JP3430705B2 - Novel diaminobenzene derivative and polyimide using it - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel diaminobenzene derivative and a polyimide synthesized by using the compound as one of the starting materials, and more specifically, it has a liquid crystal molecule-like substituent which is industrially easy to produce. The present invention relates to a diamine and a polyimide having a substituent similar to a liquid crystal molecule, which is synthesized by using the compound as one of the raw materials. The polyimide synthesized by using the diamine of the present invention is particularly useful for use as an alignment film of a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, polyimide has been widely used as a protective material and an insulating material in the electric and electronic fields because of its high mechanical strength, heat resistance and solvent resistance. However, in recent years, the electric and electronic fields have been remarkably developed, and correspondingly, materials used are required to have higher and higher properties. Among them, polyimide has been used mainly in the past for alignment film applications of liquid crystal display devices because of the homogeneity and durability of the coating film surface. However, with the trend toward higher density and higher performance of display devices, the surface characteristics of the polyimide coating film are particularly important, and it has become necessary to provide new characteristics that conventional polyimides do not have.

A liquid crystal display element is a display element that utilizes electro-optical changes in liquid crystal, and has attracted attention for its characteristics such as small size and light weight and low power consumption. In recent years, it has been used as a display device for various displays. It has made remarkable progress. Among them, nematic liquid crystal having positive dielectric anisotropy is used, and liquid crystal molecules are arranged parallel to the substrates at the interfaces of a pair of electrode substrates facing each other, and the alignment directions of the liquid crystal molecules are orthogonal to each other. A typical example is a twisted nematic type (TN type) field effect liquid crystal display element in which both substrates are combined with each other.

In such a TN type liquid crystal display device, the long axis direction of the liquid crystal molecules is uniformly aligned in parallel with the substrate surface, and further, the liquid crystal molecules are tilted at a certain angle (hereinafter, It is important to orient with a tilt angle. Conventionally, two methods are known as typical methods for aligning liquid crystal molecules in this way.

The first method is a method in which an inorganic material such as silicon oxide is obliquely vapor-deposited on a substrate to form an inorganic film on the substrate and liquid crystal molecules are oriented in the vapor-deposition direction.
Although this method can obtain a stable alignment having a constant tilt angle, it is not industrially efficient. The second method is a method in which an organic coating is provided on the surface of a substrate, and the surface is rubbed with a cloth such as cotton, nylon, or polyester in a certain direction to align liquid crystal molecules in the rubbing direction. Since this method can obtain stable alignment relatively easily, this method is industrially used exclusively. As an organic film,
Polyvinyl alcohol, polyoxyethylene, polyamide, polyimide and the like can be mentioned, but polyimide is most commonly used in terms of chemical stability, thermal stability and the like. However, the tilt angle obtained by rubbing polyimide is usually about 1 to 3 °, and it is difficult to obtain a higher tilt angle.

[0006]

In the field of liquid crystal alignment film, it has been difficult to obtain a high tilt angle stably by rubbing an organic film such as polyimide. As means for solving this, Japanese Patent Laid-Open No. 62-297.
No. 819 proposes a liquid crystal alignment treatment agent composed of a reaction product of a long-chain alkylamine and a polyimide precursor. In addition, JP-A-1-262527 and JP-A-1-2625-
Japanese Patent No. 262528 proposes a liquid crystal aligning agent composed of a mixture of a long-chain alkyl compound and a polyimide precursor. Further, Japanese Patent Application Laid-Open No. 64-25126 proposes a liquid crystal alignment treatment agent made of polyimide using a diamine having an alkyl group as a raw material. As described above, many attempts have been made to introduce an alkyl group into polyimide to increase the tilt angle of liquid crystal, and it has been possible to increase the tilt angle to some extent. However, on the other hand, when an alkyl group is introduced into the polyimide, the surface of the polyimide becomes water-repellent and the wettability of the liquid crystal with respect to the surface of the polyimide deteriorates. To increase the tilt angle, excessive introduction to Rukoto is an alkyl group in the polyimide, to reduce the wettability of the liquid crystal, the worst case causes a liquid crystal orientation defect, resulting in display of the liquid crystal display device performance It has also lowered.

As described above, it has been desired to develop a polyimide for an alignment film which can obtain a high tilt angle by rubbing, has high wettability with a liquid crystal, and has a good alignment property.

[0008]

[Means for Solving the Problems] Liquid crystals are classified into nematic, smectic, cholesteric, etc., depending on the alignment state of the molecules, but the common point is that the major axes of the constituent molecules are aligned parallel to each other. Is to be. From such a regular molecular arrangement, it is necessary for a certain compound to exhibit liquid crystallinity: (1) the molecular structure has a geometric shape suitable for the parallel arrangement, and (2) the parallel arrangement. There are two points that the intermolecular attractive force is sufficient to maintain the above. From these two requirements, it is necessary that the compound exhibiting liquid crystallinity has a rod-shaped or plate-shaped molecular shape and further has a permanent dipole or a chemical bonding group (functional group) that is easily polarized. Furthermore, it is said that the type of liquid crystal phase is determined by the balance of moderate intermolecular attractive forces between the ends and side faces of this rod-shaped molecule ("Latest liquid crystal technology").
Shoichi Matsumoto, Ichiyo Tsunoda p62 1983 Industrial Research Committee).

As a result of extensive studies by the inventor of the present invention for further improving the orientation of liquid crystals by the liquid crystal alignment film, the inventor exerts an action corresponding to the intermolecular attractive force acting between these liquid crystal molecules, between the alignment film polyimide and the liquid crystal molecules. It was found that the orientation of the liquid crystal was remarkably improved by introducing a structure that can be held between them into the molecular structure of polyimide, and the present invention has been completed.

That is, the present invention has the general formula [I]

[0011]

[Chemical 2]

(In the formula, P and Q are single bonds or -O- ,
It is a divalent organic group selected from —COO— and —CONH—, and P and Q may be the same or different from each other. R ₁ is a straight chain having 2 to 22 carbon atoms. Is an alkylene group, R ₂ is a benzene ring, cyclohexane
Ring, biphenyl ring, bicyclohexyl ring, phenyl ring
Rohekisan Ri cyclic substituent der selected from ring, the annular
Substituents may be unsubstituted or halogen atoms, trifluoro
Substituted by a substituent selected from a toxy group and a cyano group
It is a thing . ) Related to the diaminobenzene derivative.

