stirred, and then the activated carbon was removed by filtration. The obtained filtrate was concentrated under reduced pressure to obtain an oily compound. The oily compound was dispersed in hexane (100 g), and crystals were precipitated under dry ice / ethanol cooling conditions, followed by filtration and drying to obtain compound [8] (yield: 27.5 g, 101 mmol, yield: 75%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-1.43 ppm (m, 20H), 1.83-1.85 ppm (m, 4H), 2.31-2.38 ppm (m, 1H), 3.54 ppm (br, 2H), 6.62-6.65 ppm (m, 2H), 6.99-7.02 ppm (m, 2H)

<Synthesis of Compound [9]>
In tetrahydrofuran (120 g) and methylene chloride (60.0 g), 4,4′-dinitro-2,2′-diphenic acid (14.9 g, 45.0 mmol) and compound [8] (25.8 g, 94.3 mmol). ), 4-dimethylaminopyridine (0.550 g, 4.50 mmol) and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (20.0 g, 104 mmol) were added under a nitrogen atmosphere at room temperature. Allowed to react for hours. After completion of the reaction, the mixture was diluted with ethyl acetate (375 g), and the organic phase was washed with pure water (149 g) three times, and the obtained organic phase was subjected to magnesium sulfate dehydration treatment. Subsequently, the organic phase was concentrated under reduced pressure to a total internal weight of 112 g, and methanol (120 g) was added to precipitate crystals. The crystals were filtered and dried to obtain compound [9] (yield: 28.0 g, 33.2 mmol, yield: 74%)
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-1.43 ppm (m, 40H), 1.82-1.84 ppm (m, 8H), 2.37-1.44 ppm (m, 2H), 7.10 ppm (d, 4H, J = 8.8 Hz), 7.26-7.30 ppm (m, 4H), 7.40 ppm (d, 2H, J = 8.4 Hz), 8.27 ppm (dd, 2H) , J = 2.4 Hz, J = 8.4 Hz), 8.53 ppm (d, 2H, J = 2.4 Hz), 9.10 ppm (s, 2H).

<Synthesis of W-A5>
Compound [9] (28.0 g, 33.2 mmol) and 5% palladium carbon (2.10 g) in tetrahydrofuran (140 g) and methanol (56.0 g) are charged and reacted under a hydrogen atmosphere at room temperature for about 3 days. Was. After completion of the reaction, palladium carbon was removed by filtration, and the mixture was concentrated under reduced pressure to a total internal weight of 122 g. Methanol (168 g) was added to the obtained solution to precipitate crystals, which were filtered and dried to obtain WA-5 (yield: 23.8 g, 30.4 mmol, yield: 92%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-1.42 ppm (m, 40H), 1.81-1.84 ppm (m, 8H), 2.36-2.42 ppm (m, 2H), 3.73 ppm (br, 4H), 6.58-6.60 ppm (m, 2H), 6.88-6.90 ppm (m, 4H), 7.07-7.09 ppm (m, 4H), 7. 34-7.36 ppm (m, 4H), 8.85 ppm (s, 2H)

<< Synthesis Example 6 Synthesis of W-A6 >>

<Synthesis of Compound [10]>
4,4′-Dinitro-2,2′-diphenic acid (25.0 g, 75.4 mmol) and cholesterol (61.7 g, 160 mmol) in tetrahydrofuran (113 g) and methylene chloride (113 g), 4-dimethylaminopyridine (0.919 g, 7.54 mmol) and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (33.6 g, 175 mmol) were charged and reacted under a nitrogen atmosphere at room temperature for 18 hours. After completion of the reaction, methylene chloride (375 g) was added to the reaction solution, and the organic phase was washed three times with saturated saline (200 g), and then the organic phase was dehydrated with magnesium sulfate. Subsequently, the resulting solution was concentrated under reduced pressure to a brown oily compound, and a mixed solution of ethyl acetate (200 g) and isopropyl alcohol (200 g) was added to precipitate crystals, which were filtered to obtain a crude product. The obtained crude product was recrystallized twice from a mixed solution of chloroform (500 g) and methanol (600 g), filtered and dried to obtain compound [10] (yield: 41.8 g, 39.1 mmol, yield). : 52%).
_{^{1 H-NMR (400MHz) in}} CDCl 3: 0.67-2.21ppm (m, 86H), 4.58-4.63ppm (m, 2H), 5.31-5.33ppm (m, 2H), 7.37-7.39 ppm (m, 2H), 8.42-8.44 ppm (m, 2H), 8.93 ppm (m, 2H)

<Synthesis of W-A6>
Compound [10] (40.4 g, 37.8 mmol) and 5% palladium carbon (3.03 g) in tetrahydrofuran (320 g) and methanol (80.8 g) are charged and reacted under a hydrogen atmosphere at room temperature for about 3 days. Was. After completion of the reaction, palladium carbon was removed by filtration, and the mixture was concentrated under reduced pressure to a total internal weight of 112 g. Methanol (160 g) was added to the obtained solution to precipitate crystals, which were filtered and dried to obtain WA-6 (yield: 35.0 g, 34.7 mmol, yield: 92%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.66 to 2.17 ppm (m, 86H), 3.74 ppm (br, 4H), 4.50 to 4.56 ppm (m, 2H), 5.28 ppm ( m, 2H), 6.78-6.80 ppm (m, 2H), 6.95-6.97 ppm (m, 2H), 7.26-7.28 ppm (m, 2H)

<< Synthesis Example 7 Synthesis of W-A7 >>

<Synthesis of Compound [11] and Compound [12]>
In tetrahydrofuran (152 g), 4,4′-dinitro-1,1′-biphenyl-2,2′-dimethanol (40.0 g, 132 mmol) and triethylamine (36.6 g, 362 mmol) were charged, and ice was added under a nitrogen atmosphere. Under cold conditions, ethanesulfonyl chloride (44.4 g, 345 mmol) was added dropwise. After completion of the dropwise addition, the mixture was stirred at a reaction temperature of 40 ° C. for 3 hours to obtain a compound [11]. Subsequently, p- (trans-4-propylcyclohexyl) phenol (63.1 g, 289 mmol) dissolved in tetrahydrofuran (240 g) and potassium hydroxide (85.0%, 45%) dissolved in pure water (228 g). .1 g, 683 mmol) was added to the reaction solution of compound [11], and the mixture was heated to 50 ° C. and reacted for 39 hours. After completion of the reaction, the reaction solution was poured into pure water (1500 g) to precipitate a crude product, which was filtered and washed with pure water. Subsequently, slurry washing was performed with a mixed solution of pure water (378 g) and methanol (378 g), followed by filtration and washing again with methanol. The obtained crude crystal was heated and dissolved in tetrahydrofuran (600 g) at 60 ° C., and methanol (400 g) was added to precipitate crystals. After stirring at room temperature, the mixture was filtered and dried to obtain compound [12]. (Yield: 77.7 g, 110 mmol, yield: 83%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.97 ppm (m, 6H), 0.97-1.05 ppm (m, 4H), 1.12-1.62 ppm (m, 14H), 1.81-1.87 ppm (m, 8H), 2.34-2.40 ppm (m, 2H), 4.77 ppm (s, 4H), 6.67-6.69 ppm (m, 4H), 7. 00-7.05 ppm (m, 4H), 7.40 ppm (d, 2H, J = 8.0 Hz), 8.25 ppm (dd, 2H, J = 2.0 Hz, J = 8.4 Hz), 8.54 ppm (S, 2H).

