JP7096534B2 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Description

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element having an excellent ability to orient liquid liquid crystals vertically.

A liquid crystal display element of a method (also called a vertical orientation (VA) method) in which liquid crystal molecules oriented perpendicular to a substrate are made to respond by an electric field is irradiated with ultraviolet rays while applying a voltage to the liquid crystal molecules in the manufacturing process. Some include steps to do.

In such a vertically oriented liquid crystal display element, a photopolymerizable compound is added to the liquid crystal composition in advance, and a polyimide-based vertically oriented film is used to irradiate the liquid crystal cell with ultraviolet rays while applying a voltage. Therefore, a technique for increasing the response speed of a liquid crystal display (PSA (Polymer Sustained Alignment) type element, for example, see Patent Document 1 and Non-Patent Document 1) is known.

As a liquid crystal alignment agent used in such a PSA system element, a liquid crystal alignment 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 orient the liquid crystal vertically, and the vertically oriented liquid crystal display element using this liquid crystal alignment agent has good display characteristics.

Japanese Patent Application Laid-Open No. 2003-307720 WO2006 / 070819 Gazette

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

However, in recent years, in the vertical alignment type liquid crystal display element, due to the influence of the thinning and large size of the substrate used, a temperature difference occurs between different parts in the same substrate at the time of firing, and the liquid crystal of the excessively heated part. The alignment film reduces the ability to orient the liquid crystal vertically, resulting in the problem that the resulting liquid crystal display element partially causes display defects.
Further, in the liquid crystal panel manufacturing process, there is a problem that the liquid crystal alignment film and the column spacer come into contact with each other and the liquid crystal alignment film is damaged, so that an orientation defect (bright spot) is generated in the portion.

The present invention is to provide a liquid crystal alignment agent that can obtain a liquid crystal alignment film that does not reduce the ability to vertically align the liquid crystal even when exposed to excessive heating.
Another object of the present invention is to provide a liquid crystal alignment agent capable of obtaining a liquid crystal alignment film that does not reduce the ability to vertically align the liquid crystal 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 alignment agent having the following constitution, and have completed the present invention.
That is, the configuration of the present invention is as follows.
1. 1. A liquid crystal containing at least one polymer selected from a polyimide precursor which is a reaction product of a diamine-containing diamine component represented by the following formula [1] and a tetracarboxylic acid component and a polyimide which is an imidized product thereof. Aligning agent.

In the formula [1], X is a single bond, -O-, -C (CH ₃ ) _2- , -NH-, -CO-, -NHCO-, -COO-,-(CH ₂ ) _m -,-. It represents a divalent organic group consisting of SO _2- and any combination thereof, and m represents an integer of 1 to 8.
Y independently represents the structure of the following equation [1-1].

In the formula [1-1], Y ¹ and Y ³ are independently single-bonded,-(CH ₂ ) _a- (a is an integer of 1 to 15), -O-, and -CH ₂ O-. , -CONH-, -NHCO-, -COO- and -OCO- show at least one selected from the group.
Y ² indicates a single bond or-(CH ₂ ) _b- (b is an integer from 1 to 15) (where Y ¹ or Y ³ is a single bond,-(CH ₂ ) _a- , then Y ² is a single bond, is Y ¹ at least one selected from the group consisting of -O-, -CH ₂ O-, -CONH-, -NHCO-, -COO- and -OCO-, and / Or if Y ³ is at least one selected from the group consisting of -O-, -CH ₂ O-, -CONH-, -NHCO-, -COO- and -OCO-, then Y ² is a single bond or-( CH ₂ ) _b- (where Y ¹ is -CONH-, it is a Y ² and Y ³ single bond).
Y4 represents at least one ^divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle, or a divalent organic group having a steroid skeleton and a tocophenol skeleton and having 17 to 51 carbon atoms. Any 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. Alternatively, it 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 and 1 carbon atom. It may be substituted with an alkoxy group having 3 to 3, 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 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 1 to 18 carbon atoms. Shown at least one selected from the group consisting of fluorine-containing alkoxy groups of. n represents an integer from 0 to 4.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a liquid crystal alignment agent that can obtain a liquid crystal alignment film that does not reduce the ability to orient the liquid crystal vertically even when exposed to excessive heating.
Further, according to the present invention, a liquid crystal alignment agent that can obtain a liquid crystal alignment film that does not reduce the ability to orient the liquid crystal vertically even when some foreign matter comes into contact with the film and is damaged in addition to or other than the above effects. 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 is a diamine component containing a diamine represented by the above formula [1] (hereinafter, "diamine represented by the above formula [1]" may be abbreviated as "specific diamine"). And at least one polymer selected from a polyimide precursor which is a reaction product with a tetracarboxylic acid component and a polyimide which 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 diamines is such that the specific diamine is 5 mol% to 70 mol%, preferably 10 mol% to 50 mol%, and more preferably 10 mol% to 40 mol% in the specific polymer. Is good.
Further, the liquid crystal alignment agent of the present invention may contain "polyimide precursor and / or polyimide which is an imidized product thereof" other than the specific polymer.
Hereinafter, the "specific diamine" will be described, and then the 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].

In the formula [1], X is a single bond, -O-, -C (CH ₃ ) _2- , -NH-, -CO-, -NHCO-, -COO-,-(CH ₂ ) _m -,-. It represents a divalent organic group consisting of SO _2- and any combination thereof, and m represents an integer of 1 to 8.
As "any combination thereof", -O- (CH ₂ ) _m -O-, -OC (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-, etc. However, it is not limited to these.
X is preferably single bond, —O—, —NH—, —O— (CH ₂ ) _m −O—.

In the formula [1], Y may be in the meta position or the ortho position from the position of X, but is preferably the 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] -a3 is preferable, and [1] -a1 is more preferable.

From the above formulas [1] -a1 to [1] -a3 and the above formula [1'], the above formula [1] may have any structure selected from the following formulas, preferably the formula [1]. ] -A1-1 is preferable.

Y independently represents the structure of the following equation [1-1].

In the formula [1-1], Y ¹ and Y ³ are independently single-bonded,-(CH ₂ ) _a- (a is an integer of 1 to 15), -O-, and -CH ₂ O-. , -CONH-, -NHCO-, -COO- and -OCO- show at least one selected from the group.
Y ² indicates a single bond or-(CH ₂ ) _b- (b is an integer from 1 to 15) (where Y ¹ or Y ³ is a single bond,-(CH ₂ ) _a- , then Y ² is a single bond, is Y ¹ at least one selected from the group consisting of -O-, -CH ₂ O-, -CONH-, -NHCO-, -COO- and -OCO-, and / Or if Y ³ is at least one selected from the group consisting of -O-, -CH ₂ O-, -CONH-, -NHCO-, -COO- and -OCO-, then Y ² is a single bond or-( CH ₂ ) _b- (where Y ¹ is -CONH-, it is a Y ² and Y ³ single bond).
Y4 represents at least one ^divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle, or a divalent organic group having a steroid skeleton and a tocophenol skeleton and having 17 to 51 carbon atoms. Any 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. Alternatively, it 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 and 1 carbon atom. It may be substituted with an alkoxy group having 3 to 3, 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 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 1 to 18 carbon atoms. Shown at least one selected from the group consisting of fluorine-containing alkoxy groups of. n represents an integer from 0 to 4.

Examples of the group represented by the above formula [1-1] include, but are not limited to, the following groups [1-1] -1 to [1-1] -22. Of these, [1-1] -1 to [1-1] -4, [1-1] -8, and [1-1] -10 are preferable. In addition, * indicates the position which is bonded to the phenyl group in the above formula [1], the above formula [1'], and the above formula [1] -a1 to the above formula [1] -a3. m indicates an integer of 1 to 15, and n indicates 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.
The photoreactive side chain is possessed by a "polyimide precursor and / or an imidized polyimide" which is a polymer other than the "specific polymer" even if the "specific polymer" has it. You may.
<Diamine containing photoreactive side chains>
In order to introduce a photoreactive side chain into a polymer other than the "specific polymer" and / or the "specific polymer", it is recommended 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 the formula [IX].

The bonding position of the two amino groups (-NH ₂ ) in the formula [VIII] and the formula [IX] is not limited. Specifically, with respect to the bonding group of the side chain, 2,3 positions, 2,4 positions, 2,5 positions, 2,6 positions, 3,4 positions, 3, on the benzene ring. The position of 5 is mentioned. Of these, the 2,4 position, the 2,5 position, or the 3,5 position is preferable from the viewpoint of reactivity in synthesizing the polyamic acid. Considering the ease of synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

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

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

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

Further, the definitions of Y ₁ , Y ₂ , Y ₃ , Y ₄ , Y ₅ and Y ₆ in the formula [IX] are as follows.
That is, Y ₁ represents -CH _2- , -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, or -CO-.
Y ₂ is an alkylene group having 1 to 30 carbon atoms, a divalent carbon ring or a heterocycle, and one or more hydrogen atoms of the alkylene group, the divalent carbon ring or the heterocycle are fluorine atoms or organic. It may be substituted with a group. In Y ₂ , -CH _2- may be substituted with these groups if the following groups are not adjacent to each other; -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. _Y5 is a single bond, an alkylene group having 1 to 30 carbon atoms, a divalent carbon ring or a heterocycle, and one or more hydrogen atoms of the alkylene group, the divalent carbon ring or the heterocycle are fluorine atoms. Alternatively, it may be substituted with an organic group.
In Y5, _-CH2- may be substituted with these groups if the following groups are not adjacent to each other; -O-, _-NHCO- , -CONH-, -COO-, -OCO-, -NH-, -NHCONH-, -CO-.
Y ₆ indicates a photopolymerizable group which is an acrylic group or a methacrylic 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 may be independently substituted with a single bond, a bond group which 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 the above definitions.
The diamine having a photoreactive side chain depends on the liquid crystal orientation when it is used as a liquid crystal alignment film, pretilt angle, voltage holding characteristics, characteristics such as accumulated charge, and the response speed of the liquid crystal when it is used as a liquid crystal display element. Therefore, one type or a mixture of two or more types 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%. Is.
Further, examples of the diamine having a photoreactive side chain include a diamine having a site having a radical generation structure in which a radical is generated by being decomposed by ultraviolet irradiation in the side chain.

