JPH0848773A - Polyamic acid, polyimide and their production - Google Patents

Abstract

PURPOSE:To obtain a polyimide having excellent mechanical strengths and a low coefficient of linear expansion by dehydrative cyclizing a polyamic acid comprising specified repeating units derived by reacting a specified aromatic tetracarboxylic acid dianhydride with a specified aromatic diamine. CONSTITUTION:An aromatic tetracarboxylic acid dianhydride (A) of formula I (wherein R is an aromatic hydrocarbon group) is reacted with an aromatic diamine (B) of formula II in an organic solvent to obtain a polyamic acid (C) mainly consisting of repeating units of formula III. Component C is cyclized through thermal or chemical dehydration to obtain a polyimide of formula IV. To obtain the polyimide in the form of a film, an organic solvent solution of component C is formed into a film of component C, and this film is dried and imidated through thermal dehydration to form a polyimide film of a thickness of 10-150mum. This film is suitable for e.g. a flexible printed wiring board. Examples of component A include dianhydride of pyromellitic acid and benzophenonetetracarboxylic acid. Component C may contain at most 10mol% diamine component other than component B.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a polyimide having excellent heat resistance, high mechanical strength and a low coefficient of thermal expansion, which is suitable for a base material such as a fine patterned flexible printed wiring board, and a method for producing the same. The present invention also relates to a polyamic acid which is an intermediate for producing the polyimide and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, polyimide resins have been extremely superior in heat resistance, chemical resistance, and
It is known to have electrical properties, mechanical properties, and other excellent properties.

For example, a polyimide obtained from 4,4'-diaminodiphenyl ether and pyromellitic dianhydride as disclosed in Japanese Patent Publication No. 36-10999 is well known. This polyimide is a wholly aromatic polyimide because it contains a flexible ether bond in its main chain, but it is highly flexible, but on the other hand, it has a low elastic modulus, a large linear expansion coefficient, and a thermal dimension. It has poor stability.

However, in recent years, in applications such as fine patterned flexible printed wiring boards, there has been a demand for the development of a polyimide resin having more excellent thermal dimensional stability and mechanical strength. Widely used polyimide resin has a linear expansion coefficient of about 3 x 10
^It is considerably large at about ^-5 / ° C. Therefore, it has poor thermal dimensional stability and has a drawback that it is warped or curled when laminated with a metal or the like. For this reason, polyimide resins of various compositions have been studied with the aim of improving thermal dimensional stability and mechanical strength, but polyimide resins that still sufficiently satisfy both thermal dimensional stability and mechanical properties. Is not obtained yet.

The present invention has been made in view of the above circumstances, and produces a polyamic acid which is a polyimide, an intermediate of the polyimide and a polyimide having both high heat resistance and excellent mechanical strength and a low linear expansion coefficient. The purpose is to provide a method.

[0006]

Means for Solving the Problems The present inventor has conducted extensive studies in order to achieve the above-mentioned object, and as a result, the aromatic tetracarboxylic dianhydride represented by the following general formula (2) and the following formula ( By reacting 1,4-bis (4-aminobenzoyloxy) benzene represented by 3),
A polyamic acid having a unit represented by the following general formula (1) as a main repeating unit is obtained, and the polyamic acid is easily represented by the following general formula (4) by thermal or chemical dehydration ring closure. The present invention has been accomplished by finding that a polyimide having a unit as a main repeating unit can be obtained, and that the obtained polyimide has excellent mechanical strength, high elastic modulus and low linear expansion coefficient.

[0007]

Embedded image (However, R represents a tetravalent aromatic hydrocarbon group.)

Accordingly, the present invention comprises reacting a polyamic acid containing the unit of the above formula (1) as a main repeating unit, an aromatic tetracarboxylic dianhydride of the formula (2) and a diamine of the formula (3). There is provided a method for producing the above polyamic acid, a polyimide having a unit of the formula (4) as a main repeating unit, and a method for producing the above polyimide, which comprises dehydrating and ring-closing the polyamic acid of the formula (1). .

