JPH05331282A - Polyimide having liquid crystal property and low dielectric constant and its production - Google Patents

Abstract

PURPOSE:To obtain a liquid crystalline polyimide having low dielectric constant, excellent heat-resistance and processability and useful for electric and electronic parts, etc., by imidating a polyamic acid produced by the reaction of a specific aromatic diamine with a specific tetracarboxylic acid dianhydride. CONSTITUTION:The polyimide consisting of the recurring structural unit of formula III and having a logarithmic viscosity of 0.01-3.0dl/g can be produced by reacting an aromatic diamine composed mainly of 1,3-bis[4-(4-amino-6- trifluoromethylphenoxy)-alpha,alpha-dimethylbenzyl]benzene of formula I with a tetracarboxylic acid dianhydride expressed mainly by formula II (R is 2-27C tetravelent group such as aliphatic, cycloaliphatic, monocyclic aromatic and condensed polycyclic aromatic group) and thermally or chemically imidating the obtained polyamic acid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal and low dielectric polyimide. More specifically, it relates to a thermoplastic polyimide having excellent liquid crystallinity and low dielectric property and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, polyimide has excellent properties such as mechanical properties, chemical resistance, flame retardancy, and electrical properties in addition to its excellent heat resistance.
Widely used in the fields of composite materials, electric and electronic parts, etc. However, even if it is excellent in heat resistance, it does not have a clear glass transition temperature, so when it is used as a molding material, it must be processed using a method such as sintering molding, and the workability is excellent. Has a low glass transition temperature, is soluble in a halogenated hydrocarbon solvent, and is not satisfactory in terms of heat resistance and solvent resistance.

On the other hand, a group of liquid crystalline polymers has recently been attracting attention as a highly functional engineering plastic.
Liquid crystalline polymers are classified into thermotropic liquid crystals and lyotropic liquid crystals due to their properties. In particular, thermotropic liquid crystals show optical anisotropy when melted, and when a shear force is applied during melt molding, the molecular chain Are oriented to improve the mechanical strength of the molded product and reduce the melt viscosity. Therefore, they are widely used in the fields of molding materials and composite materials. Currently known liquid crystalline polymers are polyester, polyesteramide, polyazomethine (above thermotropic liquid crystal), polyamide,
Examples include polybenzothiazole (above lyotropic liquid crystal). In addition, recently, liquid crystal polymers having an imide group in the molecular skeleton such as polyester imide and polyester ether imide have been reported (for example, JP-A-60).
-4531, JP-A-4-33925, USP-4,38.
3, 105, etc.), the site of these polymers that exhibits liquid crystallinity is substantially an ester moiety, and cannot be called a liquid crystalline polyimide. Further, since the glass transition temperature of these polymers is around 180 ° C. at the maximum, it cannot be said that they have sufficient heat resistance. That is, conventionally, no polyimide showing liquid crystallinity is known.

On the other hand, in recent years in the field of electric / electronic parts, the development of microelectronics has been remarkable. In particular,
In large computers, high-speed signal transmission is indispensable due to the adoption of a multi-layer circuit board. However, if the dielectric constant of the substrate material is large, signal transmission is delayed, which is an obstacle to high-speed operation. Polyimide is used for an interlayer insulating film of a multi-layer wiring structure, but for these reasons, the need for lowering the dielectric constant has been highlighted in addition to the excellent properties that conventional polyimide has.

Teflon resin has been known for a long time as a resin having a low dielectric constant, but it is possible to reduce the dielectric constant by introducing a fluoro group into the polyimide structure.
St. Clair et.al., Polymeric Materials Science and En
gineering, 59 , 28-32 (1988) and EP 0299865.

However, polyimides containing a large amount of fluorine cannot give a polymer having a sufficiently high molecular weight (for example, T. Ichino et al., J. Polym. Sci., Part A, Poly Che).
m., 28 , 323 (1990) and Japanese Patent Laid-Open No. 01-182324), and also in terms of price, it is very expensive, and production at an industrial level is difficult. Further, as represented by Teflon resin, when a large amount of fluorine is contained, the adhesiveness is deteriorated, so that it is expected that the interlayer adhesion of the multilayer circuit board will be difficult.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic polyimide having liquid crystallinity and low dielectric property and good moldability in addition to the excellent heat resistance inherent in polyimide.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the inventors have found that a polyimide containing an aromatic diamine having a specific structure as a monomer component impairs various properties peculiar to the polyimide. The present invention was completed without finding that it was a thermoplastic polyimide having liquid crystallinity and low dielectric properties and excellent moldability. That is, the present invention has the general formula (1)

[0009]

[Chemical formula 12] (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group which is directly or cross-linked to each other. Showing a tetravalent group selected from the group consisting of non-fused polycyclic aromatic groups), a method for producing the same, and a polymer molecule having the repeating structural unit A polyimide that is an aromatic ring that has essentially no substituents or is substituted with a group that has no reactivity with amines or dicarboxylic acid anhydrides, and the polyamic acid that is the precursor of this polyimide is converted to dimethylacetamide. After dissolving at a concentration of 0.5 g / dl, the value of the logarithmic viscosity at 35 ° C. is 0.01 to 3.0 dl / g, or 9 parts by weight of this polyimide powder and 1 part by weight of p-chlorophenol. In a mixed solvent of phenol 0.5
A polyimide having a logarithmic viscosity value of 0.01 to 3.0 dl / g measured at 35 ° C. after being heated and dissolved at a concentration of g / dl, and a method for producing the same. More specifically, the present invention provides a compound represented by the general formula (1)

