WO2010092989A1 - Tetracarboxylic acid derivatives, processes for producing same, and liquid-crystal alignment material - Google Patents

Abstract

A novel tetracarboxylic acid dialkyl ester including a cyclobutane ring having an alkyl group thereon; a novel bis(chlorocarbonyl) compound obtained by chlorinating the ester; and processes for producing the compounds.  Furthermore provided is a process for producing specific isomers of these. The tetracarboxylic acid dialkyl ester is represented by formula [1] or [2]. (In the formulae, R1 is a C1-5 alkyl, R2 is a C1-5 alkyl, and n is 1-4.)

Description

Tetracarboxylic acid derivative, method for producing the same, and liquid crystal aligning agent

The present invention relates to a novel tetracarboxylic acid dialkyl ester, a bis (chlorocarbonyl) compound obtained by chlorinating the same, a production method thereof, and a liquid crystal aligning agent containing polyamic acid and / or polyimide using these compounds as raw materials.

Tetracarboxylic acid dialkyl esters and tetracarboxylic acid derivatives such as chlorinated bis (chlorocarbonyl) compounds are important substances that serve as raw materials for polyamide, polyester, polyimide, and the like.
For example, as a synthesis example of a polyimide having a cyclobutane skeleton in the main chain, bis (chlorocarbonyl) cyclobutanedicarboxylic acid dimethyl ester and diamine are reacted to obtain polyamic acid methyl ester, and then heated to obtain a polyimide. Examples have been reported (see Non-Patent Document 1).
However, for cyclobutanetetracarboxylic acids having a substituent on the cyclobutane ring, there are no reports of synthesizing tetracarboxylic acid dialkyl esters and bis (chlorocarbonyl) compounds obtained by chlorinating them.
On the other hand, resins such as polyimide are widely used as electronic materials such as protective materials, insulating materials, and color filters in liquid crystal display elements and semiconductors because of their high mechanical strength, heat resistance, insulation, and solvent resistance. In recent years, applications as optical communication materials such as optical waveguide materials are also expected. In recent years, resins used in such fields are increasingly required to have more advanced characteristics and quality, and the structure and quality of monomers used as raw materials for these resins are higher than ever. Has become important.
On the other hand, a liquid crystal display element used for a liquid crystal television, a liquid crystal display or the like is usually provided with a liquid crystal alignment film for controlling the alignment state of the liquid crystal in the element.
According to the most widespread industrial method, this liquid crystal alignment film is a so-called rubbing method in which the surface of a polyimide film formed on an electrode substrate is rubbed in one direction with a cloth such as cotton, nylon or polyester. It is produced by processing.
The method of rubbing the polyimide film is an industrially useful method that is simple and excellent in productivity. However, demands for higher performance, higher definition, and larger size of liquid crystal display elements are increasing, and scratches on the alignment film surface caused by rubbing, dust generation, the effects of mechanical force and static electricity, and the surface of alignment processing Various problems such as internal uniformity have become apparent.
As means for replacing the rubbing treatment, a photo-alignment method is known in which liquid crystal alignment ability is imparted by irradiating polarized radiation. As a mechanism of liquid crystal alignment by the photo-alignment method, one utilizing a photoisomerization reaction, one utilizing a photocrosslinking reaction, one utilizing a photolysis reaction, and the like have been proposed (see Non-Patent Document 2).
Patent Document 1 proposes that a polyimide having an alicyclic structure such as a cyclobutane ring in the main chain is used for the photo-alignment method. When used for an alignment film for photo-alignment using polyimide, its usefulness is expected because it has higher heat resistance than others.
The photo-alignment method as described above is advantageous in that it can be produced industrially by a simple manufacturing process as a rubbing-less alignment treatment method, and has attracted attention as a new liquid crystal alignment treatment method. However, there are problems in the alignment regulating power of liquid crystals, electrical characteristics as liquid crystal display elements, stability of these characteristics, and the like, and in general, they have not been put into practical use.
That is, the liquid crystal alignment film subjected to the alignment treatment by the rubbing method has high anisotropy with respect to the rubbing direction because the polymer chain is stretched by physical force. The higher the anisotropy, the higher the liquid crystal alignment regulating power. On the other hand, the liquid crystal alignment film obtained by the photo-alignment method has a problem that the anisotropy with respect to the alignment treatment direction of the polymer film is smaller than that by rubbing.

JP-A-9-297313

The present invention relates to a novel tetracarboxylic acid dialkyl ester having an alkyl group on a cyclobutane ring, a novel bis (chlorocarbonyl) compound obtained by chlorinating the same, a production method thereof, and production of these specific isomers It aims to provide a method.
Another object of the present invention is to provide a liquid crystal aligning agent containing polyamic acid and / or polyimide using the bis (chlorocarbonyl) compound as a raw material.

This invention solves said subject and has the following summaries.
1. Tetracarboxylic acid dialkyl ester represented by the following formula [1] or formula [2].

(Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
2. 2. The tetracarboxylic acid dialkyl ester according to 1 above, which is represented by the following formula [1-a], formula [2-a] or formula [2-b].

(Wherein R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² represents an alkyl group having 1 to 5 carbon atoms)
3. A bis (chlorocarbonyl) compound represented by the following formula [3] or formula [4].

(Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
4). 4. The bis (chlorocarbonyl) compound according to 3 above, represented by the following formula [3-a], formula [4-a] or formula [4-b].

(Wherein R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² represents an alkyl group having 1 to 5 carbon atoms)
5). A process for producing a tetracarboxylic acid dialkyl ester represented by the above formula [1] or formula [2], wherein a tetracarboxylic dianhydride represented by the following formula [5] is reacted with an alcohol having 1 to 5 carbon atoms. .

(Wherein R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
6). A tetracarboxylic dianhydride represented by the following formula [5-a] is reacted with an alcohol having 1 to 5 carbon atoms, and the tetracarboxylic acid represented by the above formula [1-a] or [2-a] is reacted. Method for producing acid dialkyl ester.

(Wherein R ² represents an alkyl group having 1 to 5 carbon atoms)
7). A process for producing a tetracarboxylic acid dialkyl ester represented by the above formula [2-b], wherein a tetracarboxylic dianhydride represented by the following formula [5-b] is reacted with an alcohol having 1 to 5 carbon atoms.

(Wherein R ² represents an alkyl group having 1 to 5 carbon atoms)
8). 8. The production method according to any one of 5 to 7 above, wherein the tetracarboxylic dianhydride and the alcohol having 1 to 5 carbon atoms are reacted in the presence of an acidic compound or a basic compound.
9. 8. The production method according to any of 5 to 7, wherein tetracarboxylic dianhydride and an alcohol having 1 to 5 carbon atoms are reacted in the presence of a basic compound.
10. Production of a bis (chlorocarbonyl) compound represented by the above formula [3] or formula [4], wherein a tetracarboxylic acid dialkyl ester represented by the formula [1] or formula [2] is reacted with a chlorinating agent. Method.
11. A process for producing a bis (chlorocarbonyl) compound represented by the above formula [3-a], wherein a tetracarboxylic acid dialkyl ester represented by the formula [1-a] is reacted with a chlorinating agent.
12 A process for producing a bis (chlorocarbonyl) compound represented by the formula [4-a], wherein a tetracarboxylic acid dialkyl ester represented by the formula [2-a] is reacted with a chlorinating agent.
13. A process for producing a bis (chlorocarbonyl) compound represented by the formula [4-b], wherein a tetracarboxylic acid dialkyl ester represented by the formula [2-b] is reacted with a chlorinating agent.
14 14. The production method according to any one of 10 to 13 above, wherein the tetracarboxylic acid dialkyl ester and the chlorinating agent are reacted in the presence of a basic compound.
15. 14. The production method according to any one of 10 to 13, wherein a tetracarboxylic acid dialkyl ester and a chlorinating agent are reacted in the presence of pyridine.
16. A bis (chlorocarbonyl) compound containing 60 mol% or more of an acid chloride represented by the following formula (101) in which a chlorocarbonyl group is bonded to the 1,3-position and an alkyl ester group is bonded to the 2,4-position of the cyclobutane ring; A liquid crystal aligning agent characterized by containing a polyamic acid ester obtained by reacting.

(Wherein R ₁ represents an alkyl group having 1 to 5 carbon atoms, R ₂ , R ₃ , R ₄ , and R ₅ represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, which may be the same or different. May be.)
17. 17. The liquid crystal aligning agent according to 16 above, wherein the acid chloride has a structure represented by the following formula (102).

(In the formula, R ₁ represents an alkyl group having 1 to 5 carbon atoms, and R ₆ represents a monovalent hydrocarbon group having 1 to 30 carbon atoms.)
18. 17. The liquid crystal aligning agent according to 16 above, wherein the acid chloride has a structure represented by the following formula (103).

(In the formula, R ₁ represents an alkyl group having 1 to 5 carbon atoms.)
19. 20. A liquid crystal alignment film obtained by irradiating a film obtained by applying and baking the liquid crystal aligning agent according to any one of 16 to 19 above with polarized radiation.
20. 20. A method for producing a liquid crystal alignment film, wherein a film obtained by applying and baking the liquid crystal aligning agent according to any one of 16 to 19 is irradiated with polarized radiation.

According to the present invention, a novel tetracarboxylic acid dialkyl ester having an alkyl group on the cyclobutane ring and a novel bis (chlorocarbonyl) compound having an alkyl group on the cyclobutane ring can be obtained. Furthermore, these specific isomers can be produced efficiently.
The liquid crystal aligning agent according to the present invention does not undergo a decomposition reaction of the polymer chain at the time of heating imidization, and a highly ordered polymer film is obtained. A liquid crystal alignment film having properties can be obtained.
Furthermore, the liquid crystal alignment film according to the present invention is stable against the external environment such as temperature and humidity, and has a high voltage holding ratio and a low ion density at a high temperature when it is used as a liquid crystal display device. A liquid crystal display element having display characteristics can be obtained.

It is an ORTEP figure of the single crystal X-ray analysis result of a compound (1-1). FIG. 5 is an ORTEP diagram of the single crystal X-ray analysis result of the compound (2-1).

[Tetracarboxylic acid dialkyl ester]
The tetracarboxylic acid dialkyl ester of the present invention is a compound represented by the following general formula [1] or [2].

(Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
R ¹ is an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, and a tertiary butyl group. And a normal pentyl group. In addition, when synthesizing a polyamic acid ester from the tetracarboxylic acid dialkyl ester of the present invention and then imidizing it, it is preferable that R ¹ has a small number of carbon atoms and is easily released, more preferably a methyl group. It is.
R ² is an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, and a tertiary butyl group. And a normal pentyl group.
n represents 1 to 4, and is preferably 2.

Specific examples of the tetracarboxylic acid dialkyl ester of the present invention when R ² is a methyl group and n is ² are shown below, but the tetracarboxylic acid dialkyl ester of the present invention is not limited thereto. . In the following table, a1 to a4 and b1 to b4 represent the respective positions shown in the following formula [6], and the symbols in the table have the following meanings, respectively.
Me: methyl group, Et: ethyl group, Pr-n: normal propyl group, Pr-iso: isopropyl group, Bu-n: normal butyl group, Bu-sec: secondary butyl group, Bu-iso: isobutyl group, Bu- t: tertiary butyl group, Pen-n: normal pentyl group, OMe: methoxy group, OEt: ethoxy group, OPr-n: normal propyl ether group, OPr-iso: isopropyl ether group, OBu-n: normal butoxy group, OBu-sec: secondary butoxy group, OBu-iso: isobutoxy group, OBu-t: tertiary butoxy group, OPen-n: normal pentyl ether group

In the case of a compound in which n is 2, and R ² is an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, a tertiary butyl group, or a normal pentyl group, Examples are compounds in which Me in b1 to b4 in the table is replaced with Et, Pr-n, Pr-iso, Bu-n, Bu-sec, Bu-iso, Bu-t, or Pen-n, respectively.
In the tetracarboxylic acid dialkyl ester of the present invention, particularly preferred compounds from the viewpoint of the ease of synthesis and yield of the compounds are represented by the following formulas [1-a], [2-a], or [2-b]. It is a compound.

Furthermore, when a high-purity product of [1-a] is used, it is higher in molecular weight and lower than a polymer using a high-purity product of [2-a] or a mixture of [1-a] and [2-a]. Since it is possible to obtain a dispersed polymer, a tetracarboxylic acid dialkyl ester represented by [1-a] is preferable from the viewpoint of obtaining a high molecular weight and low dispersion polymer.
The tetracarboxylic acid dialkyl ester of the present invention is produced by reacting tetracarboxylic dianhydride [5] with an alcohol having 1 to 5 carbon atoms represented by R ¹ OH as shown in the following reaction formula. can do.

(Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n is 1 to 4)
The above reaction can be carried out in the corresponding alcohol (R ¹ OH), and a solvent can be used if necessary. The solvent is not particularly limited as long as it is inert to the reaction. For example, hydrocarbons such as hexane, heptane or toluene, halogenated hydrocarbons such as chloroform, 1,2-dichloroethane or chlorobenzene, diethyl ether or Examples include ethers such as 1,4-dioxane, esters such as ethyl acetate, ketones such as acetone or methyl ethyl ketone, nitriles such as acetonitrile or propionitrile, and mixtures thereof. Preferably, ethyl acetate or acetonitrile is mentioned, More preferably, it is acetonitrile.

The alcohol (R ¹ OH) is generally used in an amount of 2 to 100 times mol, preferably 2 to 40 times mol, more preferably 2 to 20 times mol, relative to the tetracarboxylic dianhydride [5].
The above reaction proceeds under neutral conditions, but a base or acid may be added. The base or acid is not particularly limited.
Examples of the base include inorganic bases such as sodium hydroxide, potassium hydroxide, potassium carbonate or sodium hydrogen carbonate, triethylamine, pyridine, quinoline, 8-quinolinol, 1,10-phenanthroline, bathophenanthroline, bathocuproine, 2 , 2′-bipyridyl, 2-phenylpyridine, 2,6-diphenylaminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2- (2-hydroxylethyl) pyridine, N, N-dimethylaniline, 1, Organic bases such as 8-diazabicyclo [5,4,0] -7-undene (DBU), and metal alkoxides such as sodium methoxide, potassium methoxide or potassium t-butoxide. Preferably, sodium methoxide, potassium methoxide, or pyridine is used. More preferably, pyridine is mentioned.
Acids include heteropolyacids such as phosphomolybdic acid and phosphotungstic acid, organic acids such as trimethylborate and triphenylphosphine, inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, hydrocarbons such as formic acid, acetic acid and p-toluenesulfonic acid Examples include acids and halogen-based hydrocarbon acids such as trifluoroacetic acid. Preferably, p-toluenesulfonic acid, phosphoric acid, or acetic acid is used. More preferred is p-toluenesulfonic acid.
The base or acid is usually used in an amount of 0 to 100-fold mol, preferably 0.01 to 10-fold mol based on tetracarboxylic dianhydride [5].
The reaction temperature is not particularly limited but is, for example, −90 to 200 ° C., preferably −30 to 100 ° C.
The reaction time is usually 0.05 to 200 hours, preferably 0.5 to 100 hours.

Among the tetracarboxylic acid dialkyl esters of the present invention in which n is 2 in the general formula [1] or [2], the above-mentioned formula [1-a], [2-a], Alternatively, a method for efficiently producing each of the compounds represented by the formula [2-b] will be described below.
In the case of a compound represented by the formula [1-a] or [2-a], a tetracarboxylic acid represented by the following formula [5-a] is used as the tetracarboxylic dianhydride [5] in the above reaction formula. It can be produced by using a dianhydride.

(Wherein R ² represents an alkyl group having 1 to 5 carbon atoms)
At this time, the lower the reaction temperature, the higher the selectivity of the formula [1-a]. Therefore, when it is desired to improve the reaction yield of the formula [1-a], a more preferable reaction temperature is 10 to 30 ° C. On the other hand, when it is desired to improve the reaction yield of the formula [2-a], a more preferable reaction temperature is 50 to 100 ° C.
Also, when the reaction is carried out by adding a base or acid, the selectivity and reaction rate of the formula [1-a] can be improved, and more preferably a basic compound is added. Examples of the base or acid used at this time include those exemplified above, and preferred bases or acids and preferred addition amounts are also as described above.

In the case of a compound represented by the formula [2-b], a tetracarboxylic dianhydride represented by the following formula [5-b] is reacted with an alcohol having 1 to 5 carbon atoms (the above R ¹ OH). Can be manufactured.

(Wherein R ² represents an alkyl group having 1 to 5 carbon atoms)
At this time, the selectivity and the reaction rate of the formula [2-b] can be improved by adding a base or an acid to react, and more preferably a basic compound is added. Examples of the base or acid used at this time include those exemplified above, and preferred bases or acids and preferred addition amounts are also as described above.

(Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, and R ² is an alkyl group having 1 to 5 carbon atoms)
Further, the present invention is characterized in that the target product produced by the reaction can be easily separated. For example, when formula [5-a] is used as a raw material, the alcohol used is distilled off after completion of the reaction, the precipitated crystals are heated to reflux in an organic solvent, and then cooled to cool the precipitated crystals. When washed and dried, primary crystals of the high purity product of the formula [1-a] are obtained. As the organic solvent, for example, toluene, acetonitrile, ethyl acetate, ethyl acetate / n-heptane mixed solution, ethyl acetate / various alcohol mixed solution, acetonitrile / various alcohol mixed solution and the like can be used. Acetonitrile, ethyl acetate, ethyl acetate / various alcohol mixtures, or acetonitrile / various alcohol mixtures are preferable. Examples of various alcohols include methanol, ethanol, propanol, butanol, isopropanol and the like.

The purity of the primary crystal can be further increased by washing and recrystallization. Examples of the recrystallization method include a method of adding an organic solvent to the primary crystal and heating, followed by ice cooling, filtration, and drying. As the organic solvent, for example, toluene, acetonitrile, ethyl acetate, ethyl acetate / n-heptane mixed solution, ethyl acetate / various alcohol mixed solution, acetonitrile / various alcohol mixed solution and the like can be used. Acetonitrile, ethyl acetate, ethyl acetate / various alcohol mixtures, or acetonitrile / various alcohol mixtures are preferable. Examples of various alcohols include methanol, ethanol, propanol, butanol, isopropanol and the like.
The amount of the organic solvent used for obtaining these primary crystals is usually used in an amount of 2 to 20 times that based on the weight when the desired product is obtained from the raw material in a yield of 100%. Further, when it is desired to improve the yield, it is preferable to reduce the amount of organic solvent used, and when it is desired to obtain a high purity product, it is preferable to increase the amount of organic solvent used. Considering these yields and purity, 2.5 to 5 times is more preferable.

On the other hand, a high purity product of the formula [2-a] can be obtained by washing and recrystallizing the filtrate when the primary crystals are obtained. That is, the solvent of the obtained filtrate was distilled off, and the precipitated crystals were heated to reflux in an organic solvent and then cooled, and the precipitated crystals were collected by filtration, washed and dried to obtain the target formula [2-a]. Secondary crystals of high purity are obtained. As the organic solvent, for example, toluene, acetonitrile, ethyl acetate, ethyl acetate / n-heptane mixed solution, ethyl acetate / various alcohol mixed solution, acetonitrile / various alcohol mixed solution and the like can be used. Acetonitrile, ethyl acetate, ethyl acetate / various alcohol mixtures, or acetonitrile / various alcohol mixtures are preferable. Examples of various alcohols include methanol, ethanol, propanol, butanol, isopropanol and the like.
The purity of the secondary crystals can be further increased by washing and recrystallization. Examples of the recrystallization method include a method in which an organic solvent is added to the secondary crystal and heated, followed by ice cooling, filtration, and drying. As the organic solvent, for example, toluene, acetonitrile, ethyl acetate, ethyl acetate / n-heptane mixed solution, ethyl acetate / various alcohol mixed solution, acetonitrile / various alcohol mixed solution and the like can be used. Acetonitrile, ethyl acetate, ethyl acetate / various alcohol mixtures, or acetonitrile / various alcohol mixtures are preferable. Examples of various alcohols include methanol, ethanol, propanol, butanol, isopropanol and the like.
The amount of the organic solvent used for obtaining these secondary crystals is usually the weight obtained by subtracting the weight of the primary crystals taken out from the weight when the target product was obtained from the raw material in a yield of 100%. 2 to 20 times the amount. Further, when it is desired to improve the yield, it is preferable to reduce the amount of organic solvent used, and when it is desired to obtain a high purity product, it is preferable to increase the amount of organic solvent used. In view of these yields and purity, 2.5 to 5 times the amount is more preferable.

When the formula [5-b] is used as a raw material, the alcohol used is distilled off after completion of the reaction, the precipitated crystals are heated to reflux in an organic solvent, and then cooled to cool the precipitated crystals by filtration and washing. When dried, a high-purity primary crystal of the formula [2-b] is obtained. As the organic solvent, for example, toluene, acetonitrile, ethyl acetate, ethyl acetate / n-heptane mixed solution, ethyl acetate / various alcohol mixed solution, acetonitrile / various alcohol mixed solution and the like can be used. Acetonitrile, ethyl acetate, ethyl acetate / various alcohol mixtures, or acetonitrile / various alcohol mixtures are preferable. In addition, the purity of the primary crystal can be further increased by a washing method or a recrystallization method. Examples of the washing method include a method in which an organic solvent is added to the primary crystal and heated, followed by ice cooling, filtration, and drying. As the organic solvent, for example, toluene, acetonitrile, ethyl acetate, ethyl acetate / n-heptane mixed solution, ethyl acetate / various alcohol mixed solution, acetonitrile / various alcohol mixed solution and the like can be used. Acetonitrile, ethyl acetate, ethyl acetate / various alcohol mixtures, or acetonitrile / various alcohol mixtures are preferable. Examples of various alcohols include methanol, ethanol, propanol, butanol, isopropanol and the like.
The amount of the organic solvent used for obtaining these primary crystals is usually used in an amount of 2 to 20 times that based on the weight when the desired product is obtained from the raw material in a yield of 100%. Further, when it is desired to improve the yield, it is preferable to reduce the amount of organic solvent used, and when it is desired to obtain a high purity product, it is preferable to increase the amount of organic solvent used. In view of these yields and purity, 2.5 to 5 times the amount is more preferable.

[Bis (chlorocarbonyl) compound]
The bis (chlorocarbonyl) compound of the present invention is a compound represented by the following general formula [3] or [4].

(Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
R ¹ is an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, and a tertiary butyl group. And a normal pentyl group. In addition, when synthesizing a polyamic acid ester from the bis (chlorocarbonyl) compound of the present invention and then imidizing it, it is preferable that R ² has a small number of carbon atoms and is easily released, more preferably methyl. It is a group.
R ² is an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, and a tertiary butyl group. And a normal pentyl group.
n represents 1 to 4, and is preferably 2.

Specific examples of the bis (chlorocarbonyl) compound of the present invention when R ² is a methyl group and n is ² are shown below, but the bis (chlorocarbonyl) compound of the present invention is limited to these. is not. In the following table, a1 to a4 and b1 to b4 represent the respective positions shown in the following formula [6], and the symbols in the table have the following meanings, respectively.
Me: methyl group, Et: ethyl group, Pr-n: normal propyl group, Pr-iso: isopropyl group, Bu-n: normal butyl group, Bu-sec: secondary butyl group, Bu-iso: isobutyl group, Bu- t: tertiary butyl group, Pen-n: normal pentyl group, OMe: methoxy group, OEt: ethoxy group, OPr-n: normal propyl ether group, OPr-iso: isopropyl ether group, OBu-n: normal butoxy group, OBu-sec: secondary butoxy group, OBu-iso: isobutoxy group, OBu-t: tertiary butoxy group, OPen-n: normal pentyl ether group

In the case of a compound in which n is 2, and R ² is an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, a tertiary butyl group, or a normal pentyl group, Examples are compounds in which Me in b1 to b4 in the table is replaced with Et, Pr-n, Pr-iso, Bu-n, Bu-sec, Bu-iso, Bu-t, or Pen-n, respectively.
In the bis (chlorocarbonyl) compound of the present invention, the tetracarboxylic acid dialkyl ester as a raw material is easily available and can be obtained in a high yield. Therefore, the following formula [3-a], [4-a] or [ 4-b] is particularly preferred.

(Wherein R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² represents an alkyl group having 1 to 5 carbon atoms)
Furthermore, the polymer using the high-purity product of the formula [3-a] is higher than the polymer using the high-purity product of the formula [4-a] or a mixture of the formula [3-a] and the formula [4-a]. Since it is possible to obtain a high molecular weight and low dispersion polymer, the compound represented by the formula [3-a] is preferable from the viewpoint of obtaining a high molecular weight and low dispersion polymer.
The bis (chlorocarbonyl) compound [3] or compound [4] of the present invention chlorinates the tetracarboxylic acid dialkyl ester represented by the formula [1] or the formula [2] as shown in the following reaction formula. Can be manufactured.

(Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
In the above reaction formula, the substitution position of R ² in the formula [3] and the formula [4] represents the same substitution position as the corresponding formula [1] and the formula [2]. That is, the bis (chlorocarbonyl) compound [3-a] can be produced by chlorinating the tetracarboxylic acid dialkyl ester [1-a]. Similarly, the compound [4-a] Compound [4-b] can be produced by chlorinating compound [2-b] by chlorinating -a].
Examples of the chlorinating agent used in the above reaction include thionyl chloride, oxalyl chloride, phosgene, chlorine, phosphorus oxychloride, phosphorus pentachloride, N-chlorosuccinimide and the like. Preferably, thionyl chloride, oxalyl chloride, phosgene, chlorine, phosphorus oxychloride, or phosphorus pentachloride is used. More preferably, thionyl chloride, oxalyl chloride, or phosgene is used. The chlorinating agent is usually used in an amount of 2 to 100 times mol, preferably 2 to 30 times mol, more preferably 2 to 3 times mol, of the tetracarboxylic acid dialkyl ester.

