JP2000297153A - New aromatic diamine and polyimide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high thermostability and transparency and excellent molding workability by forming an aromatic polyimide having a specified repeated structural unit wherein a monomer component is an aromatic diamine having a specified structure. SOLUTION: An aromatic polyimide is represented by formula II (wherein R is a substitute represented by formula III and the like) containing an aromatic diamine (A) of 1,3-bis(4-aminophenoxy)-4-rifluoromethylbenzene represented by formula I and an aromatic tetracarboxylic acid dianhydride (B) as constituents. The aromatic polyimide is obtained by proceeding simultaneously with generation of a polyamic acid and a thermal imidation reaction by reacting an aromatic dicarboxylic acid anhydride or an aromatic monoamine using the amount of inactivating components A and B and an excess amino group or acid anhydride group, in a solvent such as m-cresol at 130-250 deg.C. As the component B is used pyromellitic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorine-containing polyimide,
Also, the present invention relates to a novel aromatic diamine having a perfluoroalkyl group, which is a raw material monomer of this polyimide. More specifically, the present invention relates to a novel aromatic polyimide having a perfluoroalkyl group in a repeating structural unit, having excellent transparency, low dielectric properties, and low hygroscopicity, and further having excellent moldability and low birefringence. In addition, the present invention relates to a novel aromatic diamine useful as a raw material monomer of these polyimides, or as a starting material such as polyamide, polyamide imide, bismaleimide, or epoxy resin, or as a raw material for organic chemicals.

[0002]

2. Description of the Related Art In recent years, research on optoelectronics for realizing a highly information-oriented society has been vigorously conducted.
At the same time, expectations are growing for organic optical materials, especially polymer materials, as basic materials that support various developments in optoelectronics such as optical communication, optical recording, optical processing, optical measurement, and optical computation. Optical polymer materials have many features, such as being lightweight and flexible, not subject to electrical induction, and being easy to mold. Optical fibers, optical waveguides, optical disc substrates, optical filters, lenses, optical It is being developed for applications such as adhesives.

The following properties are required for optical polymer materials. That is, it has high transparency, high refractive index, low birefringence, cleanliness, easy moldability, high heat resistance, low water absorption, and appropriate strength characteristics. Representative optical polymer materials such as polymethyl methacrylate and polycarbonate are excellent in transparency, mechanical properties, moldability, and the like, and are being developed for optical disks and optical fibers. However, these polymers, for example, polycarbonates belonging to engineering plastics have a glass transition temperature of about 150 ° C., and cannot be said to have sufficient heat resistance. Therefore, in fields requiring high heat resistance, such as optical components for aviation, automobiles, and industrial equipment, quartz glass, which has poor processability, is still used.

In recent years, ARTON (manufactured by Nippon Synthetic Rubber Co., Ltd.)
Alicyclic polymers excellent in optical properties, such as ZEONEX (manufactured by Zeon Corporation) and Apel (manufactured by Mitsui Chemicals, Inc.), have been developed. Since these alicyclic polymers have no aromatic ring, they are excellent in transparency in the visible light region, low birefringence, and low water absorption. On the other hand, the absorption loss in the infrared region derived from the aliphatic C—H bond is large, and the heat resistance cannot be said to be high.

As an optical polymer material having high heat resistance, a fluorinated polyimide having a perfluoroalkylene group introduced into a repeating structural unit has been developed. Among them, "FLUPI" developed by Nippon Telegraph and Telephone Corporation (JP-A-08-063061, JP-A-08-14366)
No. 6 is an excellent polymer material for optical use. That is, the polyimide has heat resistance of 300 ° C. or more, has extremely high transparency in the visible light region, and has a birefringence of 0.005 to 0.008, which is much smaller than that of the conventional polyimide. Furthermore, since the polyimide does not have an aliphatic CH bond in a repeating structural unit, it is a single-mode communication wavelength region suitable for large-capacity information transmission.
It has no absorption at 3,1.55 μm.

However, since the fluorinated polyimide "FLUPI" has poor thermoplasticity, it has a problem that it cannot be made into a fiber by melt spinning, or into a disk or a lens by injection molding. The present inventors have previously developed an optical polyimide represented by the chemical formula (a) and having both optical properties, particularly low birefringence, and moldability (Japanese Patent Application Laid-Open No. 06-207015, Japanese Patent Application No. -226
052).

