JPH08157597A - Copolyimide and its production - Google Patents

Abstract

PURPOSE: To provide a copolyimide which has an excellent heat resistance, high mechanical strengths, and low thermal expansion coefficient and water absorption properties and is suitable for a substrate of a fine-patterned flexible printed circuit board. CONSTITUTION: This copolyimide mainly comprises repeating units repesented by formula I and repeating units repesented by formula II. In those formulas, R is a tetravalent arom. group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides a polyimide having excellent heat resistance, high mechanical strength, low coefficient of thermal expansion and low water absorption, 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, polyimide resins have been extremely superior in heat resistance and chemical resistance.
It is known to have excellent electrical and mechanical properties and other properties. For example, Japanese Patent Publication No. 36-1099.
Well-known are flexible wholly aromatic polyimides and the like obtained from 4,4′-diaminodiphenyl ether and pyromellitic dianhydride as disclosed in Japanese Patent Publication No.

Since this polyimide resin contains an ether bond with a high degree of flexibility in its main chain, it is a fully aromatic polyimide but is highly flexible, but on the other hand, it has a low elastic modulus and poor thermal dimensional stability. there were. Particularly, the polyimide resin which has been widely used in the past has a linear expansion coefficient of about 3 × 10 ⁻⁵ /
℃ is large, the thermal dimensional stability is poor, and when laminated with metal etc., it tends to warp or curl, and because the water absorption rate is extremely large, the dimensional stability and insulation properties decrease, so the electrical characteristics The problem is that the

On the other hand, in recent years, there has been an increasing demand for polyimides having higher heat resistance and higher mechanical strength, which are superior to polyimide resins, and more excellent thermal dimensional stability and low hygroscopicity. , Various studies have been conducted. Among such attempts, many efforts are made to use two or more kinds of aromatic diamines to improve mechanical properties, thermal dimensional stability, etc. and to improve low water absorption. However, in any of these approaches, thermal dimensional stability and water absorption, which are the problems to be solved, are still not sufficiently satisfied.

The present invention has been made in view of the above circumstances.
To provide a polyimide copolymer having excellent heat resistance, mechanical strength, high thermal dimensional stability, low linear expansion coefficient equivalent to that of metal, and low water absorption, and a method for producing the same. To aim.

[0006]

Means and Actions for Solving the Problems As a result of intensive studies made by the present inventors to achieve the above object, 1,4-
An aromatic diamine containing bis (4-aminobenzoyloxy) -2-chlorobenzene and 4,4′-diaminodiphenyl ether as main components and an aromatic tetracarboxylic dianhydride are polymerized to obtain a polyamic acid copolymer. A polyimide copolymer containing, as a main constituent unit, a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2) by thermally or chemically dehydrating and ring-closing. Preferably, a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2) have a molar ratio of (1) / (2) = 5/95 to 90/10. Along with obtaining a polyimide copolymer containing, this polyimide copolymer has excellent heat resistance, mechanical strength, and high thermal dimensional stability, low linear expansion coefficient and low water absorption rate equivalent to metal, Higher The present invention has been completed on the basis of the finding that it has a high elastic modulus and flexibility and therefore can be effectively used as a base material for a fine patterned flexible printed wiring board or the like.

[0007]

Embedded image (However, in the formula, R represents a tetravalent aromatic group.)

Therefore, the present invention is a polyimide copolymer characterized by containing a repeating unit represented by the general formula (1) and a repeating unit represented by the general formula (2) as main constituent units, preferably The repeating unit of the above formula (1) and the repeating unit of the above formula (2) are (1) / (2) = 5/9 in molar ratio.
A polyimide copolymer of 5 to 90/10, and 1,
Aromatic diamine containing 4-bis (4-aminobenzoyloxy) -2-chlorobenzene and 4,4′-diaminodiphenyl ether as main components and tetracarboxylic dianhydride are polymerized to obtain a polyamic acid copolymer. Then, the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2) are characterized in that the polyamic acid copolymer is subjected to dehydration ring closure thermally or chemically. Provided is a method for producing a polyimide copolymer containing a structural unit.

The present invention will be described in more detail below.
The polyimide copolymer of the present invention contains a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2) as main constituent units.

[0010]

Embedded image

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

Here, the repeating unit (1) and the repeating unit (2) are contained in the polyimide copolymer in a molar ratio of (1) /
(2) = 5/95 to 90/10, especially 15/85 to 80
It is desirable to exist in a ratio of / 20. When the molar ratio of the repeating unit (1) exceeds 90%, the flexibility of the polyimide copolymer is extremely reduced. On the other hand, when the molar ratio of the repeating unit (2) exceeds 95%, the water absorption of the polyimide copolymer becomes high, and the effect of improving the coefficient of linear expansion and elastic modulus may not be sufficiently obtained.