<Synthesis of W-A7>
Compound [12] (77.7 g, 110 mmol) and 3% platinum carbon (6.22 g) in tetrahydrofuran (741 g) and methanol (155 g) were charged and reacted at room temperature under a hydrogen atmosphere for about 2 days. After completion of the reaction, platinum carbon was removed by filtration, and the filtrate was concentrated under reduced pressure. Tetrahydrofuran (122 g) was added to the obtained concentrated crude product, and the mixture was heated and dissolved at 60 ° C., and acetonitrile (159 g) was added to precipitate crystals. After stirring at room temperature, the mixture was filtered and dried to obtain W-A7. (Yield: 58.6 g, 88.1 mmol, yield: 80%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.86-0.91 ppm (m, 6H), 0.96-1.06 ppm (m, 4H), 1.12-1.44 ppm (m, 14H), 1.81-1.84 ppm (m, 8H), 2.32-2.34 ppm (m, 2H), 3.71-3.75 ppm (br, 4H), 4.67-4.76 ppm (q, 4H) , J = 10.0 Hz), 6.61-6.64 ppm (m, 2H), 6.71-6.75 ppm (m, 4H), 6.91-6.92 ppm (m, 2H), 6.97. -7.03 ppm (m, 6H).

<< Synthesis Example 8 Synthesis of W-A8 >>

<Synthesis of Compound [11] and Compound [13]>
In tetrahydrofuran (156 g), 4,4'-dinitro-1,1'-biphenyl-2,2'-dimethanol (39.2 g, 129 mmol) and triethylamine (35.0 g, 346 mmol) were charged, and ice was added under a nitrogen atmosphere. Under cold conditions, ethanesulfonyl chloride (34.8 g, 271 mmol) was added dropwise. After the dropwise addition, the mixture was stirred at a reaction temperature of 40 ° C. for 3 hours to obtain a compound [11]. Subsequently, 4-cyclohexylphenol (50.0 g, 284 mmol) dissolved in tetrahydrofuran (230 g) and potassium hydroxide (85.0% product, 47.1 g, 714 mmol) dissolved in pure water (231 g) were used as compounds. The mixture was added to the reaction solution of [11], and the mixture was heated to 50 ° C. and reacted for 39 hours. After completion of the reaction, the reaction solution was poured into pure water (660 g), and separated and extracted with chloroform (588 g × 4 times). The collected organic phase was concentrated under reduced pressure, and the crude product was heated and dissolved in tetrahydrofuran (118 g) at 60 ° C., methanol (235 g) was added to precipitate crystals, and the mixture was stirred at room temperature and filtered. The crystals were washed with a cake of pure water / methanol = 1/1 mixed solvent (118 g) and methanol (118 g × 2) and dried to obtain compound [13] (yield: 67.6 g, 120 mmol, yield). : 93%).
¹ H-NMR (400 MHz) in CDCl ₃ : 1.18-1.30 ppm (m, 2H), 1.31-1.38 ppm (m, 8H), 1.71-1.75 ppm (m, 2H), 1.80-1.82 ppm (m, 8H), 2.36-2.44 ppm (m, 2H), 4.77 ppm (s, 4H), 6.67-6.70 ppm (m, 4H), 7. 03-7.06 ppm (m, 4H), 7.40 ppm (d, 2H, J = 8.4 Hz), 8.24 ppm (d, 1H, J = 2.0 Hz), 8.26 ppm (d, 1H, J = 2.0 Hz), 8.54 ppm (d, 2H, J = 2.0 Hz).

<Synthesis of W-A8>
Compound [13] (65.0 g, 105 mmol) and 3% platinum carbon (5.20 g) in tetrahydrofuran (325 g) and methanol (65.0 g) were charged and reacted under a hydrogen atmosphere at room temperature for about 2 days. After the reaction was completed, platinum carbon was removed by filtration, and the mixture was concentrated under reduced pressure. The crude product was heated and dissolved in tetrahydrofuran (70.4 g) at 60 ° C., and methanol (130 g) was added to precipitate crystals. The mixture was stirred at room temperature and filtered. The crystals were washed with a cake of methanol (130 g × 2 times) and dried to obtain WA-8 (yield: 54.2 g, 96.7 mmol, yield: 92%).
¹ H-NMR (400 MHz) in CDCl ₃ : 1.19 to 1.28 ppm (m, 2H), 1.31-1.41 ppm (m, 8H), 1.70-1.73 ppm (m, 2H), 1.79-1.87 ppm (m, 8H), 1.87-2.39 ppm (m, 2H), 3.60-3.79 ppm (br, 4H), 4.67-4.76 ppm (q, 4H) , J = 9.6 Hz), 6.61-6.64 ppm (m, 2H), 6.72-6.75 ppm (m, 4H), 6.91-6.92 ppm (d, 2H, J = 2. 4 Hz), 6.97-7.03 ppm (m, 6H).