The present invention will be described in more detail below. As described above, the polyamic acid of the present invention comprises an aromatic tetracarboxylic dianhydride represented by the following general formula (2) and 1,4-bis (4-aminobenzoyloxy) represented by the following formula (3). It is obtained by reacting with benzene and has a unit represented by the following general formula (1) as a main repeating unit.

[0010]

[Chemical 6]

R in the above formula is a tetravalent aromatic hydrocarbon group, which is derived from the main skeleton of the aromatic tetracarboxylic dianhydride of formula (2). Specifically as the aromatic tetracarboxylic dianhydride, pyromellitic dianhydride,
3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride, 3,3'4,4'-benzophenonetetracarboxylic dianhydride Anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane Dianhydride, bis (3,4-
Dicarboxyphenyl) ethane dianhydride, bis (3,4
-Dicarboxyphenyl) ether dianhydride, 1,1-
Bis (3,4-carboxyphenyl) ethane dianhydride,
3,4,9,10-berylene tetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, Examples thereof include 1,2,7,8-phenylenetetracarboxylic dianhydride, and these can be used alone or in combination of two or more.

The polyamic acid having the repeating unit of the formula (1) of the present invention is a high molecular weight polymer, for example, 0.5
It is desirable that the logarithmic viscosity is 0.5 to 5.0 at a measurement temperature of 30 ° C. in g / 100 ml DMF.

As described above, the polyamic acid of the formula (1) is obtained by reacting the aromatic tetracarboxylic dianhydride of the formula (2) with the diamine of the formula (2) in an organic solvent. However, in this case, as the number of moles of the acid dianhydride to be reacted with the diamine, the acid dianhydride is 0.95 to 1.05 with respect to 1 diamine, and more preferably 0.98 to
1.02 is suitable. If the molar ratio is out of this range, the molecular weight of the polymer obtained will decrease, and sufficient mechanical strength will not be obtained.

In the polyamic acid of the present invention,
In addition to the diamine of the above formula (2), other diamine components may be contained in the range of 10 mol% or less of the total diamine components. Other diamine components include, for example, 4,
4'-bis (4-aminophenoxy) biphenyl, 4,
4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4-
(2-Aminophenoxy) phenyl] sulfone, 1,
4-bis (4-aminophenoxy) benzene, 1,3-
Bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4
-Aminophenyl) benzene, bis [4- (4-aminophenoxy) phenyl] ether, 4,4'-diaminodiphenylmethane, bis (3-ethyl-4-aminophenyl) methane, bis (3-chloro-4-amino) Phenyl) methane, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,
3'-dimethoxy-4,4'-diaminodiphenyl,
3,3'-dimethyl-4,4'-diaminobiphenyl,
3,3'-dichloro-4,4'-diaminobiphenyl,
2,2 ', 5,5'-Tetrachloro-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'
-Diaminobiphenyl, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl ether,
3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminobiphenyl, 4,4 '
-Diaminooctafluorobiphenyl, 2,4-diaminotoluene, paraphenylenediamine, metaphenylenediamine, 4,4'-diaminobenzanilide, 3,
4'-diaminobenzanilide, 4,3'-diaminobenzanilide, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-
Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (3-hydroxy-4-aminophenyl) propane, 2,2-bis (3-hydroxy-4-aminophenyl) hexafluoropropane, 9,9-bis (4-aminophenyl) -10-hydro-anthracene, orthotolidine sulfone, and further, for example 3,
3 ', 4,4'-biphenyltetraamine, 3,3',
It is also possible to use a part of tetraamines such as 4,4′-tetraaminodiphenyl ether. 1,4-bis (4-
A polyvalent amine other than aminobenzoyloxy) benzene can be used in an amount within the range in which the objects and effects of the present invention are achieved, but the amount is 10 mol% or less, preferably 5 mol% or less based on the total amines. A small amount is suitable.