The above reaction can be carried out in a chlorinating agent such as thionyl chloride, but a solvent can be used if necessary. The solvent is not particularly limited as long as it is inert to the reaction. For example, hydrocarbons such as hexane, heptane or toluene, halogenated hydrocarbons such as chloroform, 1,2-dichloroethane or chlorobenzene, diethyl ether Or ethers such as 1,4-dioxane, esters such as ethyl acetate, ketones such as acetone or methyl ethyl ketone, nitriles such as acetonitrile or propionitrile, and mixtures thereof. Preferably, hexane, heptane, or toluene is used. More preferably, hexane or heptane is used.
In addition, the above reaction proceeds even without a catalyst, but by adding a catalyst, the amount of chlorinating agent used can be reduced and the reaction can be accelerated. Specific examples of the catalyst include organic bases such as triethylamine, pyridine, quinoline, N, N-dimethylaniline, N, N-dimethylformamide, and metals such as sodium methoxide, potassium methoxide or potassium t-butoxide. Although alkoxide is mentioned, it is not limited to these. Preferably, triethylamine, pyridine, or N, N-dimethylformamide is used. More preferably, pyridine is used. These catalysts are generally used in an amount of 0 to 100 times mol, preferably 0.01 to 10 times mol for the tetracarboxylic acid dialkyl ester.

The reaction temperature is not particularly limited, but is usually −90 to 200 ° C., preferably −30 to 100 ° C., more preferably 50 to 80 ° C.
The reaction time is usually 0.05 to 200 hours, preferably 0.5 to 100 hours, more preferably 0.5 to 5 hours.
Further, the bis (chlorocarbonyl) compound obtained as described above can be isolated and purified as follows, for example.
After completion of the reaction, the remaining chlorinating agent is distilled off, and then a certain amount of solvent is added and heated and stirred. Thereafter, the crystals precipitated by cooling are collected by filtration, washed and dried to obtain primary crystals of the desired product. Further, when the above-described heating and stirring are performed, the crystals are dissolved, and if necessary, the insoluble matter is further filtered by hot filtration, and then the same operation is performed to obtain a higher-purity target product. If the chlorinating agent is easier to distill off than the solvent used, after the chlorinating agent and the solvent remaining after the completion of the reaction are distilled off, a residual solution is heated to dissolve the crystals or heat and stir. After cooling, the precipitated crystals are collected by filtration, washed and dried to obtain primary crystals of the target product. The temperature at the time of distilling off the solvent and at the time of dissolution by heating or at the time of heating and stirring is, for example, 30 to 100 ° C., preferably 30 to 50 ° C. As the organic solvent, for example, toluene, acetonitrile, ethyl acetate, n-hexane, n-heptane, an ethyl acetate / n-heptane mixed solution, an ethyl acetate / n-hexane mixed solution, or the like can be used. N-hexane or n-heptane, an ethyl acetate / n-hexane mixture, or an ethyl acetate / n-heptane mixture is preferred. In addition, the purity of the primary crystal can be further increased by a washing method or a recrystallization method. As the recrystallization method, toluene, acetonitrile, ethyl acetate, n-hexane, n-heptane, ethyl acetate / n-heptane mixed solution, ethyl acetate / n-hexane mixed solution or the like is added to the primary crystal, and the crystals are heated. After being dissolved, a high purity product can be obtained by ice cooling, filtration and drying.

As another treatment method, the desired product can be obtained by distilling off the remaining chlorinating agent after the reaction and distilling the remaining liquid.
On the other hand, a chlorination reaction is carried out using a high-purity single stereoisomer [1] obtained by purifying the raw material tetracarboxylic acid dialkyl ester, and after completion of the reaction, the same procedure as described above is followed. 3] can be obtained in high yield. Similarly, by using a high purity single stereoisomer [2], a high purity compound [4] can be obtained in a high yield.
The tetracarboxylic acid dialkyl ester or bis (chlorocarbonyl) compound of the present invention obtained as described above can be used as a monomer raw material for polyamide, polyimide, polyester and the like. For example, polyamides can be obtained by polycondensing the tetracarboxylic acid dialkyl ester of the present invention and various diamine compounds in the presence of a condensing agent, or by reacting the bis (chlorocarbonyl) compound of the present invention with various diamine compounds. Can be synthesized. Moreover, a polyimide can also be synthesize | combined by adding a catalyst to these polyamides as needed and heating. On the other hand, polyester can be synthesized by using various dialcohol compounds instead of the diamine compounds.
As described above, these compounds of the present invention can provide a polyimide, polyamide or polyester having an alkyl group on a cyclobutane ring, which is useful in the field of materials.

[Liquid crystal aligning agent]
A liquid crystal alignment film obtained by a photo-alignment method using an anisotropic photodecomposition reaction of polyimide by polarized radiation generally has anisotropy with respect to the alignment direction of polymer chains as compared with that by rubbing. Get smaller. This is considered to be due to the fact that the molecular weight of the polyimide is lowered by the photodecomposition reaction and that many low molecular weight components exist in addition to the orientation direction.
When a polyamic acid is used as the polyimide precursor, a reverse reaction to diamine and acid dianhydride proceeds simultaneously with imidization during firing, and the molecular weight of the resulting polyimide is lower than that of the original polyamic acid. Therefore, a decrease in molecular weight due to firing also causes a decrease in anisotropy. In addition, the polyamic acid obtained from acid dianhydride and diamine has four types of structures with different amide bond bonding positions as shown in the following formulas (A), (B), (C), (D), In addition, these structures are present randomly in the molecular chain. Polyamic acid coating film can be dehydrated and ring-closed by firing to form polyimide, but if imidization does not proceed completely, the polyamic acid in which the above four types of structures are present at random remains. The order of the polymer chain is reduced. When the order of the polymer chain is lowered, the interaction between the polymers is lowered due to steric repulsion, and a highly ordered polyimide film cannot be obtained. Therefore, it is considered that the anisotropy with respect to the orientation direction of the obtained polyimide film is small when the bonding position of the amide group is random like polyamic acid.

As a result of intensive research, the inventors of the present invention have used a polyimide precursor that has a high order of polymer chains and that does not have a reduced molecular weight during firing. It has been found that a polyimide film having high anisotropy can be obtained. Specifically, by using, as a liquid crystal aligning agent, a highly symmetrical polyamic acid ester obtained by using a highly symmetrical acid chloride and diamine with controlled substitution positions of the chlorocarbonyl group and the ester group on the cyclobutane ring, Also in the photo-alignment method, it discovered that the polyimide film which has high anisotropy with respect to the alignment process direction was obtained, and based on this knowledge, this invention was completed.

[Acid chloride]
The acid chloride in which a chlorocarbonyl group is bonded to the 1,3-position and an ester group is bonded to the 2,4-position of the cyclobutane ring used in the present invention is represented by the following formula (101).

(Wherein R ₁ represents an alkyl group having 1 to 5 carbon atoms, R ₂ , R ₃ , R ₄ , and R ₅ represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, which may be the same or different. May be.)
In the acid chloride represented by the formula (101), R ₁ represents an alkyl group having 1 to 5 carbon atoms. Here, specific examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, a tertiary butyl group, and a normal pentyl group. In general, the polyamic acid ester has a higher temperature at which imidization proceeds as the number of carbon atoms increases, such as a methyl group, an ethyl group, and a propyl group. Therefore, from the viewpoint of easiness of imidization by heat, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
In the acid chloride represented by the formula (101), R ₂ , R ₃ , R ₄ and R ₅ represent a hydrogen atom and a monovalent hydrocarbon group having 1 to 30 carbon atoms, and may be the same or different.

Examples of the monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a hexyl group, an octyl group, and a decyl group; a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; A bicycloalkyl group such as a cyclohexyl group; an alkenyl group such as a vinyl group, a 1-propenyl group, a 2-propenyl group, an isopropenyl group, a 1-methyl-2-propenyl group, a 1 or 2 or 3-butenyl group, a hexenyl group; Examples thereof include aryl groups such as phenyl group, xylyl group, tolyl group, biphenyl group and naphthyl group; aralkyl groups such as benzyl group, phenylethyl group and phenylcyclohexyl group.
In addition, some or all of the hydrogen atoms of these monovalent hydrocarbon groups are halogen atoms, phosphate ester groups, ester groups, thioester groups, amide groups, nitro groups, organooxy groups, organosilyl groups, organothio groups, It may be substituted with an acyl group, an alkyl group, a cycloalkyl group, a bicycloalkyl group, an alkenyl group, an aryl group, an aralkyl group, or the like.

From the viewpoint of liquid crystal alignment, R ₂ , R ₃ , R ₄ and R ₅ are preferably a substituent having a small steric hindrance, and particularly preferably a hydrogen atom or a methyl group. In order to obtain a liquid crystal alignment film having high anisotropy with respect to the alignment direction, all of R ₂ , R ₃ , R ₄ , and R ₅ are the same substituent, or R ₂ , R _4, and R ₃ and R ₅ are preferably the same substituent.
Specific examples of the configuration of R ₂ , R ₃ , R ₄ , R ₅ , chlorocarbonyl group and ester group include the following formulas (106) to (121).

Among the above, the higher the acid chloride symmetry, the higher the order of the polyamic acid ester, and the higher the linearity of the polymer chain, the lower the imidization rate, the higher the order of the polymer film. Since a liquid crystal alignment film having high anisotropy is obtained, the formulas (106), (107), (108), and (109) are particularly preferable.
Specific structures of the acid chloride when one or more of R ₂ , R ₃ , R ₄ , and R _{5 in} the formula (101) are hydrogen atoms include the following formulas (122) to (129). It is done.

Among the above, the higher the symmetry of the acid chloride, the higher the order of the polyamic acid ester, and the higher the linearity of the polymer chain, the higher the order of the polymer film, even if the imidization rate is low. Since a liquid crystal alignment film having a directivity can be obtained, the formula (126) or (127) is preferable. Further, by substituting the chlorocarbonyl group and R ₂ or R ₄ with the same carbon of the cyclobutane ring, isomerization due to heat is suppressed, and the symmetry of the monomer or polymer is not lost even at high temperatures. 126) is particularly preferred.
In addition, when R ₂ , R ₃ , R ₄ , and R ₅ are the same substituent, the symmetry of the acid chloride is improved and a highly ordered polyamic acid ester is obtained. Therefore, the following formula (102) is preferable. .

In formula (102), R ₁ represents an alkyl group having 1 to 4 carbon atoms, and R ₆ represents a monovalent hydrocarbon group having 1 to 30 carbon atoms. Examples of the monovalent hydrocarbon group include structures similar to those exemplified as the structures of R ₂ , R ₃ , R ₄ and R ₅ .
From the above, as a specific example of the acid chloride represented by the formula (101), the formula (103) or (104) is particularly preferable.

The acid chloride of formula (101) can be synthesized by a two-stage reaction of esterification of tetracarboxylic dianhydride and chlorination of carboxylic acid as described below.

The esterification reaction in the first stage can be performed by reacting tetracarboxylic dianhydride with an alcohol represented by R ₁ OH. The reaction temperature is, for example, −90 to 200 ° C., preferably −30 to 100 ° C. The reaction time is, for example, 0.5 to 200 hours, preferably 0.5 to 100 hours. The alcohol used in this reaction is, for example, 2 to 100 times mol, preferably 2 to 40 times mol, more preferably 2 to 20 times mol based on tetracarboxylic dianhydride.
After the above esterification reaction, there are many isomers in which positions other than the 2 and 4 positions are ester groups. Therefore, in order to obtain the acid chloride used in the present invention, 2, It is desirable to purify the diester body in which the 4-position is an ester group. Examples of the purification method include various purification methods such as recrystallization and column chromatography, and purification by recrystallization is preferable from the viewpoint of simplicity of operation. Various organic solvents can be combined as the recrystallization solvent.

The second-stage chlorination reaction can be performed by reacting the ester obtained above with a chlorinating agent in the presence of an organic solvent. The reaction temperature is, for example, −90 to 200 ° C., preferably −30 to 100 ° C., more preferably 50 to 80 ° C. The reaction time is, for example, 0.5 to 200 hours, preferably 0.5 to 100 hours, more preferably 0.5 to 5 hours. The chlorinating agent used in this reaction is, for example, 2 to 100 times mol, preferably 2 to 30 times mol, more preferably 2 to 3 times mol, of the ester.
Examples of the chlorinating agent include thionyl chloride, oxalyl chloride, phosgene, chlorine, phosphorus oxychloride, phosphorus pentachloride, N-chlorosuccinimide and the like.