Further, in the present invention, a diamine containing at least 1 mol% or more of the diaminobenzene derivative represented by the above-mentioned general formula [I] is reacted with a tetracarboxylic acid and its derivative to obtain a reduced viscosity of 0.05 to 0.05. 5.0 dl / g
(In N-methylpyrrolidone at a temperature of 30 ° C., a concentration of 0.5 g
/ Dl) as a polyimide precursor and ring-closed polyimide.

The present invention will be described in detail below. The diaminobenzene derivative of the present invention is easy to synthesize and is useful as a raw material for polyimide, polyamide and the like. Furthermore, by using this as one of the raw materials, a polyimide having a liquid crystal molecule-like substituent in its side chain is obtained. This polyimide is particularly useful for use as an alignment film of a liquid crystal display device, has good liquid crystal alignment, and can obtain a high tilt angle.

Except for discotic ones, liquid crystal molecules have almost all a rod-like chemical structure, and a cyclic substituent substituted with a polar group called a "core" having a considerable degree of rigidity and a linear substituent. Consists of an alkyl group ("Liquid Crystal Basics" by Koji Okano and Shunsuke Kobayashi, p1
79 1985 Baifukan). General formula [I] of the present invention
Diaminobenzene derivative represented by

[0016]

[Chemical 3]

Is a diamine having a structure similar to this liquid crystal molecule,

[0018]

[Chemical 4]

It is composed of a spacer portion R ₁ , a cyclic substituent R ₂ , and connecting portions P and Q thereof, and the synthesis method is not particularly limited, but, for example, it may be synthesized by the method described below. You can In the synthesis of diamine, the corresponding general formula [II]

[0020]

[Chemical 5]

It is general to synthesize a dinitro compound and then reduce the nitro group into an amino group by a conventional method. Dinitro club

[0022]

[Chemical 6]

And the spacer portion R ₁ are bonded via the connecting portion P, and then the cyclic substituent R ₂ is bonded via the connecting portion Q. Alternatively, the cyclic substituent R ₂ and the spacer portion R ₁ are previously combined. It is general to employ a method of bonding via the connecting portion Q and then connecting the dinitro portion via the connecting portion P. The linking portion P and / or Q is a bonding group such as a single bond, an ether bond —O—, an ester bond —COO—, an amide bond —CONH—, and these bonding groups are formed by a usual organic synthetic method. Can be made.
For example, for an ether bond, the corresponding halogen derivative and a hydroxyl-substituted derivative are reacted in the presence of an alkali, for an ester bond, the corresponding acid chloride and a hydroxyl-substituted derivative are reacted in the presence of an alkali, and for an amide bond, the corresponding acid chloride is reacted. A general method is to react the amino group-substituted derivative in the presence of an alkali.

A specific example of the raw material for forming the dinitro moiety is a substituent for forming the bonding moiety P, for example, dinitrobenzene substituted with a halogen atom, a hydroxyl group, or an acyl halide group. Specific examples of dinitrobenzene include 2,3-dinitrobenzene, 2,
4-dinitrobenzene, 2,5-dinitrobenzene,
2,6-dinitrobenzene, 3,4-dinitrobenzene, 3,5-dinitrobenzene and the like can be mentioned, but from the viewpoint of availability of raw materials and reactivity during polyimide polymerization,
2,4-Dinitrochlorobenzene, 2,4-dinitrophenol and 2,4-dinitrobenzoic acid chloride are the most common.

The spacer portion R ₁ is a linear alkylene group having a structure similar to a linear alkyl group forming a rod-shaped structure of liquid crystal molecules. Specific examples of the raw material for forming the spacer portion R ₁ include a straight chain having both ends substituted with a substituent for forming the connecting portions P and Q, for example, a halogen atom, a hydroxyl group, an acyl halide group or an amino group. It is a linear alkyl, and its carbon number is preferably selected appropriately in accordance with the linear alkyl group of the liquid crystal molecule. In view of availability of raw materials, easiness of synthetic reaction, etc., substantially, a straight-chain alkylene diol having 2 to 22 carbon atoms, dihalide, diacyl halide, diamine, halogenated alcohol, amino alcohol, halogenated carboxylic acid. , Hydroxycarboxylic acids, aminocarboxylic acids and the like are the most common.

The cyclic substituent R ₂ is a cyclic substituent having a structure similar to that of the cyclic compound forming the “core” part of the liquid crystal molecule. The cyclic compound forming the "core" portion is, for example, a compound in which a plurality of 6-membered rings are directly connected or these are bonded via a linking group, and the 6-membered ring is a benzene ring, a heterocyclic ring, The cyclohexane ring is the main one. Further specific examples thereof include biphenyl ring, terphenyl ring, bicyclohesyl ring, tercyclohexyl ring,
Phenylcyclohexyl ring, phenylpyridine ring, cyclohexylpyridine ring, phenyldioxane ring, phenylpyrimidine ring, cyclohexylpyrimidine ring, phenylpyrazine ring, cyclohexylpyrazine ring, and further these cyclic compounds ethylene, acetylene, ester, oxymethylene, azo, Those linked via a linking group such as azoxy and azomethine are known. The cyclic substituent R ₂ of the present invention can be substituted with these substituents. In particular, it is preferable to use a benzene ring, a cyclohexane ring, a biphenyl ring, a bicyclohexyl ring, or a phenylcyclohexane ring from the viewpoint of availability of raw materials and easiness of synthetic reaction.

Furthermore, the cyclic compounds forming the "core" part of the liquid crystal molecule are usually substituted with various end groups. As the terminal substituent, methyl group, ethyl group, other alkyl group, halogen atom, methoxy group, trifluoromethoxy group, nitro group, amino group, cyano group, azo group,
Formyl group, acetyl group, acetoxy group and the like are known. The cyclic substituent R ₂ of the present invention can be substituted with these substituents. In particular, the availability of raw materials, the synthetic reaction easiness, halogen atom, Application Benefits fluoromethoxy group is preferably a cyclic substituent that is substituted with a substituent selected Ri by a cyano group.