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 independently alkyl groups or alkoxy groups having 1 to 10 carbon atoms.
T1 and T2 are independently single-bonded or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N (CH ₃ )-, -CON (CH ₃ )-,-N (CH ₃ ) CO-binding group.
S is an alkylene group having 1 to 20 carbon atoms which is single-bonded, unsubstituted or substituted with a fluorine atom. However, the alkylene group -CH _2- or -CF _2- may be arbitrarily replaced with -CH = CH-, and if any of the following groups are not adjacent to each other, they are replaced with these groups. May be; -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocycles, divalent heterocycles.
Q is a structure selected from the following (in the structural formula, R represents water, an elementary atom or an alkyl group having 1 to 4 carbon atoms, and R ₃ is -CH _2- , -NR-, -O-, or -S. -Represents.) Represents.

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

In the formula (I), when Ar has a structure like naphthylene or biphenylene, the solubility becomes poor and the difficulty of synthesis becomes high. If the wavelength of ultraviolet rays 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.

Further, R ₁ and R ₂ are independently alkyl groups having 1 to 10 carbon atoms, an alkoxy group, a benzyl group, or a phenethyl group, and in the case of an alkyl group or an alkoxy group, the rings are R ₁ and R ₂ . May be formed.

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

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

Specifically, the structure represented by the following formula is most preferable from the viewpoint 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 diamines) may be contained. Such a diamine is represented by the following general formula [2]. Other diamines may be used alone or in combination of two or more.

In the above formula [2], A ₁ and A ₂ are independently hydrogen atoms or alkyl groups having 1 to 5 carbon atoms, alkenyl groups having 2 to 5 carbon atoms, or alkynyl groups having 2 to 5 carbon atoms. Is. From the viewpoint of monomer reactivity, A ₁ and A ₂ are preferably hydrogen atoms or methyl groups. An example of the structure of Y ₁ 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.

The other diamine components used in the liquid crystal alignment agent of the present invention are not particularly limited, but are (Y-7), (Y-8), from the viewpoints of coatability, voltage retention characteristics, residual DC voltage characteristics, and the like. (Y-16), (Y-17), (Y-21), (Y-22), (Y-28), (Y-37), (Y-38), (Y-60), (Y) It is particularly preferable to select and use a diamine selected from -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 acid dianhydride, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, and tetracarboxylic acid dialkyl ester dihalide. Then, these are collectively also referred to as a tetracarboxylic acid component.
Examples of the tetracarboxylic acid component include tetracarboxylic acid dianhydride, its derivatives, tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, and tetracarboxylic acid dialkyl ester dihalide (collectively, the first). 1) is also referred to as a tetracarboxylic acid component).

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

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

[2] Examples of the alicyclic tetracarboxylic acid dianhydride include acid dianhydrides having the following formulas (X1-1) to (X1-13).

In the formulas (X1-1) to (X1-4), R ₃ to R ₂₃ are independently hydrogen atom, halogen atom, alkyl group having 1 to 6 carbon atoms, alkenyl group having 2 to 6 carbon atoms, and carbon. It is an alkynyl group having a number of 2 to 6, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, and 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-tetrahydrofuran, etc.;

[4] As aromatic tetracarboxylic acid dianhydride, for example, pyromellitic acid anhydride, 4,4'-(hexafluoroisopropyridene) diphthalic acid anhydride, 3,3', 4,4'-diphenylsulfone tetracarboxylic acid. Acid dianhydride, acid dianhydride represented by the following formulas (Xb-1) to (Xb-10), and the like, and

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

The tetracarboxylic acid dianhydride may be used alone or in combination of two or more.
The tetracarboxylic acid dianhydride component used in the liquid crystal aligning agent of the present invention is not particularly limited, but is (X1-1), (X1-) from the viewpoints of coatability, voltage retention characteristics, residual DC voltage characteristics and the like. 2), (X1-3), (X1-6), (X1-7), (X1-8), (X1-9), (Xa-2), pyromellitic acid anhydride, 3,3', It is preferable to select and use a tetracarboxylic acid dianhydride selected from 4,4'-diphenylsulfone tetracarboxylic acid dianhydride, (Xb-6), and (Xb-9).

<Polymer manufacturing method>
The method for producing these polymers is usually obtained by reacting a diamine component with a tetracarboxylic acid component. Polyamide acid is obtained by reacting at least one tetracarboxylic acid component selected from the group consisting of tetracarboxylic acid dianhydride and its derivative of tetracarboxylic acid with a diamine component consisting of one or more diamines. The method can be mentioned. Specifically, a method of polycondensing a tetracarboxylic acid 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 obtained by dialkyl esterifying a carboxylic acid group with a primary or secondary diamine, a tetracarboxylic acid dihalide obtained by halogenating a carboxylic acid group and a primary acid group are obtained. Alternatively, a method of polycondensing with a secondary diamine or a method of converting the carboxy group of polyamic acid into an ester is used.
In order to obtain polyimide, the method of ring-closing the above-mentioned polyamic acid or polyamic acid alkyl ester to form polyimide is used.

The reaction between the diamine component and the tetracarboxylic acid component is usually carried out in a solvent. The solvent used at that time is not particularly limited as long as it dissolves the produced polyimide precursor. Specific examples of the solvent used in the reaction are given 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, dimethyl sulfoxide or 1,3-dimethyl-imidazolidinone. Will be. When the polyimide precursor has high solvent solubility, it is represented by methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the following formulas [D-1] to [D-3]. A solvent can be used.

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

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

When the diamine component and the tetracarboxylic acid component are reacted in a solvent, the 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 after being dispersed or dissolved in the solvent. Methods, conversely, a method of adding a diamine component to a solution in which a tetracarboxylic acid component is dispersed or dissolved in a solvent, a method of alternately adding a diamine component and a tetracarboxylic acid component, and the like can be mentioned. May be used. Further, when a plurality of diamine components or tetracarboxylic acid components are used for reaction, they may be reacted in a premixed state, may be reacted individually in sequence, or may be further reacted individually as a low molecular weight compound. May be mixed and reacted to form a polymer.

The temperature at which the diamine component and the tetracarboxylic acid component are polycondensed can be selected from any temperature 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 becomes difficult to obtain a polymer having a high molecular weight, 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 reaction can be carried out at a high concentration and then 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. Similar to a normal polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the polyimide precursor produced.

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

The temperature at which the polyimide precursor is thermally imidized in a solution is 100 to 400 ° C., preferably 120 to 250 ° C., and a method is preferable in which water generated by the imidization reaction is removed from the system. The catalytic imidization 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 250 ° C., preferably 0 to 180 ° C.

The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times, the amount of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 3 times the amid acid group. It is 30 mol times.
Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has an appropriate basicity for advancing the reaction.
Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like. In particular, acetic anhydride is preferable because it facilitates purification after the reaction is completed.
The imidization rate by catalytic imidization can be controlled by adjusting the amount of catalyst, the reaction temperature, and the reaction time.

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

More specific methods for producing the polyamic acid alkyl ester of the present invention are shown in the following (1) to (3).
(1) Method for producing by esterification reaction of polyamic acid Polyamic acid is produced from a diamine component and a tetracarboxylic acid component, and a chemical reaction, that is, an esterification reaction is carried out on the carboxy group (COOH group) of the polyamic acid. A method for producing an alkyl ester.
The esterification reaction is a method in which a polyamic acid and an esterifying agent are reacted 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). be.

The esterifying agent is preferably one that can be easily removed after the esterification reaction, and is preferably N, N-dimethylformamide dimethylacetal, N, N-dimethylformamide diethylacetal, N, N-dimethylformamide dipropylacetal, N, N-dimethylformamide dineopentylbutyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriasel, 1-ethyl-3-p-tolyltriasel, 1-propyl Examples thereof include -3-p-tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazine-2-yl) -4-methylmorpholinium chloride and the like. The amount of the esterifying agent used is preferably 2 to 6 mol equivalents with respect to 1 mol of the repeating unit of the polyamic acid. Of these, 2 to 4 molar equivalents are preferred.

Examples of the solvent used for the esterification reaction include a solvent used for the reaction between the diamine component and the tetracarboxylic acid component from the viewpoint of the solubility of the polyamic acid in the solvent. Of these, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone are preferable. These solvents may be used alone or in admixture of two or more.
The concentration of the polyamic acid in the solvent in the esterification reaction is preferably 1 to 30% by mass from the viewpoint that precipitation of the polyamic acid is unlikely to occur. Of these, 5 to 20% by mass is preferable.

(2) Method for producing by reaction of diamine component and tetracarboxylic acid diester dichloride Specifically, the diamine component and tetracarboxylic acid diester dichloride are heated at −20 to 150 ° C. (preferably) in the presence of a base and a solvent. It is a method of reacting at 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. Of these, pyridine is preferable because the reaction proceeds moderately. 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 acid diester dichloride. Of these, 2 to 3 times the mole is more preferable.

Examples of the solvent include a solvent used for the reaction between the diamine component and the tetracarboxylic acid component from the viewpoint of the solubility of the obtained polymer, that is, the polyamic acid alkyl ester in the solvent. Of these, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone are preferable. These solvents may be used alone or in admixture 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 is unlikely to occur. Of these, 5 to 20% by mass is preferable. Further, in order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used for producing the polyamic acid alkyl ester is preferably dehydrated as much as possible. Further, it is preferable that the reaction is carried out in a nitrogen atmosphere to prevent contamination with outside air.