<< Synthesis Example 9 Synthesis of W-A9 >>

<Synthesis of Compound [11] and Compound [14]>
In tetrahydrofuran (83.6 g), 4,4′-dinitro-1,1′-biphenyl-2,2′-dimethanol (20.9 g, 68.7 mmol) and triethylamine (15.3 g, 151 mmol) were charged. Under a nitrogen atmosphere and ice cooling conditions, ethanesulfonyl chloride (18.6 g, 145 mmol) was added dropwise. After the dropwise addition, the mixture was stirred at a reaction temperature of 40 ° C. for 3 hours to obtain a compound [11]. Subsequently, 4-[(trans, trans) -4′-pentyl [1,1′-bicyclohexyl] -4-yl] phenol (48.6 g, 149 mmol) dissolved in tetrahydrofuran (188 g) and pure water ( Potassium hydroxide (85.0% product, 20.9 g, 317 mmol) dissolved in 119.2 g) was added to the reaction solution of compound [11], and the mixture was reacted for 20 hours. After completion of the reaction, the reaction solution was poured into pure water (800 g) to precipitate a crude product, which was filtered and washed with pure water. Subsequently, slurry washing was performed with a mixed solution of pure water (100 g) and methanol (100 g), followed by filtration, and washing with pure water and methanol again. The crude product was dissolved in tetrahydrofuran (400 g) by heating at 60 ° C., and methanol (100 g) was added to precipitate crystals. After stirring at room temperature, the mixture was filtered and dried to obtain compound [14] (yield: 49). 0.7 g, 53.9 mmol, yield: 78%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.83-1.34 ppm (m, 44H), 1.71-1.85 ppm (m, 16H), 2.29-2.36 ppm (m, 2H), 4.77 ppm (s, 4H), 6.66-6.68 ppm (m, 4H), 7.01-7.03 ppm (m, 4H), 7.39 ppm (d, 2H, J = 8.0 Hz), 8.24 ppm (dd, 2H, J = 2.0 Hz, J = 8.4 Hz), 8.54 ppm (d, 2H, J = 2.4 Hz)

<Synthesis of W-A9>
Compound [14] (45.1 g, 48.7 mmol) and 3% platinum carbon (3.60 g) in tetrahydrofuran (361 g) and methanol (90.2 g) were charged, and 0.4 MPa under a hydrogen pressure atmosphere at 40 ° C. The reaction was performed for about 9 hours. After the completion of the reaction, the solvent was removed by filtration and concentration under reduced pressure, and methanol (135 g) was added to carry out slurry washing. Subsequently, the crude product obtained by filtration was heated and dissolved in tetrahydrofuran (180 g) at 60 ° C., ethyl acetate (120 g) was added, and the mixture was stirred at room temperature to precipitate crystals. -A9 was obtained (yield: 17.8 g, 20.7 mmol, yield: 43%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.88-1.34 ppm (m, 44H), 1.71-1.86 ppm (m, 16H), 2.29-2.36 ppm (m, 2H), 3.69 ppm (br, 4H), 4.70 ppm (d, 2H, J = 12.4 Hz), 4.76 ppm (d, 2H, J = 12.4 Hz), 6.62 ppm (dd, 2H, J = 2) 0.4 Hz, J = 8.0 Hz), 6.71-6.73 ppm (m, 4H), 6.91 ppm (d, 2H, J = 2.4 Hz), 6.96-6.99 ppm (m, 6H)

<< Synthesis Example 10 Synthesis of W-A10 >>

<Synthesis of Compound [15]>
In N-methylpyrrolidone (540 g), 2-fluoro-5-nitrotoluene (91.0 g, 587 mmol), 1,3-propanediol (22.3 g, 291 mmol), potassium hydroxide (85.0% product, 71.0%). 6 g, 1.08 mol) and stirred at 80 ° C. for 20 hours under a nitrogen atmosphere. After completion of the reaction, pure water (1440 g) was added to perform water splitting crystallization. After filtration, the crystals were washed with pure water (540 g × 3 times) and methanol (360 g × 2 times), and dried to obtain a compound. [15] was obtained (yield: 57.2 g, 165 mmol, yield: 54%).

<Synthesis of Compound [16]>
In 1,2-dichloroethane (540 g), compound [15] (40.0 g, 116 mmol), N-bromosuccinimide (45.2 g, 254 mmol), 2,2′-azobis (isobutyronitrile) (3.79 g) , 23.1 mmol), and the mixture was purged with nitrogen and stirred at 100 ° C. for about 7 days. After the reaction solution was filtered to remove insoluble succinimide, ethyl acetate (250 g) was added to the filtrate, liquid separation extraction and washing with pure water (250 g × 3 times) were performed, and the organic phase was recovered and concentrated. The obtained concentrate was crystallized from ethyl acetate (346 g) and hexane (395 g) and filtered to collect crystals. Further, the filtrate was concentrated, crystallized and filtered again with chloroform (223 g) and hexane (434 g), and dried to obtain a crude compound [16] (crude yield: 21.3 g, crude yield). : 37%).

<Synthesis of Compound [17]>
In N, N-dimethylacetamide (96.0 g), p- (trans-4-heptylcyclohexyl) phenol (24.0 g, 87.5 mmol) and potassium carbonate (12.1 g, 87.5 mmol) were charged at 100 ° C. Stirred. A crude compound [16] (20.0 g) dissolved in N, N-dimethylacetamide (54.0 g) was added dropwise and reacted for 24 hours. Crystals precipitated from the reaction solution were separated by filtration, washed with methanol (66.0 g) and pure water (67.0 g), respectively, and then filtered and dried again to obtain compound [17] (yield: 4). 0.23 g, 4.75 mmol, yield: 4.1% (yield based on charged compound [15])).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.89 ppm (t, 6H, J = 6.8 Hz), 0.99-1.07 ppm (m, 4H), 1.19-1.43 ppm (m, 30H) ), 1.84-1.87 ppm (m, 8H), 2.36-2.44 ppm (m, 4H), 4.29 ppm (t, 4H, J = 6.0 Hz), 5.04 ppm (s, 4H). ), 6.84-6.90 ppm (m, 6H), 7.10-7.13 ppm (m, 4H), 8.17 ppm (dd, 2H, J = 3.2 Hz, 9.0 Hz), 8.38 ppm (D, 2H, J = 2.8 Hz).

<Synthesis of W-A10>
Compound [17] (3.60 g, 4.04 mmol) and 3% platinum carbon (0.290 g) in tetrahydrofuran (28.8 g) and methanol (7.5 g) were charged, and the pressure was increased under a hydrogen atmosphere at 0.4 MPa. And stirred at 40 ° C. for 3 hours. After the reaction was completed, platinum carbon was removed by filtration, and the mixture was concentrated under reduced pressure. Ethyl acetate and methanol were added to the crude product to precipitate crystals, which were stirred at room temperature, filtered, and dried to obtain W-A10 (yield: 2.05 g, 2.47 mmol, yield: 54). %).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.89 ppm (t, 6H, J = 6.8 Hz), 0.98 to 1.06 ppm (m, 4H), 1.18 to 1.44 ppm (m, 30H) ), 1.83-1.86 ppm (m, 8H), 2.15-2.21 ppm (m, 2H), 2.36-2.42 ppm (m, 2H), 3.42 ppm (br, 4H), 4.09 ppm (t, 4H, J = 6.0 Hz), 5.00 ppm (s, 4H), 6.55-6.57 ppm (m, 2H), 6.70 ppm (d, 2H, J = 8.8 Hz) ), 6.82-6.89 ppm (m, 6H), 7.07-7.10 ppm (m, 4H).