The reaction solvent is not particularly limited as long as it is inert to the reaction. For example, hydrocarbons such as hexane, heptane, or toluene, and halogenated hydrocarbons such as chloroform, 1,2-dichloroethane, or chlorobenzene. , Ethers such as diethyl ether or 1,4-dioxane, esters such as ethyl acetate, ketones such as acetone or methyl ethyl ketone, nitriles such as acetonitrile or propionitrile, and mixtures thereof.
The chlorination reaction proceeds even without a catalyst, but the addition of a catalyst can reduce the amount of chlorinating agent used and can accelerate the reaction. Examples of the catalyst include organic bases such as triethylamine, pyridine, quinoline, N, N-dimethylaniline, N, N-dimethylformamide, and metal alkoxides such as sodium methoxide, potassium methoxide or potassium t-butoxide. It is done. These catalysts are used in an amount of, for example, 0 to 100 times mol, preferably 0.01 to 10 times mol for the ester.
Since the molecular weight of the polyamic acid ester obtained increases as the purity of the acid chloride increases, it is preferable to purify the reaction product after the chlorination reaction. Examples of the purification method include recrystallization, and the recrystallization solvent is not particularly limited as long as it is an organic solvent that does not react with acid chloride.

[Polyamide ester]
The polyamic acid ester used in the liquid crystal aligning agent of the present invention is obtained by a reaction between a bis (chlorocarbonyl) compound containing the acid chloride represented by the above formula (101) as an essential component and a diamine.
The bis (chlorocarbonyl) compound used in this reaction is an acid chloride other than that represented by formula (101), for example, a chlorocarbonyl group bonded to the 1,4-position and an alkyl ester group bonded to the 2,3-position of the cyclobutane ring. The acid chloride may be mixed, but in this case, the acid chloride represented by the formula (101) is preferably 60 mol% or more. From the viewpoint of making the obtained polyamic acid ester more highly ordered and further increasing the anisotropy with respect to the orientation treatment direction, the acid chloride represented by the formula (101) is preferably 80 mol% or more, more Preferably, it is 95 to 100 mol%.
Examples of the diamine to be reacted with the bis (chlorocarbonyl) compound include a diamine represented by the following formula (130).

(X represents a divalent organic group.)
Specific examples of the structure of X in formula (130) are shown below, but the present invention is not limited thereto.

In the method for producing a liquid crystal alignment film of the present invention, when an aromatic ring is present in the diamine compound, the aromatic ring becomes a light absorption site, and the cleavage reaction of the cyclobutane ring is promoted. Therefore, from the viewpoint of photoreaction efficiency, the diamine compound is preferably an aromatic diamine. Furthermore, the higher the linearity of the polyimide molecular chain generated by imidization, the better the liquid crystal alignment, so A-7, A-11, A-12, A-13, A-14, A-20, A- 22, A-23, A-24, A-26, A-27, A-28, A-30, A-42, A-43, A-44, A-45, A-46, A-48, A-63, A-69, A-71, A-72, A-73, A-74, or A-75 are particularly preferred.

[Synthesis of polyamic acid ester]
The polyamic acid ester comprises a diamine and a bis (chlorocarbonyl) compound in the presence of a base and an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., for 30 minutes to 24 hours, preferably 1 to 4 It can synthesize | combine by making it react for time.
As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently. If the amount of the base is too large, removal is difficult, and if it is too small, the molecular weight is small. Therefore, the amount is preferably 2 to 4 times the mole of the bis (chlorocarbonyl) compound.
The solvent used for the synthesis of the polyamic acid ester is preferably N-methyl-2-pyrrolidone or γ-butyrolactone in view of the solubility of the monomer and polymer, and these may be used alone or in combination. When the concentration at the time of synthesis is too high, polymer precipitation is likely to occur, and when it is too low, the molecular weight does not increase, so 1 to 30% by weight is preferable, and 5 to 20% by weight is more preferable. In addition, in order to prevent hydrolysis of the bis (chlorocarbonyl) compound, the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.
The solution of the polyamic acid ester obtained as described above can be precipitated by pouring into a poor solvent while stirring well. Precipitation is performed several times, and after washing with a poor solvent, a purified polyamic acid ester powder can be obtained by normal temperature or heat drying.
Although the said poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.

[Molecular weight of polyamic acid ester]
The ratio of the diamine component used in the polymerization reaction to the bis (chlorocarbonyl) compound is preferably 1.0 / 0.5 to 1.0 in terms of molar ratio from the viewpoint of molecular weight control. The closer the molar ratio is to 1: 1, the greater the molecular weight of the polymer obtained. The molecular weight of the polymer affects the viscosity of the liquid crystal aligning agent and the physical strength of the liquid crystal aligning film. If the molecular weight of the polymer is too large, the coating workability and coating film uniformity of the liquid crystal aligning agent will deteriorate. If the molecular weight is too small, the strength of the coating film obtained from the liquid crystal aligning agent may be insufficient. Accordingly, the molecular weight of the polymer used in the liquid crystal aligning agent of the present invention is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and still more preferably 10,000 in terms of weight average molecular weight. ~ 100,000.

[Liquid crystal aligning agent]
The liquid crystal aligning agent of the present invention is a coating liquid for forming a liquid crystal aligning agent in which the polymer obtained as described above is uniformly dissolved in an organic solvent.
The solvent used in the liquid crystal aligning agent of the present invention is not particularly limited as long as it dissolves the polymer contained in the liquid crystal aligning agent. Specific examples thereof include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N- Examples include ethyl pyrrolidone, N-vinyl pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide and the like. You may use these 1 type or in mixture of 2 or more types. Furthermore, even a solvent that does not dissolve the polymer alone may be mixed as long as the polymer does not precipitate.

Further, a solvent for improving the uniformity of the coating film when the liquid crystal aligning agent is applied to the substrate may be added. Such solvents include ethyl cellosolve, butyl cellosolve, hexyl cellosolve, ethyl cellosolve acetate, butyl cellosolve acetate, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, butyl carbitol acetate, ethylene glycol, diethylene glycol diethyl ether, 1-methoxy -2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate , Propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, dipropylene glycol Methyl ether, 2- (2-ethoxy propoxy) propanol, methyl lactate ester, ethyl lactate esters, lactate n- propyl ester, lactate n- butyl ester, and the like lactic isoamyl ester. Two types of these solvents may be used in combination.

The polymer concentration of the liquid crystal aligning agent of the present invention can be appropriately changed depending on the thickness of the liquid crystal alignment film to be formed, but is preferably 1 to 10% by weight. If it is less than 1% by weight, it is difficult to form a uniform and defect-free coating film, and if it exceeds 10% by weight, the storage stability of the solution may deteriorate.
In order to improve the adhesion of the coating film to the substrate, an additive such as a silane coupling agent may be added to the liquid crystal aligning agent of the present invention. If the said silane coupling agent is a well-known thing, the kind will not be chosen.
In blending the coupling agent, the adhesiveness is improved by heating and reacting with the polymer after the addition, and the influence on the properties of the liquid crystal aligning agent can be suppressed. After the addition, the reaction may be performed at 20 ° C. to 80 ° C., more preferably at 40 ° C. to 60 ° C. for 1 to 24 hours.
If the addition amount of the silane coupling agent is too large, unreacted ones may adversely affect the liquid crystal orientation, and if it is too little, the effect on the adhesion will not appear. 5.0 wt% is preferable, and 0.1 to 1.0 wt% is more preferable.
It goes without saying that various additives such as a crosslinking agent and an imidization accelerator may be further used in the liquid crystal aligning agent of the present invention. Moreover, the polymer contained in the liquid crystal aligning agent of this invention may be 2 or more types, and if at least 1 type is the polyamic acid ester of this invention, the kind will not be limited about another polymer.

[Method for producing liquid crystal aligning agent]
The liquid crystal aligning agent of this invention can be manufactured with the following method.
The polyamic acid ester powder is dissolved in the solvent to form a polyamic acid ester solution. At this time, the polymer concentration is preferably 10 to 30%, particularly preferably 10 to 15%. Further, heating may be performed when the polyamic acid ester powder is dissolved. The heating temperature is preferably 20 ° C to 150 ° C, particularly preferably 20 ° C to 80 ° C.
The obtained polyamic acid ester solution can be used as the liquid crystal aligning agent of the present invention by diluting with the above-mentioned solvent so as to have a predetermined polymer concentration.
When a silane coupling agent or a crosslinking agent is added, it is preferably added before adding a solvent having low polymer solubility in order to prevent polymer precipitation. When adding an imidation accelerator, since imidation may advance by heating, it is preferable to add it after a dilution process.

[Method for producing liquid crystal alignment film]
The liquid crystal aligning agent of the present invention can be applied to a substrate after filtration, dried and baked to form a coating film, and is used as a liquid crystal alignment film by orienting the coating surface. .
Examples of the method for applying the liquid crystal aligning agent include a spin coating method, a printing method, and an ink jet method.
Arbitrary temperature and time can be selected for the drying and baking steps after applying the liquid crystal aligning agent. For example, in order to sufficiently remove the organic solvent contained in the liquid crystal aligning agent, it is dried at 50 to 120 ° C. for 1 to 10 minutes and then baked at 150 to 300 ° C. for 5 to 120 minutes.
If the thickness of the coating film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered, so that it is 5 to 300 nm, preferably 10 to 200 nm. It is.
Examples of the method for aligning the coating film include a rubbing method and a photo-alignment method. The liquid crystal aligning agent of the present invention is particularly useful when used in the photo-alignment method.
As a specific example of the photo-alignment treatment method, there is a method of imparting liquid crystal alignment ability by irradiating the coating film surface with radiation deflected in a certain direction, and further subjecting to a temperature of 150 to 250 ° C. in some cases. Can be mentioned. As the radiation, ultraviolet rays and visible rays having a wavelength of 100 nm to 800 nm can be used. Among these, ultraviolet rays having a wavelength of 100 nm to 400 nm are preferable, and those having a wavelength of 200 nm to 400 nm are particularly preferable. Further, in order to improve the liquid crystal orientation, radiation may be irradiated while heating the coated substrate at 50 to 250 ° C. Dose of the radiation is preferably in the range of 1 ~ 10,000mJ / cm ^2, and particularly preferably in the range of 100 ~ 5,000mJ / cm ^2.
The liquid crystal alignment film produced as described above can stably align liquid crystal molecules in a certain direction.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention should not be construed as being limited thereto.

Example 1 Synthesis of tetracarboxylic acid dialkyl ester under neutral conditions at 65 ° C.

Under a nitrogen stream, a 3-L four-necked flask was charged with 1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride (compound of formula (5-1), hereinafter referred to as 1,3-DM). -CBDA (abbreviated) 220 g (0.981 mol) and methanol 2200 g (6.87 mol, 10 wt times with respect to 1,3-DM-CBDA) were charged and refluxed at 65 ° C. for 30 minutes. A homogeneous solution was obtained. The reaction solution was stirred for 4 hours and 30 minutes under heating and reflux. This reaction solution was measured by high performance liquid chromatography (hereinafter abbreviated as HPLC). The analysis of the measurement result will be described later.
After evaporating the solvent from the reaction solution with an evaporator, 1301 g of ethyl acetate was added, heated to 80 ° C., and refluxed for 30 minutes. Thereafter, the mixture was cooled at a rate of 2 to 3 ° C. for 10 minutes until the internal temperature reached 25 ° C., and stirred at 25 ° C. for 30 minutes. The precipitated white crystals were taken out by filtration, washed twice with 141 g of ethyl acetate, and then dried under reduced pressure to obtain 103.97 g of white crystals.
This crystal was confirmed to be compound (1-1) by the results of 1H NMR analysis and X-ray crystal structure analysis (HPLC relative area 97.5%) (yield 36.8%).
1H NMR (DMSO-d6, δppm); 12.82 (s, 2H), 3.60 (s, 6H), 3.39 (s, 2H), 1.40 (s, 6H).