(3) Method for producing by reaction of diamine component and tetracarboxylic acid diester Specifically, the diamine component and the tetracarboxylic acid diester are heated at 0 to 150 ° C. (preferably) in the presence of a condensing agent, a base and a solvent. It is a method of polycondensation reaction at 0 to 100 ° C. for 30 minutes to 24 hours (preferably 3 to 15 hours).

Condensing agents include triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinyl. Methylmorpholinium, O- (benzotriazole-1-yl) -N, N, N', N'-tetramethyluronium tetrafluoroborate, O- (benzotriazole-1-yl) -N, N, N', N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate diphenyl and the like can be used. The amount of the condensing agent to be used is preferably 2 to 3 times mol, and particularly preferably 2 to 2.5 times mol, with respect to the tetracarboxylic acid diester.

As the base, a tertiary amine such as pyridine or triethylamine can be used. The amount of the base used is preferably an amount that can be easily removed after the polycondensation reaction, preferably 2 to 4 times by mole, more preferably 2 to 3 times by mole with respect to the diamine component.
Examples of the solvent used for the polycondensation reaction include the solvent used for the reaction between the diamine component and the tetracarboxylic acid component from the viewpoint of the solubility of the obtained polymer, that is, the polyamic acid alkyl ester in the solvent. Of these, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone are preferable. These solvents may be used alone or in combination of two or more.

Further, in the polycondensation reaction, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halide such as lithium chloride and lithium bromide is preferable. The amount of Lewis acid used is preferably 0.1 to 10 times the molar amount of the diamine component. Of these, 2.0 to 3.0 times the molar amount is preferable.

When recovering the polyamic acid alkyl ester from the polyamic acid alkyl ester solution obtained by the above methods (1) to (3), the reaction solution may be added to a solvent for precipitation. Examples of the solvent used for precipitation include water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, toluene and the like. The polymer which has been put into a solvent and precipitated is preferably washed with the above solvent a plurality of times for the purpose of removing the additives and catalysts used above. After washing, filtering and recovering, the polymer can be dried under normal pressure or reduced pressure at room temperature or by heating. Further, by repeating the operation of re-dissolving the polymer recovered by precipitation in a solvent and re-precipitating and recovering it 2 to 10 times, impurities in the polymer can be reduced.
As the polyamic acid alkyl ester, the production method of (2) or (3) above is preferable.

<Liquid crystal alignment 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 alignment agent is preferably 2 to 10% by mass, more preferably 3 to 8% by mass in the liquid crystal alignment agent.

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

The good solvent used for the liquid crystal alignment agent of the present invention is not particularly limited as long as it dissolves the specific polymer of the present invention. Specific examples of the solvent used for the liquid crystal alignment agent are given 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, dimethyl sulfoxide or 1,3-dimethyl-imidazolidinone. Will be.
When the polyimide precursor has high solvent solubility, it is represented by methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the above formulas [D-1] to [D-3]. It is also possible to use the solvent to be used.
The above-mentioned good solvent may be used alone, or may be used in a more suitable combination and ratio according to the coating method and the like.
The good solvent in the liquid crystal alignment agent of the present invention is preferably 20 to 99% by mass of the total solvent contained in the liquid crystal alignment agent. Of these, 20 to 90% by mass is preferable. More preferably, it is 30 to 80% by mass.

As the liquid crystal alignment agent of the present invention, a solvent (also referred to as a poor solvent) that improves the coating film property and surface smoothness of the liquid crystal alignment film when the liquid crystal alignment 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-Butandiol, 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-butoxyetan, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl 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-methylpentylace Tart, 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, Flufuryl Alcohol, Diethylene Glycol, Pu Lopyrene 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 Propropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetylate, 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, acetate Ethyl, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate , 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionic acid, butyl 3-methoxypropionic acid, lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-butyl ester, lactic acid isoamyl ester , Solvents represented by the above formulas [D-1] to [D-3] and the like can be mentioned.

Among them, the preferred solvent combinations are N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether, and 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, propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2 -Pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether, and the like can be mentioned. The poor solvent is preferably 1 to 80% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass, based on the total amount of the solvent contained in the liquid crystal alignment agent. The type and content of such a solvent are appropriately selected depending on the liquid crystal alignment agent coating device, coating conditions, coating environment, and the like.

In addition to the above, the liquid crystal alignment agent of the present invention includes polymers other than the polymers described in the present invention, dielectrics for the purpose of changing electrical properties such as dielectric constant and conductivity of the liquid crystal alignment film, and liquid crystal alignment films. A silane coupling agent for the purpose of improving adhesion to the substrate, a crosslinkable compound for the purpose of increasing the hardness and density of the liquid crystal alignment film, and heating of the polyimide precursor when firing the coating film. It may contain an imidization accelerator or the like for the purpose of efficiently advancing imidization by the above method.

Examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds and epoxy group-containing compounds, and examples thereof include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-. Glycydoxypropyltriethoxysilane, 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-Aminopropyltrimethoxysilane, 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-aminopropyltrimethoxysilane, 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-xylene diamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane or Examples thereof include N, N, N', N',-tetraglycidyl-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 above 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 alignment agent. If it is less than 0.1 part by mass, the effect cannot be expected, and if it exceeds 30 parts by mass, the orientation of the liquid crystal is lowered, so that it is more preferably 0.5 to 20 parts by mass.

<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 alignment agent of the present invention on a substrate and firing it.
For example, a cured film obtained by applying the liquid crystal alignment agent of the present invention to a substrate, drying it if necessary, and firing it can be used as it is as a liquid crystal alignment film. In addition, this cured film is rubbed, irradiated with polarized light or light of a specific wavelength, treated with an ion beam, etc., and a voltage is applied to the liquid crystal display element after filling the liquid crystal as a PSA alignment film. It is also possible to irradiate with UV. 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 highly transparent substrate, and is a glass plate, polycarbonate, poly (meth) acrylate, polyether sulfone, polyarylate, polyurethane, polysulphon, polyether, polyether ketone. , Trimethylpentene, polyolefin, polyethylene terephthalate, (meth) acrylonitrile, triacetyl cellulose, diacetyl cellulose, acetate butyrate cellulose and other plastic substrates can be used. Further, it is preferable to use a substrate on which an ITO electrode or the like for driving a liquid crystal display is formed from the viewpoint of simplifying the process. Further, in the reflective liquid crystal display element, an opaque object such as a silicon wafer can be used if only one side of the substrate is used, and in this case, a material that reflects light such as aluminum can also be used as the electrode.

The method for applying the liquid crystal alignment 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, spinners, and the like. 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 alignment agent by the above method can be fired to form a cured film. The drying step after applying the liquid crystal alignment agent is not always necessary, but if the time from coating to firing is not constant for each substrate, or if firing is not performed immediately after coating, a drying step is performed. Is preferable. The drying is not particularly limited as long as the solvent is removed to the extent that the shape of the coating film is not deformed by transporting the substrate or the like, and the drying means thereof is not particularly limited. For example, a method of drying on a hot plate having a temperature of 40 ° C. to 150 ° C., preferably 60 ° C. to 100 ° C. for 0.5 minutes to 30 minutes, preferably 1 minute to 5 minutes can be mentioned.

The firing 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 ° C 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. The 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.

The liquid crystal display element can produce a liquid crystal cell 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 arranged so as to face each other, a liquid crystal layer provided between the substrates, and the above-mentioned liquid crystal aligning agent provided between the substrates and the liquid crystal layer. It is a vertical alignment type liquid crystal display element including a liquid crystal cell having a liquid crystal alignment film. Specifically, a liquid crystal alignment film is formed by applying a liquid crystal alignment agent on two substrates and firing, and the two substrates are arranged so that the liquid crystal alignment films face each other, and the two substrates are arranged. It is a vertically oriented liquid crystal display element including a liquid crystal cell manufactured by sandwiching a liquid crystal layer made of liquid crystal between substrates.

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

The substrate of the liquid crystal display element is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate on which a transparent electrode for driving a liquid crystal is formed. As a specific example, the same substrate as that described in the liquid crystal alignment film can be mentioned. A conventional substrate provided with an electrode pattern or a protrusion pattern may be used, but in the PSA liquid crystal display element, since the liquid crystal alignment agent containing the polyimide-based polymer of the present invention is used, for example, one side of the substrate may be used. It is possible to operate even in a structure in which a line / slit electrode pattern of 1 to 10 μm is formed and no slit pattern or protrusion pattern is formed on the facing substrate. The liquid crystal display element having this structure simplifies the manufacturing process. And high transmittance can be obtained.

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

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element is not particularly limited, and the liquid crystal material used in the conventional vertical orientation method, for example, a negative type such as MLC-6608, MLC-6609, MLC-3023 manufactured by Merck Co., Ltd. Liquid crystal can be used. Further, in the PSA type liquid crystal display element, for example, a liquid crystal containing a polymerizable compound as 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 mentioned. For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared, and spacers such as beads are sprayed on the liquid crystal alignment film of one substrate so that the surface on the side where the liquid crystal alignment film is formed is on the inside. Another method is to bond the other substrate together and inject the liquid crystal under reduced pressure to seal it. In addition, a pair of substrates on which the liquid crystal alignment film is formed is prepared, spacers such as beads are sprayed on the liquid crystal alignment film of one substrate, liquid crystal is dropped, and then the surface on the side where the liquid crystal alignment film is formed. A liquid crystal cell can also be produced by a method in which the other substrate is bonded and sealed so that the surface is on the inside. The thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

In the process of producing a liquid crystal cell by irradiating a liquid crystal alignment film and a liquid crystal layer with an ultraviolet ray while applying a voltage, for example, an electric field is applied to the liquid crystal alignment film and the liquid crystal layer by applying a voltage between electrodes installed on a substrate. Is applied, and an ultraviolet ray is irradiated while maintaining this 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 ultraviolet rays is, for example, 1 to 60 J, preferably 40 J or less, and the smaller the irradiation amount of ultraviolet rays, the more the reliability deterioration caused by the destruction of the members constituting the liquid crystal display element can be suppressed and the ultraviolet irradiation time can be reduced. This is suitable because the manufacturing efficiency is improved.