<Synthesis of polyimide polymer>
[Synthesis Example 1]
D2 (2.50 g, 10.0 mmol), W-A1 (3.03 g, 4.00 mmol) and C1 (1.73 g, 16.0 mmol) were mixed in NMP (36.2 g), and mixed at 60 ° C. After reacting for an hour, D1 (1.78 g, 9.10 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid content concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 840 mPa · s.
After NMP was added to the obtained polyamic acid solution (20.0 g) to dilute it to 6.5% by mass, acetic anhydride (4.43 g) and pyridine (1.37 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (382 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (1). The imidation ratio of this polyimide was 76.4%, the number average molecular weight was 16,165, and the weight average molecular weight was 49,988.

[Synthesis Example 2]
D2 (2.50 g, 10.0 mmol), WA2 (3.14 g, 4.00 mmol) and C1 (1.84 g, 16.0 mmol) were mixed in NMP (36.9 g), After reacting for an hour, D1 (1.84 g, 9.38 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 658 mPa · s.
After NMP was added to the obtained polyamic acid solution (20.0 g) to dilute it to 6.5% by mass, acetic anhydride (4.38 g) and pyridine (1.36 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (382 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (2). The imidation ratio of this polyimide was 75.8%, the number average molecular weight was 15,430, and the weight average molecular weight was 45,756.

[Synthesis Example 3]
D2 (2.50 g, 10.0 mmol), WA3 (3.25 g, 4.00 mmol) and C1 (1.73 g, 16.0 mmol) were mixed in NMP (37.3 g), After reacting for an hour, D1 (1.84 g, 9.38 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 656 mPa · s.
After NMP was added to the obtained polyamic acid solution (20.0 g) to dilute it to 6.5% by mass, acetic anhydride (4.32 g) and pyridine (1.34 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (382 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (3). The imidation ratio of this polyimide was 74.7%, the number average molecular weight was 13,340, and the weight average molecular weight was 41,948.

[Control Synthesis Example 1]
D2 (1.50 g, 6.0 mmol), C2 (1.83 g, 12.0 mmol), C3 (2.18 g, 9.0 mmol) and A1 (3.43 g, 9.0 mmol) in NMP (41.1 g) After reacting at 60 ° C. for 3 hours, D3 (1.31 g, 6.0 mmol) was added, followed by D1 (3.47 g, 17.7 mmol) and NMP (13.71 g). For 10 hours to obtain a polyamic acid solution.
After NMP was added to this polyamic acid solution (50 g) to dilute it to 6.5% by mass, acetic anhydride (11.1 g) and pyridine (3.4 g) were added as imidation catalysts and reacted at 60 ° C. for 3 hours. Was. This reaction solution was poured into methanol (700 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (4). The imidation ratio of this polyimide was 79%, the number average molecular weight was 11,000, and the weight average molecular weight was 24,000.

[Comparative Synthesis Example 1]
D2 (2.88 g, 11.5 mmol), A1 (3.50 g, 9.20 mmol) and C1 (1.49 g, 13.8 mmol) are mixed in NMP (40.2 g) and reacted at 60 ° C. for 3 hours. After that, D1 (2.19 g, 11.2 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 680 mPa · s.
After NMP was added to the obtained polyamic acid solution (20.0 g) to dilute it to 6.5% by mass, acetic anhydride (4.64 g) and pyridine (1.44 g) were added as imidation catalysts. The reaction was performed for 3 hours. This reaction solution was poured into methanol (382 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (R1). The imidation ratio of this polyimide was 75.1%, the number average molecular weight was 15,322, and the weight average molecular weight was 45,800.

[Synthesis Example 5]
D2 (2.50 g, 10.0 mmol), WA4 (4.62 g, 6.00 mmol) and C1 (1.51 g, 14.0 mmol) were mixed in NMP (24.5 g), After reacting for an hour, D1 (1.92 g, 9.80 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid content concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 783 mPa · s.
After NMP was added to the obtained polyamic acid solution (20.0 g) to dilute it to 6.5% by mass, acetic anhydride (3.86 g) and pyridine (1.20 g) were added as imidation catalysts. The reaction was performed for 3 hours. This reaction solution was poured into methanol (233 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (5). The imidation ratio of this polyimide was 76.7%, the number average molecular weight was 14,399, and the weight average molecular weight was 38,573.

[Synthesis Example 6]
D2 (2.50 g, 10.0 mmol), WA5 (4.70 g, 6.00 mmol) and C1 (1.51 g, 14.0 mmol) were mixed in NMP (24.9 g), and mixed at 60 ° C. After reacting for an hour, D1 (1.92 g, 9.80 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid content concentration of 20% by mass. The viscosity of this polyamic acid solution was measured to be 769 mPa · s.
After NMP was added to the obtained polyamic acid solution (20.0 g) to dilute it to 6.5% by mass, acetic anhydride (3.83 g) and pyridine (1.19 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (232 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (6). The imidation ratio of this polyimide was 73.4%, the number average molecular weight was 13,841 and the weight average molecular weight was 37,284.

[Synthesis Example 7]
D2 (6.26 g, 25.0 mmol), W-A6 (5.05 g, 5.00 mmol) and C1 (4.87 g, 45.0 mmol) were mixed in NMP (62.0 g), and mixed at 60 ° C. for 3 hours. After reacting for an hour, D1 (4.51 g, 23.0 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 658 mPa · s.
After NMP was added to the obtained polyamic acid solution (75.0 g) to dilute it to 6.5% by mass, acetic anhydride (18.2 g) and pyridine (5.6 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (1000 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (7). The imidation ratio of this polyimide was 72.9%, the number average molecular weight was 13,362 and the weight average molecular weight was 38,725.

[Synthesis Example 8]
D2 (6.26 g, 25.0 mmol), W-A7 (8.06 g, 12.5 mmol) and C1 (4.06 g, 37.5 mmol) were mixed in NMP (69.2 g), and mixed at 60 ° C. for 3 hours. After reacting for an hour, D1 (4.71 g, 24.0 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 725 mPa · s.
After NMP was added to the obtained polyamic acid solution (75.0 g) to dilute it to 6.5% by mass, acetic anhydride (16.5 g) and pyridine (5.1 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (1000 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (8). The imidation ratio of this polyimide was 73.1%, the number average molecular weight was 13,628, and the weight average molecular weight was 39,937.