Hereinafter, the compound (1-1) which is 2,4-bis (methoxycarbonyl) -1,3-dimethylcyclobutane-1,3-dicarboxylic acid is also abbreviated as 1,3-DM-CBDE.
On the other hand, when the filtrate after taking out the above-mentioned white crystals was distilled off with an evaporator, 172.24 g of white crystals were obtained. When 380.09 g of acetonitrile was added to 156.01 g of this white crystal and heated to 65 ° C., the crystal was completely dissolved. Then, it cooled to 30 degreeC over 1 hour, and then cooled until the internal temperature became 25 degreeC over 2 hours. After stirring for 30 minutes at 25 ° C., the precipitated white crystals were taken out by filtration, and the crystals were washed with 30.7 g of acetonitrile. This was dried under reduced pressure to obtain 52.74 g of white crystals.
This crystal was confirmed to be the compound (2-1) by the results of 1H NMR analysis and X-ray crystal structure analysis (HPLC relative area 99.2%) (yield 20.6%).
1H NMR (DMSO-d6, δppm); 12.82 (s, 2H), 3.60 (s, 6H), 3.48 (s, 1H), 3.30 (s, 1H), 1.45 (s, 3H), 1.38 (s, 3H ).
The HPLC measurement data at the end of the reaction was analyzed using the compound (1-1), compound (2-1), etc. obtained above as a sample, and the compound (1- The proportion of 1) was 50% in terms of HPLC relative area, and 47% for compound (2-1). Further, in the filtrate after removing the crystal of the compound (1-1) from the reaction solution, the ratio of the compound (1-1) was 21% in terms of HPLC relative area, and the compound (2-1) was 74%. .

[X-ray crystal structure analysis]
Device: DIP2030 (manufactured by MacScience)
X-ray: Mokα (40 kV, 200 mA)
Measurement temperature: 298.0K
As a measurement sample, the obtained compound was dissolved in acetonitrile and slowly concentrated at room temperature to prepare a single crystal.

FIG. 1 shows an ORTEP diagram of the analysis result of the single crystal X-ray measurement of the compound (1-1).
Crystal data Molecular formula C ₁₂ H ₁₆ O ₈
Molecular weight 288.252
Hue, shape colorless, block
Crystalline Monoclinic
Space group P2 ₁ / c
Lattice constant a = 8.3460 (10) Å, b = 8.256 (2) Å, c = 10.630 (2) Å
α = 90.00 °, β = 109.738 (10) °, γ = 90.00 °
V = 689.4 ⁽³⁾ Å 3
Z value = 2
R (gt) = 0.111
wR (gt) = 0.548

FIG. 2 shows an ORTEP diagram of the analysis result of the single crystal X-ray measurement of the compound (2-1).
Crystal data Molecular formula C ₁₂ H ₁₆ O ₈
Molecular weight 288.252
Hue, shape colorless, cube
Crystalline triclinic
Space group P-1
Lattice constant a = 7.422 (2) Å, b = 8.0390 (10) Å, c = 12.2232 (2) Å
α = 106.0055 (10) °, β = 99.018 (10) °, γ = 103.537 (10) °
V = 662.4 (2) Å ³
Z value = 2
R (gt) = 0.06
wR (gt) = 0.07

Example 2 Synthesis of Tetracarboxylic Acid Dialkyl Ester under Neutral Conditions at 20 ° C. Under a nitrogen stream, 10 g (0.045 mol) of 1,3-DM-CBDA and methanol were placed in a 200 mL four-necked flask. Was stirred at 69 ° C. for 69 hours at 14 to 20 ° C. to obtain a uniform reaction solution. When this reaction solution was analyzed by HPLC, the HPLC relative area of the compound (1-1) was 56%, and the HPLC relative area of the compound (2-1) was 44%.
After evaporating the solvent from the reaction solution with an evaporator, 60 g of ethyl acetate was added, heated to 80 ° C., and refluxed for 30 minutes. Thereafter, the mixture was cooled at a rate of 2 to 3 ° C. for 10 minutes until the internal temperature reached 25 ° C., and stirred at 25 ° C. for 30 minutes. The precipitated white crystals were taken out by filtration, washed twice with 6.43 g of ethyl acetate, and then dried under reduced pressure to obtain 5.50 g of white crystals.
This crystal was confirmed to be the compound (1-1) by the results of 1H NMR analysis and X-ray crystal structure analysis (HPLC relative area 99.0%) (yield 45.7%).

Example 3 Synthesis of Tetracarboxylic Acid Dialkyl Ester under Neutral Conditions at 40 ° C. Under a nitrogen stream, 10 g (0.045 mol) of 1,3-DM-CBDA and methanol were placed in a 200 mL four-necked flask. Was added at 50 g (1.56 mol, 5 wt times with respect to 1,3-DM-CBDA) and stirred at 40 ° C. for 7 hours and 30 minutes to obtain a uniform reaction solution. When this reaction solution was analyzed by HPLC, the HPLC relative area of the compound (1-1) was 48%, and the HPLC relative area of the compound (2-1) was 45%.

Example 4 Synthesis of tetracarboxylic acid dialkyl ester in the presence of pyridine at 25 ° C. Under a nitrogen stream, 240 g (1.07 mol) of 1,3-DM-CBDA and ethyl acetate were placed in a 3 L four-necked flask. 720 g was added, 8.47 g (0.107 mol) of pyridine was added, and the mixture was suspended at 25 ° C. with stirring with a magnetic stirrer. To this suspension, 600 g of methanol (18.73 mol, 2.5 wt times with respect to 1,3-DM-CBDA) was added dropwise over 1 hour so that the internal temperature was 25 ° C. or less. When stirred for 20 minutes, a uniform reaction solution was obtained. When this reaction solution was analyzed by HPLC, the HPLC relative area of compound (1-1) was 77%, and the HPLC relative area of compound (2-1) was 22%.
The solvent of this reaction solution was distilled off with an evaporator at a water bath of 40 ° C. and 170 to 140 Torr until the internal volume reached 561.65 g. Subsequently, 1450 g of ethyl acetate was added and stirred, and then the solvent was distilled off with an evaporator at a water bath of 40 ° C. and 170 to 140 Torr until the internal volume reached 597.51 g. Thereafter, 1450 g of ethyl acetate was added again and stirred, and then the solvent was distilled off with an evaporator at a water bath of 40 ° C. and 170 to 140 Torr until the internal volume reached 1852 g. Moreover, when the solvent distilled off at this time was analyzed by gas chromatography, the area% of methanol was 0.3%. Subsequently, the remaining slurry solution was heated to 80 ° C., refluxed for 30 minutes, and then cooled for 10 minutes at a rate of 2 to 3 ° C. until the internal temperature reached 25 ° C. After stirring as it was at 25 ° C. for 30 minutes, the precipitated white crystals were taken out by filtration, and the crystals were washed twice with 192.88 g of ethyl acetate. This was dried under reduced pressure to obtain 223.77 g of white crystals. This crystal was confirmed to be the compound (1-1) by 1H NMR analysis (HPLC relative area 99.0%) (yield 72.5%).

Example 5 Synthesis of tetracarboxylic acid dialkyl ester in the presence of pyridine at 0 ° C. In a nitrogen stream, 5 g (0.022 mol) of 1,3-DM-CBDA and methanol were placed in a 100 mL four-necked flask. 25 g (0.78 mol, 5 wt times with respect to 1,3-DM-CBDA) and 0.176 g (0.0022 mol) of pyridine were charged and stirred at 0 ° C. for 8 hours under magnetic stirrer stirring. A homogeneous reaction solution was obtained. When this reaction solution was analyzed by HPLC, the HPLC relative area of compound (1-1) was 79%, and the HPLC relative area of compound (2-1) was 20%.

Example 6 Synthesis of tetracarboxylic acid dialkyl ester in the presence of pyridine at 40 ° C. In a nitrogen stream, 5 g (0.022 mol) of 1,3-DM-CBDA and methanol were placed in a 100 mL four-necked flask. 25 g (0.78 mol, 5 wt times with respect to 1,3-DM-CBDA) and 0.176 g (0.0022 mol) of pyridine were charged and stirred for 20 minutes at 40 ° C. with magnetic stirrer stirring. A homogeneous reaction solution was obtained. When this reaction solution was analyzed by HPLC, the HPLC relative area of compound (1-1) was 74%, and the HPLC relative area of compound (2-1) was 25%.

<Examples 7 to 14>
A series of operations were carried out in the same manner as in Example 4 with the number of equivalents of pyridine added and the temperature shown in the following table. The analysis results by HPLC of the reaction solutions obtained here and the results of the reaction solutions obtained in Examples 1 to 6 are also shown in the table.

HPLC analysis condition column: Atlantis cd18 (Waters), 5um, 4.6x250mm
Oven: 40 ° C
Eluent: acetonitrile / 0.5% phosphoric acid aqueous solution = 22/78, detection wavelength: 209 nm
Flow rate: 1.0 mL / min, sample injection volume: 10 μL

<Examples 15 to 43>
A series of operations were carried out in the same manner as in Example 4, and the reaction was carried out by adding various additives instead of pyridine. The following table shows the types of additives, the number of equivalents of the additives, the temperature, the reaction time, and the analysis results of the reaction solution by HPLC. In addition, the additive described in the table | surface is as showing next.
Add-1: potassium methoxide Add-2: potassium carbonate Add-3: triethylamine Add-4: t-butoxypotassium Add-5: quinoline Add-6: 8-quinolinol Add-7: 1,10-phenanthroline Add -8: Bathophenanthroline Add-9: Bathocuproin Add-10: 2,2'-bipyridyl Add-11: 2-phenylpyridine Add-12: 2,6-diphenylaminopyridine Add-13: 2-dimethylaminopyridine Add-14: 4-dimethylaminopyridine Add-15: 2- (2-hydroxyethyl) pyridine Add-16: 5-bromo-2-chloropyridine Add-17: 1,8-diazabicyclo [5,4,0] -7-Unden Add-18: p-toluenesulfonic acid Add-19: phosphoric acid A dd-20: formic acid Add-21: triphenylphosphine Add-22: trimethyl borate Add-23: phosphotungstic acid (H ₃ [PW ₁₂ O ₄₀ ] .30H ₂ O)
Add-24: Phosphomolybdic acid (H ₃ [PMo ₁₂ O ₄₀ ] .30H ₂ O)
Add-25: Water

Example 44 Synthesis of compounds (1-4) and (2-4)

Under a nitrogen stream, 10 g (0.045 mol) of 1,3-DM-CBDA and 50 g of tetrahydrofuran were charged into a 200 mL four-necked flask, and 10.59 g (0.004 mol) of pyridine was added. After suspending at 25 ° C. with stirring with a stirrer, 50 g of ethanol (1.561 mol, 5 wt times with respect to 1,3-DM-CBDA) was added dropwise over 1 hour. When the mixture was stirred for 5 days after completion of the dropwise addition, a uniform reaction solution was obtained.
After the solvent of this reaction solution was distilled off with an evaporator, 70.55 g of ethyl acetate was added, the mixture was heated to 80 ° C. with stirring and refluxed for 30 minutes, and then the internal temperature was 25 ° C. at a rate of 2-3 ° C. over 10 minutes. Cooled until. After stirring as it was at 25 ° C. for 30 minutes, the precipitated white crystal was taken out by filtration, and this crystal was washed twice with 7.05 g of ethyl acetate. This was dried under reduced pressure to obtain 9.15 g of white crystals.
The crystals were confirmed to be compound (1-4) by 1H NMR analysis results (HPLC relative area 99.6%) (yield 64.8%).
1H NMR (DMSO-d6, δppm): 12.82 (s, 2H), 4.09-4.04 (q, 4H), 3.36 (s, 2H), 1.41 (s, 6H), 1.16-1.41 (t, 6H).
As a result of analyzing the HPLC measurement data of the reaction solution using a sample, the HPLC relative areas of the compounds (1-4) and (2-4) were 83% and 17%, respectively.

Example 45 Synthesis of compounds (1-10) and (2-10)

Under a nitrogen stream, 10 g (0.045 mol) of 1,3-DM-CBDA and 50 g of acetonitrile were charged into a 200 mL four-necked flask, and 0.353 g (0.0045 mol) of pyridine was added, and magnetic. After suspending at 25 ° C. with stirring with a stirrer, 50 g of 2-propanol (0.416 mol, 2.5 wt times with respect to 1,3-DM-CBDA) was added dropwise over 1 hour. It stirred for 12 days after completion | finish of dripping.
After the solvent of this reaction liquid was distilled off with an evaporator (13.05 g), 52.20 g of acetonitrile and 6.53 g of 2-propanol were added, dissolved by heating to 71 ° C., and allowed to cool to 27 ° C. for 1 hour. After stirring this for 1 hour under water cooling, the precipitated white crystals were taken out by filtration, and the crystals were washed with 13.05 g of acetonitrile. This was dried under reduced pressure to obtain 6.08 g of white crystals.
This crystal was confirmed to be (1-10) by 1H NMR analysis (HPLC relative area 88.8%) (yield 46.6%).
1H NMR (DMSO-d6, δppm): 12.76 (s, 2H), 4.92-4.85 (m, 2H), 3.31 (s, 2H), 1.41 (s, 6H), 1.19-1.17 (q, 6H).
As a result of analyzing the HPLC measurement data of the reaction solution using a sample, the HPLC relative areas of the compounds (1-10) and (2-10) were 88% and 12%, respectively.

