JPH07316294A - Polyimide copolymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain a polyimide copolymer giving a film which is excellent in properties including heat resistance, is satisfactory in mechanical strength and thermal dimensional stability, and has low hygroscopicity. CONSTITUTION:A polyimide copolymer comprises, as major structural units, repeating units represented by formula I and repeating units represented by formula 1, 1. In the formulae, R<1> is a tetravalent aromatic group and R<2> is CH3 or CF3.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a polyimide having excellent heat resistance, high mechanical strength, thermal dimensional stability and low hygroscopicity, which is suitable as a base material for fine patterned flexible printed wiring boards and the like. The present invention relates to a copolymer and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Polyimide resin is known to have excellent heat resistance, chemical resistance, electrical properties, mechanical properties, and other excellent properties, and is particularly useful for various applications such as electrical insulation films that require heat resistance. Widely used. However, the polyimide resin is superior in heat resistance to other plastics, but has a significantly high water absorption. Therefore, it has a drawback that dimensional stability and insulation are deteriorated.

In recent years, there has been an increasing demand for polyimide resins having excellent low hygroscopicity and excellent mechanical strength, and various studies have been conducted. Among such attempts, many attempts are made to improve low hygroscopicity by using an aromatic diamine having a hydrophobic group or an aromatic tetracarboxylic dianhydride. However, in each of these approaches, the mechanical properties, in particular the elastic modulus and the tensile strength, tend to decrease in exchange for the improvement of the low hygroscopicity, and both the low hygroscopicity and the mechanical properties are reduced. I was not satisfied.

The present invention has been made in view of the above circumstances.
An object of the present invention is to provide a polyimide copolymer having excellent heat resistance, high thermal dimensional stability, high mechanical strength and low hygroscopicity, and a method for producing the same.

[0005]

Means and Actions for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, 4,4 '
-Bis (4-aminobenzamido) -3,3'-dihydroxybiphenyl and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane or 2,
A polyamic acid copolymer obtained by polymerizing an aromatic diamine mainly containing 2-bis [4- (4-aminophenoxy) phenyl] propane and an aromatic tetracarboxylic dianhydride is thermally and A polyimide copolymer containing a repeating unit (A) represented by the following general formula (1) and a repeating unit (B) represented by the following general formula (2) as main constitutional units by chemically dehydrating and ring-closing. Combined, preferably the following repeating unit (A) and the following repeating unit (B) are (A) /
(B) A polyimide copolymer containing repeating units of 15/85 to 90/10 is obtained, and the polyimide copolymer has excellent low hygroscopicity and excellent mechanical strength. That is, the present invention has been completed.

[0006]

[Chemical 2] (However, in the formula, R ¹ represents a tetravalent aromatic group, and R ² represents CH ₃
Or CF ₃ is shown. )

Accordingly, the present invention provides a polyimide copolymer containing the repeating unit (A) represented by the general formula (1) and the repeating unit (B) represented by the general formula (2) as main constituent units. In combination, preferably the repeating unit (A) and the repeating unit (B) are in a molar ratio of (A) / (B) = 15 / 85-90.
/ 10 polyimide copolymer, and 4,4'-bis (4-aminobenzamido) -3,3'-dihydroxybiphenyl and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoro Propane or 2,2-
An aromatic diamine containing bis [4- (4-aminophenoxy) phenyl] propane as a main component and an aromatic tetracarboxylic acid dianhydride are polymerized to obtain a polyamic acid, and then the polyamic acid copolymer is prepared. The main constitutional unit comprises a repeating unit (A) represented by the above general formula (1) and a repeating unit (B) represented by the above general formula (2), which are characterized by undergoing dehydration ring closure thermally and chemically. A method for producing a polyimide copolymer containing the above is provided.

The present invention will be described in more detail below. The polyimide copolymer of the present invention has the following general formula (1).
The repeating unit (A) represented by and the repeating unit (B) represented by the following general formula (2) are included as main constitutional units.