The starting material for forming the cyclic substituent R ₂ of the present invention is a substituent for forming a bond Q in the above cyclic compound or the above cyclic compound substituted with the above terminal substituent, such as a halogen atom or a hydroxyl group. , A cyclic compound having a halogenated acyl group. The diaminobenzene derivative of the present invention represented by the above general formula [I] obtained by the above-described production method is a tetracarboxylic acid such as tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dianhydride and the like. By carrying out polycondensation with a derivative, a polyimide having a liquid crystal molecule-like substituent in its side chain can be synthesized.

The method for obtaining the polyimide of the present invention is not particularly limited. Specifically, it can be obtained by reacting and polymerizing a tetracarboxylic acid and its derivative with a primary diamine to obtain a polyimide precursor, and ring-closing imidization. The tetracarboxylic acid and its derivative used for obtaining the polyimide of the present invention are not particularly limited.

Specific examples thereof include pyromellitic acid,
2,3,6,7-naphthalene tetracarboxylic acid, 1,
2,5,6-naphthalene tetracarboxylic acid, 1,4
5,8-naphthalenetetracarboxylic acid, 2,3,6,7
-Anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 3,3 ^/ , 4,4 ^/ -biphenyltetracarboxylic acid, 2,3,3 ^/ , 4-biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ^/ , 4,4 ^/ -benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl)
Propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3,4) -Dicarboxyphenyl) pyridine and other aromatic tetracarboxylic acids and their dianhydrides and their dicarboxylic acid diacid halides, 1,2,3,4-cyclobutanetetracarboxylic acid,
1,2,3,4-cyclopentanetetracarboxylic acid,
1,2,4,5-cyclohexanetetracarboxylic acid,
2,3,5-tricarboxycyclopentyl acetic acid, 3,
4-dicarboxy-1,2,3,4-tetrahydro-1
Alicyclic tetracarboxylic acids such as naphthalene succinic acid and dianhydrides thereof, dicarboxylic acid diacid halides thereof, aliphatic tetracarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid, and these Examples thereof include dianhydrides and dicarboxylic acid diacid halides.

In particular, for use as an alignment film, alicyclic tetracarboxylic acids, their dianhydrides and their dicarboxylic acid diacid halides are preferable from the viewpoint of the transparency of the coating film, and further 1,2,3 , 4-Cyclobutanetetracarboxylic dianhydride is preferred. Further, one or more of these tetracarboxylic acids and their derivatives can be mixed and used.

In the present invention, tetracarboxylic acid and its derivative, a diaminobenzene derivative represented by the general formula [I] (hereinafter abbreviated as diamine [I]) and other general diamines (hereinafter abbreviated as general diamine). ) Is copolymerized to obtain a polyimide having a liquid crystal molecule-like substituent in the side chain. Therefore, the diamine used to obtain the polyimide of the present invention contains diamine [I] as an essential component.

The general diamine other than the diamine [I] is a primary diamine generally used in polyimide synthesis and is not particularly limited. Specific examples thereof are p-phenylenediamine, m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4 ^/ -diaminobiphenyl, 3,3 ^/ -.
Dimethyl-4,4 ^/ -diaminobiphenyl, 3,3 ^/ -
Dimethoxy-4,4 ^/ -diaminobiphenyl, diaminodiphenylmethane, diaminodiphenyl ether, 2,
2 ^/ -diaminodiphenylpropane, bis (3,5-diethyl-4-aminophenyl) methane, diaminodiphenylsulfone, diaminobenzophenone, diaminonaphthalene, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene,
9,10-bis (4-aminophenyl) anthracene,
1,3-bis (4-aminophenoxy) benzene, 4,
4 ^/ -bis (4-aminophenoxy) diphenyl sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis (4-aminophenyl)
Hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] aromatic diamine such as hexafluoropropane, bis (4-aminocyclohexyl)
Alicyclic diamines such as methane and bis (4-amino-3-methylcyclohexyl) methane, and aliphatic diamines such as tetramethylenediamine and hexamethylenediamine, and

[0034]

[Chemical 7]

(Wherein, n represents an integer of 1 to 10) and the like. Further, one kind or two or more kinds of these diamines can be mixed and used. When polymerizing the polyimide of the present invention, by adjusting the ratio of the number of moles of the diamine [I] to the total number of moles of the diamine used, the surface properties of the polyimide such as water repellency can be modified, and further the liquid crystal alignment film. When it is used as, it is possible to enhance the wettability with the liquid crystal and further increase the tilt angle of the liquid crystal. At this time, the ratio of the number of moles of diamine [I] to the total number of moles of diamine used is 1 mol% or more, preferably 5 mol% or more.

After tetracarboxylic acid and its derivative are reacted with diamine [I] and general diamine to form a polyimide precursor, which is subjected to ring-closing imidization, tetracarboxylic acid and its derivative to be used are tetracarboxylic acid and its derivative. It is common to use a carboxylic acid dianhydride. The ratio of the number of moles of tetracarboxylic dianhydride to the total number of moles of diamine [I] and general diamine is preferably 0.8 to 1.2. As in the usual polycondensation reaction, the closer the molar ratio is to 1, the higher the degree of polymerization of the polymer produced.

If the degree of polymerization is too small, the strength of the polyimide film is insufficient when used as an alignment film, and the alignment of the liquid crystal becomes unstable. If the degree of polymerization is too large, the workability at the time of forming the polyimide film may deteriorate. Therefore, the polymerization degree of the product in this reaction is 0.05 to 5.0 dl / g (N-at a temperature of 30 ° C.) in terms of reduced viscosity of the polyimide precursor solution.
The concentration in methylpyrrolidone is preferably 0.5 g / dl).

The method of reacting and polymerizing the tetracarboxylic dianhydride and the primary diamine is not particularly limited, and generally N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, etc. The primary diamine is dissolved in the organic polar solvent, and tetracarboxylic acid dianhydride is added to the solution to cause a reaction to synthesize a polyimide precursor, followed by dehydration ring-closure imidization.

The reaction temperature when the tetracarboxylic dianhydride and the primary diamine are reacted to form a polyimide precursor is −
Any temperature can be selected from 20 to 150 ° C, preferably -5 to 100 ° C. Further, this polyimide precursor can be heated to dehydrate at 100 to 400 ° C., or chemically imidized using a commonly used imidization catalyst such as triethylamine / acetic anhydride to obtain a polyimide. .