[0007]

Embedded image The polyimide is thermoplastic and has a birefringence of 0.003.
Since it is as low as 0.005, it is possible to mold an optical disk by injection molding, and the obtained optical disk has high reading reliability.

However, the polyimide has good optical properties and moldability, but has a glass transition temperature of 1%.
It is as low as 96 to 229 ° C, and it is difficult to say that the heat resistance is sufficiently high. Therefore, optical parts for aviation, automobile, industrial equipment, etc.
There has been a demand for the development of an optical polymer having good moldability, which can be used in fields requiring high heat resistance.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical polyimide having high heat resistance and moldability.

[0010]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, a polyimide containing an aromatic diamine having a specific structure as a monomer component has high heat resistance and excellent molding properties. The present inventors have found that they have workability, and that they have high transparency and low birefringence, and have completed the present invention. That is, the present invention is specified by the matters described in the following [1] and [2]. [1] An aromatic diamine represented by the chemical formula (1).

[0011]

Embedded image [2] An aromatic polyimide having a repeating structural unit represented by the chemical formula (2) (in the chemical formula (2), R is
It is at least one selected from the group of R substituents. ).

[0012]

Embedded image

[0013]

[Image Omitted] R substituent groups

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic diamine of the present invention is a novel fluorine-containing aromatic diamine, and represented by the above formula (1), 1,3-bis (4-aminophenoxy) -4-.
It is trifluoromethylbenzene. The method for producing the aromatic diamine of the present invention is not particularly limited, and a general method for producing an aromatic diamino compound can be used. That is, the aromatic diamine of the present invention can be prepared, for example, by adding 2,4-dichlorobenzotrifluoride and p-aminophenol to an aprotic polar solvent in the presence of a base in an amount of from 100 to 100.
It can be obtained by reacting at 250 ° C.

The polyimide of the present invention has the chemical formula (2)
A novel fluorine-containing aromatic polyimide having a repeating structural unit represented by the following formula: Since the polyimide having the repeating structural unit has a high fluorine atom content per mole volume, the molar polarizability per mole volume decreases, and as a result, the polyimide exhibits high transparency, low dielectric properties, and low water absorption. further,
In the polyimide having the repeating structural unit, the two benzene rings sandwiching the ether bond are almost orthogonal to each other due to the steric hindrance of the trifluoromethyl group at the ortho position of the ether bond, and the polarization anisotropy thereof is canceled out. Intrinsic birefringence is small. When the trifluoromethyl group is located at the meta or para position of the ether bond, the two benzene rings sandwiching the ether bond form an angle of about 60 degrees, and the polarizability anisotropy is not canceled out. , Large birefringence is not preferred.

The polyimide of the present invention is obtained by reacting 1,3-bis (4-aminophenoxy) -4-trifluoromethylbenzene, a novel aromatic diamine of the present invention, with aromatic tetracarboxylic dianhydride. Can be obtained by thermally or chemically imidizing the resulting polyamic acid.

Here, the aromatic tetracarboxylic acid used is not particularly limited, and polyimides having various glass transition temperatures, transparency and refractive index can be obtained by using a conventionally known aromatic tetracarboxylic acid. . Specific examples of the aromatic tetracarboxylic acid include, for example, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,3 ′, 3,4′-benzophenone tetraanhydride. Carboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3', 3,4'-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4 -Dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (3,4- Dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride,
2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3, 4,9,10-perylenetetracarboxylic dianhydride, 2,
3,6,7, -anthracenetetracarboxylic dianhydride, 1,2,
7,8-phenanthrenetetracarboxylic dianhydride and the like. These may be used alone or in combination of two or more.

The polyimide of the present invention has a molecular weight by shifting the molar ratio of 1,3-bis (4-aminophenoxy) -4-trifluoromethylbenzene and aromatic tetracarboxylic dianhydride from the theoretical equivalent value. Can be adjusted. In this case, the excess amino group or acid anhydride group is deactivated by reacting it with an aromatic dicarboxylic anhydride or aromatic monoamine which is at least the theoretical equivalent of the excess amino group or acid anhydride group. I do. Polyimide which does not inactivate excess amino groups or acid anhydride groups has poor thermal stability at the time of melting and cannot be used for melt molding. That is, when a polyimide having a molecular end at an amino group or an acid anhydride group is melted in a cylinder of a melt molding machine, its fluidity is rapidly reduced, and molding is extremely difficult or impossible.