[0010]

[Chemical 13] (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group, which are directly or crosslinked to each other. A tetravalent group selected from the group consisting of non-condensed polycyclic aromatic groups) and a polyimide having a repeating structural unit represented by the formula (3)

[0011]

[Chemical 14] 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] represented by
Aromatic diamines mainly composed of benzene, and mainly represented by the general formula (4)

[0012]

[Chemical 15] (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group, which are directly or crosslinked to each other. A tetracarboxylic acid dianhydride represented by the formula (4) which represents a tetravalent group selected from the group consisting of non-condensed polycyclic aromatic groups) and thermally or chemically imidize the resulting polyamic acid. Is a method of manufacturing. Furthermore, an aromatic ring in which the terminal of the repeating structural unit represented by the general formula (1) has essentially no substituent or is substituted with a group having no reactivity with an amine or a dicarboxylic acid anhydride. Is a polyimide,
And these polyimides represented by the above formula (3)
An aromatic diamine mainly composed of 3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, and mainly the above-mentioned general formula (4)
The tetracarboxylic acid dianhydride represented by the formula (5)

[0013]

[Chemical 16] (In the formula, Z ₁ is an aliphatic group having 6 to 15 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group is directly or cross-linked with each other An aromatic dicarboxylic acid anhydride represented by a divalent group selected from the group consisting of the following non-fused polycyclic aromatic groups) or a compound represented by the formula (6)

[0014]

Embedded image Z ₂ —NH ₂ (6) (In the formula, Z ₂ is an aliphatic group having 6 to 15 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, A monovalent group selected from the group consisting of non-condensed polycyclic aromatic groups in which aromatic groups are connected to each other directly or by a cross-linking member), and are reacted in the presence of an aromatic monoamine represented by A method for producing a polyimide, characterized in that the obtained polyamic acid is thermally or chemically imidized. The polyimide of the present invention has the general formula (1)

[0015]

[Chemical 18] (In the formula, R is as described above.) A polyimide having a repeating structural unit represented by the formula, and the polyimide has an aromatic terminal. Polyimide of this repeating structural unit, as an aromatic diamine component,
The above formula (3)

[0016]

[Chemical 19] 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] represented by
Benzene is used.

The method for producing 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene used as the raw material of the present invention is 1,3-bis [ It can be produced by reducing 4- (4-nitro-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene. 1,3-bis [4- (4
-Nitro-6-trifluoromethylphenoxy) -α,
α-Dimethylbenzyl] benzene includes, for example, 1,3-bis [(4-hydroxy) -α, α-dimethylbenzyl] benzene and 2-chloro-5-nitrotrifluoromethylbenzene in the presence of a base. It is produced by a method of reacting in an aprotic polar solvent. The method for reducing the dinitro compound is not particularly limited, and usually, a method for reducing a nitro group to an amino group, for example, the method described in Shin Jikken Kagaku Koza, Volume 15, Oxidation and Reduction, Maruzen (1977) can be applied. Specifically, it can be produced by a catalytic reduction method using a metal catalyst such as a palladium catalyst.

In the polyimide of the present invention, the above 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene is used as an essential monomer raw material for the aromatic diamine. However, other aromatic diamines can be mixed and used as long as the good physical properties of the polyimide are not impaired.

Examples of diamines which can be mixed and used include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4,4'-diaminodiphenyl ether, 3, 3'-diaminodiphenyl ether, 3,
4'-diaminodiphenyl ether, bis (3-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, bis (4 -Aminophenyl) sulfoxide, (3
-Aminophenyl) (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, bis (4-
Aminophenyl) sulfone, (3-aminophenyl)
(4-aminophenyl) sulfone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3, 4'-diaminodiphenylmethane, bis [4- (3-aminophenoxy)
Phenyl] methane, bis [4- (4-aminophenoxy)
Phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4 −
Aminophenoxy) phenyl] ethane, 1,2-bis [4
-(4-aminophenoxy) phenyl] ethane, 2,2 bis [4- (3-aminophenoxy) phenyl] propane, 2,
2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [3- (3-aminophenoxy)
Phenyl] -1,1,1,3,3,3-hexafluoropropane,
2,2-bis [4- (4-aminophenoxy) phenyl]-
1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3
-Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,
4'-bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis [4- (3-
Aminophenoxy) phenyl] ketone, bis [4- (4-
Aminophenoxy) phenyl] ketone, bis [4- (3-
Aminophenoxy) phenyl] sulfide, bis [4-
(4-Aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- (3-aminophenoxy) phenyl] Sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy))
Phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-
Aminophenoxy) benzoyl] benzene, 4,4'-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'- Bis [4- (4-
Amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenyl sulfone, bis [4- {4- (4-amino Phenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α , α-Dimethylbenzyl] benzene, etc., and these may be used alone or in admixture of two or more. The aromatic tetracarboxylic acid dianhydride may be represented by the general formula (4)

[0020]

[Chemical 20] The tetracarboxylic dianhydride represented by In the general formula (4), R is an aliphatic group having 2 to 27 or more carbon atoms,
Cyclic aliphatic group, monocyclic aromatic group, condensed polycyclic aromatic group,
A tetravalent group selected from the group consisting of non-condensed polycyclic aromatic groups in which aromatic groups are linked to each other directly or by a cross-linking member is shown, and specifically, R in the general formula (4) is 2 to 1 carbon atoms
0 aliphatic group, C 4-10 cycloaliphatic group, formula (a)