[0009]

[Chemical 3] (However, in the formula, R ¹ represents a tetravalent aromatic group, and R ² represents CH ₃
Or CF ₃ is shown. )

R ¹ in the above formula is a tetravalent aromatic group,
This is derived from the main skeleton of tetracarboxylic dianhydride described later.

Here, the repeating unit (A) and the repeating unit (B) have a molar ratio (A) in the polyimide copolymer.
/ (B) = 15/85 to 90/10, especially 25/75 to
It is preferably present in a ratio of 75/25. When the molar ratio of the repeating unit (A) exceeds 90%, the effect of improving the water absorption of the polyimide copolymer cannot be sufficiently obtained, and the flexibility decreases. On the other hand, when the molar ratio of the repeating unit (B) exceeds 85%, the mechanical strength, elastic modulus and thermal dimensional stability of the polyimide copolymer become very low.

The polyimide copolymer of the present invention contains, in addition to the repeating units (A) and (B), 4,4'-bis (4-aminobenzamido) -3,3'-dihydroxybiphenyl and 2,2- Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane or 2,2-bis [4-
Containing units derived from an aromatic diamine compound other than (4-aminophenoxy) phenyl] propane in a proportion of preferably 10 mol% or less, more preferably 5 mol% or less of the units derived from the wholly aromatic diamine. You may stay.

The above-mentioned polyimide copolymer is a high molecular weight polymer, and its viscosity as a polyamic acid is, for example, 0.5.
Measurement temperature 30 when measured in g / 100 ml DMF
The logarithmic viscosity at 0 ° C. is preferably 0.5 to 5.0 dl / g.

The above polyimide copolymer is obtained by polymerizing an aromatic diamine and an aromatic tetracarboxylic dianhydride to obtain a polyamic acid copolymer, and the polyamic acid copolymer is thermally or chemically prepared by a known method. It can be produced by dehydration ring closure (imidization).

In the present invention, as the aromatic diamine, 4,4'-bis (4-aminobenzamide) is used.
Mainly -3,3'-dihydroxybiphenyl and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane or 2,2-bis [4- (4-aminophenoxy) phenyl] propane Used as an ingredient.
In addition, 4,4'-bis (4-aminobenzamide)-
Mixing ratio of 3,3′-dihydroxybiphenyl and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane or 2,2-bis [4- (4-aminophenoxy) phenyl] propane Is a molar ratio of 15/85 to 90/10, especially 25/75 to 75/25.
It is preferable that

In the present invention, 4,4'-bis (4-aminobenzamide) -3,3 'is used as the aromatic diamine component.
-Dihydroxybiphenyl and 2,2-bis [4- (4
It is most preferred to use only -aminophenoxy) phenyl] hexafluoropropane or 2,2-bis [4- (4-aminophenoxy) phenyl] propane, but with these aromatic diamines other aromatic polyamines The compounds can be used in combination. Specific examples of the aromatic diamine compound that can be used in combination include 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, and 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-methyl-4-aminophenyl) methane, bis (3-chloro-4-aminophenyl) methane,
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, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4 '
-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 (3-hydroxy-4)
-Aminophenyl) propane, 2,2-bis (3-hydroxy-4-aminophenyl) hexafluoropropane, 9,9-bis (4-aminophenyl) -10-hydro-anthracene, orthotolidine sulfone, and also, for example A part of tetraamines such as 3,3′4,4′-biphenyltetraamine and 3,3′4,4′-tetraaminodiphenylether can be used. 4,
4'-bis (4-aminobenzamido) -3,3'-dihydroxybiphenyl and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane or 2,2-bis [4- (4 A polyvalent amine other than -aminophenoxy) phenyl] propane can be used in an amount within the range in which the objects and effects of the present invention are achieved, but an amount not exceeding 10 mol%, preferably 5 mol% based on the total amines. A small amount that does not exceed is suitable.