The dicarboxylic anhydrides used herein include phthalic anhydride, 2,3-benzophenone dicarboxylic anhydride, 3,4-benzophenone dicarboxylic anhydride, 2,3-dicarboxyphenyl phenyl ether anhydride, 3,4-dicarboxyphenylphenyl ether anhydride, 2,3-biphenyldicarboxylic anhydride, 3,4-biphenyldicarboxylic anhydride, 2,3-dicarboxyphenylphenylsulfone anhydride, 3,4-dicarboxy Phenylphenyl sulfone anhydride, 2,3-dicarboxyphenylphenyl sulfide anhydride, 3,4-dicarboxyphenyl phenyl sulfide anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, 1,2-anthracene dicarboxylic anhydride, 2,3-anthracene dicarboxylic anhydride, 1,9-ant Helixene dicarboxylic anhydride and the like. These dicarboxylic anhydrides may be substituted with a group having no reactivity with amine or dicarboxylic anhydride. When an aromatic monoamine is used, examples of the aromatic monoamine 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-aminophenol, m-aminophenol, p-aminophenol, o-anisidine, m-anisidine, p-anisidine, o-phenezine,
m-phenezine, p-phenezine,

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-aminophenylphenyl ether, 2-aminobenzophenone,
3-aminobenzophenone, 4-aminobenzophenone, 2-
Aminophenylphenyl sulfide, 3-aminophenylphenyl 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-
Examples thereof include naphthol, 7-amino-2-naphthol, 8-amino-1-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-aminoanthracene, and 9-aminoanthracene. These aromatic monoamines may be substituted with a group having no reactivity with amine or dicarboxylic anhydride.

In the polyimide of the present invention, the above-mentioned aromatic diamine is used as an essential monomer, but other aromatic diamines may be mixed and used as long as the good physical properties of the polyimide are not impaired. By appropriately copolymerizing another aromatic diamine, a polyimide having an arbitrary refractive index and birefringence can be obtained. Examples of diamines that can be used in combination include, for example, 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] diphenylsulfone, bis [4- [4- (4-aminophenoxy) phenoxy] phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethyl Benzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy)- α, α-dimethylbenzyl]
Benzene, 1,3-bis [4- (4-amino-6-fluorophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4-
(4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene, 3, 3'-diamino-4,4'-diphenoxybenzophenone, 4,4'-diamino-5,5'-diphenoxybenzophenone, 3,4'-diamino-
4,5'-diphenoxybenzophenone, 3,3'-diamino-4-
Phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4 '-Dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-diamino-4,5'-dibiphenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone ,Four,
4'-diamino-5-biphenoxybenzophenone, 3,4'-diamino-4-biphenoxybenzophenone, 3,4'-diamino
-5'-biphenoxybenzophenone, 1,3-bis (3-amino-
4-phenoxybenzoyl) benzene, 1,4-bis (3-amino
-4-phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-phenoxybenzoyl) benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-
(Amino-4-biphenoxybenzoyl) benzene, 1,4-bis
(3-amino-4-biphenoxybenzoyl) benzene, 1,3-
Bis (4-amino-5-biphenoxybenzoyl) benzene,
1,4-bis (4-amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethylbenzyl)
Phenoxy] benzonitrile, 2,6-bis [4- (4-amino-
α, α-bistrifluoromethylbenzyl) phenoxy)
Benzonitrile, 2,6-bis [4- (4-aminophenoxy) phenoxy] benzonitrile, 2,6-bis [4- (4-aminobenzoyl) phenoxy] benzonitrile, and the like,
These can be used alone or in combination of two or more.

The method for producing the polyimide of the present invention includes:
All methods capable of producing polyimide can be applied, including known methods. Among them, the reaction is preferably performed in an organic solvent. As the solvent used in such a reaction,
For example, N, N-dimethylformamide, N, N-dimethylacetamide, 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, tetra Examples include methylurea, hexamethylphosphoramide, phenol, o-cresol, m-cresol, p-cresol, m-cresol, p-chlorophenol, anisole, benzene, toluene, xylene and the like. These organic solvents may be used alone or as a mixture of two or more.