Example 46 Synthesis of Compounds (1-10) and (2-10) In a 200 mL four-necked flask under a nitrogen stream, 1,3-DM-CBDA 10 g (0.045 mol), acetonitrile 50 g (1 .22 mol, 5 wt times with respect to 1,3-DM-CBDA), 0.353 g (0.0045 mol) of pyridine was added, and the mixture was heated and stirred at 50 ° C. with stirring with a magnetic stirrer. 416 mol, 2.5 wt times with respect to 1,3-DM-CBDA) was added dropwise over 1 hour. It stirred for 7 days after completion | finish of dripping.
As a result of analyzing the reaction solution by HPLC, the HPLC relative area percentages of the compounds (1-10) and (2-10) were 83% and 17%, respectively.

Example 47 Synthesis of bis (chlorocarbonyl) compound (3-1)

Under a nitrogen stream, 234.15 g (0.81 mol) of the compound (1-1) and 117.77 g (11.68 mol.5 times by weight) of n-heptane were charged into a 3 L four-necked flask, 64 g (0.01 mol) was added, and the mixture was heated and stirred to 75 ° C. while stirring with a magnetic stirrer. Subsequently, 289.93 g (11.68 mol) of thionyl chloride was added dropwise over 1 hour. Foaming started immediately after the dropping, and the reaction solution became uniform 30 minutes after the completion of the dropping, and the foaming stopped. Subsequently, the mixture was stirred as it was at 75 ° C. for 1 hour and 30 minutes, and then the solvent was distilled off with an evaporator until the internal volume reached 924.42 g in a water bath at 40 ° C. This was heated to 60 ° C., the crystals precipitated when the solvent was distilled off were dissolved, the insoluble matter was filtered by performing hot filtration at 60 ° C., and then the filtrate was heated to 25 ° C. at a rate of 1 ° C. for 10 minutes. It was cooled with. After stirring for 30 minutes at 25 ° C., the precipitated white crystals were taken out by filtration, and the crystals were washed with 264.21 g of n-heptane. This was dried under reduced pressure to obtain 226.09 g of white crystals.
Subsequently, 226.09 g of the white crystals obtained above and 454.18 g of n-heptane were charged in a 3 L four-necked flask in a nitrogen stream, and heated and stirred at 60 ° C. to dissolve the crystals. Thereafter, the mixture was cooled and stirred at a rate of 1 ° C. for 10 minutes to 25 ° C. to precipitate crystals. After stirring for 1 hour at 25 ° C., the precipitated white crystals were taken out by filtration, washed with 113.04 g of n-hexane, and dried under reduced pressure to obtain 203.91 g of white crystals. According to the result of 1H NMR analysis, this crystal was found to be compound (3-1), that is, dimethyl-1,3-bis (chlorocarbonyl) -1,3-dimethylcyclobutane-2,4-dicarboxylate (hereinafter referred to as 1,3 -DM-CBDE-C1) (HPLC relative area 99.5%) (yield 77.2%).
1H NMR (CDCl3, δppm): 3.78 (s, 6H), 3.72 (s, 2H), 1.69 (s, 6H).

<Examples 48 to 53>
A series of operations were carried out in the same manner as in Example 47, and the type of catalyst, the number of catalyst equivalents, and the temperature were each set to the values shown in the following table. The reaction end time was the time when the reaction solution was a homogeneous solution and gas generation was completely stopped.

Example 54 Synthesis of bis (chlorocarbonyl) compound (4-1)

Under a nitrogen stream, 20.01 g (69.38 mmol) of compound (2-1) and 100 g of n-heptane were charged into a 200 mL four-necked flask, and 0.055 g (0.69 mmol) of pyridine was then added. The mixture was heated to 70 ° C. with stirring with a tic stirrer. Subsequently, 24.75 g (208.15 mmol) of thionyl chloride was added dropwise at 72 ° C. over 1 hour. Foaming started immediately after the dropping, and the foaming stopped 1 hour after the dropping. Subsequently, the mixture was stirred as it was at 73 ° C. for 1 hour and 30 minutes, and the solvent was distilled off with an evaporator until the internal volume reached 53.9 g in a water bath at 40 ° C. Subsequently, the remaining liquid was heated to 60 ° C., stirred for 30 minutes, and then cooled to 28 ° C. over 30 minutes. After stirring for 30 minutes at 20 ° C., the precipitated white crystals were taken out by filtration, and the crystals were washed with 22.57 g of n-heptane. This was dried under reduced pressure to obtain 21.93 g of white crystals. The crystals were confirmed to be compound (4-1) by 1H NMR analysis (HPLC relative area: 98.5%) (yield: 97.2%).
1H NMR (CDCl3, δppm): 4.15 (s, 1H), 3.84 (s, 3H), 3.80 (s, 3H), 3.44 (s, 1H), 1.74 (s, 3H), 1.59 (s, 3H).

Example 55 Synthesis of compound (2-2)

Under a nitrogen stream, a 3-L four-necked flask was charged with 1,2-dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride (compound of formula (5-2), hereinafter 1,2-DM). -CBDA) 19.9 g (0.089 mol) and ethyl acetate 49.7 g were charged, 0.70 g (0.009 mol) of pyridine was added, and the mixture was suspended at 25 ° C. with stirring with a magnetic stirrer. 49.75 g (1.55 mol, 2.5 wt times with respect to 1,2-DM-CBDA) was added dropwise over 1 hour so that the internal temperature was 30 ° C. or lower. 20 minutes after the completion of the dropping, the reaction solution was completely dissolved and stirred as it was at 20-30 ° C. for 40 minutes.
The solvent of this reaction solution was distilled off with an evaporator at a water bath of 40 ° C. and 170 to 140 Torr until the internal volume reached 51.18 g. Subsequently, 127.94 g of ethyl acetate was added and stirred, and then the solvent was distilled off with an evaporator at a water bath of 40 ° C. and 170 to 140 Torr until the internal volume reached 51.18 g. Thereafter, 127.94 g of ethyl acetate was added again and stirred, and then the solvent was distilled off with an evaporator at a water bath of 40 ° C. and 170 to 140 Torr until the internal volume reached 117.71 g. Moreover, as a result of measuring the solvent distilled off at this time by gas chromatography, the area of methanol was 0.3%. Subsequently, the remaining slurry solution was heated to 80 ° C. and refluxed for 30 minutes, and then cooled at a rate of 2-3 ° C. for 10 minutes until the internal temperature reached 25 ° C. After stirring for 30 minutes at 25 ° C., the precipitated white crystals were taken out by filtration, and the crystals were washed twice with 12.8 g of ethyl acetate. This was dried under reduced pressure to obtain 16.96 g of white crystals. The crystals were confirmed to be the compound (2-2) by 1H NMR analysis results (HPLC relative area 95.5%) (yield 66.7%).
1H NMR (DMSO-d6, δppm): 13.16 (s, 2H), 3.56 (s, 6H), 3.21 (s, 2H), 1.30 (s, 6H).
As a result of analyzing the HPLC measurement data of the reaction solution using a sample, the HPLC relative area of the compound (2-2) was 96%.

Example 56 Synthesis of bis (chlorocarbonyl) compound (4-2)

Under a nitrogen stream, 16.46 g (0.06 mol) of compound (2-2) and 82.3 g of n-heptane were charged into a 3 L four-necked flask, and 0.045 g (0.6 mmol) of pyridine was added. The mixture was heated and stirred to 75 ° C. with stirring with a magnetic stirrer. Subsequently, 20.38 g (0.17 mol) of thionyl chloride was added dropwise over 1 hour. Foaming started immediately after the dropping, and the reaction solution became uniform 30 minutes after the dropping, and the foaming stopped. Subsequently, the mixture was stirred as it was at 75 ° C. for 1 hour and 30 minutes, and then the solvent was distilled off with an evaporator at a water bath of 40 ° C. until the internal volume reached 64.98 g. This was heated to 60 ° C., the crystals precipitated when the solvent was distilled off were dissolved, the insoluble matter was filtered by performing hot filtration at 60 ° C., and then the filtrate was heated to 25 ° C. at a rate of 1 ° C. for 10 minutes. It was cooled with. After stirring for 30 minutes at 25 ° C., the precipitated white crystals were taken out by filtration, and the crystals were washed with 18.57 g of n-heptane. This was dried under reduced pressure to obtain 16.42 g of white crystals. This crystal was confirmed to be the compound (4-2) by 1H NMR analysis (HPLC relative area 95.5%) (yield 88.5%).
1H NMR (CDCl3, δppm): 3.72 (s, 6H), 3.42 (s, 2H), 1.82 (s, 6H).

<Reference Example 1>

Under a nitrogen stream, in a 3 L four-necked flask, 300 g (1.53 mol) of cyclobutane-1,2,3,4-tetracarboxylic acid-1: 2,3: 4-dianhydride (hereinafter abbreviated as CBDA) After adding 900 g of acetonitrile, adding 12.1 g (0.153 mol) of pyridine and suspending at 25 ° C. with magnetic stirrer stirring, 750 g of methanol (23.4 mol, 2.5 wt times with respect to CBDA) was added. It was dripped over 1 hour so that internal temperature might be 30 degrees C or less. 20 minutes after the completion of dropping, the reaction solution was completely dissolved and stirred as it was at 20 to 30 ° C. for 1 hour. As a result of analyzing this reaction solution by HPLC, the relative areas of CB-2,4-DME and CB-2,3-DME were 49.2% and 49.8%, respectively, and the reaction was performed in the presence of pyridine. The selectivity of the regioisomer was not obtained even after the operation.
The solvent of this reaction liquid was distilled off at 40 ° C. in a water bath until the internal volume became 796.08 g using an evaporator. Subsequently, 995.10 g of acetonitrile was added and stirred, and then the solvent was distilled off at 40 ° C. in a water bath until the internal volume reached 796.08 g using an evaporator. Further, 995.10 g of acetonitrile was again added and stirred, and then the solvent was distilled off at 40 ° C. in a water bath using an evaporator until the internal volume reached 796.08 g. Moreover, as a result of measuring the solvent distilled off at this time by gas chromatography, the area of methanol was 0.3%. Subsequently, 398.04 g of acetonitrile was added, heated to 80 ° C. and refluxed for 30 minutes, and then cooled at a rate of 2-3 ° C. for 10 minutes until the internal temperature reached 25 ° C. After stirring for 30 minutes at 25 ° C., the precipitated white crystals were taken out by filtration, and the crystals were washed twice with 199.02 g of acetonitrile. This was dried under reduced pressure to obtain 157.54 g of white crystals. The crystals were confirmed to be CB-2,4-DME (HPLC relative area 96.4%) (yield 39.6%) by 1H NMR analysis.
1H NMR (DMSO-d6, δppm): 12.81 (s, 2H), 3.61 (s, 6H), 3.59-3.54 (m, 2H).

<Application Example 1> Polymerization of Compound (3-1) and Paraphenylenediamine In a 50 mL two-necked flask under nitrogen flow, 0.6005 g (5.5527 mmol) of paraphenylenediamine, 10 mL of N-methylpyrrolidone, and γ-butyrolactone 10 mL and 1.06 mL of pyridine were charged and stirred with a magnetic stirrer at 25 ° C. to completely dissolve paraphenylenediamine. Thereafter, the reaction solution was ice-cooled, and compound (3-1) was added over 30 seconds using a funnel while stirring with a magnetic stirrer. Thereafter, the funnel used for the addition was washed with 3 mL of N-methylpyrrolidone, purged with nitrogen, and stirred at 0 ° C. for 20 minutes. After 20 minutes, the temperature was raised to 20 ° C. and then stirred for 3 hours at 20 ° C. The polymerization solution was sampled 1 hour later, 2 hours later, and the viscosity was measured to find that it was 1 hour later (1300 mPa · s) and 2 hours later (1500 mPa · s).

<Application Example 2> Polymerization of Compound (4-1) and Paraphenylenediamine In a 50 mL two-necked flask under a nitrogen stream, 0.6005 g (5.5527 mmol) of paraphenylenediamine, 10 mL of N-methylpyrrolidone, and γ-butyrolactone 10 mL and 1.06 mL of pyridine were charged and stirred with a magnetic stirrer at 25 ° C. to completely dissolve paraphenylenediamine. Thereafter, the reaction solution was ice-cooled, and compound (4-1) was added using a funnel over 30 seconds while stirring with a magnetic stirrer. Thereafter, the funnel used for the addition was washed with 3 mL of N-methylpyrrolidone, purged with nitrogen, and stirred at 0 ° C. for 20 minutes. After 20 minutes, the temperature was raised to 20 ° C. and then stirred for 3 hours at 20 ° C. The polymerization solution was sampled 1 hour later, 2 hours later, and the viscosity was measured to find that it was 1 hour later (28 mPa · s) and 2 hours later (28 mPa · s).