Examples of the organic polar solvent used in the polyamic acid production reaction of the present invention include sulfoxide solvents such as dimethyl sulfoxide, N, N-dimethylformamide, N, N-diethylformamide and the like. Formamide solvent, acetamide solvent such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone,
Pyrrolidone-based solvent such as N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol, halogenated phenol, phenolic solvent such as catechol, hexamethylphosphoramide, γ-
Butyrolactone and the like can be mentioned, and it is desirable to use them alone or as a mixture, but it is also possible to partially use an aromatic hydrocarbon such as xylene and toluene.

Polyamic acid is obtained by polymerizing in these organic polar solvents at a temperature of 0 to 70 ° C., preferably 0 to 30 ° C. for 1 to 50 hours, preferably 3 to 20 hours. This polyamic acid is contained in an organic polar solvent in an amount of 5 to 30% by weight, particularly 1
It is preferably dissolved in the range of 0 to 20% by weight,
It is preferable to determine the amounts of the raw material and the organic solvent used so that the amount of dissolution will be as described above.

Next, the polyimide of the present invention is obtained by dehydration ring closure of the polyamic acid of the above formula (1),
It has a repeating unit represented by the following general formula (4).

[0018]

[Chemical 7] (However, R has the same meaning as above.)

The molecular weight of this polyimide has a molecular weight defined by the molecular weight (logarithmic viscosity) of the above polyamic acid.

The dehydration ring closure of the polyamic acid copolymer can be carried out by an ordinary method, and thermal or chemical dehydration ring closure (imidization) can be preferably adopted. As a thermal dehydration ring-closing method, 5 to 1 at 200 to 500 ° C.
A method of heating for 20 minutes is preferable.

A method using a dehydrating agent and a catalyst is suitable for chemically dehydrating and ring-closing the polyamic acid copolymer. In this case, examples of the dehydrating agent include aliphatic acid anhydrides, aromatic acid anhydrides, N, N-dialkylcarbodiimides, lower fatty acid halides, halogenated lower fatty acid halides, halogenated lower fatty acid anhydrides, and allylphosphon. Examples thereof include acid dihalides and thionyl halides, and these can be used alone or in combination of two or more. The dehydrating agent is used in an amount of about 0.1 to 10 mol per repeating unit of the polyamic acid, particularly, 0.1.
A 5 to 4 molar amount is preferred.

Examples of the catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, β-picoline and isoquinoline. These can be used alone or in combination of two or more. The amount of the catalyst used is preferably about 0.01 to 4 mols, and particularly preferably 0.1 to 2 mols per repeating unit of polyamic acid.

The reaction conditions for the chemical dehydration ring closure are as follows:
0.2 to 20 hours at 20 to 400 ° C., especially 50 to 350
Preference is given to 0.5 to 5 hours at 0 ° C.

To obtain a polyimide copolymer in the form of a film, a solution of the above polyamic acid copolymer in an organic solvent is cast or applied on a support such as an endless belt to form a film, and this film is 100-150. Dry at 0 ° C and add 10-
A polyamic acid self-supporting membrane containing 30% is obtained.
Then, the film is peeled off from the support, the ends are fixed, the solvent is removed by heating to about 150 to 250 ° C., and dehydration imidization is further performed at 250 to 500 ° C. to give a thickness of 10 to 150 μm. Can be obtained.

The thus obtained polyimide copolymer has excellent heat resistance, high mechanical strength and a low coefficient of thermal expansion, so that it can be used, for example, as a film base for an electrically insulating material or a fine patterned flexible printed wiring board. It is suitable as a material.

[0026]

EXAMPLES The present invention will be specifically shown below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Reference Example First, 1,4-bis (4-aminobenzoyloxy) benzene was synthesized as follows.

Hydroquinone (33.0 g, 0.300 mol) and triethylamine (66.8 g, 0.660 mol) were dissolved in tetrahydrofuran (500 ml) and cooled to 0 ° C., and then tetrahydrofuran (150 ml) was added with p-nitrobenzoyl chloride 116. A solution in which 9 g (0.630 mol) was dissolved was added dropwise so that the temperature of the reaction liquid was 10 ° C or lower. Then, it returned to room temperature and continued stirring for 2 hours.

