JPH07207023A - Polyimide copolymer and its production - Google Patents

Abstract

PURPOSE:To obtain a polyimide copolymer excellent not only in heat resistance but also in flexibility, mechanical strengths, and thermal dimensional stability by selecting a polyimide copolymer mainly comprising specific repeating units. CONSTITUTION:The polyimide copolymer mainly comprises repeating units of formula I (wherein R<1> is an arom. hydrocarbon group) and repeating units of formula II in a molar ratio of pref. (10:90)-(90:10), is produced by polymerizing a tetracarboxylic dianhydride with an arom. diamine component mainly comprising 2-hydroxy-4,4'-diaminobenzanilide and 4,4'-diaminodiphenyl ether and subjecting the resulting polyamic acid to thermal or chemical cyclodehydration, and is suitable for a fine-patterned flexible printed circuit board.

Description

Detailed Description of the Invention

[0001]

The present invention has excellent heat resistance, flexibility, high mechanical strength and a low coefficient of thermal expansion.
The present invention relates to a polyimide copolymer suitable as a base material for a fine patterned flexible printed wiring board and the like and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, polyimide resins have been extremely superior in heat resistance and chemical resistance.
It is known to have excellent electrical and mechanical characteristics and other various characteristics. For example, Japanese Patent Publication No. 36-1099.
Polyimides obtained from 4,4′-diaminodiphenyl ether and pyromellitic dianhydride as seen in Japanese Patent Publication No. 9 are well known. Since this polyimide contains a highly flexible ether bond in the main chain, it is a fully aromatic polyimide but is highly flexible, but on the other hand, its elastic modulus is low, its linear expansion coefficient is large, and its thermal dimensional stability is poor. It is a thing.

Therefore, there has been an increasing demand for the development of a polyimide resin having more excellent thermal dimensional stability and mechanical strength, and various studies have been conducted. Among such attempts, many efforts have been made to use two or more kinds of aromatic diamines to improve mechanical properties and thermal dimensional stability. However, neither of these approaches was satisfactory in both the above thermal dimensional stability and mechanical properties.

That is, conventionally widely used polyimide resins have a large coefficient of linear expansion of about 3 × 10 ^-5 / ° C., poor thermal dimensional stability, and warp and curl occur when laminated with metal or the like. There is a problem, and there is a need to solve such a problem.

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, flexibility, high mechanical strength, and excellent thermal dimensional stability, and a method for producing the same.

[0006]

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, 2-hydroxy-4,4'-diaminobenzanilide and 4,4 '
A polyamic acid containing a repeating unit represented by the following formulas (3) and (4) as a main constituent unit by polymerizing an aromatic diamine containing diaminodiphenyl ether as a main component and an aromatic tetracarboxylic dianhydride. A copolymer is obtained, and the polyamic acid is thermally or chemically dehydrated and cyclized to form a repeating unit (A) represented by the following general formula (1) and a repeating unit represented by the following general formula (2). A polyimide copolymer containing (B) as a main constituent unit, preferably the following repeating unit (A) and the following repeating unit (B) in a molar ratio of (A) / (B) = 10/90 to 90/10. A polyimide copolymer containing a repeating unit is obtained, which is excellent in heat resistance, has a high elastic modulus and flexibility, has high mechanical strength, and has a low coefficient of thermal expansion. , Low water absorption and heat And finding that it is superior in dimensional stability, in which the present invention has been accomplished.

[0007]

[Chemical 2]

Therefore, 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. Preferably the above repeating unit (A) and repeating unit (B)
Is a molar ratio of (A) / (B) = 10/90 to 90/10.
Is a polyimide copolymer and 2-hydroxy-
An aromatic diamine containing 4,4'-diaminobenzanilide and 4,4'-diaminodiphenyl ether as main components is polymerized with a tetracarboxylic acid dianhydride to obtain a polyamic acid copolymer, and then the polyamic acid copolymer is obtained. There is provided a method for producing the above polyimide copolymer, which comprises thermally or chemically dehydrating and ring-closing the polymer.