[0021]

[Chemical 21] A monocyclic aromatic group represented by the formula (b):

[0022]

[Chemical formula 22] A condensed polycyclic aromatic group represented by the formula:
3]

[0023]

[Chemical formula 23] (In the formula, X is a direct bond, -CO-, -O-, -S-,-.
_{SO 2 -, - CH 2 -} , - C (CH 3) 2 -, - C (CF
₃ ) ₂₋ , formula (d) [Chemical formula 24], formula (e) [Chemical formula 24]

[0024]

[Chemical formula 24] Or formula (f)

[0025]

[Chemical 25] (Where Y is a direct bond, -CO-, -O-, -S-,
_{-SO 2 -, - CH 2 -} , - C (CH 3) 2 -, - C (C
Tetracarboxylic acid, which is a tetravalent group selected from the group consisting of non-condensed polycyclic aromatic groups in which the aromatic group represented by F ₃ ) _2- ) is directly or mutually linked by a crosslinking member. The dianhydride is used.

Examples of the tetracarboxylic acid dianhydride represented by the general formula (4) used in the present invention include ethylene tetracarboxylic acid dianhydride, cyclopentane tetracarboxylic acid dianhydride and pyromellitic acid dianhydride. Anhydrous, 3,
3 ', 4,4'-benzophenone tetracarboxylic dianhydride,
2,2 ', 3,3'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic acid Dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride Anhydrate, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride Product, 2,2-bis (3,4-dicarboxyphenyl)-
1,1,1,3,3,3-hexafluoropropane dianhydride, 2,
3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,
8-naphthalene tetracarboxylic dianhydride, 1,2,5,6-
Naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7, -anthracene Examples thereof include tetracarboxylic dianhydride and 1,2,7,8-phenanthrenetetracarboxylic dianhydride. These may be used alone or in combination of two or more.

The polyimide obtained by using the aromatic diamine component and the aromatic tetracarboxylic dianhydride component as monomer components is mainly a polyimide having a repeating structural unit represented by the general formula (1), and mainly represented by the general formula (1) ) Polyimide having a repeating structural unit, a polyimide having an aromatic ring substituted with a group that does not have a substituent at the polymer molecule terminal, or does not react with an amine or dicarboxylic acid anhydride, or these Compositions containing polyimide are also included.

The polyimide having an aromatic ring having no substituent at the terminal or substituted with a group having no reactivity with amine or dicarboxylic acid anhydride is a 1,3-bis group represented by the above formula (3). [4- (4-Amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene-based aromatic amine and tetracarboxylic dianhydride mainly represented by the general formula (4) Is expressed by the formula (5)

[0029]

[Chemical formula 26] (In the formula, Z ₁ is an aliphatic group having 6 to 15 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group is directly or cross-linked with each other. An aromatic dicarboxylic acid anhydride represented by a divalent group selected from the group consisting of a non-fused polycyclic aromatic group represented by the formula:

[0030]

Embedded image Z ₂ —NH ₂ (6) (In the formula, Z ₂ is an aliphatic group having 6 to 15 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, A monovalent group selected from the group consisting of non-condensed polycyclic aromatic groups in which aromatic groups are connected to each other directly or by a cross-linking member), and are reacted in the presence of an aromatic monoamine represented by It is obtained by thermally or chemically imidizing the obtained polyamic acid.

Here, Z ₁ and Z ₂ in the formulas (5) and (6) include those having the same definition as R in the polyimide formula represented by the above formula (1). Dicarboxylic anhydrides used in these methods include phthalic anhydride, 2,3
-Benzophenone dicarboxylic acid anhydride, 3,4-benzophenone dicarboxylic acid anhydride, 2,3-dicarboxyphenyl phenyl ether anhydride, 3,4-dicarboxyphenyl phenyl ether anhydride, 2,3-biphenyl dicarboxylic acid anhydride , 3,4-biphenyldicarboxylic acid anhydride, 2,
3-dicarboxyphenyl phenyl sulfone anhydride, 3,
4-dicarboxyphenyl phenyl sulfone anhydride, 2,
3-dicarboxyphenyl phenyl sulfide anhydride,
3,4-Dicarboxyphenyl phenyl sulfide anhydride, 1,2-naphthalenedicarboxylic acid anhydride, 2,3-naphthalenedicarboxylic acid anhydride, 1,8-naphthalenedicarboxylic acid anhydride, 1,2-anthracene dicarboxylic acid anhydride object,
Examples thereof include 2,3-anthracene dicarboxylic acid anhydride and 1,9-anthracene dicarboxylic acid anhydride. These dicarboxylic acid anhydrides may be substituted with groups that are not reactive with amines or dicarboxylic acid anhydrides.

Among these dicarboxylic acid anhydrides, phthalic anhydride is most preferable from the viewpoint of properties and practical use of the polyimide obtained. That is, it is a polyimide excellent in molding stability during high temperature molding, has excellent chemical resistance, considering the excellent workability, for example,
It is a polyimide that is extremely useful as a base material for aerospace and electrical and electronic parts.

When phthalic anhydride is used, it may be used by substituting a part of it with another dicarboxylic acid anhydride as long as the good physical properties of the polyimide are not impaired. The amount of the dicarboxylic acid anhydride used is 1 mol of 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene represented by the formula (3). The molar ratio is 0.001 to 1.0. If it is less than 0.001 mol, the viscosity is increased during high temperature molding, which causes deterioration of molding processability. Also, 1.0
If it exceeds the molar amount, mechanical properties are deteriorated. The preferred amount used is 0.01 to 0.5 mol.