Then, the precipitate was filtered, washed with tetrahydrofuran, further washed with water and methanol, and then dried to obtain white crystals of 1,4-bis (4-nitrobenzoyloxy) benzene. The yield was 121.0 g (yield 98.8%). The crude crystal was recrystallized from N, N-dimethylformamide to obtain a pure product.

In a 1000 ml autoclave, 102.1 g (0.250 mol) of 1,4-bis (4-nitrobenzoyloxy) benzene obtained above was added to 5% Pd / C.
Charged with 3 g and 700 ml of dimethylformamide. Hydrogen was introduced with vigorous stirring at 60 ° C., and stirring was continued until hydrogen absorption was no longer observed.

After cooling, the catalyst was removed by filtration, concentrated under reduced pressure and poured into 1000 ml of water. The precipitate was filtered, washed with water and dried under reduced pressure to give 1,4-bis (4-aminobenzoyloxy). A pale brown white solid of benzene was obtained. Yield 83.
It was 6 g (yield 96.0%). The crude crystal was recrystallized with a mixed solvent of DMF / methanol to obtain a pure product.

[Example 1] D was added to a 1000 ml flask.
MF509.8g was put, and 34.836 g (0.100 mol) of 1,4-bis (4-aminobenzoyloxy) benzene as an aromatic diamine was added as D while flowing nitrogen gas.
Dissolved in MF. Next, 21.812 g (0.100 mol) of pyromellitic dianhydride was added as an acid dianhydride, and 2
The reaction was carried out at 5 ° C for 3 hours. Then, the obtained polyamic acid solution was thinly spread on a glass plate with an applicator, dried in a vacuum oven under reduced pressure at 110 ° C. for 60 minutes, and then peeled off, and then fixed on an iron frame, 200 ° C. for 60 minutes, then 300 Desolvation imidization at ℃, 60 minutes, about 25μ
A m-thick film was obtained.

[Example 2] D was added to a 1000 ml flask.
MF578.3g was put, and 34.836 g (0.100 mol) of 1,4-bis (4-aminobenzoyloxy) benzene as an aromatic diamine was added as D while flowing nitrogen gas.
Dissolved in MF. Next, as acid dianhydride, 3,3 ', 4,4
4'-biphenyltetracarboxylic dianhydride 29.42
2 g (0.100 mol) was added and reacted at 25 ° C. for 3 hours. Then, the obtained polyamic acid solution was thinly spread on a glass plate with an applicator, dried in a vacuum oven under reduced pressure at 110 ° C. for 60 minutes, and then peeled off, and then fixed on an iron frame, 200 ° C. for 60 minutes, then 300 ℃, 60
It was desolvated and imidized in minutes to obtain a film having a thickness of about 25 μm.

[Example 3] D was added to a 1000 ml flask.
MF603.5g was put, and 34.836 g (0.100 mol) of 1,4-bis (4-aminobenzoyloxy) benzene as an aromatic diamine was added while flowing nitrogen gas.
Dissolved in MF. Next, as acid dianhydride, 3,3 ', 4,4
4'-benzophenone tetracarboxylic dianhydride 32.
223g (0.100mol) was added and it was made to react at 25 ° C for 3 hours. Then, the obtained polyamic acid solution was thinly spread on a glass plate with an applicator, dried in a vacuum oven under reduced pressure at 110 ° C. for 60 minutes, and then peeled off, and then fixed on an iron frame, 200 ° C. for 60 minutes, then 300
Desolvation imidization was carried out at 60 ° C. for 60 minutes to obtain a film having a thickness of about 25 μm.

[Comparative Example 1] D was added to a 1000 ml flask.
376.5 g of MF was added, and 20.024 g (0.100 mol) of 4,4′-diaminodiphenyl ether as an aromatic diamine was dissolved in DMF while flowing a nitrogen gas. Next, pyromellitic dianhydride 2 as acid dianhydride
1.812 g (0.100 mol) was added and reacted at 25 ° C. for 3 hours. Then, the obtained polyamic acid solution was thinly spread on a glass plate with an applicator, dried in a vacuum oven under reduced pressure at 110 ° C. for 60 minutes, and then peeled off, and then fixed on an iron frame, 200 ° C. for 60 minutes, then 300
Desolvation imidization was carried out at 60 ° C. for 60 minutes to obtain a film having a thickness of about 25 μm.