On the other hand, as the aromatic tetracarboxylic dianhydride, specifically, pyromellitic dianhydride, 3,3 ',
4,4'-biphenyltetracarboxylic dianhydride, 2,
3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3′4,4′-benzophenonetetracarboxylic dianhydride, 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-berylenetetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride,
2,3,6,7-anthracene tetracarboxylic dianhydride, 1,2,7,8-phenylene tetracarboxylic dianhydride and the like can be mentioned, and one of these can be used alone or two or more can be used. It can be used in combination.

In the polymerization reaction of the aromatic diamine and the aromatic tetracarboxylic dianhydride, both compounds are mixed with 100 parts of the aromatic dicarboxylic acid dianhydride per 100 aromatic diamine mixture in an organic polar solvent in a molar ratio. It is desirable to mix them in a proportion of 95 to 105, especially equimolar.

Further, as the organic polar solvent, for example, sulfoxide-based solvent such as dimethyl sulfoxide, N, N
Formamide solvents such as dimethylformamide, N, N-diethylformamide, acetamide solvents such as N, N-dimethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol , Phenol solvent such as o-, m- or p-cresol, xylenol, halogenated phenol, and catechol, or hexamethylphosphoramide, γ-butyrolactone, and the like. These may be used alone or in combination of two or more, and may also be used in combination with an aromatic hydrocarbon-based organic nonpolar solvent such as xylene or toluene. The amount of the above organic polar solvent used is not particularly limited, but the aromatic diamine is such that the polyamic acid copolymer obtained by the polymerization reaction is dissolved in the organic polar solvent in an amount of 5 to 30% by weight, particularly 10 to 20% by weight. It is desirable to determine the amounts of the aromatic tetracarboxylic dianhydride and organic polar solvent used.

The polymerization reaction conditions are 0 to 70 ° C., especially 0 to
It is preferable to carry out the reaction at a temperature of 30 ° C. for 1 to 40 hours, particularly 2 to 20 hours, and a polyamic acid copolymer can be obtained more efficiently by this polymerization reaction.

Next, 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. Here, as the thermal dehydration ring-closing method, 5 at 200 to 500 ° C.
A method of heating for 120 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, allyl phosphite. Examples thereof include phonic acid dihalide and thionyl halide. These can be used alone or in combination of two or more. The amount of the dehydrating agent used is preferably about 0.1 to 10 mols, and particularly preferably 0.5 to 4 mols per repeating unit of the polyamic acid.

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 above 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 coated on a support such as an endless belt to form a film, and the film is 100 to 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, and then heated to about 200 to 250 ° C. to remove the solvent, and further dehydrated and imidized at 200 to 500 ° C. to have a thickness of 10 to 150 μm. Can be obtained.

[0026]

The polyimide film composed of the polyimide copolymer of the present invention is excellent in various properties such as heat resistance, and has high mechanical strength and thermal dimensional stability.
Moreover, since it has low hygroscopicity, it is suitable as a film material such as an electrically insulating material or a fine patterned flexible printed circuit board. Further, according to the production method of the present invention, the polyimide copolymer can be industrially advantageously produced.

[0027]

EXAMPLES The present invention will be specifically described below with reference to Reference Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Reference Example First, as shown below, 4,4'-
Bis (4-aminobenzamido) -3,3′-dihydroxybiphenyl was synthesized.

300 ml of tetrahydrofuran and N, N-
Add 3,3'- to a mixture of 300 ml of dimethylformamide.
Dihydroxy-4,4'-diaminobiphenyl 35.0
g (0.162 mol) and triethylamine 36.0 g
(0.356 mol) was dissolved and cooled to 0 ° C., and then a solution of p-nitrobenzoyl chloride 63.1 g (0.340 mol) in 150 ml of tetrahydrofuran was added so that the temperature of the reaction solution became 10 ° C. or lower. Was added dropwise. Then, it returned to room temperature and continued stirring for 2 hours.