When an aromatic monoamine is used,
Examples of aromatic monoamines include aniline, o-toluidine, m-toluidine, p-toluidine, 2,3-xylidine, 2,6-xylidine, 3,4-xylidine, 3,5-
Xylidine, o-chloroaniline, m-chloroaniline, p-chloroaniline, o-bromoaniline, m-bromoaniline, p-bromoaniline, o-nitroaniline, m-nitroaniline, p-nitroaniline, o-amino Phenol, m-aminophenol, p-aminophenol, o-anisidine, m-anisidine, p-anisidine, o-phenidine, m-phenidine, p-phenidine, o-aminobenzaldehyde, m-aminobenzaldehyde, p- Aminobenzaldehyde, o-aminobenzonitrile, m-aminobenzonitrile, p-aminobenzonitrile, 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl, 2-aminophenylphenyl ether, 3-aminophenylphenyl ether , 4-aminoph Alkenyl phenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, 2-aminophenyl phenyl sulfide, 3-aminophenyl phenyl sulfide, 4
Aminophenylphenyl sulfide, 2-aminophenylphenyl sulfone, 3-aminophenylphenyl sulfone, 4-aminophenylphenyl sulfone, α-naphthylamine, β-naphthylamine, 1-amino-2-naphthol, 2-amino-1-naphthol, 4-amino-
1-naphthol, 5-amino-1-naphthol, 5-amino-2-naphthol, 7-amino-2-naphthol,
8-amino-1-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene and the like can be mentioned. These aromatic monoamines may be substituted with groups that are not reactive with amines or dicarboxylic acid anhydrides.

The amount of the aromatic monoamine used is 0.001 to 1.0 mol ratio per 1 mol of the tetracarboxylic dianhydride represented by the general formula (4). If it is less than 0.001 mol, the viscosity is increased during high temperature molding, which causes deterioration of molding processability. On the other hand, if the molar ratio exceeds 1.0, the mechanical properties will deteriorate. The preferred amount used is 0.01-0.
It is a ratio of 5 mol.

As described above, when a polyimide of the present invention having no substituent or a substituted aromatic ring at the terminal is produced, tetracarboxylic dianhydride, aromatic diamine, and dicarboxylic anhydride or The molar ratio of the aromatic monoamine is 0.9 to 1.0 mol for the aromatic diamine and 0.001 to 1.0 for the dicarboxylic acid anhydride or the aromatic monoamine, per 1 mol of the tetracarboxylic dianhydride.
It is a mole. In the production of polyimide, it is usual to adjust the amount ratio of tetracarboxylic dianhydride and aromatic diamine in order to adjust the molecular weight of the produced polyimide. In the method of the present invention, the molar ratio of the aromatic diamine to the tetracarboxylic dianhydride, which is suitable for obtaining the polyimide having good melt fluidity, is 0.9 to 1.0.
The range is.

The method for producing the polyimide of the present invention includes:
Although any method including a known method that can produce a polyimide can be applied, it is particularly preferable to carry out the reaction in an organic solvent. The solvent used in such a reaction is preferably N, N-dimethylacetamide, but other usable solvents include, for example,
N, N-dimethylformamide, N, N-diethylacetamide, N, N-dimethoxyacetamide, N-methyl-2
-Pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2
-Methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) ethyl] ether, tetrahydrofuran, 1,
3-dioxane, 1,4-dioxane, pyrroline, picoline, dimethyl sulfoxide, dimethyl sulfone, tetramethylurea, hexamethylphosphoramide, phenol, o-cresol, m-cresol, p-cresol, m-cresylic acid, p -Chlorophenol, anisole, benzene, toluene, xylene and the like.
These organic solvents may be used alone or in combination of two or more.

According to the method of the present invention, 1,3-bis [4] was added to an organic solvent.
-(4-amino-6-trifluoromethylphenoxy)-
α, α-Dimethylbenzyl] benzene, tetracarboxylic acid dianhydride, aromatic dicarboxylic acid anhydride or aromatic monoamine can be added and reacted by (i) tetracarboxylic acid dianhydride and 1,3-bis-anhydride. [4- (4-amino-
6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, followed by addition of aromatic dicarboxylic acid anhydride or aromatic monoamine to continue the reaction, (b) 1,3-bis [ 4- (4-amino-6-
Trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene to which an aromatic dicarboxylic acid anhydride is added and reacted, and then tetracarboxylic dianhydride is added, and the reaction is further continued, (C) tetracarboxylic acid After the aromatic monoamine was added to the acid dianhydride and reacted, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene was added,
Further continuous reaction, (di) tetracarboxylic dianhydride, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, aromatic dicarboxylic acid Examples thereof include a method in which an anhydride or an aromatic monoamine is added at the same time and the reaction is performed, and any addition method may be used.

The reaction temperature is usually 250 ° C. or lower, preferably 50 ° C. or lower. The reaction pressure is not particularly limited and can be carried out at normal pressure. The reaction time varies depending on the type of tetracarboxylic dianhydride, the type of solvent and the reaction temperature, and usually 4 to 24 hours is sufficient. Further, by heating the resulting polyamic acid to 100 to 400 ° C. for imidization or chemically imidizing with an imidizing agent such as acetic anhydride, a polyimide having a repeating structural unit corresponding to the polyamic acid is obtained. can get.