As described above, when ultraviolet rays are applied to the liquid crystal alignment film and the liquid crystal layer while applying a voltage, the polymerizable compound reacts to form a polymer, and the direction in which the liquid crystal molecules are tilted is memorized by this 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 orienting the liquid crystal and a photoreactive side chain, and this polyimide precursor are imide. Since the polymerizable compound reacts with the photoreactive side chains of at least one polymer selected from the polyimide obtained by the conversion, or with the photoreactive side chains of the polymer, the liquid crystal display element obtained can be obtained. The response speed can be increased.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto. The abbreviations for the compounds used are as follows.
(liquid crystal)
MLC-3023 (Merck & Co., liquid crystal containing negative polymerizable compound)

(Specific side chain 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 W-A7 represented by formula [W-A6]: Formula [W-A7] Compound W-A8: Compound represented by formula [W-A8] W-A9: Compound represented by formula [WA9] W-A10: Compound represented by formula [W-A10]

(Other side chain 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: Compound represented by formula [C5] Compound C6: Compound represented by formula [C6] C7: Compound represented by formula [C7] C8: Compound represented by formula [C8] C9: Compound represented by formula [C9] C10 : Compound represented by the formula [C10]

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

(Measurement of molecular weight)
The molecular weights of the polyimide precursor and the polyimide are as follows 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). It was measured as follows.
Column temperature: 50 ° C
Eluent: N, N'-dimethylformamide (30 mmol / L (liter) of lithium bromide-hydrate (LiBr · _H2O ) as an additive, 30 mmol of phosphoric acid / anhydrous crystals (o-phosphoric acid) / L, tetrahydrofuran (THF) is 10 ml / L)
Flow velocity: 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 imidization rate of polyimide)
20 mg of polyimide powder is placed in an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku Co., Ltd.)) and deuterated dimethyl sulfoxide (DMSO-d6, 0.05 mass% TMS (tetramethylsilane)). (Mixed product) (0.53 ml) was added and ultrasonically applied to completely dissolve it. This solution was measured for proton NMR at 500 MHz with an NMR measuring machine (JNW-ECA500) (manufactured by JEOL Datum). The imidization rate is determined by using a proton derived from a structure that does not change before and after imidization as a reference proton, and the peak integrated value of this proton and the proton peak derived from the NH group of amic acid appearing in the vicinity of 9.5 to 10.0 ppm. It was calculated by the following formula using the integrated value.
Imidization rate (%) = (1-α · x / y) × 100
In the above formula, x is the integrated proton peak value derived from the NH group of amic acid, y is the integrated peak value of the reference proton, and α is one NH group proton of the amic acid in the case of polyamic acid (imidization rate is 0%). It is the number ratio of the reference protons to.

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

W-A1 to WA3 and W-A4 to WA10 are novel compounds that have not been published in the literature, and the synthetic method will be described in detail below.
The products described in Synthesis Examples 1 to 3 and Synthesis Examples 4 to 10 below were identified by ¹ H-NMR analysis (analytical conditions are as follows).
Equipment: Varian NMR System 400 NB (400 MHz).
Measuring solvent: CDCl _3, DMSO-d ₆ .
Reference substance: Tetramethylsilane (TMS) (δ0.0 ppm for ¹ H).

<< Synthesis Example 1 W-A1 synthesis >>

<Synthesis of compound [1] and compound [2]>
4,4'-Dinitro-1,1'-biphenyl-2,2'-dimethanol (41.1 g, 135 mmol) and triethylamine (31.5 g) were charged in tetrahydrofuran (165.6 g), and nitrogen atmosphere was ice-cooled. Under the conditions, methanesulfonyl chloride (33.2 g) was added dropwise and reacted 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 dissolved in tetrahydrofuran (574 g) by heating at 50 ° C., methanol (328 g) was added to precipitate crystals, and the mixture was filtered and dried to obtain compound [2] (yield: 97.9 g, yield). Rate: 89%).
^{1 1} H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6H), 0.96-1.05 ppm (m, 4H), 1.19-1.39 ppm (m, 30H), 1.80-1.85ppm (m, 8H), 2.33-2.40ppm (m, 2H), 4.77ppm (s, 4H), 6.66-6.70ppm (m, 4H), 7. 02-7.06ppm (m, 4H), 7.40ppm (d, 2H, 8.4), 8.25ppm (dd, 2H, J = 2.4Hz, J = 8.4Hz), 8.54ppm (d) , 2H, J = 2.4Hz).

<Synthesis of WA1>
Compound [2] (74.3 g, 90.9 mmol) and 3% platinum carbon (5.94 g) were charged in tetrahydrofuran (1783 g) and reacted under hydrogen atmosphere at room temperature. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated under reduced pressure to bring the total internal weight to 145 g. Subsequently, methanol (297 g) was added to the concentrated solution, and the mixture was stirred with ice and cooled, filtered and dried to obtain WA1 (yield: 59.2 g, yield: 86%).
^{1 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), 1.81-1.84ppm (m, 8H), 2.32-2.38ppm (m, 2H), 3.67ppm (s, 4H), 4.69ppm (d, 2H, J = 12.0Hz), 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 W-A2 synthesis >>

<Synthesis of compound [3]>
4,4'-Dinitro-2,2'-diphenylic acid (40.9 g, 123 mmol) and p- (trans-4-heptylcyclohexyl) phenol (72.1 g), 4-dimethyl in tetrahydrofuran (327.2 g). Aminopyridine (1.50 g) was charged, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (56.6 g) was added under nitrogen atmosphere room temperature conditions, 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 recovered by filtration. Subsequently, the crude product was washed with a slurry of methanol (245 g) and then filtered, and the obtained crude product was dissolved in tetrahydrofuran (245 g) by heating at 60 ° C. After removing the insoluble matter by filtration, the total internal weight was adjusted to 232 g by concentration under reduced pressure, and then methanol (163 g) was added to precipitate crystals, which were stirred under ice-cooled conditions, filtered, and dried to form the compound [3]. Was obtained (yield: 73.9 g, yield: 71%).
^{1 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), 1.83-1.86ppm (m, 8H), 2.41-2.47ppm (m, 2H), 6.89-6.92ppm (m, 4H), 7.17-7.20ppm (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 WA2>
Compound [3] (73.9 g, 87.4 mmol) and 5% palladium carbon (8.80 g) were charged in tetrahydrofuran (443 g) and methanol (73.9 g) and reacted under hydrogen atmosphere room temperature conditions. After completion of the reaction, palladium carbon was removed by filtration, and the total internal weight was adjusted to 171 g by concentration under reduced pressure. Subsequently, methanol (222 g) was added to the concentrated solution to precipitate crystals, and the crystals were stirred by ice-cooling, filtered, and dried to obtain WA2 (yield: 66.6 g, yield: 97%).
^{1 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 W-A3 synthesis >>

<Synthesis of compound [4] and compound [5]>
4- (Trans-4-heptylcyclohexyl) -benzoic acid (73.1 g, 242 mmol) and N, N-dimethylformamide (0.73 g) were charged in toluene (366 g), and thionyl chloride was charged under a nitrogen atmosphere of 50 ° C. (35.9 g) was added dropwise. After the dropping, the reaction was carried out 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 nitrogen atmosphere ice was added. Under cold conditions, compound [4] dissolved in tetrahydrofuran (73.1 g) was added dropwise. After completion of the dropping, the reaction temperature was set to room temperature and the reaction was carried out for 18 hours. After completion of the reaction, triethylamine hydrochloride was removed by filtration, and then concentrated under reduced pressure to obtain an oily compound. The obtained oily compound was added to pure water (1015 g) to precipitate crystals, and the crude product was recovered by filtration. Subsequently, the obtained crude product was washed with methanol (291 g) at room temperature slurry, washed with ethyl acetate (175 g) at room temperature, filtered and dried to obtain compound [5] (yield: 92.7 g, yield). Rate: 92%).
^{1 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), 1.85-1.88ppm (m, 8H), 2.46-2.52ppm (m, 2H), 5.14ppm (s, 4H), 7.23-7.26ppm (m, 4H), 7. 45ppm (d, 2H, J = 8.4Hz), 7.83-7.86ppm (m, 4H), 8.27ppm (dd, 2H, J = 2.4Hz, J = 8.4Hz), 8.47ppm (D, 2H, J = 2.4Hz).