[Synthesis Example 9]
D2 (6.26 g, 25.0 mmol), W-A8 (7.01 g, 12.5 mmol) and C1 (4.06 g, 37.5 mmol) were mixed in NMP (66.1 g) and mixed at 60 ° C. for 3 hours. After reacting for an hour, D1 (4.71 g, 24.0 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 674 mPa · s.
After NMP was added to the obtained polyamic acid solution (75.0 g) to dilute it to 6.5% by mass, acetic anhydride (17.2 g) and pyridine (5.3 g) were added as imidation catalysts. The reaction was performed for 3 hours. This reaction solution was poured into methanol (1000 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (9). The imidation ratio of this polyimide was 73.2%, the number average molecular weight was 10,425, and the weight average molecular weight was 37,759.

[Synthesis Example 10]
D2 (6.26 g, 25.0 mmol), W-A9 (2.16 g, 2.5 mmol) and C1 (5.14 g, 47.5 mmol) were mixed in NMP (54.8 g), After reacting for an hour, D1 (4.71 g, 24.0 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 823 mPa · s.
After NMP was added to the obtained polyamic acid solution (75.0 g) to dilute it to 6.5% by mass, acetic anhydride (20.7 g) and pyridine (6.4 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (1000 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (10). The imidation ratio of this polyimide was 71.5%, the number average molecular weight was 13,732, and the weight average molecular weight was 38,921.

[Synthesis Example 11]
D2 (2.50 g, 10.0 mmol), WA10 (3.31 g, 4.00 mmol) and C1 (1.73 g, 16.0 mmol) were mixed in NMP (30.2 g), After reacting for an hour, D1 (1.84 g, 9.40 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid content concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 695 mPa · s.
After NMP was added to the obtained polyamic acid solution (20.0 g) to dilute it to 6.5% by mass, acetic anhydride (4.35 g) and pyridine (1.35 g) were added as imidation catalysts. The reaction was performed for 3 hours. This reaction solution was poured into methanol (235 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (11). The imidation ratio of this polyimide was 76.1%, the number average molecular weight was 12,913, and the weight average molecular weight was 39,182.

[Synthesis Example 12]
D2 (25.0 g, 100 mmol), W-A1 (37.9 g, 50.0 mmol), C3 (12.1 g, 50.0 mmol), and C8 (33.0 g, 100 mmol) were mixed in NMP (432 g). After reacting at 60 ° C. for 3 hours, D1 (18.8 g, 96.0 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid content concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 721 mPa · s.
After NMP was added to the obtained polyamic acid solution (100 g) to dilute it to 6.5% by mass, acetic anhydride (16.0 g) and pyridine (4.96 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. for 3 hours. Reacted. This reaction solution was poured into methanol (1150 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (12). The imidation ratio of this polyimide was 75.1%, the number average molecular weight was 14,736 and the weight average molecular weight was 39,645.

[Synthesis Example 13]
D2 (25.0 g, 100 mmol), W-A1 (37.9 g, 50.0 mmol), C6 (20.5 g, 60.0 mmol), C8 (6.61 g, 20,0 mmol), C7 (27.9 g, 70,0 mmol) in NMP (471 g), and reacted at 60 ° C. for 3 hours. Then, D1 (18.8 g, 96.0 mmol) was added, and the mixture was reacted at 40 ° C. for 3 hours. A mass% polyamic acid solution was obtained. When the viscosity of this polyamic acid solution was measured, it was 771 mPa · s.
After NMP was added to the obtained polyamic acid solution (100 g) to dilute it to 6.5% by mass, acetic anhydride (14.9 g) and pyridine (4.63 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. for 3 hours. Reacted. This reaction solution was poured into methanol (1150 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 60 ° C. under reduced pressure to obtain a polyimide powder (13). The imidation ratio of this polyimide was 76.2%, the number average molecular weight was 15,835 and the weight average molecular weight was 39,145.

[Synthesis Example 14]
D2 (25.0 g, 100 mmol), W-A1 (37.9 g, 50.0 mmol), C6 (17.0 g, 50.0 mmol), C8 (16.5 g, 50.0 mmol), C3 (12.1 g, 50.0 mmol) was mixed in NMP (434 g) and reacted at 60 ° C. for 3 hours. Then, D1 (18.8 g, 96.0 mmol) was added, and the mixture was reacted at 40 ° C. for 3 hours. A mass% polyamic acid solution was obtained. When the viscosity of this polyamic acid solution was measured, it was 701 mPa · s.
After NMP was added to the obtained polyamic acid solution (100 g) to dilute it to 6.5% by mass, acetic anhydride (16.0 g) and pyridine (4.97 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. for 3 hours. Reacted. This reaction solution was poured into methanol (1150 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried at 60 ° C. under reduced pressure to obtain a polyimide powder (14). The imidation ratio of this polyimide was 74.8%, the number average molecular weight was 17,635 and the weight average molecular weight was 41,647.

[Synthesis Example 15]
D4 (43.9 g, 196 mmol), W-A1 (30.3 g, 40.0 mmol), C4 (13.9 g, 70.0 mmol), C8 (16.5 g, 50.0 mmol), C5 (7.59 g, 40.0 mmol) in NMP (455 g) and reacted at 60 ° C. for 15 hours to obtain a polyamic acid solution having a resin solid content concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 662 mPa · s.
After NMP was added to the obtained polyamic acid solution (100 g) to dilute it to 6.5% by mass, acetic anhydride (17.9 g) and pyridine (5.55 g) were added as imidation catalysts, and the mixture was added at 100 ° C. for 3 hours. Reacted. This reaction solution was poured into methanol (1160 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 60 ° C. under reduced pressure to obtain a polyimide powder (15). The imidation ratio of this polyimide was 71.7%, the number average molecular weight was 13,329 and the weight average molecular weight was 40,527.

[Synthesis Example 16]
D2 (25.0 g, 100 mmol), C2 (21.3 g, 140 mmol) and C10 (24.6 g, 60.0 mmol) were dissolved in NMP (284 g) and reacted at 60 ° C. for 3 hours. 14.3 g, 40.0 mmol), followed by D1 (11.0 g, 56.0 mmol) and NMP (100 g) were reacted at 25 ° C. for 10 hours to obtain a polyamic acid solution.
After NMP was added to this polyamic acid solution (100 g) to dilute it to 6.5% by mass, acetic anhydride (21.0 g) and pyridine (6.52 g) were added as imidation catalysts, and reacted at 80 ° C. for 3 hours. Was. This reaction solution was poured into methanol (1170 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (16). The imidation ratio of this polyimide was 75.8%, the number average molecular weight was 14,679 and the weight average molecular weight was 35,747.