When the polyimide of the present invention is used as an insulating film for electric / electronic devices, a protective film, and an alignment film for liquid crystal display devices, it is necessary to form a polyimide coating film having a uniform thickness on a substrate. To form this polyimide coating film, the polyimide precursor solution is usually applied directly to the substrate,
It can be heated and imidized on the substrate to form a polyimide coating film. As the polyimide precursor solution used at this time, the above-mentioned polymerization solution may be used as it is, or the produced polyimide precursor may be added to a large excess of water or a poor solvent such as methanol, and the precipitate may be recovered and then re-used in the solvent. You may melt | dissolve and use it. The diluent solvent for the polyimide precursor solution and / or the solvent for re-dissolving the polyimide precursor precipitated and recovered is not particularly limited as long as it dissolves the polyimide precursor.

Specific examples of these solvents include N-methylpyrrolidone, N, N-dimethylacetamide, N, N
-Dimethylformamide and the like can be mentioned. These may be used alone or in combination. Furthermore, even a solvent that cannot obtain a uniform solution by itself may be used by adding the solvent within a range where a uniform solution can be obtained.

The temperature at which the substrate is heated and imidized is 1
Any temperature from 00 to 400 ° C can be adopted, but especially 15
The range of 0 to 350 ° C. is preferable. On the other hand, when the polyimide of the present invention is dissolved in a solvent, a polyimide precursor obtained by reacting a tetracarboxylic dianhydride and a primary diamine can be imidized in a solution to obtain a polyimide solution. When a polyimide precursor is converted into a polyimide in a solution, a method of dehydration ring closure by heating is usually adopted. The ring-closing temperature due to this heat dehydration is 150 to
Any temperature of 350 ° C, preferably 120 to 250 ° C can be selected.

As another method for converting the polyimide precursor into polyimide, a known dehydration ring-closing catalyst may be used for chemical ring closure. The polyimide solution thus obtained may be used as it is, or may be used by re-dissolving in a suitable solvent after precipitation and isolation in a poor solvent such as methanol or ethanol.
The solvent to be redissolved is not particularly limited as long as it can dissolve the obtained polyimide, and examples thereof include 2-
Examples thereof include pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and γ-butyrolactone.

In addition, even a solvent which does not dissolve the polyimide by itself may be added to the above solvent as long as the solubility is not impaired. Examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol and the like. In addition, it is of course preferable to add an additive such as a coupling agent to the obtained polyimide solution for the purpose of further improving the adhesion between the polyimide film and the substrate.

A polyimide coating film can be formed on a substrate by coating this solution on the substrate and evaporating the solvent. The temperature at this time is sufficient if the solvent evaporates, and usually 80 to 150 ° C. is sufficient. Further, a liquid crystal alignment film can be obtained by forming a polyimide film having a film thickness of 200 to 3000 Å on a transparent substrate such as glass or a plastic film having a transparent electrode in this way, and then subjecting the polyimide layer to a rubbing treatment. .

The present invention is described in more detail below by referring to Examples, but the invention is not limited thereto.

[0047]

EXAMPLES Example 1 4- [3- (4-biphenyloxy) propoxy]-
Synthesis of 1,3-diaminobenzene.

[0048]

[Chemical 8]

In a 200 ml flask, 7.82 g (41.1 mmol) of 4-hydroxybiphenyl and 8 parts of ethanol were added.
3 ml, 3-bromo-1-propanol 6 g (43.2
mmol), an aqueous NaOH solution (NaOH 1.73 g (4
3.2 mmol) / water (6 ml) were sequentially added, and then 6.5
Heated to reflux for hours. 50 ml of water was added to the reaction solution, and the precipitated crystals were filtered off and recrystallized from ethanol to give 4- (3-hydropropoxy) biphenyl (1) as colorless powder.
4.0 g (yield = 43%) was obtained.

4- (3 obtained in a 200 ml flask
-Hydropropoxy) biphenyl (1) 3 g (13.1
mmol) in THF 47 ml and NaOH 578
mg (14.5 mmol) was added and the mixture was heated under reflux for 2 hours.
The reaction mixture was returned to room temperature, a THF solution (15 ml) of 2.54 g (12.5 mmol) of 2,4-dinitrochlorobenzene was added dropwise thereto, and the mixture was stirred overnight. The reaction mixture was poured into water and extracted with 300 ml of chloroform. The chloroform layer was washed with water and saturated saline and then dried over anhydrous sodium sulfate. Further, the solvent was distilled off under reduced pressure, and the residue (4.
After purification of 43 g) with a silica gel column, 3.93 g of a yellow powder was obtained. This was recrystallized from acetonitrile to obtain 2.55 g (yield = 49%) of yellow crystals. According to IR, NMR, and MASS spectra, this crystal shows that the desired diamine precursor dinitride 4-
[3- (4-biphenyloxy) propoxy] -1,3
-It was confirmed to be dinitrobenzene (2).

2 g (5.1 mmol) of the obtained dinitride (2) and 27 ml of isopropyl alcohol were added to a 50 ml flask and the reaction system was replaced with nitrogen, and then 5% P was added.
170 mg (10.1 mmol) of d-C powder was added, then 1.7 ml of 98% hydrazine aqueous solution was added, and the temperature was 40 ° C.
Stirred overnight. 250 ml of chloroform in the reaction mixture
Was added, and the Pd-C powder was filtered off. The filtrate was washed with water and saturated saline and then dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 1.67 g of a pale yellow powder. This was recrystallized from benzene to give 1.42 g of pale yellow crystals (yield =
84%) was obtained.