<Synthesis of WA3>
Compound [5] (80.5 g, 92.2 mmol) and 3% platinum carbon (6.44 g) were charged in tetrahydrofuran (484 g) and methanol (161 g) and reacted under hydrogen atmosphere room temperature conditions. After completion of the reaction, platinum carbon was removed by filtration, and the solvent was removed by concentration under reduced pressure to bring the total internal weight to 96.6 g. Subsequently, methanol (322 g) was added to the concentrated solution to precipitate crystals, and the mixture was stirred with ice 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-cooled conditions, and the crystals were filtered and dried to obtain WA3. (Yield: 67.9 g, yield: 91%).
^{1 1} H-NMR (400 MHz) in CDCl ₃ : 0.87-0.91 ppm (m, 6H), 0.98-1.08 ppm (m, 4H), 1.19-1.47 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 W-A4 synthesis >>

<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 the nitrogen atmosphere was 50 ° C. Below, thionyl chloride (13.6 g, 114 mmol) was added dropwise. After the dropping, the reaction was carried out at the same temperature for 1 hour, and then the reaction solution was concentrated under reduced pressure to obtain compound [6]. Subsequently, in tetrahydrofuran (63.0 g), 4,4'-dinitro-1,1'-biphenyl-2,2'-dimethanol (12.6 g, 41.4 mmol) and triethylamine (10.9 g, 108 mmol). Was charged, and the compound [6] dissolved in tetrahydrofuran (12.6 g) was added dropwise under ice-cooled conditions in a nitrogen atmosphere. After completion of the dropping, the reaction temperature was set to room temperature and the reaction was carried out for 17 hours. After completion of the reaction, crystals were precipitated by adding a reaction solution to pure water (731 g), and after filtration, washing with pure water and washing with methanol, the crude product was recovered. Subsequently, the obtained crude product was heated and dissolved in toluene (56.0 g), hexane (112 g) was added to precipitate crystals, and the mixture was stirred under room temperature conditions, filtered, and dried to obtain the compound [7]. Obtained (yield: 17.0 g, 20.6 mmol, yield: 50%).
^{1 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), 2.19-2.25ppm (m, 2H), 4.82ppm (d, 2H, J = 13.6Hz), 4.88ppm (d, 2H, J = 13.6Hz), 7.39ppm (d, 2H) , J = 8.4Hz), 8.26ppm (dd, 2H, J = 2.4Hz, J = 8.4Hz), 8.38ppm (d, 2H, J = 2.0Hz)

<Synthesis of W-A4>
Compound [7] (17.0 g, 20.6 mmol) and 3% platinum carbon (1.36 g) were charged in tetrahydrofuran (136 g) and methanol (34.0 g), and reacted under normal temperature conditions in a hydrogen atmosphere for about 41 hours. rice field. After completion of the reaction, the total internal weight was adjusted to 40 g by filtration and concentration under reduced pressure. Subsequently, methanol (68.0 g) was added to precipitate crystals, and the crystals were filtered and dried to obtain W-A4 (yield: 15.2 g, 19.9 mmol, yield: 97%).
^{1 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), 2.14-2.20ppm (m, 2H), 3.71ppm (br, 4H), 4.73ppm (d, 2H, J = 12.4Hz), 4.78ppm (d, 2H, J = 12.4Hz) ), 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. 0Hz)

<< Synthesis Example 5 W-A5 Synthesis >>

<Synthesis of compound [8]>
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) in toluene (227 g). ), Tri-tert-butylphosphonium tetrafluoroborate (1.58 g, 5.44 mmol), bis (dibenzylideneacetone) palladium (0) (3.14 g, 5.46 mmol), and nitrogen atmosphere at room temperature. It was reacted for 17 hours. After completion of the reaction, 5.7 mol / L aqueous hydrochloric acid solution (80.0 mL) was added to precipitate crystals, and the hydrochloride salt of compound [8] was recovered by filtration. The obtained hydrochloride is dispersed in a mixed solution of toluene (300 g), ethyl acetate (200 g) and tetrahydrofuran (100 g), separated by a 3.0 mol / L sodium hydroxide aqueous solution (200 g), and further saturated the organic phase. It was washed with saline solution. Subsequently, activated carbon (brand: special Shirasagi, 2.27 g) was added to the organic phase and stirred, and then the activated carbon was removed by filtration. An oily compound was obtained by concentrating the obtained filtrate under reduced pressure. The oily compound was dispersed in hexane (100 g), crystals were precipitated under dry ice / ethanol cooling conditions, filtered, and dried to obtain compound [8] (yield: 27.5 g, 101 mmol, yield:). 75%).
^{1 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]>
4,4'-Dinitro-2,2'-diphenylic acid (14.9 g, 45.0 mmol) and compound [8] (25.8 g, 94.3 mmol) in tetrahydrofuran (120 g) and methylene chloride (60.0 g). ), 4-Dimethylaminopyridine (0.550 g, 4.50 mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (20.0 g, 104 mmol), and nitrogen atmosphere at room temperature. Reacted for time. After completion of the reaction, the reaction was diluted with ethyl acetate (375 g), the organic phase was washed 3 times with pure water (149 g), and the obtained organic phase was dehydrated with magnesium sulfate. Subsequently, the organic phase was concentrated under reduced pressure to bring the total internal weight to 112 g, and then methanol (120 g) was added to precipitate crystals, which were then filtered and dried to obtain compound [9] (yield: 28.0 g,). 33.2 mmol, yield: 74%)
^{1 1} H-NMR (400 MHz) in CDCl ₃ : 0.87 to 1.43 ppm (m, 40H), 1.82-1.84 ppm (m, 8H), 2.37-2.44 ppm (m, 2H), 7.10ppm (d, 4H, J = 8.8Hz), 7.26-7.30ppm (m, 4H), 7.40ppm (d, 2H, J = 8.4Hz), 8.27ppm (dd, 2H) , J = 2.4Hz, J = 8.4Hz), 8.53ppm (d, 2H, J = 2.4Hz), 9.10ppm (s, 2H)

<Synthesis of WA5>
Compound [9] (28.0 g, 33.2 mmol) and 5% palladium carbon (2.10 g) were charged in tetrahydrofuran (140 g) and methanol (56.0 g) and reacted under normal temperature conditions in a hydrogen atmosphere for about 3 days. rice field. After completion of the reaction, palladium carbon was removed by filtration and concentrated under reduced pressure to bring the total internal weight to 122 g. Methanol (168 g) was added to the obtained solution to precipitate crystals, and the crystals were filtered and dried to obtain WA5 (yield: 23.8 g, 30.4 mmol, yield: 92%).
^{1 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. 34-7.36ppm (m, 4H), 8.85ppm (s, 2H)

<< Synthesis Example 6 W-A6 Synthesis >>

<Synthesis of compound [10]>
4,4'-Dinitro-2,2'-diphenylic acid (25.0 g, 75.4 mmol) and cholesterol (61.7 g, 160 mmol), 4-dimethylaminopyridine in tetrahydrofuran (113 g) and methylene chloride (113 g). (0.919 g, 7.54 mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (33.6 g, 175 mmol) was charged and reacted under nitrogen atmosphere room temperature conditions for 18 hours. After completion of the reaction, methylene chloride (375 g) was added to the reaction solution, the organic phase was washed 3 times with saturated brine (200 g), and the organic phase was dehydrated with magnesium sulfate. Subsequently, the obtained solution was concentrated under reduced pressure to give a brown oily compound, and a mixed solution of ethyl acetate (200 g) and isopropyl alcohol (200 g) was added to precipitate crystals, and the mixture was filtered to obtain a crude product. The obtained crude product was recrystallized twice with 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 1} H-NMR (400 MHz) in CDCl ₃ : 0.67-2.21 ppm (m, 86H), 4.58-4.63 ppm (m, 2H), 5.31-5.33 ppm (m, 2H), 7.37-7.39ppm (m, 2H), 8.42-8.44ppm (m, 2H), 8.93ppm (m, 2H)

<Synthesis of WA6>
Compound [10] (40.4 g, 37.8 mmol) and 5% palladium carbon (3.03 g) were charged in tetrahydrofuran (320 g) and methanol (80.8 g) and reacted under hydrogen atmosphere room temperature conditions for about 3 days. rice field. After completion of the reaction, palladium carbon was removed by filtration and concentrated under reduced pressure to bring the total internal weight to 112 g. Methanol (160 g) was added to the obtained solution to precipitate crystals, and the crystals were filtered and dried to obtain WA6 (yield: 35.0 g, 34.7 mmol, yield: 92%).
^{1 1} H-NMR (400 MHz) in CDCl ₃ : 0.66-2.17 ppm (m, 86H), 3.74 ppm (br, 4H), 4.50-4.56 ppm (m, 2H), 5.28 ppm ( m, 2H), 6.78-6.80ppm (m, 2H), 6.95-6.97ppm (m, 2H), 7.26-7.28ppm (m, 2H)

<< Synthesis Example 7 W-A7 synthesis >>

<Synthesis of compound [11] and compound [12]>
4,4'-Dinitro-1,1'-biphenyl-2,2'-dimethanol (40.0 g, 132 mmol) and triethylamine (36.6 g, 362 mmol) were charged in tetrahydrofuran (152 g), and ice under a nitrogen atmosphere was charged. Ethanesulfonyl chloride (44.4 g, 345 mmol) was added dropwise under cold conditions. After completion of the dropping, the reaction temperature was stirred at 40 ° C. for 3 hours to obtain compound [11]. Subsequently, p- (trans-4-propylcyclohexyl) phenol (63.1 g, 289 mmol) dissolved in tetrahydrofuran (240 g) and potassium hydroxide (85.0% product, 45) dissolved in pure water (228 g) were added. .1 g, 683 mmol) was added to the reaction solution of compound [11], 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 crude products, which were then filtered and washed with pure water. Subsequently, the slurry was washed with a mixed solution of pure water (378 g) and methanol (378 g), and again filtered and washed with methanol. The obtained crude crystal was dissolved in tetrahydrofuran (600 g) by heating at 60 ° C., methanol (400 g) was added to precipitate crystals, and the mixture was stirred under room temperature conditions, filtered and dried to obtain the compound [12]. (Yield: 77.7 g, 110 mmol, yield: 83%).
^{1 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. 00-7.05ppm (m, 4H), 7.40ppm (d, 2H, J = 8.0Hz), 8.25ppm (dd, 2H, J = 2.0Hz, J = 8.4Hz), 8.54ppm (S, 2H).