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 constituent units.

[0010]

[Chemical 3]

In this case, R ¹ represents a tetravalent aromatic group,
Specifically, it is derived from the aromatic group of the aromatic tetracarboxylic dianhydride described later.

Here, the repeating unit (A) and the repeating unit (B) are present in the polyimide copolymer in a molar ratio of (A) /
(B) = 10/90 to 90/10, especially 30/70 to 8
It is preferably present in a ratio of 0/20. When the molar ratio of the repeating unit (A) exceeds 90%, the flexibility of the obtained polyimide copolymer may decrease. On the other hand, when the molar ratio of the repeating unit (B) exceeds 90%, the effect of improving the linear expansion coefficient and elastic modulus of the polyimide copolymer may not be sufficiently obtained.

The polyimide copolymer of the present invention is preferably a polyvalent polyamine such as a diamine compound represented by the formula (3) described below in an amount not exceeding 10 mol%, more preferably not exceeding 5 mol%. It may contain a repeating unit derived from a reaction product of an amine and an aromatic tetracarboxylic dianhydride.

The above-mentioned polyimide copolymer is a high molecular weight polymer, and the 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.

The polyimide copolymer of the present invention has a 2-
Hydroxy-4,4'-diaminobenzanilide and 4,
An aromatic diamine containing 4'-diaminodiphenyl ether as a main component and an aromatic tetracarboxylic dianhydride are preferably polymerized in an organic polar solvent to obtain a polyamic acid copolymer, and the polyamic acid copolymer obtained is obtained. The combined product can be produced by a known method such as thermal or chemical dehydration ring closure.

Here, as the aromatic acid tetracarboxylic acid 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 Anhydrous, bis (3,4-
Dicarboxyphenyl) ethane dianhydride, bis (3,4
-Dicarboxyphenyl) ether dianhydride, 1,1-
Bis (3,4-carboxyphenyl) ethane dianhydride,
3,4,9,10-perylenetetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1 , 2,7,8-phenylenetetracarboxylic dianhydride and the like can be mentioned, and one of these can be used alone or two or more can be used in combination.

As the aromatic diamine component, 2-hydroxy-4,4'-diaminobenzanilide and 4,
It is most preferable to use only two kinds of diamines with 4′-diaminodiphenyl ether to obtain the effect of the present invention, but if necessary, the following general formula (3) H ₂ N—R—NH ₂ (3) ( In the formula, R is a divalent organic group.), For example, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diaminodiphenylsulfone, 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-
Methyl-4-aminophenyl) methane, bis (3-chloro-4-aminophenyl) methane, 3,3′-dimethoxy-4,4′-diaminodiphenyl, 3,3′-dimethyl-4,4′-diamino Biphenyl, 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'-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 also, 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. 2-hydroxy-
Polyhydric amines other than 4,4'-diaminobenzanilide and 4,4'-diaminodiphenyl ether can be used in an amount within the range in which the objects and effects of the present invention are achieved. Suitable amount is not more than 5 mol%, preferably a small amount not exceeding 5 mol%.

Further, as the organic polar solvent, for example, a sulfoxide-based solvent such as dimethyl sulfoxide, N, N
Formamide solvents such as dimethylformamide and N, N-diethylformamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol , Halogenated phenols, phenolic solvents such as catechol, or hexamethylphosphoramide, γ-butyrolactone, and the like. These are preferably used alone or as a mixture, and further aromatic such as xylene and toluene. Partial use of hydrocarbons is also possible.

Polymerization in these organic polar solvents at a temperature of 0 to 70 ° C., preferably 0 to 30 ° C. gives a polyamic acid. The polymerization time is not particularly limited, but is usually 2 to 20.
The time is preferably 3 to 8 hours. The polyamic acid is contained in an organic polar solvent in an amount of 5 to 30% by weight, particularly 10 to
It is preferable that the amount is dissolved in the range of 20% by weight, and it is preferable to determine the amounts of the raw material and the organic solvent to be used so that the amount is dissolved.