According to IR, NMR and MASS spectra, this crystal shows that the desired diamine 4- [3- (4-
It was confirmed to be biphenyloxy) propoxy] -1,3-diaminobenzene (3). The analysis results are shown below. Melting point: 144 ° C. Mass spectrum (m / e): 334 (M ⁺ ) ¹ H-NMR (CDCl ₃ , δppm): 2.30 (2H
, Dd, CH ₂ ), 3.60 (4H, bs, N
H ₂ ), 4.10 (2H, t, OCH ₂ ), 4.20
(2H, t, OCH ₂ ), 6.10 (1H, d,
H _arom ), _6.20 (1H, s, H _arom ), _6.80
(1H, d, H _arom ), _7.00 (2H, d,
H _arom ), 7.32 to 7.60 (7H, m, H _arom ) IR (KBr, cm ^-1 ): 3438 (NH ₂ ), 33
53 (NH ₂ ), 2959 (CH ₂ ), 2938 (C
H ₂ ), 2882 (CH ₂ )

Example 2 4- [8- (4-biphenyloxy) octyloxy]
Synthesis of -1,3-diaminobenzene (6)

[0054]

[Chemical 9]

In a 100 ml flask, 2,4-dinitrochlorobenzene 4.36 g (21.5 mmol), 8-bromooctanol 5.0 g (23.9 mmol), dimethylacetamide 14 ml, triethylamine 483 m.
g (4.8 mmol), NaOH 1.05 g (26.3
mmol) was added and the mixture was stirred at 40 ° C. for 2.5 hours. The reaction mixture was poured into water and extracted with 300 ml of chloroform.

The chloroform layer was washed with water and saturated saline and then dried over anhydrous sodium sulfate. Further, the solvent was distilled off under reduced pressure and the residue was purified by a silica gel column to give a yellow oily substance 4- (8-bromooctyloxy) -1,3-
3.90 g (yield = 59%) of dinitrobenzene (4) was obtained. In a 200 ml flask, 3.90 g (10.4 mmol) of dinitro compound (4), 1.98 g (10.4 mmol) of 4-hydroxybiphenyl and 2.87 g (20.8 mmol) of anhydrous potassium carbonate were added, and 1
The mixture was heated under reflux for 5 hours. After the solvent was distilled off under reduced pressure, the reaction mixture was poured into water and extracted with chloroform. The chloroform layer was washed with water and saturated saline and then dried over anhydrous sodium sulfate. Further, the solvent was distilled off under reduced pressure, and the residue (4.43 g) was purified by a silica gel column to obtain 2.4 g of yellow powder. This was recrystallized from acetonitrile to obtain 2.33 g (yield = 48%) of yellow crystals. IR, NM
From the R and MASS spectra, it was confirmed that this crystal was the desired diamine precursor dinitride 4- [8- (4-biphenyloxy) octyloxy] -1,3-dinitrobenzene (5). .

2 g (4.3) of the obtained dinitride (5)
mmol), 5% Pd-C powder 152 mg (9 mmo
l), 24 ml of isopropanol and 1.7 ml of a 98% aqueous hydrazine solution were added and treated in the same manner as in Example to obtain 1.72 g of a pale yellow powder. This was recrystallized from benzene / hexane to obtain 1.56 g (yield = 90%) of dark yellow crystals. It was confirmed by IR, NMR and MASS spectra that this crystal was the target diamine 4- [8- (4-biphenyloxy) octyloxy] -1,3-diaminobenzene (6). The analysis results are shown below.

Melting point: 111 ° C. Mass spectrum (m / e): 405 (M ⁺ ) ¹ H-NMR (CDCl ₃ , δppm): 1.30 to 1.
90 (12H, m, CH ₂ ), 3.60 (4H, b
_{s, NH 2), 4.} 10 (2H, t, OCH 2), 4.
20 (2H, t, OCH ₂ ), 6.10 (1H, d, H
_arom ), _6.20 (1H, s, H _arom ), _6.80 (1
H, d, H _arom ), _7.05 (2H, d, H _arom ),
_{7.30 to 7.60} (7H, m, _Harom ) IR (KBr, cm ^-1 ): 3466 (NH ₂ ), 33
74 (NH ₂ ), 2931 (CH ₂ ), 2861 (C
H ₂ )

Example 3 Synthesis of 4- [3- (4-cyanobiphenyl-4 ^/ -oxy) propoxy] -1,3-diaminobezene (9).

[0060]

[Chemical 10]

4-cyano-4 ^/ -in a 300 ml flask
20 g (102.4 mmol) of hydroxybiphenyl,
140 ml of ethanol, NaOH aqueous solution (NaOH 7.
48 g (132.2 mmol) / water 40 ml) was added. After stirring at 80 ° C. for 10 minutes, 10.66 g (112.8 mmol) of 3-chloro-1-propanol was added dropwise to 1
The mixture was heated under reflux for 8 hours. After distilling off ethanol, 300 ml of water was added to the reaction solution, the mixture was neutralized with hydrochloric acid, the precipitated crystals were filtered off, 1200 ml of toluene was added, the toluene layer was washed with water and saturated saline, and then with anhydrous sodium sulfate. Dried.

Further, the solvent was distilled off under reduced pressure and recrystallized from ethanol to give 5.34 g of colorless crystals of 4-cyano-4 ^/ -(3-hydroxypropoxy) biphenyl (7) (yield =
21%) was obtained. 4-cyano-4 ^/ -(3-hydroxypropoxy) biphenyl (7) 3.2 g (12.6
mmol), THF 40 ml, NaOH 850 mg (1
5.2 mmol) and 2,4-dinitrochlorobenzene (2.47 g, 12.6 mmol) were used, and the following Example 1 was used.
The same synthetic treatment as in (2) above was carried out to obtain 2.76 g of yellow powder. This was recrystallized from chloroform-hexane to obtain 2.14 g (yield = 40%) of pale yellow crystals. I
According to R, NMR and MASS spectra, this crystal
Precursor of diamine of interest Dinitride 4- [3-
(4-Cyanobiphenyl-4 ^/ -oxy) propoxy]
It was confirmed to be -1,3-dinitrobenzene (8).

Dinitride (8) 1.6 g (3.8 mm
ol), 21 ml of isopropyl alcohol, 5% Pd-
Using 128 mg (7.6 mmol) of C powder and 1.1 ml of 98% hydrazine aqueous solution, the same synthetic treatment as in Example 1 was performed, and a pale yellow powder was obtained. This was dissolved in methylene chloride and precipitated and purified with n-hexane to obtain 1.25 g of a yellow powder (yield = 91%). IR, NM
According to R and MASS spectra, this crystal shows that the target diamine 4- [3- (4-cyanobiphenyl-4 ^/ -
(Oxy) propoxy] -1,3-diaminobenzene (9)
Was confirmed. The analysis results are shown below.