Then, the reaction solution was poured into 1 liter of methanol to precipitate a reaction product, which was filtered, washed with tetrahydrofuran, further washed with water and methanol, and then dried to 4,4'-. Red crude crystals of bis (4-nitrobenzamido) -3,3'-dihydroxybiphenyl were obtained. The yield was 82.01 g (yield 98.4%).
Met. The crude crystal was recrystallized from N, N-dimethylformamide to obtain a pure product.

4,4'-bis (4-nitrobenzamide) -obtained above in 1,000 ml autoclave
6,3'-dihydroxybiphenyl 68.8 g (0.1
34 mol) was charged together with 5% Pd / C (5 g) and dimethylformamide (500 ml). 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 1,000 ml of methanol. The precipitate was filtered, washed with methanol and dried under reduced pressure to obtain 4,4'-bis (4-aminobenzamide). ) -3,3'-Dihydroxybiphenyl white crystals were obtained. The yield was 60.7 g (yield 99.7%). The crude crystal was recrystallized with a mixed solvent of dimethylformamide / methanol to obtain a pure product.

Example 1 A 500 ml flask was charged with N,
259.3 g of N-dimethylformamide (DMF) was added, and 4.54 g (0.010 mol) of 4,4′-bis (4-aminobenzamide) -3,3′-dihydroxybiphenyl and 2,2 while flowing nitrogen gas. -Bis [4
15.55 g (0.030 mol) of-(4-aminophenoxy) phenyl] hexafluoropropane was added to N, N-
It was dissolved in dimethylformamide. Next, 8.72 g (0.040 mol) of pyromellitic dianhydride was added, and 2
The reaction was carried out at 5 ° C for 3 hours.

Next, these polyamic acid solutions are thinly spread on a glass plate with an applicator, and then 110% in an oven.
After drying for 60 minutes at ℃, peel it off and fix it on the iron frame.
The film was desolvated at 00 ° C. for 60 minutes, then heated to 200 to 400 ° C. for 60 minutes, and then at 400 ° C. for 15 minutes to obtain a film having a thickness of about 25 μm. The characteristics of the film are shown in Table 1.

Example 2 In a 500 ml flask, N,
253.6 g of N-dimethylformamide (DMF) was added, and 9.09 g (0.020 mol) of 4,4′-bis (4-aminobenzamide) -3,3′-dihydroxybiphenyl and 2,2 while flowing nitrogen gas. -Bis [4
10.37 g (0.020 mol) of-(4-aminophenoxy) phenyl] hexafluoropropane was added to N, N-
It was dissolved in dimethylformamide. Next, 8.72 g (0.040 mol) of pyromellitic dianhydride was added, and 2
After reacting at 5 ° C. for 3 hours, a film was obtained by the same method as in Example 1. The characteristics of the film are shown in Table 1.

Example 3 A 500 ml flask was charged with N,
247.8 g of N-dimethylformamide (DMF) was added, and 4,4′-bis (4-aminobenzamide) -3,3′-dihydroxybiphenyl 1 was added while flowing nitrogen gas.
3.63 g (0.030 mol) and 2,2-bis [4
5.18 g (0.010 mol) of-(4-aminophenoxy) phenyl] hexafluoropropane was dissolved in N, N-dimethylformamide. Next, add 8.72 g (0.040 mol) of pyromellitic dianhydride, and add 25
After reacting at 3 ° C. for 3 hours, a film was obtained by the same method as in Example 1. The characteristics of the film are shown in Table 1.

[Example 4] A 500 ml flask was charged with N,
234.2 g of N-dimethylformamide (DMF) was added, and 9.09 g (0.020 mol) of 4,4′-bis (4-aminobenzamide) -3,3′-dihydroxybiphenyl and 2,2 while flowing nitrogen gas. -Bis [4
-(4-Aminophenoxy) phenyl] propane 8.2
1 g (0.020 mol) was dissolved in N, N-dimethylformamide. Next, pyromellitic dianhydride 8.7
After adding 2 g (0.040 mol) and reacting at 25 ° C. for 3 hours, a film was obtained by the same method as in Example 1. The characteristics of the film are shown in Table 1.