[Synthesis Example 17]
D2 (25.0 g, 100 mmol), C6 (50.0 g, 120 mmol), C9 (15.1 g, 60.0 mmol), and W-A1 (15.1 g, 20.0 mmol) were dissolved in NMP (385 g). After reacting at 60 ° C. for 3 hours, D1 (18.8 g, 96.0 mmol) and NMP (75.3 g) were added, and the mixture was reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. Got. When the viscosity of this polyamic acid solution was measured, it was 753 mPa · s.
After NMP was added to this polyamic acid solution (100 g) to dilute it to 6.5% by mass, acetic anhydride (17.6 g) and pyridine (5.47 g) were added as imidation catalysts and reacted at 80 ° C. for 3 hours. Was. This reaction solution was poured into methanol (1160 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 60 ° C. under reduced pressure to obtain a polyimide powder (17). The imidation ratio of this polyimide was 71.1%, the number average molecular weight was 17635 and the weight average molecular weight was 38427.

[Comparative Synthesis Example 2]
D2 (6.26 g, 25.0 mmol), A2 (12.23 g, 30.0 mmol) and C1 (2.16 g, 20.0 mmol) were mixed in NMP (76.7 g) and reacted at 80 ° C. for 5 hours. After that, D1 (4.90 g, 25.0 mmol) was added and reacted at 40 ° C. for 12 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 338 mPa · s.
After NMP was added to the obtained polyamic acid solution (75.0 g) to dilute it to 6.5% by mass, acetic anhydride (15.0 g) and pyridine (4.6 g) were added as imidation catalysts. The reaction was performed for 3 hours. This reaction solution was poured into methanol (1000 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (R2). The imidation ratio of this polyimide was 73.0%, the number average molecular weight was 10,175, and the weight average molecular weight was 23,642.

[Comparative Synthesis Example 3]
D2 (6.26 g, 25.0 mmol), A3 (7.06 g, 25.0 mmol) and C1 (2.70 g, 25.0 mmol) are mixed in NMP (62.8 g) and reacted at 80 ° C. for 5 hours. After that, D1 (4.90 g, 25.0 mmol) was added and reacted at 40 ° C. for 12 hours to obtain a polyamic acid solution having a resin solid concentration of 20% by mass. When the viscosity of this polyamic acid solution was measured, it was 446 mPa · s.
After NMP was added to the obtained polyamic acid solution (75.0 g) to dilute it to 6.5% by mass, acetic anhydride (18.3 g) and pyridine (5.7 g) were added as imidation catalysts, and the mixture was heated at 80 ° C. The reaction was performed for 3 hours. This reaction solution was poured into methanol (1000 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol and dried at 100 ° C. under reduced pressure to obtain a polyimide powder (R3). The imidation ratio of this polyimide was 72.2%, the number average molecular weight was 11,636, and the weight average molecular weight was 24,624.
Table 1 summarizes the compositions of the polyimide powders obtained in the synthesis examples and the comparative synthesis examples.

<Preparation of liquid crystal alignment treatment agent>
In Examples and Comparative Examples, preparation examples of liquid crystal alignment treatment agents will be described. Using the liquid crystal alignment treating agents obtained in Examples and Comparative Examples, production of liquid crystal display elements and various evaluations were performed.

<Example 1>
NMP (28.2 g) was added to the polyimide powder (1) (3.00 g) obtained in Synthesis Example 1, and the mixture was stirred at 70 ° C. for 24 hours to be dissolved. NMP (g) and BCS (18.8 g) were added to this solution, and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal alignment agent (V-1). No abnormality such as turbidity or precipitation was observed in this liquid crystal alignment treatment agent, and it was confirmed that the solution was a uniform solution.

<Example 2> and <Example 3>
In Example 1, the liquid crystal aligning agents (V-2) and (V-3) were prepared in the same manner as in Example 1, except that the polyimide powder (2) and (3) were used instead of the polyimide powder (1). Got. No abnormality such as turbidity or precipitation was observed in this liquid crystal alignment treatment agent, and it was confirmed that the solution was a uniform solution.

<Control 1>
In Example 1, a liquid crystal alignment agent (V-4) was obtained in the same procedure as in Example 1, except that the polyimide powder (4) obtained in Control Synthesis Example 1 was used instead of the polyimide powder (1). Was. No abnormality such as turbidity or precipitation was observed in this liquid crystal alignment treatment agent, and it was confirmed that the solution was a uniform solution.

<Example 4>
3.0 g of the liquid crystal alignment agent (V-1) obtained in Example 1 as the first component and 7.0 g of the liquid crystal alignment agent (V-4) obtained in Control 1 as the second component were mixed. By stirring for 1 hour, a liquid crystal alignment treating agent (V-5) was obtained.

<Example 5> to <Example 6>
In Example 4, a liquid crystal alignment agent (V-2) or (V-3) was used as the first component instead of the liquid crystal alignment agent (V-1), and the procedure was the same as in Example 4. Liquid crystal aligning agents (V-6) and (V-7) were obtained.

<Comparative Example 1>
NMP (28.2 g) and BCS (18.8 g) were added to the polyimide powder (R1) (3.00 g) obtained in Comparative Synthesis Example 1, and the mixture was stirred at 70 ° C. for 24 hours. R-V1) was obtained. No abnormality such as turbidity or precipitation was observed in this liquid crystal alignment treatment agent, and it was confirmed that the solution was a uniform solution.
Using the obtained liquid crystal alignment treatment agent (R-V1), a liquid crystal display device, evaluation of vertical alignment, evaluation of pretilt angle, evaluation of voltage holding ratio, and evaluation of afterimage characteristics were performed.

<Example 7>
NMP (22.0 g) was added to the polyimide powder (5) (3.00 g) obtained in Synthesis Example 5 and dissolved by stirring at 70 ° C. for 24 hours. To this solution, 3.0 g of E2 (1 wt% NMP solution) and BCS (20.0 g) were added, and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal alignment agent (V-8). No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment treatment agent, and it was confirmed that the solution was a uniform solution.

<Examples 8 to 13, 15 to 17, 19, 20, Comparative Examples 2 to 4>
The polyimide powders (6) to (11), (13) to (13) obtained in Synthesis Examples 6 to 11, 13 to 15, and Comparative Synthesis Examples 1 to 3 and Control Synthesis Example 1 by the same operation as in Example 7. 15), (17), (R1 to R3) and (4) were used to prepare liquid crystal alignment treatment agents (V-9 to V-21) and (R-V2 to R-V4).