<Synthesis of WA7>
Compound [12] (77.7 g, 110 mmol) and 3% platinum carbon (6.22 g) were charged in tetrahydrofuran (741 g) and methanol (155 g), and reacted under hydrogen atmosphere at room temperature 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) is added to the obtained concentrated crude product to dissolve it by heating at 60 ° C., acetonitrile (159 g) is added to precipitate crystals, and the mixture is stirred under room temperature conditions, filtered, and dried to obtain WA7. (Yield: 58.6 g, 88.1 mmol, yield: 80%).
^{1 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), 1.81-1.84ppm (m, 8H), 2.32-2.34ppm (m, 2H), 3.71-3.75ppm (br, 4H), 4.67-4.76ppm (q, 4H) , J = 10.0Hz), 6.61-6.64ppm (m, 2H), 6.71-6.75ppm (m, 4H), 6.91-6.92ppm (m, 2H), 6.97 -7.03 ppm (m, 6H).

<< Synthesis Example 8 W-A8 Synthesis >>

<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 under a nitrogen atmosphere was charged. Ethanesulfonyl chloride (34.8 g, 271 mmol) was added dropwise under cold conditions. After the dropping, the reaction temperature was stirred at 40 ° C. for 3 hours to obtain 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 compounded. In addition to the reaction solution of [11], 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 the solution was separated and extracted with chloroform (588 g × 4 times). The recovered organic phase was concentrated under reduced pressure, the crude product was dissolved in tetrahydrofuran (118 g) by heating at 60 ° C., methanol (235 g) was added to precipitate crystals, and the mixture was stirred under room temperature conditions and then filtered. The crystals were cake-washed with pure water / methanol = 1/1 mixed solvent (118 g) and methanol (118 g x 2 times) and dried to obtain compound [13] (yield: 67.6 g, 120 mmol, yield). : 93%).
^{1 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), 1.80-1.82ppm (m, 8H), 2.36-2.44ppm (m, 2H), 4.77ppm (s, 4H), 6.67-6.70ppm (m, 4H), 7. 03-7.06ppm (m, 4H), 7.40ppm (d, 2H, J = 8.4Hz), 8.24ppm (d, 1H, J = 2.0Hz), 8.26ppm (d, 1H, J) = 2.0Hz), 8.54ppm (d, 2H, J = 2.0Hz).

<Synthesis of WA8>
Compound [13] (65.0 g, 105 mmol) and 3% platinum carbon (5.20 g) were charged in tetrahydrofuran (325 g) and methanol (65.0 g), and reacted under hydrogen atmosphere at room temperature for about 2 days. After completion of the reaction, platinum carbon was removed by filtration and concentrated under reduced pressure. The crude product was dissolved in tetrahydrofuran (70.4 g) by heating at 60 ° C., methanol (130 g) was added to precipitate crystals, and the crystals were stirred under room temperature conditions and then filtered. The crystals were cake-washed with methanol (130 g × 2 times) and dried to obtain WA8 (yield: 54.2 g, 96.7 mmol, yield: 92%).
^{1 1} H-NMR (400 MHz) in CDCl ₃ : 1.19-1.28 ppm (m, 2H), 1.31-1.41 ppm (m, 8H), 1.70-1.73 ppm (m, 2H), 1.79-1.87ppm (m, 8H), 1.87-2.39ppm (m, 2H), 3.60-3.79ppm (br, 4H), 4.67-4.76ppm (q, 4H) , J = 9.6Hz), 6.61-6.64ppm (m, 2H), 6.72-6.75ppm (m, 4H), 6.91-6.92ppm (d, 2H, J = 2. 4 Hz), 6.97-7.03 ppm (m, 6H).

<< Synthesis Example 9 W-A9 synthesis >>

<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. Ethanesulfonyl chloride (18.6 g, 145 mmol) was added dropwise under ice-cooled conditions in a nitrogen atmosphere. After the dropping, the reaction temperature was stirred at 40 ° C. for 3 hours to obtain compound [11]. Subsequently, 4-[(trans, trans) -4'-pentyl [1,1'-bicyclohexyl] -4-yl] phenol (48.6 g, 149 mmol) and pure water (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 reacted for 20 hours. After completion of the reaction, the reaction solution was poured into pure water (800 g) to precipitate crude products, which were then filtered and washed with pure water. Subsequently, the slurry was washed with a mixed solution of pure water (100 g) and methanol (100 g), filtered again, and washed with pure water and methanol. The crude product was dissolved in tetrahydrofuran (400 g) by heating at 60 ° C., methanol (100 g) was added to precipitate crystals, and the mixture was stirred under room temperature conditions, filtered and dried to obtain compound [14] (yield: 49). .7 g, 53.9 mmol, yield: 78%).
^{1 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), 4.77ppm (s, 4H), 6.66-6.68ppm (m, 4H), 7.01-7.03ppm (m, 4H), 7.39ppm (d, 2H, J = 8.0Hz), 8.24 ppm (dd, 2H, J = 2.0 Hz, J = 8.4 Hz), 8.54 ppm (d, 2H, J = 2.4 Hz)

<Synthesis of WA9>
Compound [14] (45.1 g, 48.7 mmol) and 3% platinum carbon (3.60 g) were charged in tetrahydrofuran (361 g) and methanol (90.2 g) under a 0.4 MPa hydrogen pressure atmosphere at 40 ° C. The reaction was carried out for about 9 hours. After 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 is dissolved in tetrahydrofuran (180 g) by heating at 60 ° C., ethyl acetate (120 g) is added, and the crystals are precipitated by stirring under room temperature conditions, and then filtered and dried to obtain W. -A9 was obtained (yield: 17.8 g, 20.7 mmol, yield: 43%).
^{1 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), 3.69ppm (br, 4H), 4.70ppm (d, 2H, J = 12.4Hz), 4.76ppm (d, 2H, J = 12.4Hz), 6.62ppm (dd, 2H, J = 2) .4Hz, J = 8.0Hz), 6.71-6.73ppm (m, 4H), 6.91ppm (d, 2H, J = 2.4Hz), 6.96-6.99ppm (m, 6H)

<< Synthesis Example 10 W-A10 synthesis >>

<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. 6 g, 1.08 mol) was charged, and the mixture was stirred at 80 ° C. for 20 hours under a nitrogen atmosphere. After completion of the reaction, pure water (1440 g) is added to perform water split crystallization, and after filtration, the crystals are cake-washed with pure water (540 g x 3 times) and methanol (360 g x 2 times), and dried to form 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) was charged, substituted with nitrogen, and then stirred at 100 ° C. for about 7 days. After filtering the reaction solution to remove insoluble succinimide, ethyl acetate (250 g) was added to the filtrate, and the liquid was separated and washed with pure water (250 g × 3 times), and the organic phase was recovered and concentrated. The obtained concentrate was crystallized and filtered with ethyl acetate (346 g) and hexane (395 g), and the crystals were recovered. Further, the filtrate was concentrated, crystallized and filtered again with chloroform (223 g) and hexane (434 g), and dried to obtain a crude product of 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] dissolved in N, N-dimethylacetamide (54.0 g) was added dropwise, and the mixture was reacted for 24 hours. The crystals precipitated from the reaction solution were separated by filtration, washed with methanol (66.0 g) and pure water (67.0 g), and then filtered again and dried to obtain compound [17] (yield: 4). .23 g, 4.75 mmol, yield: 4.1% (yield based on the charged compound [15]).
^{1 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) ), 6.84-6.90ppm (m, 6H), 7.10-7.13ppm (m, 4H), 8.17ppm (dd, 2H, J = 3.2Hz, 9.0Hz), 8.38ppm (D, 2H, J = 2.8Hz).