<Synthesis Examples 101-104, Comparative Synthesis Examples 101-103, Examples 101-111, Comparative Examples 101-107>
The abbreviations and structures of the compounds used in the following synthesis examples, comparative synthesis examples, examples, and comparative examples are shown below.
1,3-DM-CBDA: 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,3-DM-CBDE: 2,4-bis (methoxycarbonyl) -1,3 -Dimethylcyclobutane-1,3-dicarboxylic acid p-PDA: p-phenylenediamine

(Organic solvent)
NMP: N-methyl-2-pyrrolidone γ-BL: γ-butyrolactone BCS: butyl cellosolve DMF: N, N-dimethylformamide DEF: N, N-diethylformamide

The measurement methods for ¹ HNMR, FT-IR, X-ray crystal structure analysis, viscosity, molecular weight, orientation film anisotropy, voltage holding ratio, and ion density are shown below.

[ ¹ HNMR]
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (manufactured by Varian): 400 MHz
Standard substance: Tetramethylsilane (TMS)

[FT-IR]
Apparatus: NICOLET5700 (manufactured by Thermo ELECTRON)
Smart Orbit accessory measurement method: ATR method

[X-ray crystal structure analysis]
Device: DIP2030 (manufactured by MacScience)
X-ray: Mokα (40 kV, 200 mA)
Measurement temperature: 298.0K

[viscosity]
In the synthesis example, the viscosity of the polyamic acid ester and the polyamic acid solution is an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.). The temperature was measured at 25 ° C.

[Molecular weight]
The molecular weights of the polyamic acid ester and the polyamic acid were measured by a GPC (normal temperature gel permeation chromatography) apparatus, and the number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated as polyethylene glycol and polyethylene oxide equivalent values.
GPC device: manufactured by Shodex (GPC-101)
Column: manufactured by Shodex (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) 30 mmol / L, tetrahydrofuran) (THF) is 10 ml / L)
Flow rate: 1.0 ml / min Standard sample for preparation of calibration curve: TSK standard polyethylene oxide (weight average molecular weight (Mw) of about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polymer laboratory Polyethylene glycol manufactured by the company (peak top molecular weight (Mp) of about 12,000, 4,000, 1,000). In order to avoid the overlapping of peaks, the measurement was performed by mixing four types of 900,000, 100,000, 12,000 and 1,000, and three types of 150,000, 30,000 and 4,000. Two samples of mixed samples are measured separately.

[Anisotropy of alignment film]
The anisotropy of the alignment film was measured as follows.
Measurement was performed using a liquid crystal alignment film evaluation system “Ray Scan Lab H” (LYS-LH30S-1A) manufactured by Moritex Corporation. The polyimide film having a thickness of 100 nm was irradiated with ultraviolet rays through a polarizing plate, and the magnitude of anisotropy with respect to the alignment direction of the obtained alignment film was measured.

[Voltage holding ratio]
The voltage holding ratio of the liquid crystal cell was measured as follows.
By applying a voltage of 4 V for 60 μs and measuring the voltage after 16.67 ms, the fluctuation from the initial value was calculated as the voltage holding ratio. At the time of measurement, the temperature of the liquid crystal cell was 23 ° C. and 60 ° C., and the measurement was performed at each temperature.

[Ion density]
The ion density of the liquid crystal cell was measured as follows.
Measurement was carried out using a 6254 type liquid crystal property evaluation apparatus manufactured by Toyo Technica. A triangular wave of 10 V and 0.01 Hz was applied, and an area corresponding to the ion density of the obtained waveform was calculated by a triangle approximation method to obtain an ion density. At the time of measurement, the temperature of the liquid crystal cell was 23 ° C. and 60 ° C., and the measurement was performed at each temperature.

(Synthesis Example 101)
<Synthesis of dimethyl 1,3-bis (chlorocarbonyl) -1,3-dimethylcyclobutane-2,4-dicarboxylate (1,3-DM-CBDE-Cl)>

Under a nitrogen stream, 234.15 g (0.81 mol) of 1,3-DM-CBDE obtained by the same operation as in Example 1 and 1170.77 g of n-heptane were placed in a 3 L four-necked flask. After the preparation, 0.64 g (0.01 mol) of pyridine was added, and the mixture was heated and stirred to 75 ° C. with stirring with a magnetic stirrer. Subsequently, 289.93 g (11.68 mol) of thionyl chloride was added dropwise over 1 hour. Foaming started immediately after the dropping, and the reaction solution became uniform 30 minutes after the completion of the dropping, and the foaming stopped. Subsequently, the mixture was stirred as it was at 75 ° C. for 1 hour and 30 minutes, and then the solvent was distilled off with an evaporator until the internal volume reached 924.42 g in a water bath at 40 ° C. This was heated to 60 ° C., the crystals precipitated when the solvent was distilled off were dissolved, the insoluble matter was filtered by performing hot filtration at 60 ° C., and then the filtrate was heated to 25 ° C. at a rate of 1 ° C. for 10 minutes. It was cooled with. After stirring for 30 minutes at 25 ° C., the precipitated white crystals were taken out by filtration, and the crystals were washed with 264.21 g of n-heptane. This was dried under reduced pressure to obtain 226.09 g of white crystals.
Subsequently, 226.09 g of the white crystals obtained above and 454.18 g of n-heptane were charged into a 3 L four-necked flask in a nitrogen stream, and heated and stirred at 60 ° C. to dissolve the crystals. Thereafter, the mixture was cooled and stirred at a rate of 1 ° C. for 10 minutes to 25 ° C. to precipitate crystals. After stirring for 1 hour at 25 ° C., the precipitated white crystals were taken out by filtration, washed with 113.04 g of n-hexane, and dried under reduced pressure to obtain 203.91 g of white crystals (HPLC Relative area 99.5%).
According to the results of analysis such as ¹ H NMR, this crystal has 1,3-DM-CBDE-Cl which is the target compound, that is, a chlorocarbonyl group at the 1,3-position and a methyl ester group at the 2,4-position of the cyclobutane ring. It was confirmed that the acid chloride was bound.
¹ H NMR (CDCl ₃ , δ ppm): 3.78 (s, 6H), 3.72 (s, 2H), 1.69 (s, 6H).

(Synthesis Example 102) Production of Polyamic Acid Ester Resin (A-1) A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, and 0.600 g (5.55 mmol) of p-PDA was added thereto, 27.5 g of NMP, As a base, 1.03 g (13.05 mmol) of pyridine was added and dissolved by stirring. Next, 1.77 g (5.44 mmol) of 1,3DM-CBDE-Cl of Synthesis Example 101 was added while stirring the diamine solution, and the mixture was reacted for 2 hours under water cooling. The obtained polyamic acid ester solution was poured into 197 g of water while stirring, and the precipitated white precipitate was collected by filtration, followed by 197 g of water once, 197 g of methanol once, and 49 g of methanol. By washing three times and drying, 1.72 g of white polyamic acid ester resin (A-1) powder was obtained. The yield was 87.4%. Moreover, the molecular weight of this polyamic acid ester was Mn = 24,868 and Mw = 51,727.
Synthesis Example 103 Production of Polyamic Acid Ester Resin (A-2) A 300 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, and 2.820 g (26.08 mmol) of p-PDA, 4,4′-diamino 1,357 g (6.519 mmol) of Tran was added, 226 g of NMP and 5.82 g (73.54 mmol) of pyridine as a base were added, and dissolved by stirring. Next, 9.963 g (30.64 mmol) of 1,3DM-CBDE-Cl of Synthesis Example 1 was added while stirring the diamine solution, and the mixture was reacted for 4 hours under water cooling. The obtained polyamic acid ester solution was poured into 1190 g of water while stirring, and the precipitated white precipitate was collected by filtration, followed by 1190 g of water once, 1190 g of ethanol once, and 298 g of ethanol. After washing 3 times and drying, 10.64 g of white polyamic acid ester resin (A-2) powder was obtained. The yield was 89.4%. Moreover, the molecular weight of this polyamic acid ester was Mn = 14,153 and Mw = 35,239.
(Synthesis Example 104) Production of Polyamic Acid Ester Resin (A-3) A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 0.998 g (4.70 mmol) of 4,4′-ethylenedianiline was added, and NMP19 0.7 g and 0.783 g (9.89 mmol) of pyridine as a base were added and dissolved by stirring. Next, 1.532 g (4.71 mmol) of 1,3DM-CBDE-Cl of Synthesis Example 101 was added while stirring the diamine solution, and the mixture was reacted for 2 hours under water cooling. The obtained polyamic acid ester solution was added to 197 g of water while stirring, and the precipitated white precipitate was collected by filtration, followed by 219 g of water once, 219 g of methanol once, and 55 g of methanol. By washing three times and drying, 1.70 g of white polyamic acid ester resin (A-3) powder was obtained. The yield was 77.7%. Moreover, the molecular weight of this polyamic acid ester was Mn = 19,210 and Mw = 35,076.
(Comparative Synthesis Example 101) Preparation of Polyamic Acid (B-1) Solution 19.05 g (85.98 mol) of 1,3DM-CBDA was placed in a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and γ- BL63g was added and it stirred and dissolved, sending nitrogen. While stirring this acid dianhydride solution, 100 g of NMP was added, then p-PDA 8.87 (82.02 mmol) was added, NMP was further added so that the solid content concentration was 10% by mass, and 24 hours at room temperature. By stirring, a solution of polyamic acid (B-1) was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 356 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 21,137 and Mw = 43,145.
(Comparative Synthesis Example 102) Preparation of polyamic acid (B-2) solution 1.730 g (16.0 mmol) of p-PDA in a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 4,4′- 0.835 g (4.01 g) of diaminotran was taken, 21.23 g of γ-BL and 24.81 g of NMP were added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution, 4.46 g (19.90 mol) of 1,3DM-CBDA was added, NMP was further added so that the solid content concentration was 10% by mass, and the mixture was stirred at room temperature for 24 hours to be polyamic acid. A solution of (B-2) was obtained. The viscosity of the polyamic acid solution at a temperature of 25 ° C. was 158.8 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 15,213 and Mw = 31,700.
(Comparative Synthesis Example 103) Preparation of Polyamic Acid (B-3) Solution 4.314 g (20.32 mmol) of 4,4′-ethylenedianiline was placed in a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. , 26.90 g of γ-BL and 30.73 g of NMP were added, and dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 4.45 g (19.85 mol) of 1,3DM-CBDA was added, NMP was further added so that the solid content concentration was 10% by mass, and the mixture was stirred at room temperature for 24 hours to be polyamic acid. A solution of (B-3) was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 168.7 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 19,322 and Mw = 45,601.

Example 101 Preparation of Liquid Crystal Alignment Agent (AI) 1.28 g of the polyamic acid ester resin (A-1) powder obtained in Synthesis Example 102 was placed in a 50 mL Erlenmeyer flask containing a stir bar, and DMF12. 71 g was added and stirred at room temperature for 24 hours to dissolve to obtain a polyamic acid ester resin solution. To this solution, 4.36 g of γ-BL and 4.20 g of BCS were added, and stirred for 30 minutes with a magnetic stirrer to obtain the liquid crystal aligning agent (AI) of the present invention.
<Example 102> Preparation of liquid crystal aligning agent (A-II) 1.66 g of the polyamic acid ester resin (A-2) powder obtained in Synthesis Example 103 was placed in a 50 mL Erlenmeyer flask containing a stir bar, and DEF14. 96 g was added, and the mixture was stirred and dissolved at room temperature for 24 hours to obtain a polyamic acid ester resin (A-2) solution. 6.61 g of this solution was dispensed into another 50 mL Erlenmeyer flask containing a stirring bar, γ-BL 2.20 g and BCS 2.20 g were added, and the mixture was stirred with a magnetic stirrer for 30 minutes, and the liquid crystal aligning agent (A -II) was obtained.
Example 103 Preparation of Liquid Crystal Alignment Agent (A-III) 1.15 g of the polyamic acid ester resin (A-3) powder obtained in Synthesis Example 104 was placed in a 50 mL Erlenmeyer flask containing a stir bar, and DEF10. 42 g was added, and the mixture was stirred and dissolved at room temperature for 24 hours to obtain a polyamic acid ester resin (A-3) solution. 5.66 g of this solution was dispensed into another 50 mL Erlenmeyer flask containing a stir bar, added with 1.90 g of γ-BL and 1.92 g of BCS, stirred for 30 minutes with a magnetic stirrer, and the liquid crystal aligning agent (A -III) was obtained.
Example 104 Preparation of Liquid Crystal Alignment Agent (A-IV) 4.12 g of the polyamic acid ester resin (A-2) solution obtained in Example 102 was placed in a 50 mL Erlenmeyer flask containing a stir bar, and γ- BL0.88 g, BCS 1.40 g, 0.1084 g (amide) of N-α, N-ω1, N-ω2-tri-t-butoxycarbonyl-L-arginine (hereinafter abbreviated as Boc-Arg) as an imidization accelerator 0.1 mol equivalent to 1 mol of acid ester group) was added, and the mixture was stirred at room temperature for 30 minutes to completely dissolve Boc-Arg to obtain the liquid crystal aligning agent (A-IV) of the present invention.
Example 105 Preparation of Liquid Crystal Alignment Agent (AV) 3.16 g of the polyamic acid ester resin (A-3) solution obtained in Example 103 was placed in a 50 mL Erlenmeyer flask containing a stirrer, and γ- Add 1.03 g of BL, 1.03 g of BCS, 0.0650 g of Boc-Arg as an imidization accelerator (0.1 mol equivalent to 1 mol of amic acid ester group), and stir at room temperature for 30 minutes to completely remove Boc-Arg. To obtain a liquid crystal aligning agent (AV) of the present invention.
Comparative Example 101 Preparation of Liquid Crystal Alignment Agent (BI) 14.10 g of the polyamic acid (B-1) solution obtained in Comparative Synthesis Example 101 was dispensed into a 50 mL Erlenmeyer flask containing a stir bar, and NMP13 .57 g and 6.93 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (BI).
Comparative Example 102 Preparation of Liquid Crystal Alignment Agent (B-II) 6.34 g of the polyamic acid (B-2) solution obtained in Comparative Synthesis Example 102 was dispensed into a 50 mL Erlenmeyer flask containing a stir bar, and NMP2 .34 g and BCS 2.17 g were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (B-II).
Comparative Example 103 Preparation of Liquid Crystal Alignment Agent (B-III) 6.47 g of the polyamic acid (B-3) solution obtained in Comparative Synthesis Example 103 was dispensed into a 50 mL Erlenmeyer flask containing a stir bar, and NMP1 .85 g and BCS 2.10 g were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (B-III).