The above-mentioned polyimide copolymer is a high molecular weight polymer, and the viscosity as a polyamic acid copolymer has a logarithmic viscosity of 0 at a measurement temperature of 30 ° C. when measured in 0.5 g / 100 ml DMF. .5-5.0
It is preferred that

The polyimide copolymer of the present invention comprises 1,4-
An aromatic diamine containing bis (4-aminobenzoyloxy) -2-chlorobenzene and 4,4′-diaminodiphenyl ether as main components and tetracarboxylic dianhydride are polymerized to obtain a polyamic acid copolymer. In addition, the polyamic acid copolymer can be produced by dehydration and ring closure.

Here, as the aromatic diamine, 1,4
It is most preferable to use only -bis (4-aminobenzoyloxy) -2-chlorobenzene and 4,4'-diaminodiphenyl ether, but it is possible to use other aromatic diamine compounds together with these aromatic diamines. As the aromatic diamine that can be used in combination,
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} sulphone,
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'-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 , Orthotrizine sulfone and the like. Furthermore, 3,
3 ', 4,4'-biphenyltetraamine, 3,3',
It is also possible to use a part of tetraamines such as 4,4′-tetraaminodiphenyl ether. Among these aromatic diamines, aromatic diamines other than 1,4-bis (4-aminobenzoyloxy) -2-chlorobenzene are:
It can be used within the range in which the objects and effects of the present invention are achieved, but the amount of these other aromatic diamine compounds used is not more than 10 mol%, particularly 5 mol% based on the total aromatic diamine compound. It is preferred to use an amount not exceeding%.

Specific examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ', 4.
4'-biphenyltetracarboxylic dianhydride, 2,3
3'4'-biphenyltetracarboxylic dianhydride, 3,
3 ', 4,4'-benzophenone tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2, 2-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) etheric acid dianhydride, 1, 1-bis (3,4
-Carboxyphenyl) ethanoic acid dianhydride, 3,4
9,10-Perylene 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.

When the above aromatic diamine is reacted with the aromatic tetracarboxylic dianhydride, the aromatic tetracarboxylic dianhydride is mixed at a ratio of 96 to 105 mol with respect to 100 mol of the aromatic diamine mixture. Desirably, if it is out of the above range, the degree of polymerization of the produced polyimide copolymer may not be increased and sufficient mechanical strength may not be maintained.

The reaction between the aromatic diamine and the aromatic tetracarboxylic dianhydride can be carried out in an organic polar solvent. In this case, examples of the organic polar solvent used include sulfoxide-based solvents such as dimethyl sulfoxide, formamide-based solvents such as N, N-dimethylformamide and N, N-diethylformamide, N, N-dimethylacetamide, N. , Acetamide-based solvents such as N-diethylacetamide, pyrrolidone-based solvents such as N-methyl-2-pyrrolidone, phenol, o-, m-, or p-
Examples thereof include phenol-based solvents such as cresol, xylenol, halogenated phenol and catechol, and hexamethylphosphoramide, γ-butyrolactone and the like. These organic polar solvents may be used singly or as a mixture of two or more, and xylene, an aromatic hydrocarbon-based organic non-polar solvent such as toluene may be used in combination with the organic polar solvent. Is also possible. The amount of the organic polar solvent used is not particularly limited, but the polyamic acid copolymer obtained by the polymerization reaction may be used in an amount of 5% in the organic polar solvent.
It is preferable to determine the amounts of the aromatic diamine, the aromatic tetracarboxylic dianhydride, and the organic polar solvent to be used so that the amount is dissolved in an amount of ˜30 wt%, particularly 10 to 20%.

The above-mentioned polymerization reaction is carried out at 0 to 70 ° C.
The polyamic acid copolymer can be more effectively obtained by conducting the treatment at 1 to 50 hours, particularly at 0 to 30 ° C. for 4 to 24 hours.

The viscosity of the polyamic acid copolymer obtained above is not particularly limited, but it is 0.5 g / 1 as described above.
The logarithmic viscosity when measured in 00 ml DMF at a measurement temperature of 30 ° C. is preferably 0.5 to 5.0 dl / g, and this is an index of the molecular weight of the polyimide copolymer.