<Synthesis of WA10>
Compound [17] (3.60 g, 4.04 mmol) and 3% platinum carbon (0.290 g) were charged in tetrahydrofuran (28.8 g) and methanol (7.5 g), and hydrogen atmosphere was 0.4 MPa under pressure. , 40 ° C. for 3 hours. After completion of the reaction, platinum carbon was removed by filtration and concentrated under reduced pressure. Crystals were precipitated by adding ethyl acetate and methanol to the crude product, stirred under room temperature conditions, filtered, and dried to obtain WA10 (yield: 2.05 g, 2.47 mmol, yield: 54). %).
^{1 1} H-NMR (400MHz) in CDCl ₃ : 0.89ppm (t, 6H, J = 6.8Hz), 0.98-1.06ppm (m, 4H), 1.18-1.44ppm (m, 30H) ), 1.83-1.86ppm (m, 8H), 2.15-2.21ppm (m, 2H), 2.36-2.42ppm (m, 2H), 3.42ppm (br, 4H), 4.09ppm (t, 4H, J = 6.0Hz), 5.00ppm (s, 4H), 6.55-6.57ppm (m, 2H), 6.70ppm (d, 2H, J = 8.8Hz) ), 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), WA1 (3.03 g, 4.00 mmol), C1 (1.73 g, 16.0 mmol) were mixed in NMP (36.2 g) and 3 at 60 ° C. After the time reaction, 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. The viscosity of this polyamic acid solution was measured and found to be 840 mPa · s.
To the obtained polyamic acid solution (20.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (4.43 g) and pyridine (1.37 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (382 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (1). The imidization 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), C1 (1.84 g, 16.0 mmol) were mixed in NMP (36.9 g) and 3 at 60 ° C. After the time reaction, D1 (1.84 g, 9.38 mmol) was added, and the reaction was carried out 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 and found to be 658 mPa · s.
To the obtained polyamic acid solution (20.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (4.38 g) and pyridine (1.36 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (382 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (2). The imidization 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), C1 (1.73 g, 16.0 mmol) were mixed in NMP (37.3 g) and 3 at 60 ° C. After the time reaction, D1 (1.84 g, 9.38 mmol) was added, and the reaction was carried out 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 and found to be 656 mPa · s.
To the obtained polyamic acid solution (20.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (4.32 g) and pyridine (1.34 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (382 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (3). The imidization 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), A1 (3.43 g, 9.0 mmol) NMP (41.1 g) After dissolving in and 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), and 25 ° C. The reaction was carried out for 10 hours to obtain a polyamic acid solution.
NMP is 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) are added as imidization catalysts, and the mixture is reacted at 60 ° C. for 3 hours. rice field. This reaction solution was put into methanol (700 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (4). The imidization 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) were 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 content concentration of 20% by mass. The viscosity of this polyamic acid solution was measured and found to be 680 mPa · s.
To the obtained polyamic acid solution (20.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (4.64 g) and pyridine (1.44 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (382 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (R1). The imidization 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), W-A4 (4.62 g, 6.00 mmol) and C1 (1.51 g, 14.0 mmol) were mixed in NMP (24.5 g) and 3 at 60 ° C. After the time reaction, 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 and found to be 783 mPa · s.
To the obtained polyamic acid solution (20.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (3.86 g) and pyridine (1.20 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (233 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (5). The imidization 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 3 at 60 ° C. After the time reaction, 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 and found to be 769 mPa · s.
To the obtained polyamic acid solution (20.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (3.83 g) and pyridine (1.19 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (232 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (6). The imidization 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), WA6 (5.05 g, 5.00 mmol) and C1 (4.87 g, 45.0 mmol) were mixed in NMP (62.0 g) and 3 at 60 ° C. After the time reaction, D1 (4.51 g, 23.0 mmol) was added, and the reaction was carried out 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 and found to be 658 mPa · s.
To the obtained polyamic acid solution (75.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (18.2 g) and pyridine (5.6 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (1000 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (7). The imidization 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), WA7 (8.06 g, 12.5 mmol) and C1 (4.06 g, 37.5 mmol) were mixed in NMP (69.2 g) and 3 at 60 ° C. After the time reaction, 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 content concentration of 20% by mass. The viscosity of this polyamic acid solution was measured and found to be 725 mPa · s.
To the obtained polyamic acid solution (75.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (16.5 g) and pyridine (5.1 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (1000 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (8). The imidization 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), WA8 (7.01 g, 12.5 mmol), C1 (4.06 g, 37.5 mmol) were mixed in NMP (66.1 g) and 3 at 60 ° C. After the time reaction, 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 content concentration of 20% by mass. The viscosity of this polyamic acid solution was measured and found to be 674 mPa · s.
To the obtained polyamic acid solution (75.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (17.2 g) and pyridine (5.3 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (1000 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (9). The imidization 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), WA9 (2.16 g, 2.5 mmol) and C1 (5.14 g, 47.5 mmol) were mixed in NMP (54.8 g) and 3 at 60 ° C. After the time reaction, D1 (4.71 g, 24.0 mmol) was added, and the reaction was carried out 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 and found to be 823 mPa · s.
To the obtained polyamic acid solution (75.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (20.7 g) and pyridine (6.4 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (1000 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (10). The imidization 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) and 3 at 60 ° C. After the time reaction, D1 (1.84 g, 9.40 mmol) was added, and the reaction was carried out 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 and found to be 695 mPa · s.
To the obtained polyamic acid solution (20.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (4.35 g) and pyridine (1.35 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (235 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (11). The imidization 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), 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. The viscosity of this polyamic acid solution was measured and found to be 721 mPa · s.
To the obtained polyamic acid solution (100 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (16.0 g) and pyridine (4.96 g) were added as imidization catalysts, and the temperature was 80 ° C. for 3 hours. It was reacted. This reaction solution was put into methanol (1150 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (12). The imidization 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) was mixed in NMP (471 g) and reacted at 60 ° C. for 3 hours, then D1 (18.8 g, 96.0 mmol) was added and reacted at 40 ° C. for 3 hours, and the resin solid content concentration was 20. A mass% polyamic acid solution was obtained. The viscosity of this polyamic acid solution was measured and found to be 771 mPa · s.
To the obtained polyamic acid solution (100 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (14.9 g) and pyridine (4.63 g) were added as imidization catalysts, and the temperature was 80 ° C. for 3 hours. It was reacted. This reaction solution was put into methanol (1150 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 60 ° C. to obtain a polyimide powder (13). The imidization 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 reacted at 40 ° C. for 3 hours, and the resin solid content concentration was 20. A mass% polyamic acid solution was obtained. The viscosity of this polyamic acid solution was measured and found to be 701 mPa · s.
To the obtained polyamic acid solution (100 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (16.0 g) and pyridine (4.97 g) were added as imidization catalysts, and the temperature was 80 ° C. for 3 hours. It was reacted. This reaction solution was put into methanol (1150 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 60 ° C. to obtain a polyimide powder (14). The imidization 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) was mixed 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. The viscosity of this polyamic acid solution was measured and found to be 662 mPa · s.
To the obtained polyamic acid solution (100 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (17.9 g) and pyridine (5.55 g) were added as imidization catalysts, and the temperature was 100 ° C. for 3 hours. It was reacted. This reaction solution was put into methanol (1160 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 60 ° C. to obtain a polyimide powder (15). The imidization 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), reacted at 60 ° C. for 3 hours, and then D5 (23.6 g, 60.0 mmol). 14.3 g, 40.0 mmol), followed by D1 (11.0 g, 56.0 mmol) and NMP (100 g) were added and reacted at 25 ° C. for 10 hours to obtain a polyamic acid solution.
NMP is 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) are added as imidization catalysts, and the mixture is reacted at 80 ° C. for 3 hours. rice field. This reaction solution was put into methanol (1170 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (16). The imidization ratio of this polyimide was 75.8%, the number average molecular weight was 14679, and the weight average molecular weight was 35747.

[Synthesis Example 17]
D2 (25.0 g, 100 mmol), C6 (50.0 g, 120 mmol), C9 (15.1 g, 60.0 mmol) and WA1 (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 prepare a polyamic acid solution having a resin solid content concentration of 20% by mass. Got The viscosity of this polyamic acid solution was measured and found to be 753 mPa · s.
NMP is 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) are added as imidization catalysts, and the mixture is reacted at 80 ° C. for 3 hours. rice field. This reaction solution was put into methanol (1160 ml), and the obtained precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 60 ° C. to obtain a polyimide powder (17). The imidization 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 content concentration of 20% by mass. The viscosity of this polyamic acid solution was measured and found to be 338 mPa · s.
To the obtained polyamic acid solution (75.0 g), NMP was added and diluted to 6.5% by mass, acetic anhydride (15.0 g) and pyridine (4.6 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (1000 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (R2). The imidization 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) were 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 content concentration of 20% by mass. The viscosity of this polyamic acid solution was measured and found to be 446 mPa · s.
To the obtained polyamic acid solution (75.0 g), NMP was added and diluted to 6.5% by mass, then acetic anhydride (18.3 g) and pyridine (5.7 g) were added as imidization catalysts, and the temperature was 80 ° C. The reaction was carried out for 3 hours. This reaction solution was put into methanol (1000 ml), and the obtained precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide powder (R3). The imidization 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 synthetic example and the comparative synthetic example.

<Preparation of liquid crystal alignment treatment agent>
Examples and Comparative Examples describe preparation examples of the liquid crystal alignment treatment agent. Using the liquid crystal alignment treatment agents obtained in Examples and Comparative Examples, liquid crystal display elements were manufactured 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 stirred at 70 ° C. for 24 hours to dissolve. 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 treatment 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 uniform.

<Example 2> and <Example 3>
In Example 1, the polyimide powders (2) and (3) were used instead of the polyimide powder (1), and the liquid crystal alignment treatment agents (V-2) and (V-3) were used in the same procedure as in Example 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 uniform.

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

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

<Example 5> to <Example 6>
In Example 4, a liquid crystal alignment treatment agent (V-2) or (V-3) was used instead of the liquid crystal alignment treatment agent (V-1) as the first component, and the procedure was the same as in Example 4, respectively. Liquid crystal alignment treatment 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 to prepare a liquid crystal alignment treatment agent (38.0 g). 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 uniform.
Using the obtained liquid crystal alignment treatment agent (R-V1), a liquid crystal display element was manufactured, vertical orientation was evaluated, pretilt angle was evaluated, voltage retention was evaluated, and afterimage characteristics were evaluated.

<Example 7>
NMP (22.0 g) was added to the polyimide powder (5) (3.00 g) obtained in Synthesis Example 5 and stirred at 70 ° C. for 24 hours to dissolve. 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 treatment agent (V-8). No abnormality such as turbidity or precipitation was observed in this liquid crystal alignment treatment agent, and it was confirmed that the solution was uniform.

<Examples 8 to 13, 15 to 17, 19, 20, Comparative Examples 2 to 4>
Polyimide powders (6) to (11), (13) to (13) to obtained in Synthesis Examples 6 to 11, 13 to 15, 17, 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 stirred at 70 ° C. for 24 hours to dissolve. NEP (3.0 g) and BCS (20.0 g) were added to this solution, and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal alignment treatment agent (V-15). No abnormality such as turbidity or precipitation was observed in this liquid crystal alignment treatment agent, and it was confirmed that the solution was uniform.

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

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

<Examples 22 to 24>
Regarding the liquid crystal alignment treatment agents (V-16) to (V-21) obtained in Examples 15 to 20, the liquid crystal alignment treatment agents (W-3) to (W-5) are obtained by the same operation as in Example 21. rice field.

Using the liquid crystal alignment treatment agent obtained in the examples and the liquid crystal alignment treatment agent obtained in the comparative example, fabrication of a liquid crystal display element, evaluation of vertical orientation, scratch test, evaluation of pretilt angle, evaluation of voltage retention rate. , Afterimage characteristics were evaluated.