<Example 106>
The liquid crystal aligning agent (AI) obtained in Example 101 was filtered through a 1.0 μm filter, spin-coated on a glass substrate, dried on a hot plate at a temperature of 80 ° C. for 5 minutes, and then 230 ° C. For 30 minutes (firing condition 1) or at 250 ° C. for 30 minutes (firing condition 2) to obtain a polyimide film having a thickness of 100 nm. The coating surface was irradiated with 1.0 J / cm ^{2 of} 254 nm ultraviolet light through a polarizing plate to obtain a liquid crystal alignment film. The anisotropic magnitude | size with respect to the orientation direction of the obtained liquid crystal aligning film was measured. Moreover, the imidation ratio in each baking condition was measured by IR. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.
<Example 107>
A liquid crystal alignment film was prepared in the same manner as in Example 106 except that the liquid crystal aligning agent (A-II) obtained in Example 102 was used, and the degree of anisotropy and the imidization ratio with respect to the alignment direction were measured. did. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.
<Example 108>
A liquid crystal alignment film was prepared in the same manner as in Example 106 except that the liquid crystal aligning agent (A-III) obtained in Example 103 was used, and the anisotropy and the imidization ratio with respect to the alignment direction were measured. did. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.
<Example 109>
The liquid crystal aligning agent (A-IV) obtained in Example 104 was filtered through a 1.0 μm filter, spin-coated on a glass substrate, dried on a hot plate at a temperature of 80 ° C. for 5 minutes, and then 230 ° C. Was fired for 30 minutes (firing condition 1) to obtain a polyimide film having a film thickness of 100 nm. The coating surface was irradiated with 1.0 J / cm ^{2 of} 254 nm ultraviolet light through a polarizing plate to obtain a liquid crystal alignment film. The anisotropic magnitude | size with respect to the orientation direction of the obtained liquid crystal aligning film was measured. Moreover, the imidation ratio in each baking condition was measured by IR. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.
<Example 110>
A liquid crystal alignment film was prepared in the same manner as in Example 109 except that the liquid crystal aligning agent (AV) obtained in Example 105 was used, and the anisotropy and the imidization ratio with respect to the alignment direction were measured. did. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.

<Comparative Example 104>
A liquid crystal alignment film was prepared in the same manner as in Example 106 except that the liquid crystal aligning agent (BI) obtained in Comparative Example 101 was used, and the degree of anisotropy and the imidization ratio with respect to the alignment direction were measured. did. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.
<Comparative Example 105>
A liquid crystal alignment film was prepared in the same manner as in Example 106 except that the liquid crystal aligning agent (B-II) obtained in Comparative Example 102 was used, and the degree of anisotropy and the imidization ratio with respect to the alignment direction were measured. did. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.
<Comparative Example 106>
A liquid crystal alignment film was prepared in the same manner as in Example 106 except that the liquid crystal aligning agent (B-III) obtained in Comparative Example 103 was used, and the degree of anisotropy and the imidization ratio with respect to the alignment direction were measured. did. The measurement results of the magnitude of anisotropy and the imidization rate are shown in the table described later.
The anisotropy measurement results with respect to the orientation direction in Examples 106 to 110 and Comparative Examples 104 to 106 are shown in Table 101 below.

The measurement results of the imidization ratio in Examples 106 to 110 and Comparative Examples 104 to 106 are shown in Table 102 below.

As described above, the liquid crystal alignment film produced by the photoalignment treatment using the liquid crystal aligning agent of the present invention has the same or lower imidation ratio than the liquid crystal alignment film of the comparative example made of polyamic acid. It was confirmed to have higher anisotropy.

<Example 111>
The liquid crystal aligning agent (AI) obtained in Example 101 was filtered through a 1.0 μm filter, spin-coated on a glass substrate with a transparent electrode, and dried on a hot plate at a temperature of 80 ° C. for 5 minutes. A polyimide film having a thickness of 100 nm was obtained after baking at a temperature of 230 ° C. for 20 minutes. The coating film surface was irradiated with 1.0 J / cm ^{2 of} 254 nm ultraviolet light through a polarizing plate to obtain a substrate with a liquid crystal alignment film. Two substrates with such a liquid crystal alignment film are prepared, and a 4 μm spacer is dispersed on the surface of the liquid crystal alignment film of one of the substrates, and then combined so that the alignment directions of the two substrates are twisted by 85 degrees from parallel. The periphery was sealed leaving the inlet, and an empty cell with a cell gap of 4 μm was produced. Liquid crystal (MLC-2041, manufactured by Merck & Co., Inc.) was vacuum-injected into this empty cell at room temperature, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.
When the alignment state of the liquid crystal cell was observed with a polarizing microscope, it was confirmed that the liquid crystal cell had a uniform alignment without defects. As a result of measuring the voltage holding ratio of this liquid crystal cell and then measuring the ion density, the voltage holding ratio was 98.5% at a temperature of 23 ° C., 97.2% at a temperature of 60 ° C., and the ion density was 23 ° C. in 79pC / cm ^2, was 584pC / cm ² at a temperature 60 ° C..

<Comparative Example 107>
A twisted nematic liquid crystal cell was produced in the same manner as in Example 111 except that the liquid crystal aligning agent (BI) obtained in Comparative Example 101 was used.
When the alignment state of the liquid crystal cell was observed with a polarizing microscope, it was confirmed that the liquid crystal cell had a uniform alignment without defects. With respect to this cell, the voltage holding ratio was measured and then the ion density was measured. As a result, the voltage holding ratio was 98.4% at a temperature of 23 ° C., 96.4% at a temperature of 60 ° C., and the ion density was 23 ° C. 247 pC / cm ^{2 at} a temperature of 60 ° C. and 1160 pC / cm ² .

As described above, it was confirmed that the liquid crystal element using the liquid crystal alignment film produced by the method of the present invention was excellent in liquid crystal alignment, high voltage holding ratio even at high temperature, and low ion density.

The tetracarboxylic acid dialkyl ester or bis (chlorocarbonyl) compound of the present invention can be used as a raw material monomer for polyamide, polyimide, polyester and the like.
The liquid crystal aligning agent of this invention can be utilized suitably for the use which produces a liquid crystal aligning film by photo-alignment processing. The liquid crystal alignment film produced by the method of the present invention is useful for producing various liquid crystal elements.
The specification, claims, drawings and abstract of Japanese Patent Application No. 2009-030285 filed on Feb. 12, 2009 and Japanese Patent Application No. 2009-030292 filed on Feb. 12, 2009. Is hereby incorporated by reference as a disclosure of the specification of the present invention.

Claims (20)

1. Tetracarboxylic acid dialkyl ester represented by the following formula [1] or formula [2].
   

   

   (Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
2. The tetracarboxylic acid dialkyl ester according to claim 1, which is represented by the following formula [1-a], formula [2-a] or formula [2-b].
   

   

   (Wherein R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² represents an alkyl group having 1 to 5 carbon atoms)
3. A bis (chlorocarbonyl) compound represented by the following formula [3] or formula [4].
   

   

   (Wherein R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
4. The bis (chlorocarbonyl) compound according to claim 3, which is represented by the following formula [3-a], formula [4-a] or formula [4-b].
   (Wherein R ¹ represents an alkyl group having 1 to 5 carbon atoms, and R ² represents an alkyl group having 1 to 5 carbon atoms)
5. The tetracarboxylic acid represented by the formula [1] or the formula [2] according to claim 1, wherein a tetracarboxylic dianhydride represented by the following formula [5] is reacted with an alcohol having 1 to 5 carbon atoms. A method for producing a dialkyl ester.
   

   

   (Wherein R ² is an alkyl group having 1 to 5 carbon atoms, and n represents 1 to 4)
6. The tetracarboxylic dianhydride represented by the following formula [5-a] is reacted with an alcohol having 1 to 5 carbon atoms in the formula [1-a] or the formula [2-a] according to claim 2. The manufacturing method of the tetracarboxylic-acid dialkyl ester represented.
   

   

   (Wherein R ² represents an alkyl group having 1 to 5 carbon atoms)
7. A dialkyl tetracarboxylate represented by the formula [2-b] according to claim 2, wherein a tetracarboxylic dianhydride represented by the following formula [5-b] is reacted with an alcohol having 1 to 5 carbon atoms. Ester production method.
   

   

   (Wherein R ² represents an alkyl group having 1 to 5 carbon atoms)
8. The production method according to any one of claims 5 to 7, wherein tetracarboxylic dianhydride and an alcohol having 1 to 5 carbon atoms are reacted in the presence of an acidic compound or a basic compound.
9. The production method according to any one of claims 5 to 7, wherein tetracarboxylic dianhydride and an alcohol having 1 to 5 carbon atoms are reacted in the presence of a basic compound.
10. The tetracarboxylic acid dialkyl ester represented by the formula [1] or the formula [2] according to claim 1 is reacted with a chlorinating agent, and represented by the formula [3] or the formula [4] according to claim 3. Process for producing a bis (chlorocarbonyl) compound.
11. A bis (chlorocarbonyl) represented by the formula [3-a] according to claim 4, wherein the tetracarboxylic acid dialkyl ester represented by the formula [1-a] according to claim 2 is reacted with a chlorinating agent. ) Method for producing compound.
12. A bis (chlorocarbonyl) represented by the formula [4-a] according to claim 4, wherein a tetraalkyl dialkyl ester represented by the formula [2-a] according to claim 2 is reacted with a chlorinating agent. ) Method for producing compound.
13. A bis (chlorocarbonyl) represented by the formula [4-b] according to claim 4, wherein the tetracarboxylic acid dialkyl ester represented by the formula [2-b] according to claim 2 is reacted with a chlorinating agent. Compound production method.
14. The production method according to any one of claims 10 to 13, wherein the tetracarboxylic acid dialkyl ester and the chlorinating agent are reacted in the presence of a basic compound.
15. The production method according to any one of claims 10 to 13, wherein the tetracarboxylic acid dialkyl ester and the chlorinating agent are reacted in the presence of pyridine.
16. A bis (chlorocarbonyl) compound containing 60 mol% or more of an acid chloride represented by the following formula (101) in which a chlorocarbonyl group is bonded to the 1,3-position and an alkyl ester group is bonded to the 2,4-position of the cyclobutane ring; A liquid crystal aligning agent characterized by containing a polyamic acid ester obtained by reacting.
    

    

    (Wherein R ₁ represents an alkyl group having 1 to 5 carbon atoms, R ₂ , R ₃ , R ₄ , and R ₅ represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, which may be the same or different. May be.)
17. The liquid crystal aligning agent according to claim 16, wherein the acid chloride has a structure represented by the following formula (102).
    

    

    (In the formula, R ₁ represents an alkyl group having 1 to 5 carbon atoms, and R ₆ represents a monovalent hydrocarbon group having 1 to 30 carbon atoms.)
18. The liquid crystal aligning agent of Claim 16 in which an acid chloride has a structure represented by following formula (103).
    

    

    (In the formula, R ₁ represents an alkyl group having 1 to 5 carbon atoms.)
19. A liquid crystal alignment film obtained by irradiating a film obtained by applying and baking the liquid crystal aligning agent according to any one of claims 16 to 19 with polarized radiation.
20. A method for producing a liquid crystal alignment film, wherein a film obtained by applying and baking the liquid crystal aligning agent according to any one of claims 16 to 19 is irradiated with polarized radiation.

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