In the present invention, the method of adding and reacting an aromatic diamine, an aromatic tetracarboxylic dianhydride, an aromatic dicarboxylic anhydride or an aromatic monoamine includes the following (a) aromatic tetracarboxylic dianhydride. And reacting the aromatic diamine, followed by adding an aromatic dicarboxylic anhydride or an aromatic monoamine to continue the reaction,
(B) a method in which an aromatic dicarboxylic acid anhydride is added to an aromatic diamine and reacted, followed by adding an aromatic tetracarboxylic acid dianhydride and continuing the reaction; (c) an aromatic tetracarboxylic acid dianhydride A method in which an aromatic monoamine is added to and reacted with an aromatic diamine, and the reaction is further continued. (D) Aromatic tetracarboxylic dianhydride, aromatic diamine, aromatic dicarboxylic anhydride or aromatic Examples include a method in which a monoamine is simultaneously added and reacted, and any method may be used.

The reaction temperature is usually from ordinary temperature to 250 ° C. The reaction pressure is not particularly limited, and the reaction can be sufficiently performed at normal pressure. The reaction time varies depending on the type of aromatic tetracarboxylic dianhydride, the type of solvent and the reaction temperature, but usually 4 to 24 hours is sufficient. By conducting the reaction at room temperature to 130 ° C., a polyamic acid which is a precursor of the polyimide of the present invention is produced. By heating this polyamic acid to 100 to 400 ° C. to imidize it, or by chemically imidizing it using an imidizing agent such as acetic anhydride, a polyimide having a repeating structural unit corresponding to the polyamic acid can be obtained.

By conducting the reaction at 130 to 250 ° C., the polyamic acid generation and the thermal imidization reaction proceed simultaneously, and the polyimide of the present invention can be obtained. That is, an aromatic diamine, an aromatic tetracarboxylic dianhydride, an aromatic monoamine and / or an aromatic dicarboxylic anhydride are suspended or dissolved in an organic solvent, and 130 to
By performing the reaction under heating at 250 ° C. to simultaneously perform the polyamic acid generation and the dehydration imidization, the polyimide of the present invention in which the terminal is inactivated can be obtained.

The molecular weight of the polyimide of the present invention is not particularly limited, and may be any molecular weight depending on the application and processing method. The polyimide of the present invention is, for example, a precursor of the present polyimide by adjusting the amount ratio of aromatic diamine, aromatic tetracarboxylic dianhydride, aromatic monoamine and / or aromatic dicarboxylic anhydride to be used. After dissolving the polyamic acid in N, N-dimethylacetamide at a concentration of 0.5 g / dl, the value of the logarithmic viscosity measured at 35 ° C. may be any value from 0.1 to 3.0 dl / g. it can. Also, the polyimide was added to a mixed solvent of 9 parts by weight of p-chlorophenol and 1 part by weight of phenol in 0.5 part.
After heating and dissolving at a concentration of g / dl, the value of the logarithmic viscosity measured at 35 ° C. can be any value of 0.1 to 3.0 dl / g.

The polyimide of the present invention is thermoplastic and can be formed by ordinary melt molding. That is,
Various molded articles such as disks and fibers can be obtained by extrusion molding, injection molding, vacuum molding, blow molding, compression molding, blow molding, calendar molding, lamination molding, and the like. The polyimide of the present invention can be made into a film or a coat by applying a varnish of a polyamic acid as a precursor on a metal foil or a glass plate and then heating or imidizing it with an imidizing agent. Polyimide of the present invention, other thermoplastic resins within the scope of the present invention, for example, polyethylene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyethersulfone, polyetherketone, polyphenylsulfide, polyamideimide, It is also possible to mix appropriate amounts of polyetherimide, modified polyphenylene oxide, polyimide other than the present invention, and the like.

The polyimide of the present invention has high heat resistance and excellent moldability, and further has low water absorption, solvent solubility,
An excellent polyimide having high transparency and low birefringence, it is suitable for applications such as optical fibers, optical waveguides, optical disc substrates, optical filters, lenses, and optical adhesives.
Also, JP-A-3-6528, JP-A-4-6528
It is suitable for use as an alignment film for a liquid crystal element described in, for example, Japanese Patent Application Publication No.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. In addition, the physical properties of the polyimide in the examples were measured by the following methods. Glass transition temperature (Tg): Measured by DSC (Shimadzu DT-40 series, DSC-41M). 5% weight loss temperature: DTG (Shimadzu DT-
40 series, measured by DTG-40M). Melt viscosity (MV): Shimadzu Koka type flow tester (CF
T500A), measured using a 100 kg load, holding at 400 ° C. for 5 minutes and melting. Logarithmic viscosity (ηinh): p-chlorophenol / phenol (weight ratio 9/1) mixed solvent of polyimide 0.5
After dissolving at a concentration of g / 100 ml, the measurement was performed at 35 ° C.