The polyamic acid, which is a precursor of the present polyimide, was dissolved in N, N-dimethylacetamide at a concentration of 0.5 g / dl, and the logarithmic viscosity value measured at 35 ° C. was 0.01.
˜3.0 dl / g, and after further dissolving the present polyimide powder in a mixed solvent of 9 parts by weight of p-chlorophenol and 1 part by weight of phenol at a concentration of 0.5 g / dl, 35
The value of logarithmic viscosity measured at ℃ is 0.01 to 3.0d
1 / g.

Further, 1,3-bis [4- (4-amino-6-
Trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene and tetracarboxylic acid dianhydride, and further, when the terminal of the polyimide is an aromatic ring, aromatic dicarboxylic acid anhydride or aromatic monoamine is added in an organic solvent. It is also possible to obtain the target polyimide by suspending or dissolving it in a solution and then heating the mixture to generate a polyamic acid which is a precursor of the polyimide and simultaneously perform imidization.

Further, as the method for producing a polyimide film in this patent, a method of applying a varnish of polyamic acid, which is a precursor of the present polyimide, on a glass plate and then heating it for imidization, or direct polyimide powder is used. A method of forming a film by heating and pressurizing is possible. That is, a film-form or powder-form polyimide can be obtained by using a conventionally known method.

When the polyimide of the present invention is subjected to melt molding, other thermoplastic resins such as polyethylene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyether sulfone, etc. may be used as long as the object of the present invention is not impaired. It is also possible to add an appropriate amount of polyether ketone, polyphenyl sulfide, polyamide imide, polyether imide, modified polyphenylene oxide, polyimide other than the present invention, etc. depending on the purpose. Further, the following fillers and the like used in ordinary resin compositions may be used within a range that does not impair the object of the invention. That is, graphite, carborundum,
Abrasion resistance improver such as silica powder, molybdenum disulfide, fluorine resin, reinforcing agent for glass fiber, carbon fiber, etc., flame retardant improver for antimony trioxide, magnesium carbonate, calcium carbonate, clay, mica, etc. Electrical property improver, tracking resistance improver such as asbestos, silica, graphite, acid resistance improver such as barium sulfate, silica, calcium metasilicate, etc., thermal conductivity improvement of iron powder, zinc powder, aluminum powder, copper powder, etc. Agent, other glass beads, glass sphere, talc, diatom degree, alumina, silasbaln,
Hydrated alumina, metal oxides, colorants and the like.

Since the polyimide of the present invention has liquid crystallinity, when blended with the thermoplastic resin as shown above,
It is possible to reduce the melt viscosity of the thermoplastic resin. Further, the polyimide of the present invention can be in the form of fiber in addition to various molding materials and films. Furthermore,
The present invention is also used as a composite material in which a fiber cloth made of fibers such as carbon fiber is impregnated with polyimide. Further, by utilizing the low dielectric property, which is a characteristic of the present polyimide, it can be used as a substrate for copper clad circuits coated with a metal foil such as copper or a metal plate, so that it can be used in a wide variety of applications.

[0045]

EXAMPLES The present invention will be described in detail below with reference to examples. The physical properties of the polyimide in the examples were measured by the following methods. Tg, Tc, Tm; DSC (Shimadzu DT-40 series,
Measured by DSC-41M). Melt viscosity; Shimadzu Koka type flow tester (CFT500
Measured with a load of 100 kg according to A). Dielectric constant; measured according to ASTM D150-87. Logarithmic viscosity; N, N-dimethylacetamide for polyamic acid, p-chlorophenol / phenol (weight ratio 9/1) mixed solvent for polyimide, 0.5 g / 10 each
Measured at 35 ° C after dissolution at a concentration of 0 ml.

Synthesis Example 1 (Synthesis of 1,3-bis [4- (4-nitro-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene) Equipped with thermometer, reflux condenser and stirrer In a container
700 ml of N, N-dimethylformamide (DMF), 30 ml of toluene, 87 g (0.386 mol) of 2-chloro-5-nitrobenzotrifluoride, 1,3-bis (4
-Hydroxycumyl) benzene 63.6 g (0.184
mol), 53.3 g of potassium carbonate (0.386 mo)
1) was charged into each, and the temperature was raised to 110 ° C. with stirring, followed by aging at 110 ° C. for 4 hours.

After completion of the reaction, the inorganic salt was removed by cooling to 80 ° C. and filtering. 30 ml of water was added to the filtrate and cooled to room temperature to crystallize the desired product. The precipitated crystals were separated by filtration and further sludged with isopropyl alcohol to obtain the desired product, 1,3-bis [4- (4-
Nitro-6-trifluoromethylphenoxy) -α, α
-Dimethylbenzyl] benzene was obtained. Melting point 127.4-128.4 [deg.] C. Yield 120 g Yield 90% 1H-NMR [delta] (CDC13, ppm) 1.69 (s, 6H) 6.90 (d, 4H) 6.94-7.34 (m, 4H) 7.26 (d, 4H) 7.18 (d, 2H) 8.28 (dd, 2H) 8.58 (d, 2H) Elemental analysis (C38H30N2O6F6) C H N F ──────── ────────────────────────── Calculated value (%) 62.98 4.17 3.87 15.73 Measured value (%) 62. 89 4.29 3.70 15.66 ──────────────────────────────────