The polyamic acid copolymer synthesized as described above can be dehydrated and ring-closed to produce a polyimide copolymer. As the dehydration ring closure method, for example, a method such as thermal / chemical dehydration ring closure can be adopted.

In the case of thermally dehydrating and ring-closing the polyamic acid copolymer, a method of heating at 200 to 500 ° C. for 5 to 120 minutes is preferable.

Further, a method using a dehydrating agent and a catalyst is suitable for the chemical dehydration ring closure. In this case, as the dehydrating agent, aliphatic acid anhydride, aromatic acid anhydride, N, N'-
Dialkyl carbonimide, lower fatty acid halide,
Examples thereof include halogenated lower fatty acid halides, halogenated lower fatty acid anhydrides, allylphosphonic acid dihalides, thionyl halides, etc. These can be used alone or in combination of two or more. The amount of the dehydrating agent used is preferably about 0.5 to 10 mols, and particularly preferably 2 to 6 mols per repeating unit of the polyamic acid copolymer.

When a catalyst is used, for example, aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, heterocyclic tertiary amines such as pyridine, β-picoline, isoquinoline, etc. These may be used alone or in combination of two or more. The amount of the above catalyst used is about 0.01 to 4 mol per repeating unit of the polyamic acid copolymer, particularly 0.1.
~ 2 molar amounts are preferred.

To carry out the above chemical dehydration ring closure reaction, 2
0.2 to 20 hours at 0 to 400 ° C, especially 50 to 350 ° C
Therefore, 0.5 to 5 hours is preferable.

In order to obtain the polyimide copolymer in the form of a film, the organic polar solvent of the polyamic acid copolymer is cast or coated on a support such as an endless belt to form a film, and the film is formed into 100 to Drying at 150 ° C. gives a self-supporting membrane of polyamic acid copolymer containing 10 to 30% of solvent. Next, after peeling off this film from the support and fixing the ends, it is heated to about 150 to 250 ° C. to remove the solvent, and further dehydrated and imidized at 250 to 500 ° C. to give a film having a thickness of about 10 to 150 μm. A polyimide film can be obtained.

The polyimide copolymer thus obtained has excellent heat resistance, high mechanical strength, a low coefficient of thermal expansion and a low water absorption rate, and is a base material for fine patterned flexible printed wiring boards and the like. Is preferably used as.

[0028]

EXAMPLES The present invention will be specifically described 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) -2-chlorobenzene was synthesized as follows.

1,4-into 300 ml of tetrahydrofuran
Dihydroxy-2-chlorobenzene 49.2 g (0.3
40 mol) and triethylamine 81.0 g (0.80
0 mol) was dissolved and cooled to 0 ° C., and then 150 ml of tetrahydrofuran and p-nitrobenzoyl chloride 13 were added to the solution.
A solution in which 9.2 g (0.750 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 dried to give 1,4-bis (4-nitrobenzoyloxy)-.
White crystals of 2-chlorobenzene were obtained. The yield is 14
It was 5.9 g (yield 96.9%). Coarse crystals N, N
-Recrystallized with dimethylformamide to obtain a pure product.

1,4-bis (4-nitrobenzoyloxy) -obtained above in 1000 ml of autoclave.
2-chlorobenzene 110.7 g (0.250 mol)
5% Pd / C 3 g and dimethylformamide 600 m
Charged with l. Hydrogen was introduced with vigorous stirring at 50 ° 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-aminobenzoyl). A white solid of (oxy) -2-chlorobenzene was obtained. The yield was 91.3 g (yield 95.4%). The crude crystal was recrystallized with a mixed solvent of dimethylformamide / methanol to obtain a pure product.

Example 1 409.4 g of N, N-dimethylformamide was placed in a 1000 ml flask, and 1,656-bis (4-bis (4-aminobenzoyloxy) -2-chlorobenzene was added while flowing nitrogen gas. 0.
020 mol) and 16.4 g of 4,4'-diaminodiphenyl ether (0.080 mol) were dissolved in N, N-dimethylformamide. Next, add 21.812 g (0.100 mol) of pyromellitic dianhydride,
The reaction was carried out at 25 ° C for 6 hours.

Next, these amic acid copolymer solutions were thinly spread on a glass plate with an applicator, and the solution was placed in an oven.
It was dried at 10 ° C. for 60 minutes, peeled off, fixed on an iron frame, desolvated at 200 ° C. for 60 minutes and then at 300 ° C. for 60 minutes to obtain a polyimide film having a thickness of about 25 μm. The properties of this polyimide film are shown in Table 1.