Example 1 A reflux condenser equipped with a separator,
In a reactor equipped with a thermometer, a dropping funnel equipped with a heater and a stirrer, 82.93 g (0.6 mol) of potassium carbonate was added.
N, N-dimethylformamide (hereinafter abbreviated as DMF)
200 g and 30 g of toluene were charged. Then
107.5 g of 2,4-dichlorobenzotrifluoride
(0.5 mol) and p-aminophenol 112.
A solution prepared by heating 4 g (1.03 mol) of DMF in 200 g of DMF by heating to 70 ° C. was charged into a dropping funnel equipped with a heater, and maintained at 70 to 80 ° C.

After the temperature was raised to 130 ° C. while stirring the inside of the reactor, the solution in the dropping funnel was dropped over 6 hours while maintaining the temperature at 130 to 135 ° C. During this time, the generated water was azeotroped with toluene, condensed in a reflux condenser, and then separated from the separator. After completion of the dropwise addition, stirring was continued for 3 hours while maintaining this temperature range. After the reaction,
When a small amount of the reaction mass was collected and the purity was measured, the purity was 83.5%.

The reaction mass is cooled to 100 ° C.
The solid matter was separated by filtration by hot filtration, and the solid matter on the filter paper was washed with 30 g of DMF at 100 ° C. While maintaining the obtained filtrate and a total of 588.9 g of the washing liquid at 90 ° C. in a flask equipped with a stirrer, 540 g of pure water was charged. 3
After cooling to 30 ° C. over time, the precipitated crystals were separated by filtration and washed on a filter paper with 100 g of methanol. The purity of the obtained crystals was 95.7%.

The obtained crystals were mixed with 1000 g of pure water and 36% H
50.0 g of Cl water was added and dissolved by stirring at 80 ° C. for 1 hour. To this was added 55.0 g of salt, and the mixture was gradually cooled to 30 ° C. over 3 hours with stirring. The precipitated crystals were collected by filtration, washed with 10% saline, and treated with 1,3-bis (4-aminophenoxy)-
4-trifluoromethylbenzene hydrochloride was obtained.

A reactor equipped with a dropping device, a stirrer, and a thermometer was charged with 1,3-bis (4-aminophenoxy) -4-trifluoromethylbenzene hydrochloride, 800 g of pure water, and 600 g of toluene. It melted by heating at ° C. Then, 200 g of 5% aqueous ammonia was dropped from the dropping device over 1 hour. After dropping, the aqueous phase was separated and removed, and pure water 1
000 g was added, the mixture was vigorously stirred, and the aqueous phase was separated and removed to remove salts. The obtained oil phase is heated at 30 ° C. for 3 hours.
And the precipitated crystals were separated by filtration and 100 g of methanol
And washed. Dry at 60 ° C. for 8 hours under reduced pressure,
124.2 g of 3-bis (4-aminophenoxy) -4-trifluoromethylbenzene (68.9% yield, purity 9)
9.6%). Figure ¹ 1 H-NMR δ (CDC
l ₃ ) Show a chart.

1,3-bis (4-aminophenoxy) -4-trifluoromethylbenzene Melting point 91.6-93.2 ° C. Elemental analysis (C19H15N2O2F3) −−−−−−−−−−−−− CHNF −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Calculated value (%) 63.3 4.2 7.8 15.8 Measured value (%) 63.2 4.3 7.8 15.7 -------------------------------------------------------- −−−−−−−−