Synthesis Example 2 (Synthesis of 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene) A thermometer, a reflux condenser and a stirrer were attached. In the reducing device, 90 g (0.124 mol) of 1,3-bis [4- (4-nitro-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 500 ml of methyl cellosolve and 5% -Pd / C5g (50% hydrous product)
Was charged and the reaction was carried out at 70 to 80 ° C. for 4 hours under a hydrogen atmosphere. After completion of the reaction, the catalyst was filtered off, the filtrate was concentrated under reduced pressure,
Light yellow crystals of 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene were obtained. Melting point 118.5-119.2 [deg.] C. Yield 73.4 g Yield 89% 1H-NMR [delta] (CDC13, ppm) 1.86 (s, 6H) 3.71 (s, 4H) 6.76-7.45 ( m, 10H) 6.95 (d, 4H) 7.29 (d, 4H) Elemental analysis (C38H34N2O2F6) C H N F ────────────────────── ──────────── Calculated value (%) 68.67 5.16 4.21 17.15 Measured value (%) 68.78 5.22 4.15 17.01 ──── ─────────────────────────────

Example 1 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α was placed in a container equipped with a stirrer, a reflux condenser, a water separator, and a nitrogen inlet tube. -Dimethylbenzyl] benzene 66.47 g (0.1 mol), pyromellitic dianhydride 21.38 g (0.098 mol), phthalic anhydride 0.592 g (0.004 mol), γ-picoline 1.40 g , M-cresol (351.4 g) was charged, and the temperature was raised to 150 ° C. with stirring under a nitrogen atmosphere. Then, it reacted at 150 degreeC for 4 hours. During this period, distillation of about 3.6 ml of water was confirmed.

After the reaction was completed, the temperature was cooled to room temperature and about 2.0 L
After discharging into the methyl ethyl ketone, the polyimide powder was filtered off. After washing this polyimide powder with methyl ethyl ketone, it was dried in air at 50 ° C. for 24 hours and then under reduced pressure at 180 ° C.
After drying for 8 hours, 83.22 g (yield 98.1%) of polyimide powder was obtained. The polyimide powder thus obtained had an inherent viscosity of 0.45 dl / g and a glass transition temperature of 196 ° C. The infrared absorption spectrum of this polyimide powder is shown in FIG. From this spectrum diagram, the imide characteristic absorption band 1
Absorption around 780 and 1720 cm ^-1 was remarkably observed. The elemental analysis values of the polyimide powder were as follows. Elemental analysis value C H N F calculated value (%) 68.08 3.82 3.31 13.46 measured value (%) 67.86 3.75 3.40 13.02 Pressure of the polyimide powder obtained here About 50 by pressing and heating under the conditions of 300 psi and temperature of 350 ℃.
It was a polyimide film of μm. When the dielectric constant was measured using this polyimide film, it was 3.
It was 2.99 at 02, 3 KHz and 2.96 at 1 MHz.

Further, the molding stability of this polyimide was measured using a Koka type flow tester, using a load of 100 kg and an orifice of 0.1 cm in diameter and 1 cm in length. 300 ℃, 320 ℃, 350 ℃, residence time 5
Melt viscosity in minutes is 13100 poise, 49 respectively
It was 10 poise and 1860 poise. Also, 320 ℃
FIG. 2 shows the results of measuring the melt viscosity by changing the residence time in the cylinder at. It can be seen that even if the residence time in the cylinder becomes long, the melt viscosity hardly changes, and the thermal stability is good.

Further, this polyimide powder is a commercially available polyether sulfone (manufactured by ICI, trade name: VICTR).
EX PES 4100P) (weight ratio: polyether sulfone / main polyimide = 7/3), and the melt viscosity at 350 ° C. and 370 ° C. was measured (residence time 5
Minutes). The results are shown below.

(Measured value of melt viscosity: unit poise) ─────────────────────────────── 350 ° C 370 ° C ─── ───────────────────────────── Polyethersulfone 12000 5700 Polyethersulfone / Polyimide 5250 3350 That is, this polyimide is polyethersulfone It was observed that melt-viscosity was drastically reduced by mixing with, and that the strands obtained were oriented in the extrusion direction and fibrous fibrils were observed, and the properties peculiar to liquid crystalline polymers were observed.

Comparative Example 1 82.33 g of polyimide powder (yield 97.6%) was prepared in the same manner as in Example 1 except that phthalic anhydride was not used.
Got The polyimide powder thus obtained had an inherent viscosity of 0.47 dl / g and a glass transition temperature of 197 ° C. The molding stability of this polyimide was measured in the same manner as in Example 1 using a flow tester. The results are shown in FIG. 2 together with the results of Example 1. It can be seen that the polyimide obtained in this Comparative Example has a higher melt viscosity as the residence time in the cylinder becomes longer, and that the molding stability is worse than that of the polyimide obtained in Example 1.

Example 2 1,3-Bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] was placed in a container equipped with a stirrer, a reflux condenser, and a nitrogen introducing tube. 66.47 g (0.1 mol) of benzene and 353.1 g of N, N-dimethylacetamide were charged, and 21.81 g (0.1 mol) of pyromellitic dianhydride was added to increase the solution temperature under a nitrogen atmosphere. Carefully split and add, about 3 at room temperature
Stir for 0 hours. The polyamic acid thus obtained had an inherent viscosity of 0.77 dl / g. After taking a part of this polyamic acid solution and casting it on a glass plate, 10
Each film was heated at 0 ° C., 200 ° C. and 300 ° C. for 1 hour to obtain a film having a thickness of about 50 μm. The glass transition temperature of this polyimide film was 198 ° C. The tensile strength of the film is 9.59 kg / mm ² , and the tensile elastic modulus is 240.
It was kg / mm ² and the elongation rate was 8.4% (the measuring method is based on ASTM D-822). When the dielectric constant was measured using this polyimide film, the frequency was 60 Hz.
At 3.01, 2.98 at 3 KHz, 2.94 at 1 MHz
Met.