Melting point: 126 ° C. Mass spectrum (m / e): 359 (M ⁺ ) ¹ H-NMR (CDCl ₃ , δppm): 2.28 (2
_{H, dd, CH 2),} 3. 60 (4H, bs, N
H ₂ ), 4.13 (2H, t, OCH ₂ ), 4.23
(2H, t, OCH ₂ ), 6.04 (1H, d,
H _arom ), _6.13 (1H, s, H _arom ), _6.66
(1H, d, H _arom ), _7.02 (2H, d,
H _arom ), _7.52 (2H, d, H _arom ), _7.64
(2H, d, H _arom ), _7.69 (2H, d, H _arom ) IR (KBr, cm ⁻¹ ): 3438 (NH ₂ ), 33
60 (NH ₂ ), 2940 (CH ₂ ), 2875 (C
H ₂ ), 2221 (CN)

Example 4 4- [12- (4-cyanobiphenyl-4 ^/ -oxy)
Dodecyloxy] -1,3-diaminobenzene (12)
Synthesis of

[0066]

[Chemical 11]

2,4-dinitrochlorobenzene 3.82
g (18.9 mmol), 12-bromododecanol 5
g (18.9 mmol), dimethylacetamide 12 m
1, triethylamine 382 mg (3.8 mmol),
Using 905 mg (22.6 mmol) of NaOH, the synthesis process was performed in the same manner as in Example 2. The resulting yellow powder was recrystallized from acetonitrile-water to give 4-color colorless powder.
4.91 g (yield = 60%) of [12-bromododecyloxy] -1,3-dinitrobenzene (10) was obtained.

4.9 g of the dinitro compound (10) (11.
4 mmol), 4-cyano-4 ^/ -hydroxybiphenyl 2.2 g (11.4 mmol), anhydrous potassium carbonate 3.14 g (22.7 mmol), potassium iodide 18
9 mg (1.1 mmol), acetonitrile 110 ml
Was used to perform the same synthesis process as in Example 2. The obtained yellow powder (5.0 g) was recrystallized from acetonitrile to obtain pale yellow crystals (4.40 g, yield = 71%). I
According to R, NMR and MASS spectra, this crystal
Precursor dinitride of desired diamine 4- [12-
It was confirmed to be (4-cyanobiphenyl-4 ^/ -oxy) dodecyloxy] -1,3-dinitrobenzene (11).

3 g of the obtained dinitride (11) (5.
5 mmol), 5% Pd-C powder 184 mg (11 mm
ol), 29 ml of isopropanol and 1.8 ml of 98% hydrazine aqueous solution were added and treated in the same manner as in Example 1 to obtain 2.66 g of a colorless powder. This was dissolved in methylene chloride and precipitated and purified with n-hexane to give colorless powder 1.
72 g (yield = 64%) was obtained. IR, NMR, M
According to the ASS spectrum, this crystal shows that the desired diamine 4- [12- (4-cyanobiphenyl-4 ^/ -oxy) dodecyloxy] -1,3-diaminobenzene (1
2) was confirmed. The analysis results are shown below.

Melting point: 129 ° C. Mass spectrum (m / e): 486 (M ⁺ ) ¹ H-NMR (CDCl ₃ , δppm): 1.10 to 1.
85 (20H, m, CH ₂ ), 3.70 (4H, b
_{s, NH 2), 3.} 90 (2H, t, OCH 2), 4.
00 (2H, t, OCH ₂ ), 6.05 (1H, d, H
_arom ), _6.15 (1H, s, H _arom ), _6.60 (1
H, d, H _arom ), _7.00 (2H, d, H _arom ),
_7.53 (2H, d, _Harom ), _7.65 (2H, d,
H _arom ), _7.70 (2H, d, H _arom ) IR (KBr, cm ^-1 ): 3473 (NH ₂ ), 34
52 (NH ₂ ), 3381 (NH ₂ ), 3360 (NH
₂ ), 2931 (CH ₂ ), 2924 (CH ₂ ), 28
54 (CH ₂ ), 2854 (CH ₂ ), 2221 (C
N)

Example 5 4- [3- (4-fluorobiphenyl-4 ^/ -oxy)
Synthesis of propoxy] -1,3-diaminobenzene (20).

[0072]

[Chemical 12]

2.8 g (14.9 mmol) of 4-fluoro-4 ^/ -hydroxybiphenyl, acetonitrile 50
ml, 3.17 g of 3-bromopropanol (15.6 m
mol), 4.11 g of anhydrous potassium carbonate (30 mmo
Using l), a synthesis process was performed in the same manner as in Example 2. When the obtained colorless powder was recrystallized from benzene-n-hexane, 3.26 g (yield = 89%) of 4-fluoro-4 ^/ -(3-hydroxyoxypropoxy) biphenyl (18) was obtained as a colorless powder. It was

4 g of the obtained 4-fluoro-4 ^/ -(3-hydroxypropoxy) biphenyl (18) (12.
2 mmol), THF44 ml, KOH820 mg (1
4.6 mmol) and 2,4-dinitrochlorobenzene (2.47 g, 12.2 mmol) were used to perform the same synthetic treatment as in Example 1. When the obtained yellow powder was recrystallized from acetonitrile, 1.40 g of yellow crystals (yield = 28
%)was gotten.

According to IR, NMR and MASS spectra, this crystal shows that the desired diamine precursor dinitride 4- [3- (4-fluorobiphenyl-4 ^/ -oxy) propoxy] -1,3-dinitrobenzene ( 19)
Was confirmed. Dinitride (19) 850
mg (2.1 mmol), isopropyl alcohol 10
ml, 5% Pd-C powder 75 mg (4.1 mmol),
The same synthetic treatment as in Example 1 was performed using 0.8 ml of a 98% hydrazine aqueous solution. The obtained colorless powder was recrystallized from benzene-n-hexane to obtain 660 mg of colorless crystals (yield = 91%).

According to IR, NMR and MASS spectra, this crystal shows that the desired diamine 4- [3- (4-
Fluorobiphenyl-4 ^/ -oxy) propoxy]-
It was confirmed to be 1,3-diaminobenzene (20) .