Example 2 The 1,3-bis (4-aminophenoxy) -4-trifluoromethylbenzene obtained in Example 1 was placed in a vessel equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube. 02g (0.05mol), 2,2-bis
21.32 g of (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride (0.048 mo
l), 0.592 g of phthalic anhydride (0.004 mol)
l), 0.70 g of γ-picoline, m-cresol 14
7.84 g was charged and heated to 150 ° C. while stirring under a nitrogen atmosphere. Thereafter, the reaction was carried out at 150 ° C. for 4 hours, during which time about 1.8 ml of water was distilled out. After the completion of the reaction, the mixture was cooled to room temperature, discharged into about 1 L of methyl ethyl ketone, and then the polyimide powder was separated by filtration. After washing this polyimide powder with methyl ethyl ketone, it was dried in air at 50 ° C. for 24 hours and in nitrogen at 220 ° C. for 4 hours to obtain 36.60 g of polyimide powder (96.0% yield).
I got

The logarithmic viscosity of the obtained polyimide powder is 0.4.
The melt viscosity was 2 dl / g and the melt viscosity was 1090 Pa · sec. The glass transition temperature of this polyimide powder was 252.
° C, 5% weight loss temperature was 515 ° C. This polyimide powder was press-molded at 400 ° C. to form a film having a thickness of 50 μm. According to ASTM D-1004, 50
The light transmittance (T%) of the film at 0 nm was measured and found to be 84.0%. ASTM D-150-87
The dielectric constant (ε) of the film at 1 MHz was measured and found to be 3.01. Also, a 10 wt% N, N-dimethylacetamide solution of this polyimide powder was prepared,
After spin coating on a silicon wafer, the temperature was raised from 50 ° C. to 250 ° C. over 2 hours in a nitrogen atmosphere.
It was dried at 0 ° C. for 2 hours. By this operation, a polyimide film having a thickness of 20 μm was obtained on the silicon wafer. When the refractive index of this film at a wavelength of 1.3 μm was measured by the prism coupling method, n _TE was 1.551 and n _TM was 1.
547 and the birefringence index Δn was 0.004.

The results are shown in Table 1. As is clear from the table, this polyimide has the same birefringence as the polyimides of Comparative Examples 1 to 3, and has a high glass transition temperature, that is, a high heat resistance. This polyimide has a higher refractive index and a lower birefringence than the polyimides of Comparative Examples 4 and 5.

Examples 3 and 4 Instead of 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride (0.048 mol) In the same manner as in Example 2 except that tetracarboxylic dianhydride (0.048 mol) shown in Table 1 was used, a polyimide powder was obtained, and its logarithmic viscosity, melt viscosity, and glass transition temperature were measured. Further, in the same manner as in Example 2, the light transmittance, the dielectric constant, the refractive index and the birefringence of the film were measured. Table 1 shows the results.

[Comparative Examples 1-4] Instead of 1,3-bis (4-aminophenoxy) -4-trifluoromethylbenzene (0.05 mol), an aromatic diamine (0.05 mol) shown in Table 1 was used. A polyimide powder was obtained and the logarithmic viscosity, the melt viscosity, and the glass transition temperature were measured in the same manner as in Example 2 except for using the polyimide powder. Further, in the same manner as in Example 2, the light transmittance, the dielectric constant, the refractive index and the birefringence of the film were measured. Table 1 shows the results.

[0043]

[Table 1]

[0044]

The polyimide of the present invention has high heat resistance and excellent moldability, and furthermore has excellent water absorption, solvent solubility, high transparency and low birefringence. It is suitable for applications such as optical fibers, optical waveguides, optical disk substrates, optical filters, lenses, and optical adhesives.

[Brief description of the drawings]

FIG. 1 shows ¹ H-NMR of 1,3-bis (4-aminophenoxy) -4-trifluoromethylbenzene.
(Measurement conditions; δ (CDCl ₃ )) A measurement chart is shown.

Continuing on the front page F-term (reference) 4H006 AA01 4J043 PA02 PA15 PA19 PC145 QB41 RA34 SA06 SA54 SB01 TA22 TB01 UA122 UA132 UA141 UB022 UB062 UB122 UB131 UB152 UB302 VA021 VA022 VA051 VA062 VA091 VA102 XA03 ZA17 ZA12 XA17 ZB21 ZB25 ZB51

Claims (2)

[Claims] 1. An aromatic diamine represented by the chemical formula (1). Embedded image 2. An aromatic polyimide having a repeating structural unit represented by the chemical formula (2) (in the chemical formula (2),
R is at least one selected from the group of R substituents. ). Embedded image [Image Omitted] R substituent groups