Example 3 21.38 g of pyromellitic dianhydride in Example 1
(0.098 mol) was changed to 3,3 ', 4,4'-diphenyl ether tetracarboxylic acid dianhydride 30.40 g (0.098 mol) except that the same procedure as in Example 1 was repeated to obtain polyimide powder 92. 12 g (yield 98.1%) was obtained. The polyimide powder thus obtained had an inherent viscosity of 0.47 dl / g and a glass transition temperature of 184 ° C. Using this polyimide powder, a polyimide film having a thickness of about 50 μm was obtained in exactly the same manner as in Example 1. The dielectric constant of this polyimide film was measured and found to be 2.9 at a frequency of 60 Hz.
It was 2.95 at 8, 3 KHz and 2.92 at 1 MHz.

Example 4 21.81 g of pyromellitic dianhydride in Example 2
Polyamide acid was prepared in the same manner as in Example 2 except that (0.1 mol) was changed to 31,02 '(0.1 mol) of 3,3', 4,4'-diphenylethertetracarboxylic dianhydride. Obtained. The polyamic acid thus obtained has an inherent viscosity of 0.
It was 68 g / dl. Using this polyamic acid, a polyimide film having a thickness of about 50 μm was obtained in exactly the same manner as in Example 2.

The glass transition temperature of this polyimide film was 190 ° C., the tensile strength was 8.56 kg / mm ² , the tensile elastic modulus was 236 kg / mm ² , and the elongation was 9.1%.
Further, when the dielectric constant was measured using this polyimide film, it was 3.00 at a frequency of 60 Hz and 2. at a frequency of 3 KHz.
It was 2.92 at 96 and 1 MHz.

Example 5 21.38 g of pyromellitic dianhydride in Example 1
(0.098 mol) to 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride 43.54 g (0.098 mol) Except for changing the above, the same procedure as in Example 1 was carried out to obtain 104.68 g of polyimide powder.
(Yield 97.8%) was obtained. The polyimide powder thus obtained had an inherent viscosity of 0.44 g / dl and a glass transition temperature of 196 ° C. Example 1 using this polyimide powder
A polyimide film having a thickness of about 50 μm was prepared in exactly the same manner as above, and the dielectric constant was measured and found to be 2.88 at a frequency of 60 Hz, 2.85 at a frequency of 3 KHz, and 2.80 at a frequency of 1 MHz.

Example 6 21.81 g of pyromellitic dianhydride in Example 2
(0.1 mol) to 2,4-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride 44.43 g (0.1 mol) Polyamide acid was obtained in the same manner as in Example 2 except that the polyamic acid was changed. The polyamic acid thus obtained had an inherent viscosity of 0.69 dl / g. Using this polyamic acid, a polyimide film having a thickness of about 50 μm was obtained in exactly the same manner as in Example 2. The glass transition temperature of this polyimide film is 199 ° C., the tensile strength is 10.28 kg / mm ² , and the tensile elastic modulus is 266 kg.
/ Mm ² , and the elongation rate was 6.0%. Further, when the dielectric constant was measured using this polyimide film, it was 2.86 at a frequency of 60 Hz, 2.82 at a frequency of 3 KHz, and 2.78 at 1 MHz.

Comparative Example 2 66.47 g (0.1 mol) of 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene in Example 2 was added to 1 part. Polyamide acid was obtained in the same manner as in Example 2 except that 52.87 g (0.1 mol) of 3,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene was used. .. The polyamic acid thus obtained has an inherent viscosity of 0.7.
It was 2 dl / g. Using this polyamic acid, a polyimide film having a thickness of about 50 μm was obtained in exactly the same manner as in Example 2. The glass transition temperature of this polyimide film was 200 ° C. When the dielectric constant was measured using the obtained polyimide film, it was 3.4 at a frequency of 60 Hz.
It was 3.40 at 6 and 3 KHz and 3.36 at 1 MHz.

The dielectric constants of the polyimide films measured in Examples 1 to 6 and Comparative Example 2 are summarized in Table 1 [Table 1].

[0063]

[Table 1] * 1) In the film production method, A indicates a method of pressing and heating polyimide powder, and B indicates a method of casting polyamic acid. * 2) 1,3-Bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene * 3) Pyromellitic dianhydride * 4) 3,3 ', 4 , 4'-Diphenyl ether tetracarboxylic acid dianhydride * 5) 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,
3,3,3-hexafluoropropane dianhydride * 6) 1,3-bis [4- (4-aminophenoxy) -α, α
-Dimethylbenzyl] benzene

[0064]

The polyimide of the present invention is 1,3-bis [4
-(4-amino-6-trifluoromethylphenoxy)-
A polyimide having excellent low dielectric properties, processability, heat resistance, and liquid crystal properties, which is characterized by using α, α-dimethylbenzyl] benzene as an aromatic diamine component. This polyimide has the same heat resistance as conventional polyimides, but also exhibits particularly excellent low dielectric properties, and since it has thermoplasticity and liquid crystallinity, it has good moldability, so it is industrially particularly useful as a molding material. It can be greatly expected to be used in the field or in the field of electric / electronic materials.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum diagram of the polyimide powder obtained in Example 1 of the present invention.