Example 6 4- [3- (4-trifluoromethoxybiphenyl-4]
Synthesis of ^/ -oxy) propoxy] -1,3-diaminobenzene (23)

[0078]

[Chemical 13]

3.5 g (13.8 mmol) of 4-trifluoromethoxy-4 ^/ -hydroxybiphenyl, 45 ml of acetonitrile, 3-bromo-1-propanol 2.
01 g (14.5 mmol), anhydrous potassium carbonate 3.8
Using 1 g (27.5 mmol), the synthesis treatment was performed in the same manner as in Example 2. The obtained gray powder was recrystallized from benzene-n-hexane to obtain 3.52 g (yield = 82%) of 4-trifluoromethoxy-4 ^/ -(3-hydroxypropoxy) biphenyl (21) as a colorless powder. Was given.

Obtained 4-trifluoromethoxy-4 ^/
-(3-Hydroxypropoxy) biphenyl (21) 3
g (9.6 mmol), THF 35 ml, KOH647
The same synthetic treatment as in Example 1 was performed using mg (11.5 mmol) and 1.95 g (9.6 mmol) of 2,4-dinitrochlorobenzene. The obtained yellow powder was recrystallized from acetonitrile-water to obtain 1.72 g (yield = 37%) of colorless powder. According to IR, NMR and MASS spectra, this crystal shows that the target diamine precursor dinitride 4- [3- (4-trifluoromethoxybiphenyl-4 ^/ -oxy) propoxy] -1,3-dinitrobenzene (22) Was confirmed.

1.4 g (2.9 m) of dinitride (22)
mol), isopropyl alcohol 14 ml, 5% Pd
The same synthesis treatment as in Example 1 was performed using 98 mg (5.9 mmol) of -C powder and 1.2 ml of 98% hydrazine aqueous solution. The obtained colorless powder was recrystallized from benzene-n-hexane to obtain 1.11 g (yield = 90%) of colorless crystals. According to IR, NMR and MASS spectra, this crystal is the target diamine 4- [3- (4-trifluoromethoxybiphenyl-4 ^/ -oxy) propoxy] -1,3-diaminobenzene (23). confirmed.

The analysis results are shown below. Melting point: 117 ° C. Mass spectrum (m / e): 418 (M ⁺ ) ¹ H-NMR (CDCl ₃ , δppm): 2.30 (2
H, dd, CH ₂ ), 3.55 (4H, bs, N
H ₂ ), 4.15 (2H, t, OCH ₂ ), 4.25
(2H, t, OCH ₂ ), 6.00 (1H, d,
H _arom ), 6.08 (1H, s, H _arom ), 6.70
(1H, d, H _arom ), 6.90 (2H, d,
H _arom ), 7.06 (2H, d, H _arom ), 7.35
_{(2H, d, H arom)} , 7.45 (2H, d, H arom) IR (KBr, Cm -1): 3466 (NH 2), 33
95 (NH ₂ ), 3374 (NH ₂ ), 2960 (CH
₂ ), 2938 (CH ₂ ), 2882 (CH ₂ ), 13
00 to 1166 (OCF ₃ )

Example 7 Synthesis of 5- [6- (4-cyanobiphenyl-4 ^/ -oxy) hexyl] -1,3-diaminobenzoate (26).

[0084]

[Chemical 14]

4-cyano-4 ^/ -hydroxybiphenyl 5 g (25.6 mmol), acetonitrile 85 ml,
6-Bromohexanol 4.63 g (25.6 mmo
l), 7.09 g (51.2 mmo) of anhydrous potassium carbonate
Using l), a synthesis process was performed in the same manner as in Example 2. When the obtained gray powder was recrystallized with methanol, 3.6 g (yield = 48%) of 4-cyano-4 ^/ -(6-hydroxyhexyloxy) biphenyl (24) was obtained as a colorless powder.

In a 100 ml flask, 3 g (10.2 mmol) of the obtained 4-cyano-4 ^/ -(6-hydroxyhexyloxy) biphenyl (24) and 4 methylene chloride were added.
0 ml, 3,5-dinitrobenzoic acid 1.96 g (9.2
mmol) was added. To this, 113 mg (0.92 mmol) of 4-dimethylaminopyridine and 1.9 g (9.2 mmol) of dicyclohexylcarbodiimide were added and stirred overnight. The precipitated crystals were separated by filtration, dissolved in methylene chloride, and the methylene chloride layer was washed with water and saturated saline,
It was dried over anhydrous sodium sulfate. Further, the solvent was distilled off under reduced pressure, and the residue was purified by a silica gel column to obtain 2.70 g of a yellow powder. This was recrystallized from acetonitrile to obtain 2.0 g of yellow crystals (yield = 44%). According to IR, NMR and MASS spectra, this crystal shows that the target diamine precursor dinitrate 5-
It was confirmed to be [6- (4-cyanobiphenyl-4 ^/ -oxy) hexyl] -1,3-dinitrobenzoate (25).

1.5 g (3.1 m) of dinitride (25)
mol), isopropyl alcohol 16 ml, 5% Pd
Using 102 mg (6.1 mmol) of -C powder and 1.0 ml of 98% hydrazine aqueous solution, the same synthesis treatment as in Example 1 was performed. The obtained yellow powder was dissolved in methylene chloride and then purified by reprecipitation with n-hexane to give 790 mg of a yellow powder.
(Yield = 60%) was obtained. IR, NMR, MASS
According to the spectrum, this crystal shows that the target diamine 5
It was confirmed to be-[6- (4-cyanobiphenyl-4 ^/ -oxy) hexyl] -1,3-diaminobenzoate (26). The analysis results are shown below.

Melting point: 115 ° C. Mass spectrum (m / e): 430 (M ⁺ ) ¹ H-NMR (CDCl ₃ , δppm): 1.40-2.
20 (8H, m, CH ₂ ), 3.60 (4H, bs, N
H ₂ ), 4.30 (2H, t, OCH ₂ ), 4.50
(2H, t, OCH ₂ ), 6.20 (1H, s,
H _arom ), 6.80 (2H, s, H _arom ), 7.04
(2H, d, H _arom ), 7.52 (2H, d,
H _arom ), 7.66 (2H, d, H _arom ), 7.72
(2H, d, H _arom ) IR (KBr, cm ⁻¹ ): 3466 (NH ₂ ), 33
60 (NH ₂ ), 2930 (CH ₂ ), 2880 (CH
₂ ), 2228 (CN)

Example 8 1 g (3.0 mmo of the diamine (3) obtained in Example 1)
l), 0.586 g (0.3 mol) of 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride was dissolved in 13.4 g of N-methylpyrrolidone and stirred at 20 ° C. for 4 hours to carry out a polycondensation reaction. Then, a polyimide precursor solution was prepared.