[Comparative Example 2] D was added to a 1000 ml flask.
MF445.0g was put and 20.024g (0.100mol) of 4,4'- diamino diphenyl ether as an aromatic diamine was melt | dissolved in DMF, flowing nitrogen gas. Next, as the acid dianhydride, 29.422 g of 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride (0.1
(00 mol) was added, and the mixture was reacted at 25 ° C. for 3 hours. Then, the obtained polyamic acid solution was thinly spread on a glass plate with an applicator, and the solution was placed in a vacuum oven under reduced pressure.
After being dried at 0 ° C. for 60 minutes and peeled off, the film was fixed on an iron frame and desolvated at 200 ° C. for 60 minutes and then at 300 ° C. for 60 minutes to obtain a film having a thickness of about 25 μm.

[Comparative Example 3] D was added to a 1000 ml flask.
470.2 g of MF was added, and 20.024 g (0.100 mol) of 4,4′-diaminodiphenyl ether as an aromatic diamine was dissolved in DMF while flowing a nitrogen gas. Next, 32.223 g of 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride as an acid dianhydride
(0.100 mol) was added, and the mixture was reacted at 25 ° C for 3 hours. Then, the obtained polyamic acid solution was thinly spread on a glass plate with an applicator, dried in a vacuum oven under reduced pressure at 110 ° C. for 60 minutes, and then peeled off, and then fixed on an iron frame, 200 ° C. for 60 minutes, then 300 Desolvation imidization was carried out at 60 ° C. for 60 minutes to obtain a film having a thickness of about 25 μm.

The mechanical properties and linear expansion coefficient of the obtained film were measured as follows. Table 1 shows the measurement results. Mechanical Properties (Tensile Strength, Elastic Modulus, Elongation ) Measured based on ASTM D882-88. Linear expansion coefficient Using a thermal analyzer TMA-7000 manufactured by Vacuum Riko Co., Ltd., an average value of linear expansion coefficients at 150 to 200 ° C was obtained at a temperature rising rate of 5 (° C / min). The logarithmic viscosity polyamic acid concentration was 0.5 g / 100 ml DMF, and the temperature was 30 ° C.

[0039]

[Equation 1]

[0040]

[Table 1]

[0041]

The polyimide of the present invention has excellent heat resistance,
It also has excellent mechanical strength, a small linear expansion coefficient, and excellent thermal dimensional stability.

Further, according to the production method of the present invention, such a polyimide and a polyamic acid useful as an intermediate thereof can be easily and reliably produced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Sugitani, 1st Higashiwada, Kamisu-cho, Kashima-gun, Kashima-gun, Ibaraki Shin-Etsu Chemical Co., Ltd. Polymer Functional Materials Research Laboratory (72) Inventor Masahiro Yuyama Kamisu, Kashima-gun, Ibaraki No. 1 Towada, Oomachi-machi, Shin-Etsu Chemical Co., Ltd., Polymer Functional Materials Research Center

Claims (4)

[Claims] 1. A polyamic acid containing a unit represented by the following general formula (1) as a main repeating unit. Embedded image (However, R represents a tetravalent aromatic hydrocarbon group.) 2. The following general formula (2): (Wherein R represents a tetravalent aromatic hydrocarbon group) and an aromatic tetracarboxylic dianhydride represented by the following formula (3): The method for producing a polyamic acid according to claim 1, which comprises reacting with an aromatic diamine represented by 3. A polyimide comprising a unit represented by the following general formula (4) as a main repeating unit. [Chemical 4] (However, R represents a tetravalent aromatic hydrocarbon group.) 4. The method for producing a polyimide according to claim 3, wherein the polyamic acid according to claim 1 is subjected to dehydration ring closure.