FIG. 2 is a result of measuring a relationship between a residence time in a cylinder of a flow tester of polyimide powder obtained in Example 1 and Comparative Example 1 and a change in melt viscosity.

(72) Inventor Hideaki Oikawa 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Akihiro Yamaguchi Inventor Mitsui Toatsu Chemical Co., Ltd. 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa

Claims (15)

[Claims] 1. General formula (1) [Chemical formula 1] (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group, which are directly or crosslinked to each other. And a tetravalent group selected from the group consisting of non-fused polycyclic aromatic groups) having a repeating structural unit represented by the formula: 2. General formula (1) [Chemical formula 2] [Chemical formula 2] (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group, which are directly or crosslinked to each other. A tetravalent group selected from the group consisting of non-condensed polycyclic aromatic groups), and the polymer molecule has essentially no substituents at the terminal end, Alternatively, a liquid crystalline and low dielectric polyimide having an aromatic ring substituted with a group having no reactivity with an amine or a dicarboxylic acid anhydride. 3. A polyimide precursor having a repeating structural unit represented by the formula (1), represented by the following formula (2): [Chemical Formula 3] [Chemical Formula 3] (In the formula, R is the same as above.)
After being dissolved in N, N-dimethylacetamide at a concentration of 0.5 g / dl, the logarithmic viscosity value measured at 35 ° C. was 0.
The liquid crystalline and low dielectric polyimide according to claim 1 or 2, which has a content of 01 to 3.0 dl / g. 4. 100 g of a mixed solvent of 9 parts by weight of p-chlorophenol and 1 part by weight of phenol 0.5 g having a repeating structural unit represented by the formula (1).
3. The liquid crystalline and low dielectric polyimide according to claim 1 or 2, which has a logarithmic viscosity value of 0.01 to 3.0 dl / g measured at 35 ° C. after being dissolved in. 5. Formula (3) [Chemical Formula 4] [Chemical Formula 4] 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] represented by
An aromatic diamine containing benzene as a main component, and mainly represented by the general formula (4) (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group, which are directly or crosslinked to each other. A tetracarboxylic acid dianhydride represented by the formula (4), which represents a tetravalent group selected from the group consisting of non-condensed polycyclic aromatic groups), and thermally or chemically imidize the resulting polyamic acid. The method for producing a liquid crystalline and low dielectric polyimide according to claim 1, wherein 6. Formula (3) [Chemical Formula 6] [Chemical Formula 6] 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] represented by
An aromatic diamine containing benzene as a main component, and mainly represented by the general formula (4) (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group, which are directly or crosslinked to each other. A tetracarboxylic acid dianhydride represented by the formula (5), which represents a tetravalent group selected from the group consisting of non-fused polycyclic aromatic groups. (In the formula, Z ₁ is an aliphatic group having 6 to 15 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group is directly or cross-linked with each other A divalent group selected from the group consisting of the non-condensed polycyclic aromatic groups represented by the following), and reacting in the presence of an aromatic dicarboxylic acid anhydride represented by
The method for producing a liquid crystalline and low dielectric polyimide according to claim 2, wherein the obtained polyamic acid is thermally or chemically imidized. 7. Formula (3) [Chemical Formula 9] [Chemical Formula 9] 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] represented by
An aromatic diamine containing benzene as a main component, and mainly represented by the general formula (4) (In the formula, R represents an aliphatic group having 2 to 27 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group, which are directly or crosslinked to each other. A tetracarboxylic dianhydride represented by a tetravalent group selected from the group consisting of non-fused polycyclic aromatic groups) represented by the formula (6)
1] Z ₂ —NH ₂ (6) (In the formula, Z ₂ is an aliphatic group having 6 to 15 carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, or a condensed polycyclic aromatic group. Group, a monovalent group selected from the group consisting of non-condensed polycyclic aromatic groups in which aromatic groups are connected to each other directly or by a crosslinking member) in the presence of an aromatic monoamine 3. The method for producing a liquid crystalline and low dielectric polyimide according to claim 2, wherein the obtained polyamic acid is thermally or chemically imidized. 8. The method for producing a liquid crystalline and low dielectric polyimide according to claim 6, wherein the aromatic dicarboxylic acid anhydride is phthalic anhydride. 9. The method for producing a liquid crystalline and low dielectric polyimide according to claim 7, wherein the aromatic monoamine is aniline. 10. The liquid crystal according to claim 6, wherein the amount of the aromatic dicarboxylic acid anhydride used is 0.001 to 1.0 mol per 1 mol of the aromatic diamine represented by the formula (3). Of low-temperature and low-dielectric polyimide. 11. The amount of phthalic anhydride used is 0.001 to 1 mol with respect to 1 mol of the aromatic diamine represented by the formula (3).
The method for producing a liquid crystalline and low dielectric polyimide according to claim 6, wherein the ratio is 1.0 mol. 12. The liquid crystallinity according to claim 7, wherein the amount of the aromatic monoamine used is 0.001 to 1.0 mol per 1 mol of the tetracarboxylic acid anhydride represented by the formula (4). And a method for producing a low dielectric polyimide. 13. The amount of aniline used is 0.001 with respect to 1 mol of the tetracarboxylic acid anhydride represented by the formula (4).
The method for producing a liquid crystalline and low dielectric polyimide according to claim 7, wherein the ratio is ˜1.0 mol. 14. A composition containing the polyimide according to claim 1 or 2. 15. A polyimide film containing the polyimide according to claim 1 or 2.