JP3493363B2 - Novel copolymer and its production method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel copolymer and a method for producing the same, more specifically, it is capable of fusion bonding at a low temperature, and has a laminated film for insulating coating such as a wire for superconducting wire and a flexible printed circuit. It can be suitably used as a base film, coverlay film, bonding sheet, cover coat ink, etc. for substrates, and also has high viscosity for exhibiting sufficient mechanical properties, and radiation resistance and flexibility. The present invention relates to a novel copolymer having excellent characteristics such as adhesiveness and a method for producing the same.

[0002]

2. Description of the Related Art Generally, a polyimide film is widely used as a material particularly for electric and electronic devices because of its excellent heat resistance, low temperature characteristics, chemical resistance and electric characteristics. However, since the polyimide used for film applications is generally insoluble and infusible, when used for coating metal wires, etc., it is applied with a thermoplastic or thermosetting resin on a polyimide film to impart adhesiveness. is doing.

One of the thermoplastic resins widely used in the past for the purpose of imparting adhesiveness is, for example, FEP.
There are such fluororesins. Fluororesin has relatively high heat resistance, chemical resistance, and low temperature characteristics, but has extremely poor radiation resistance, so it has specific applications, such as space applications, superconducting wire applications, and nuclear power generation applications. Was not suitable for.

Epoxy resin or the like is used as the thermosetting resin, but these conventional thermosetting resins require high temperature and a long time for curing, so that they cause deterioration of the wire. However, it was not suitable for use in coating metal wires, especially superconducting wires.

In view of the above situation, the development of a film having excellent heat resistance and heat resistance, which is excellent in chemical resistance, low temperature characteristics, adhesiveness, and the like, has been awaited.

When an adhesive is used for a flexible printed circuit board or the like, a method is used in which the adhesive is applied on a film-shaped polyimide or copper foil and the polyimide film and the copper foil are bonded together. Therefore, the characteristics such as heat resistance of the printed circuit board are determined by the characteristics of the adhesive. However, since the heat resistance of the adhesive layer used is inferior to that of polyimide, there is a problem that the high performance of polyimide cannot be exhibited.

As a method of solving these problems, it is possible to use a polyimide having an aliphatic group. Polyimides having an aliphatic group are relatively inexpensive and have a practical softening temperature as compared with aromatic polyimides, and have excellent heat resistance, chemical resistance, etc. required as an electronic material as a film. It is said.

However, the polyimide having an aliphatic group has a slow polymerization rate, and in reality, it was practically impossible to obtain a high molecular weight sufficient to form a film.
That is, in order to produce a polyimide film, usually, a polyamic acid solution as a precursor is cast and coated on a metal belt or a resin film to volatilize a solvent, and is peeled from a support as a polyamic acid film, and then heated. A method of imidizing to obtain a polyimide film is adopted, and a high molecular weight polyimide is required to maintain the strength of the resulting polyimide film. However,
In the case of a polyimide having an aliphatic group, since the molecular weight is extremely low as described above, so-called film self-supporting property is not obtained, only a brittle film is obtained, and peeling from the support is difficult. On the other hand, when it is sufficiently heated on the support to imidize it, it adheres to the support and cannot be peeled off, which is insufficient for use for the above purpose.

[0009]

[Means for Solving the Problems] As a result of extensive studies to solve the above-mentioned problems, as a result, while having sufficient mechanical strength,
That is, while having a sufficient high molecular weight, it is also excellent in heat resistance, chemical resistance, low temperature characteristics, adhesiveness, etc., and also excellent in radiation resistance. And a method for producing the same were found.

The gist of the novel copolymer according to the present invention is that the compound represented by the general formula (1):

[Chemical 10] (In the formula, R 1 is a divalent organic group, R 2 is a tetravalent organic group, and X is

[Chemical 11] It is a trivalent linking group selected from Further, m and n are positive integers. ) And a number average molecular weight of 50,000 or more
Is to be on .

Further, in such a copolymer, in the general formula (1), R 2 is

[Chemical 12] Is one selected from the group of tetravalent organic groups represented by.

Further, in the above copolymer, in the general formula (1), R 1 is

[Chemical 13] Is one selected from the group of divalent organic groups represented by.

Next, the gist of the novel method for producing a copolymer according to the present invention is to prepare a compound of the formula 14 in an organic polar solvent.