The reduced viscosity of the obtained polyimide precursor is
0.58 dl / g (concentration 0.5 g / dl, in NMP 3
Was 0 ° C). This solution is coated on a glass substrate and 2
Heat treatment was performed at 50 ° C. for 1 hour to form a uniform polyimide coating film. The obtained coating film was subjected to IR measurement and confirmed to be a polyimide containing a biphenyl group.

Examples 9 to 12 Using the diamines obtained in Examples 2 to 5 , a polyimide precursor solution was prepared in the same manner as in Example 8 . Reduced viscosity of the obtained polyimide precursor (concentration 0.5 g / dl, NM
In P, 30 ° C) is as shown in Table-1. Example
IR measurement was performed in the same manner as in 8, and it was confirmed that the polyimide had a cyclic substituent corresponding to each diamine.

Example 13 Using the diamine obtained in Example 6 , a polyimide precursor solution was prepared in the same manner as in Example 8 . Reduced viscosity of the obtained polyimide precursor (concentration 0.5 g / dl, NMP
Table 1 shows the temperature at 30 ° C. To 2 g of this solution, 4.66 g of N-methylpyrrolidone was added, and acetic anhydride of 0.1.
After adding 33 g and pyridine 0.16 g and stirring at room temperature / 1 hour, it stirred at 40 degreeC / 3 hours. The obtained solution was put into 250 ml of methanol, and the precipitated powder was separated by filtration and dried.

IR measurement of the obtained powder was performed, and it was confirmed that the powder was a polyimide containing a trifluoromethoxybiphenyl group.

Example 14 Using the diamine obtained in Example 7, a polyimide precursor solution was prepared in the same manner as in Example 8 . Reduced viscosity of the obtained polyimide precursor (concentration 0.5 g / dl, NMP
Table 1 shows the temperature at 30 ° C. In addition, Example 8
Perform IR measured in the same manner as was confirmed to be a polyimide having a cyclic substituent that corresponds to the di amine.

[0095]

[Table 1]

Reference Example Next, the polyimide precursor solution obtained in Example 10 was coated on a glass substrate and heat-treated at a predetermined temperature to form a polyimide coating film, and the polyimide surface was formed by the following method. The water repellency and liquid crystal alignment property and tilt angle of the liquid crystal alignment film were measured. The results are shown in Table-2.

Evaluation of water repellency: N the polyimide precursor solution
-Diluted with methylpyrrolidone to make a solution with a resin concentration of 6%, and spin-coat it on a glass substrate at 3500 rpm.
Heat treatment at 80 ° C for 10 minutes and 180 ° C for 1 hour to form a uniform polyimide coating film, measure the contact angle between water and methylene iodide on this coating film, and calculate the surface energy of the polyimide from the Fowkes equation. It was calculated.

Evaluation of tilt angle: A polyimide precursor solution was diluted with N-methylpyrrolidone to obtain a solution having a resin concentration of 6%, which was spin-coated on a glass substrate with a transparent electrode at 3500 rotations / minute, and at 80 ° C. for 10 minutes. It heat-processed at 250 degreeC for 1 hour, and formed the uniform polyimide coating film. After rubbing this coating film with a cloth, a 23 μm spacer was sandwiched between the rubbing directions so that the rubbing directions were parallel.
LI-2293) was injected to prepare a homogeneously oriented cell.

With respect to this cell, the uniformity of liquid crystal orientation was confirmed under a polarization microscope, and then the tilt angle was measured by the magnetic field capacitance method.

[0100]

[Table 2]

A uniform alignment with no cell defects was observed,
A high tilt angle was obtained.

[0102]

INDUSTRIAL APPLICABILITY The diaminobenzene derivative of the present invention is easy to synthesize, and by using this as a raw material to synthesize a polyimide having a liquid crystal molecule-like structure, the surface properties of the polyimide such as water repellency are modified. be able to. Furthermore, in the case of polyimide for the alignment film of the liquid crystal display element,
The liquid crystal can be uniformly aligned and the tilt angle can be increased.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C07C 229/40 C07C 229/40 229/54 229/54 237/20 237/20 237/32 237/32 237/34 237/34 237/36 237/36 C09K 19/56 C09K 19/56 G02F 1/1337 525 G02F 1/1337 525 (56) Reference JP-A-5-216046 (JP, A) JP-A-4-7333 (JP, A ) JP-A-3-250028 (JP, A) JP-A-60-6726 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 73/00-73/26 CAS ONLINE

Claims (6)

(57) [Claims] 1. A compound represented by the general formula [I]: (In the formula, P and Q are single bonds or -O- , -COO- ,
A divalent organic group selected from —CONH—, P and Q
R ₁ may be the same or different, R ₁
Is a linear alkylene group having 2 or more and 22 or less carbon atoms, R ₂ is a benzene ring, a cyclohexane ring, or a biphenyl group.
Le ring, bicyclohexyl ring, cyclic substituent der selected from phenyl cyclohexane ring <br/> is, the cyclic substituents are no
Substituted or halogen atom, trifluoromethoxy group,
It is substituted with a substituent selected from an ano group . ) A diaminobenzene derivative represented by. 2. The diaminobenzene derivative according to claim 1, wherein P and Q in the general formula [I] are —O—. 3. A diamine containing at least 1 mol% or more of a diaminobenzene derivative represented by the general formula [I] is reacted with tetracarboxylic acid and its derivative to obtain a reduced viscosity of 0.05 to 5.0 dl / g. A polyimide obtained by ring-closing the polyimide precursor (concentration: 0.5 g / dl in N-methylpyrrolidone at a temperature of 30 ° C.). 4. The polyimide according to claim 3, which contains at least 5 mol% of the diaminobenzene derivative represented by the general formula [I]. 5. The polyimide according to claim 3 or 4 , wherein the tetracarboxylic acid and its derivative are alicyclic tetracarboxylic acid and its derivative. 6. A tetracarboxylic acid and its derivative are
The polyimide according to any one of claims 3 to 5, which is 1,2,3,4-cyclobutanetetracarboxylic dianhydride.