The polyamic acid thus obtained can be thermally or chemically dehydrated and cyclized by a conventional method to obtain the polyimide copolymer of the present invention as a film or the like.

In this case, as a method for producing a polyimide film by the thermal ring-closing method, for example, polyamic acid is cast or applied on a support such as an endless belt to form a film, and the film is dried at 100 to 150 ° C. , Solvent 10-30%
A self-supporting membrane of the polyamic acid containing is obtained. Next, the polyimide film can be obtained by peeling off this film from the support, fixing the ends, heating to about 200 to 250 ° C. to remove the solvent, and further dehydrating at 300 to 450 ° C. By this heat treatment, an imide ring is formed and -CONH bonded to the benzene ring is formed.
A benzoxazole ring is formed by a dehydration condensation reaction between the -group and the OH group in the ortho position.

When employing the chemical dehydration ring closure method, a method using a dehydrating agent and a catalyst is preferable. In this case, examples of the dehydrating agent include aliphatic acid anhydrides, aromatic acid anhydrides, N, N-dialkylcarbonimides, lower fatty acid halides, halogenated lower fatty acid halides, halogenated lower fatty acid anhydrides and allyl phosphite. Examples thereof include phosphonic acid dihalide, thionyl halide, or a mixture of two or more thereof. The amount of the dehydrating agent used is preferably about 0.5 to 10 mols, and particularly preferably 2 to 6 mols per polyamic acid repeating unit. 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, or two of them. The above mixture may be mentioned. The amount of the catalyst used is about 0.01 to about 0.1 per repeating unit of polyamic acid.
An amount of 4 moles, particularly 0.1 to 2 moles is preferred. The reaction conditions for this chemical dehydration ring closure are 70 to 400 ° C.
It is preferably 2 to 20 hours, particularly 1 to 5 hours at 100 to 300 ° C.

The polyimide polymer thus obtained has excellent heat resistance, flexibility, high mechanical strength and low coefficient of thermal expansion, so that it can be used, for example, in electrically insulating materials and fine patterned flexible printed wiring boards. And the like, and in this case, the thickness of the film can be about 10 to 150 μm.

[0024]

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

Reference Example First, 2-hydroxy-4,4'-diaminobenzanilide was synthesized as follows.

77.1 g (0.500 mol) of 2-amino-5-nitrophenol and 50.6 g (0.520 mol) of triethylamine in 500 ml of tetrahydrofuran.
Was dissolved and cooled to 0 ° C., and then tetrahydrofuran (150 ml) was added with p-nitrobenzoyl chloride (92.8 g).
A solution in which (0.500 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 reaction solution was poured into 1 liter of methanol to precipitate the reaction product, which was filtered, washed with tetrahydrofuran, further washed with water and methanol, and then dried to give 2-hydroxy-4. Yellow crystals of 4'-dinitrobenzanilide were obtained. The yield is 147.7g
(Yield 97.4%). The crude crystal was recrystallized from N, N'-dimethylformamide / methanol to obtain a pure product.

In a 1000 ml autoclave, 70.0 g (0.231 mol) of 2-hydroxy-4,4'-dinitrobenzanilide obtained above was added to 4 g of 5% Pd / C.
Charged with 500 ml N, N-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 obtain 2-hydroxy-4,4'-diaminobenzanilide. Red purple crystals were obtained. Yield 53.8g
(Yield 95.7%). The crude crystal was recrystallized with a mixed solvent of water / methanol to obtain a pure product.