<Example 14>
NEP (22.0 g) was added to the polyimide powder (12) (3.00 g) obtained in Synthesis Example 12 and dissolved by stirring at 70 ° C. for 24 hours. To this solution, NEP (3.0 g) and BCS (20.0 g) were added, and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal alignment agent (V-15). No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment treatment agent, and it was confirmed that the solution was a uniform solution.

<Example 18>
The same operation as in Example 14 was performed on the polyimide powder (16) obtained in Synthesis Example 16 to obtain a liquid crystal alignment film treating agent (V-19).

<Example 21>
3.0 g of the liquid crystal alignment agent (V-15) obtained in Example 14 as the first component, 7.0 g of the liquid crystal alignment agent (V-19) obtained in Example 18 as the second component, The crosslinking agent E1 was mixed at 5% by weight with respect to the resin component in the liquid crystal alignment film agent, and stirred for 1 hour to obtain a liquid crystal alignment treatment agent (W-2).

<Examples 22 to 24>
With respect to the liquid crystal aligning agents (V-16) to (V-21) obtained in Examples 15 to 20, liquid crystal aligning agents (W-3) to (W-5) were obtained by the same operation as in Example 21. Was.

  Using the liquid crystal aligning agent obtained in the example and the liquid crystal aligning agent obtained in the comparative example, production of a liquid crystal display element, evaluation of vertical alignment, scratch test, evaluation of pretilt angle, evaluation of voltage holding ratio The afterimage characteristics were evaluated.

<Preparation of liquid crystal display element for voltage holding ratio measurement>
The liquid crystal aligning agent obtained in the example and the liquid crystal aligning agent obtained in the comparative example were filtered under pressure with a membrane filter having a pore diameter of 1 μm. The obtained solution was spin-coated on a 40 mm × 30 mm glass substrate with an ITO electrode (length: 40 mm, width: 30 mm, thickness: 1.1 mm) washed with pure water and IPA (isopropyl alcohol), Heat treatment was performed on a hot plate at 70 ° C. for 90 seconds and in a heat-circulating clean oven at 230 ° C. for 30 minutes to obtain a 100-nm-thick ITO substrate with a liquid crystal alignment film. Two ITO substrates with the obtained liquid crystal alignment film were prepared, and a bead spacer (manufactured by Nikki Shokubai Kasei Co., Ltd., Shin-yoku ball, SW-D1) having a diameter of 4 μm was applied to the liquid crystal alignment film surface of one of the substrates.
Next, the periphery was applied with a sealing agent (XN-1500T manufactured by Mitsui Chemicals, Inc.). Next, the other substrate was bonded to the previous substrate with the surface on the side where the liquid crystal alignment film was formed facing inside, and then the sealing material was cured to form empty cells. Liquid crystal MLC-3023 (trade name, manufactured by Merck) was injected into the empty cell by a reduced pressure injection method to prepare a liquid crystal cell.
Thereafter, while applying a DC voltage of 15 V to the obtained liquid crystal cell, an ultraviolet ray irradiating apparatus using a high-pressure mercury lamp as a light source was irradiated with 15 J / cm ^{2 of} ultraviolet light through a band-pass filter having a wavelength of 365 nm. Thus, a vertical alignment type liquid crystal display device was obtained. Note that a UV-35 light receiver was connected to UV-M03A manufactured by ORC for measurement of the amount of ultraviolet irradiation.

<Preparation of pretilt angle and afterimage evaluation liquid crystal display element>
The liquid crystal aligning agent obtained in the example was subjected to pressure filtration with a membrane filter having a pore diameter of 1 μm. The obtained solution was washed with pure water and IPA (isopropyl alcohol), and an ITO electrode substrate (length: 35 mm, width: 30 mm) on which an ITO electrode pattern having a pixel size of 200 μm × 600 μm and a line / space of 3 μm each was formed. , Thickness: 0.7 mm) and a 3.2 μm-height photo spacer on the ITO surface of a glass substrate with an ITO electrode (length: 35 mm, width: 30 mm, thickness: 0.7 mm). Spin coating was performed on a hot plate at 70 ° C. for 90 seconds and in a heat circulating clean oven at 230 ° C. for 30 minutes to obtain a 100 nm thick ITO substrate with a liquid crystal alignment film.
The ITO electrode substrate on which the ITO electrode pattern is formed is divided into four in a cross checker (checkered) pattern, and can be driven separately for each of the four areas.
Next, the periphery was applied with a sealing agent (XN-1500T manufactured by Mitsui Chemicals, Inc.). Next, the other substrate was bonded to the previous substrate with the surface on the side where the liquid crystal alignment film was formed facing inside, and then the sealing material was cured to form empty cells. Liquid crystal MLC-3023 (trade name, manufactured by Merck) was injected into the empty cell by a reduced pressure injection method to prepare a liquid crystal cell.
Then, a DC voltage of 15 V was applied to the obtained liquid crystal cell, and in a state where all the pixel areas were driven, the liquid crystal cell was passed through a band-pass filter having a wavelength of 365 nm using an ultraviolet irradiation apparatus using a high-pressure mercury lamp as a light source. Ultraviolet rays were irradiated at 10 J / cm ² to obtain a vertical alignment type liquid crystal display device. A UV-35 light receiver was connected to ORC's UV-M03A for measurement of the amount of ultraviolet irradiation.
Further, in Examples 1 to 3 and Comparative Example 1, in addition to the above standard conditions, vertical alignment was performed under the same conditions as above except that the heat treatment was performed at 230 ° C. for 120 minutes as a severe condition. Type liquid crystal display device was prepared.

<Evaluation>
(Vertical orientation)
The liquid crystal orientation of the liquid crystal display element was observed with a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) to confirm whether the liquid crystal was vertically aligned. More specifically, samples in which no defect due to liquid crystal flow and no bright spot due to alignment defects were observed were evaluated as good. Table 2 shows the evaluation results.

(Voltage holding ratio)
After applying a voltage of 1 V to the liquid crystal display device for voltage holding ratio evaluation prepared above at an application time of 60 microseconds and at an interval of 1667 milliseconds, the voltage holding ratio (%) after 1667 milliseconds after the application was released. Was measured. The measuring device used was VHR-1 manufactured by Toyo Technica. Table 2 shows the evaluation results.

(Pretilt angle)
Using an LCD analyzer (LCA-LUV42A manufactured by Meisho Technica Co., Ltd.), the liquid crystal display element for evaluation of the pretilt angle prepared above was measured for a liquid crystal display element in which no defect due to liquid crystal flow was observed. . Table 2 shows the evaluation results.