<Manufacturing of liquid crystal display element for voltage retention measurement>
The liquid crystal alignment treatment agent obtained in Examples and the liquid crystal alignment treatment agent obtained in Comparative Examples were pressure-filtered with a membrane filter having a pore diameter of 1 μm. The obtained solution was spin-coated on the ITO surface of 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 circulation type clean oven at 230 ° C. for 30 minutes to obtain an ITO substrate with a liquid crystal alignment film having a film thickness of 100 nm. Two ITO substrates with the obtained liquid crystal alignment film were prepared, and a bead spacer having a diameter of 4 μm (manufactured by JGC Catalysts and Chemicals Co., Ltd., silk ball, SW-D1) was applied to the liquid crystal alignment film surface of one of the substrates.
Next, the periphery was coated with a sealing agent (XN-1500T manufactured by Mitsui Chemicals). Next, the surface of the other substrate on which the liquid crystal alignment film was formed was turned inside, and after laminating with the previous substrate, the sealing material was cured to create an empty cell. A liquid crystal MLC-3023 (trade name manufactured by Merck & Co., Inc.) was injected into this empty cell by a vacuum injection method to prepare a liquid crystal cell.
Then, with a DC voltage of 15 V applied to the obtained liquid crystal cell, an ultraviolet irradiation device using a high-pressure mercury lamp as a light source was used to irradiate 15 J / cm ² of ultraviolet rays through a bandpass filter having a wavelength of 365 nm. A vertically oriented liquid crystal display element was obtained. For the measurement of the ultraviolet irradiation amount, a UV-35 receiver was connected to the UV-M03A manufactured by ORC.

<Manufacturing of liquid crystal display element for pre-tilt angle and afterimage evaluation>
The liquid crystal alignment treatment agent obtained in the examples was pressure-filtered 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 having an ITO electrode pattern having a pixel size of 200 μm × 600 μm and a line / space of 3 μm was formed (length: 35 mm, width: 30 mm). , Thickness: 0.7 mm) and a glass substrate with an ITO electrode (length: 35 mm, width: 30 mm, thickness: 0.7 mm) in which a photospacer with a height of 3.2 μm is patterned, respectively, on the ITO surface. It was spin-coated and heat-treated at 70 ° C. for 90 seconds on a hot plate and at 230 ° C. for 30 minutes in a heat-circulating clean oven to obtain an ITO substrate with a liquid crystal alignment film having a film thickness of 100 nm.
The ITO electrode substrate on which this ITO electrode pattern is formed is divided into four in a cross checker (checkerboard) pattern, and can be driven separately in each of the four areas.
Next, the periphery was coated with a sealing agent (XN-1500T manufactured by Mitsui Chemicals). Next, the surface of the other substrate on which the liquid crystal alignment film was formed was turned inside, and after laminating with the previous substrate, the sealing material was cured to create an empty cell. A liquid crystal MLC-3023 (trade name manufactured by Merck & Co., Inc.) was injected into this empty cell by a vacuum injection method to prepare a liquid crystal cell.
After that, a DC voltage of 15 V was applied to the obtained liquid crystal cell, and the band pass filter having a wavelength of 365 nm was passed through an ultraviolet irradiation device using a high-pressure mercury lamp as a light source in a state where all the pixel areas were driven. A vertically oriented liquid crystal display element was obtained by irradiating with ultraviolet rays at 10 J / cm ² . For the measurement of the ultraviolet irradiation amount, a UV-35 receiver was connected to the UV-M03A manufactured by ORC.
Further, in Examples 1 to 3 and Comparative Example 1, in addition to the above standard conditions, vertical alignment is performed under the same conditions as above, except that a liquid crystal alignment film is formed by heat treatment at 230 ° C. for 120 minutes as a harsh condition. A type liquid crystal display element was created.

<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), and it was confirmed whether or not the liquid crystal was vertically oriented. Specifically, those in which no defects due to liquid crystal flow or bright spots due to orientation defects were observed were considered good. The evaluation results are shown in Table 2.

(Voltage retention rate)
After applying a voltage of 1V to the liquid crystal display element for voltage retention evaluation manufactured above at an application time of 60 microseconds and an interval of 1667 ms, the voltage retention rate (%) 1667 ms after the application is released. Was measured. The measuring device used was VHR-1 manufactured by Toyo Corporation. The evaluation results are shown in Table 2.

(Pre-tilt angle)
Using an LCD analyzer (LCA-LUV42A manufactured by Meiryo Technica), measurements were made on the liquid crystal display element for pre-tilt angle evaluation manufactured above, in which no defect due to the flow of liquid crystal was observed. .. The evaluation results are shown in Table 2.

(Afterimage characteristics)
Using the liquid crystal display element for afterimage evaluation produced above, an AC voltage of 60 Hz and 20 Vpp was applied to two diagonal areas out of the four pixel areas, and the mixture was driven at a temperature of 23 ° C. for 168 hours. After that, all four pixel areas were driven by an AC voltage of 5 Vp-p, and the difference in the brightness of the pixels was visually observed. The condition in which the difference in brightness could hardly be confirmed was considered good. The evaluation results are shown in Table 3.

(Scratch test)
A scratch test was performed on the alignment film surface of the polyimide coated substrate obtained in the examples using UMT-2 (manufactured by Bruker AXS Co., Ltd.).
FVL was selected for the UMT-2 sensor, and a 1.6 mm sapphire ball was attached to the tip of the scratch portion.
A scratch test was performed in a state where the tip of the scratch portion was in contact with the surface of the liquid crystal alignment film with a load of 1 mN, and the load was changed from 1 mN to 20 mN over a range of 0.5 mm in width and 2.0 mm in length over 100 seconds. At this time, the moving direction of the tip of the scratch portion was a lateral reciprocation, and the moving speed was 5.0 mm / sec. The scratch area was moved in the vertical direction by moving the substrate 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 & Co., Inc.) was dropped onto the surface of the liquid crystal alignment film that had been scratch-tested. A 4 μm spacer was sprayed on another substrate with a liquid crystal alignment film obtained in Example 1 and superposed on the substrate so that the liquid crystal alignment film surfaces faced each other, and the dropped MLC-3022 was sandwiched therein.
With the polarization axes of the upper and lower polarizing plates of the polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) set to 90 ° (cross Nicol), observe the scratch test and see if light is transmitted. Observed. For the parts where the scratch test was performed, the state where no bright spots or light omissions were seen was marked with ○, the state where slight bright spots or light leaks were seen was marked with △, and the state where the entire scratched spot was marked with light spots was marked with ×. It is shown in Table 6.

As a result of the above, 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 element using the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention is It was found that the pretilt angle did not change even under harsh conditions, and the liquid crystal orientation was good.
Further, as shown in Table 5, it was found that the afterimage characteristics were good in Examples 4 to 6 in which the liquid crystal alignment treatment agent (V-4) was mixed.
Furthermore, from this example, it was found that the liquid crystal alignment film obtained by using a specific side chain diamine is excellent in the stability of the pretilt angle even when fired under harsh conditions. It was also confirmed that even when there is physical contact with the liquid crystal alignment film as in the scratch test, there is little damage to the alignment film and good vertical alignment can be maintained.

A liquid crystal display element using a liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention can be suitably used for a liquid crystal display element. These elements are also useful in liquid crystal displays for display purposes, as well as in dimming windows and optical shutters that control the transmission and blocking of light.

Claims (9)

A liquid crystal containing at least one polymer selected from a polyimide precursor which is a reaction product of a diamine-containing diamine component represented by the following formula [1] and a tetracarboxylic acid component and a polyimide which is an imidized product thereof. Aligning agent:
In formula [1], X is a single bond, -O-, -C (CH ₃ ) _2- , -NH-, -CO-,-(CH ₂ ) _m- , -SO _2- , and any of them. Represents a divalent organic group consisting of a combination of, m represents an integer of 1 to 8, and Y independently represents the structure of the following formula [1-1];
In the formula [1-1], Y ¹ and Y ³ are independently single-bonded,-(CH ₂ ) _a- (a is an integer of 1 to 15), -O-, and -CH ₂ O-. , -CONH-, -NHCO-, -COO- and -OCO- show at least one selected from the group;
Y ² indicates a single bond or-(CH ₂ ) _b- (b is an integer from 1 to 15) (where Y ¹ or Y ³ is a single bond,-(CH ₂ ) _a- , then Y ² is a single bond, is Y ¹ at least one selected from the group consisting of -O-, -CH ₂ O-, -CONH-, -NHCO-, -COO- and -OCO-, and / Or if Y ³ is at least one selected from the group consisting of -O-, -CH ₂ O-, -CONH-, -NHCO-, -COO- and -OCO-, then Y ² is a single bond or-( CH ₂ ) _b- (where Y ¹ is -CONH-, it is a Y ² and Y ³ single bond);
Y4 represents at least one ^divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle, or a divalent organic group having a steroid skeleton and a tocophenol skeleton and having 17 to 51 carbon atoms. Any 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. Alternatively, it 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 and 1 carbon atom. It may be substituted with an alkoxy group having 3 to 3, 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. Shows at least one species selected from the group consisting of groups;
n represents an integer from 0 to 4.

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

The liquid crystal alignment agent according to claim 1, wherein 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.

The diamine represented by the above formula [1] is the following formula [1] -a1-1, the following formula [1] -a2-1 to the following formula [1] -a2-4, the following formula [1] -a3-. 1 or the liquid crystal alignment agent according to claim 1 represented by the following formula [1] -a3-2.

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

The diamine component further contains a diamine represented by the following formula [2] (in the formula [2], A ₁ and A ₂ are independently hydrogen atoms or alkyl groups 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 alignment agent according to any one of claims 1 to 5.

A liquid crystal alignment film formed by using the liquid crystal alignment agent according to any one of claims 1 to 6. A step of applying the liquid crystal alignment agent according to any one of claims 1 to 6 onto a substrate to form a coating film;
A step of firing the coating film; and a step of orienting the film obtained by firing;
A method for producing a liquid crystal alignment film, which forms a liquid crystal alignment film. A liquid crystal display element comprising the liquid crystal alignment film according to claim 7; or the liquid crystal alignment film obtained by the manufacturing method according to claim 8.