Example 1 A 500 ml flask was charged with N,
142.9 g of N-dimethylformamide (DMF) was added, and 2-hydroxy-4,4 ′ was added while flowing nitrogen gas.
-Diaminobenzanilide 2.250 g (0.0092
5 mol) and 4,4'-diaminodiphenyl ether 5.
557 g (0.02775 mol) was dissolved in DMF. Next, 8.070 g of pyromellitic dianhydride (0.0
37 mol) was added, and the mixture was reacted at 25 ° C. for 3 hours.

Next, these amic acid solutions were thinly spread on a glass plate with an applicator and heated in an oven at 110 ° C.
After drying for 60 minutes, peel it off, fix it to the iron frame, and
℃, 60 minutes, while raising the temperature from 200 ℃ to 400 ℃ 60
For about 25μ after desolvation imidization at 400 ℃ for 15 minutes
A film having a thickness of m was obtained.

[Examples 2 to 3] 2 as aromatic diamine
-Hydroxy-4,4'-diaminobenzanilide and 4,4'-diaminodiphenyl ether were used, and the molar ratio thereof was variously changed as shown in Table 1 to obtain a film by the same method as in Example 1.

[Example 4] A film was obtained in the same manner as in Example 2 except that 171.8 g of DMF was used and the acid dianhydride was 3,3 ', 4,4'-biphenyltetracarboxylic. .

Comparative Example 1 A film was obtained in the same manner as in Example 1 except that 139.3 g of DMF was used and only 4,4′-diaminodiphenyl ether was used as the aromatic diamine.

[Comparative Example 2] 153.6 g of DMF was used, and 2-hydroxy-4, as an aromatic diamine.
A film was obtained in the same manner as in Example 1 except that only 4'-diaminobenzanilide was used.

[Comparative Example 3] The same method as in Comparative Example 2 except that 179.0 g of DMF was used and the acid dianhydride was 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride. To obtain a film.

Mechanical properties of the obtained film,
The linear expansion coefficient was measured as follows. The measurement results are also 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).

[0038]

[Table 1]

From the results shown in Table 1, it is recognized that the polyimide copolymer of the present invention has flexibility and good mechanical strength, a low coefficient of linear expansion, and excellent thermal dimensional stability.

On the other hand, as an aromatic diamine, 4,
When only 4'-diaminodiphenyl ether was used (Comparative Example 1), the linear expansion coefficient was large, and when only 2-hydroxy-4,4'-diaminobenzanilide was used (Comparative Example 2), the flexibility was high. Is poor, and when 3.3 ', 4,4'-biphenyltetracarboxylic dianhydride is used as the aromatic tetracarboxylic dianhydride (Comparative Example 3), the flexibility is also inferior.

[0041]

INDUSTRIAL APPLICABILITY The polyimide copolymer of the present invention is excellent in heat resistance, is flexible and has high mechanical strength and low thermal expansion coefficient, and is therefore suitable as a base material for fine patterned flexible substrates and the like. .

Further, according to the production method of the present invention, such a polyimide copolymer can be produced easily and reliably.

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[Procedure amendment]

[Submission date] January 10, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

[0038]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masahiro Yuyama, Inventor Masahiro Yuyama 1 Towada, Kamisu-cho, Kashima-gun, Ibaraki Shin-Etsu Chemical Co., Ltd., Polymer Functional Materials Research Center (72) Inventor Kiyoshi Motoumi Kashima-gun, Ibaraki Prefecture No. 1 Towada, Kamisu Town, Shin-Etsu Chemical Co., Ltd.

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 hydrocarbon group.) 2. The repeating unit (A) and the repeating unit (B) according to claim 1 are in a molar ratio of (A) / (B) = 10/90 to 90.
The polyimide copolymer according to claim 1, which is / 10. 3. Polyamic acid copolymerization by polymerizing an aromatic diamine containing 2-hydroxy-4,4′-diaminobenzanilide and 4,4′-diaminodiphenyl ether as main components and tetracarboxylic dianhydride. The method for producing a polyimide copolymer according to claim 1, wherein the polyamic acid copolymer is dehydrated and ring-closed thermally or chemically.