(Afterimage characteristics)
Using the above-prepared liquid crystal display device for image lag evaluation, an alternating voltage of 60 Hz and 20 Vp-p was applied to two diagonal areas of the four pixel areas, and driving was performed at a temperature of 23 ° C. for 168 hours. Thereafter, all four pixel areas were driven with an AC voltage of 5 Vp-p, and the luminance difference between the pixels was visually observed. A state in which a luminance difference was hardly confirmed was regarded as good. Table 3 shows the evaluation results.

(Scratch test)
A scratch test was performed using UMT-2 (manufactured by Bruker AXS) on the alignment film surface of the polyimide-coated substrate obtained in the example.
FVL was selected for the UMT-2 sensor, and a 1.6 mm sapphire ball was attached to the tip of the scratch part.
With the tip of the scratch portion in contact with the surface of the liquid crystal alignment film at a load of 1 mN, a scratch test was performed in a range of 0.5 mm in width and 2.0 mm in length while changing the load from 1 mN to 20 mN over 100 seconds. At this time, the moving direction of the tip of the scratch portion was reciprocating sideways, and the moving speed was 5.0 mm / sec. The vertical movement of the scratch area was performed by moving the substrate provided with the liquid crystal alignment film in the vertical direction at 20 μm / sec.
After the scratch test, MLC-3022 (negative liquid crystal manufactured by Merck) was dropped onto the liquid crystal alignment film surface after the scratch test. Thereto, another 4 μm spacer with a liquid crystal alignment film obtained in Example 1 on which a 4 μm spacer was scattered was overlapped so that the surfaces of the liquid crystal alignment films faced each other, and the dropped MLC-3022 was sandwiched.
In a state where the polarization axes of the upper and lower polarizing plates of a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) are set to 90 ° (crossed Nicols), the place where the scratch test was performed is observed, and it is determined whether light is transmitted. Observed. Regarding the places where the scratch test was performed, the state where no bright spots or light leakage was observed was marked as ○, the state where slight bright spots or light leakage was seen was marked as △, and the state where the entire scratched area became light lost was marked as x It is shown in Table 6.

As a result, specifically, as can be seen from the comparison between Examples 1 to 3 and Comparative Example 1 shown in Table 4, the liquid crystal display device using the liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention is It was also found that there was no change in the pretilt angle even under severe conditions, and the liquid crystal orientation was good.
Further, as shown in Table 5, it was found that in Examples 4 to 6 in which the liquid crystal alignment agent (V-4) was mixed, good results were obtained in the afterimage characteristics.
Further, from this example, it was found that the liquid crystal alignment film obtained by using a specific side chain type diamine was excellent in pretilt angle stability even when fired under severe conditions. Further, it was confirmed that even when there was physical contact with the liquid crystal alignment film as in the scratch test, it was possible to maintain good vertical alignment with little damage to the alignment film.

  A liquid crystal display device using a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention can be suitably used for a liquid crystal display device. These elements are also useful in a liquid crystal display for display purposes, and also in a light control window or an optical shutter for controlling transmission and blocking of light.

Claims (9)

Liquid crystal containing at least one polymer selected from a polyimide precursor which is a reaction product of a diamine component containing a diamine represented by the following formula [1] and a tetracarboxylic acid component, and a polyimide which is an imidized product thereof. Alignment agent:
Wherein [1], X is a single _{bond, -O -, - C (CH} 3) 2 -, - NH -, - CO -, - (CH 2) m -, - SO 2 -, and combinations of any Wherein m represents an integer of 1 to 8, and Y independently represents a structure of the following formula [1-1];
In the formula [1-1], Y ¹ and Y ³ are each independently a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CH ₂ O— , -CONH-, -NHCO-, -COO- and -OCO- at least one selected from the group consisting of:
Y ² represents a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 15) (provided that when Y ¹ or Y ³ is a single bond or — (CH ₂ ) _a —, ² is a single bond, and Y ¹ is at least one selected from the group consisting of —O—, —CH ₂ O—, —CONH—, —NHCO—, —COO—, and —OCO—, and / or Or when Y ³ is at least one selected from the group consisting of —O—, —CH ₂ O—, —CONH—, —NHCO—, —COO—, and —OCO—, Y ² is a single bond or — ( CH ₂ ) _b — (however, when Y ¹ is —CONH—, it is a single bond of Y ² and Y ³ ));
Y ⁴ represents a benzene ring, at least one divalent cyclic group selected from the group consisting of a cyclohexane ring and a heterocyclic ring, or a divalent organic group having 17 to 51 carbon atoms having a steroid skeleton and a tocophenol skeleton; An arbitrary hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, and a fluorine-containing alkoxy group having 1 to 3 carbon atoms. Or may be substituted with a fluorine atom;
Y ⁵ represents at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocyclic ring, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, An alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom;
Y ⁶ is an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and a fluorine-containing alkoxy group having 1 to 18 carbon atoms. At least one member selected from the group consisting of groups;
n shows the integer of 0-4.

The liquid crystal aligning agent according to claim 1, wherein the diamine represented by the formula [1] is represented by the following formula [1 '].

The diamine represented by the formula [1] is represented by the following formula [1] -a1, the following formula [1] -a2, or the following formula [1] -a3. Liquid crystal alignment agent.

The diamine represented by the formula [1] is represented by the following formula [1] -a1-1, the following formula [1] -a2-1 to the following formula [1] -a2-4, or the following formula [1] -a3- The liquid crystal aligning agent according to any one of claims 1 to 3, which is represented by the following formula [1] -a3-2.

Y represented by the structure of the formula [1-1] is represented by the following formulas [1-1] -1 to [1-1] -22 (where * represents the formulas [1] and [1] '] Indicates the position of the bond with the phenyl group in the formulas [1] -a1 to [1] -a3; m indicates an integer of 1 to 15, and n indicates an integer of 0 to 18 The liquid crystal aligning agent according to any one of claims 1 to 4, which is represented by any one of the above.

The diamine component further contains a diamine represented by the following formula [2] (wherein A ₁ and A ₂ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) Represents an alkenyl group having 2 to 5 carbon atoms or an alkynyl group having 2 to 5 carbon atoms;
Y ₁ represents a divalent organic group. )
The liquid crystal aligning agent according to claim 1.

  A liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1. A step of applying a liquid crystal aligning agent according to any one of claims 1 to 6 on a substrate to form a coating film;
Baking the coating film; and orienting the film obtained by baking;
A method for producing a liquid crystal alignment film, comprising: forming a liquid crystal alignment film.   A liquid crystal display device comprising: the liquid crystal alignment film according to claim 7; or a liquid crystal alignment film obtained by the manufacturing method according to claim 8.