Example 5 A 500 ml flask was charged with N,
238.1 g of N-dimethylformamide (DMF) was added, and 4,4′-bis (4-aminobenzamide) -3,3′-dihydroxybiphenyl 1 was added while flowing nitrogen gas.
3.63 g (0.030 mol) and 2,2-bis [4
-(4-Aminophenoxy) phenyl] propane 4.1
0 g (0.010 mol) was dissolved in N, N-dimethylformamide. Next, pyromellitic dianhydride 8.7
After adding 2 g (0.040 mol) and reacting at 25 ° C. for 3 hours, a film was obtained by the same method as in Example 1. The characteristics of the film are shown in Table 1.

Comparative Example 1 A 500 ml flask was charged with N,
211.8 g of N-dimethylformamide (DMF) was added, and 4,4′-bis (4-aminobenzamide) -3,3′-dihydroxybiphenyl 1 was added while flowing nitrogen gas.
5.91 g (0.035 mol) was added and dissolved in DMF. Next, 7.63 g of pyromellitic dianhydride (0.
(035 mol) and reacted at 25 ° C. for 3 hours,
A film was obtained by the same method as in Example 1. The characteristics of the film are shown in Table 1.

Comparative Example 2 A 500 ml flask was charged with N,
232.1 g of N-dimethylformamide (DMF) was added, and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane 1 was added while flowing nitrogen gas.
8.15 g (0.035 mol) was added and dissolved in DMF. Next, 7.63 g of pyromellitic dianhydride (0.
(035 mol) and reacted at 25 ° C. for 3 hours,
A film was obtained by the same method as in Example 1. The characteristics of the film are shown in Table 1.

Comparative Example 3 A 500 ml flask was charged with N,
N-Dimethylformamide (DMF) (197.9 g) was added, and 2,2-bis [4- (4-aminophenoxy) phenyl] propane (14.36 g) was introduced while flowing nitrogen gas.
(0.035 mol) was added and dissolved in DMF. Next, 7.63 g of pyromellitic dianhydride (0.035 mo
l) was added and reacted at 25 ° C. for 3 hours, and then a film was obtained by the same method as in Example 1. The characteristics of the film are shown in Table 1.

Mechanical properties of the obtained film,
The linear expansion coefficient was measured as follows. The results are shown in Table 1. 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). Water absorption The polyimide film was left at 90% RH for 24 hours, and the weight before and after that was measured to determine the water absorption. The logarithmic viscosity polyamic acid concentration was 0.5 g / 100 ml DMF, and the measurement temperature was 30 ° C.

[0043]

[Equation 1]

[0044]

[Table 1]

From the results shown in Table 1, it was confirmed that the polyimide copolymer of the present invention has excellent mechanical strength, low linear expansion coefficient and water absorption, high elastic modulus and flexibility.

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[Procedure amendment]

[Submission date] January 10, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction content]

[0044]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Atsushi Sugitani, Atsushi Sugitani, Kamisu-cho, Kashima-gun, Ibaraki, Towada, 1st place, Shin-Etsu Chemical Co., Ltd. Towada 1

Claims (3)

[Claims] 1. A polyimide copolymer containing a repeating unit (A) represented by the following general formula (1) and a repeating unit (B) represented by the following general formula (2) as main constituent units. [Chemical 1] (However, in the formula, R ¹ represents a tetravalent aromatic group, and R ² represents CH ₃
Or CF ₃ is shown. ) 2. The polyimide copolymer according to claim 1, wherein the repeating unit (A) and the repeating unit (B) have a molar ratio of (A) / (B) = 15/85 to 90/10. 3. 4,4′-bis (4-aminobenzamido) -3,3′-dihydroxybiphenyl and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane or 2,2- Aromatic diamine containing bis [4- (4-aminophenoxy) phenyl] propane as a main component and tetracarboxylic dianhydride are polymerized to obtain a polyamic acid copolymer, and then the polyamic acid copolymer. The method for producing a polyimide copolymer according to claim 1, wherein the dehydration ring closure is carried out thermally or chemically.