[Example 2] 442.2 g of N, N-dimethylformamide was placed in a 1000 ml flask, and 15.312 g of 1,4-bis (4-aminobenzoyloxy) -2-chlorobenzene was added while flowing nitrogen gas.
(0.040 mol) and 4,4'-diaminodiphenyl ether 12.014 g (0.060 mol) were added to N,
It was dissolved in N-dimethylformamide. Next, 21.812 g (0.100 mol) of pyromellitic dianhydride was added, and after reacting at 25 ° C. for 6 hours, a polyimide film was obtained by the same method as in Example 1. The properties of this polyimide film are shown in Table 1.

[Example 3] 475.1 g of N, N-dimethylformamide was placed in a 1000 ml flask, and 2,2.968 g of 1,4-bis (4-aminobenzoyloxy) -2-chlorobenzene was added while flowing nitrogen gas.
(0.060 mol) and 4,4′-diaminodiphenyl ether (8.010 g, 0.040 mol) in N, N
-Dissolved in dimethylformamide. Next, 21.812 g (0.100 mol) of pyromellitic dianhydride was added, and after reacting at 25 ° C. for 6 hours, a polyimide film was obtained by the same method as in Example 1. The properties of this polyimide film are shown in Table 1.

[Example 4] 508.0 g of N, N-dimethylformamide was placed in a 1000 ml flask, and 30.624 g of 1,4-bis (4-aminobenzoyloxy) -2-chlorobenzene was added while flowing nitrogen gas.
(0.080 mol) and 4.05 g (0.020 mol) of 4,4'-diaminodiphenyl ether were added to N, N.
-Dissolved in dimethylformamide. Next, 21.812 g (0.100 mol) of pyromellitic dianhydride was added, and after reacting at 25 ° C. for 6 hours, a polyimide film was obtained by the same method as in Example 1. The properties of this polyimide film are shown in Table 1.

Comparative Example 1 540.8 g of N, N-dimethylformamide was placed in a 1000 ml flask and 38.280 g of 1,4-bis (4-aminobenzoyloxy) -2-chlorobenzene was added while flowing nitrogen gas.
(0.100 mol) was added and dissolved in N, N-dimethylformamide. Next, pyromellitic dianhydride 21.
After adding 812 g (0.100 mol) and reacting at 25 ° C. for 6 hours, a polyimide film was obtained by the same method as in Example 1. The characteristics of this polyimide film are shown in Table 1.
Shown in

[Comparative Example 2] 376.5 g of N, N-dimethylformamide was placed in a 1000 ml flask, and 20.24 g (0.100 mol) of 4,4'-diaminodiphenyl ether was added while flowing nitrogen gas.
It was dissolved in N-dimethylformamide. Next, 21.812 g (0.100 mol) of pyromellitic dianhydride was added, and after reacting at 25 ° C. for 3 hours, a polyimide film was obtained by the same method as in Example 1. The properties of this polyimide film are shown in Table 1.

Mechanical properties, coefficient of linear expansion, water absorption and logarithmic viscosity of the obtained polyimide film were measured. The measuring method is shown below. 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. Logarithmic viscosity polyamic acid copolymer concentration 0.5g / 100ml DMF
In addition, from the result of measurement under the condition that the measurement temperature is 30 ° C., it was calculated by the following calculation formula. Logarithmic viscosity = natural logarithm (viscosity of solution / viscosity of solvent) / polymer concentration in solution These measurement results are shown in Table 1.

[0042]

[Table 1]

[0043]

EFFECTS OF THE INVENTION The polyimide film composed of the polyimide copolymer of the present invention is excellent in various properties such as heat resistance, has high mechanical strength, and has a low linear expansion coefficient and low like metal. Since it has a water absorption rate, it is suitably used as a film material for, for example, an electric insulating material and a fine patterned flexible printed wiring board.

Claims (3)

[Claims] 1. A polyimide copolymer comprising a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2) as main constituent units. Embedded image (However, in the formula, R represents a tetravalent aromatic group.) 2. The repeating unit of the formula (1) and the repeating unit of the formula (2) have a molar ratio of (1) / (2) = 5/95 to 90 /.
10. The polyimide copolymer according to claim 1, which is 10. 3. An aromatic diamine containing 1,4-bis (4-aminobenzoyloxy) -2-chlorobenzene and 4,4′-diaminodiphenyl ether as main components, and tetracarboxylic dianhydride are polymerized. The method for producing a polyimide copolymer according to claim 1, wherein a polyamic acid copolymer is obtained, and then the polyamic acid copolymer is thermally or chemically subjected to dehydration ring closure.