[Chemical 14] 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride represented by

[Chemical 15] Any one selected from the group of diamine compounds represented by the following formula is added, and the compound represented by the general formula (2) is used as the third component.

[Chemical 16] (In the formula, Ar3 is

[Chemical 17] Which is one selected from the group of tetravalent organic groups represented by the formula (4), the molar amount of the acid dianhydride and the diamine compound is substantially equimolar. The present invention is directed to a method for producing a copolymer obtained by adding the above components.

Another feature of the method for producing a novel copolymer according to the present invention is that it is added in an organic polar solvent.
2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride is dissolved and then

[Chemical 18] Is added, and the acid dianhydride represented by the general formula (2) is added as a third component, and the molar amount of the acid dianhydride and the diamine compound is added. Is added so as to be substantially equimolar, and then dehydrated and ring-closed to produce a copolymer.

[0015]

The features for obtaining the novel copolymer according to the present invention are, firstly, an acid dianhydride having an aliphatic group as an essential component for having the above-mentioned properties in the polyimide copolymer. 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride is used. This polyimide copolymer has a clear glass transition point between 100 ° C. and 250 ° C. and exhibits thermoplasticity at a temperature close to or above the glass transition point. Secondly, in this production method, the acid dianhydride of the third component having high reactivity with the acid dianhydride having the aliphatic group, that is, the acid dianhydride of the third component having a large electron affinity is copolymerized. To use a new manufacturing method. This novel production method has solved the problem that a high molecular weight cannot be obtained when an acid dianhydride having an aliphatic group is used.

[0016]

EXAMPLES The method for producing the novel aromatic polyamic acid copolymer and the novel aromatic polyimide or polyisoimide polymer of the present invention will be described below.

First, in an atmosphere of an inert gas such as argon or nitrogen, a mol of 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ', 4 is used.
4'-Tetracarboxylic acid dianhydride is dissolved in an organic solvent. The temperature of the solvent to be dissolved is preferably 10 ° C or higher, more preferably 40 ° C or higher. To this solution, b mol of
That is, 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride is used in an excess amount of 19

[Chemical 19] Is added in the form of a solution with a solid or an organic solvent selected from the group of diamine compounds represented by to prepare a telechelic polyamic acid solution having amine groups as precursors of a copolymerized polyimide at both ends. .

Next, so that the molar ratio of the diamine compound and the acid dianhydride is substantially equimolar, that is, about b =
In order to obtain a + c, c mol of the compound of the general formula (2)

[Chemical 20] (In the formula, Ar3 is

[Chemical 21] Is one selected from the tetravalent organic groups represented by. By adding the acid dianhydride as the third component represented by), a polyamic acid copolymer having a high viscosity, that is, having a high molecular weight is obtained. The acid dianhydride as the third component can be added to the polyamic acid solution as a solution or slurry of an organic solvent or as a solid, but is preferably added as a powder.

The reaction temperature at this time is 10 ° C. or higher, preferably 20 ° C. or higher. The reaction time can be arbitrarily set from 30 minutes to 10 hours or more.

Examples of the organic solvent used in the reaction for producing the polyamic acid copolymer solution include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide, N, N-diethylformamide. Formamide solvents such as N, N
Examples thereof include acetamide-based solvents such as dimethylacetamide and N, N-diethylacetamide.
These may be used alone or as a mixed solvent of two or three or more. Further, it can be used as a mixed solvent with a non-solvent of polyamic acid such as acetone, methanol, ethanol, isopropanol and benzenemethylcellosolve together with these polar solvents.

Next, in order to obtain a polyimide copolymer from the precursor polyamic acid copolymer solution, a method of thermally and / or chemically dehydrating and ring-closing may be used.

Explaining by way of example, in the method of thermal dehydration ring closure (imidization), a solution of the above polyamic acid copolymer is applied onto a support plate, an organic film such as PET, or a support such as a drum or an endless belt. It is cast or coated on to form a film, and after drying, a film having self-supporting property is obtained. Drying is preferably performed at a temperature of 150 ° C. or lower for about 5 to 90 minutes. Next, this is heated and dried to imidize to obtain a polyimide film made of the polyimide copolymer according to the present invention. The temperature during heating is preferably in the range of 100 to 200 ° C, particularly preferably 100 to 180 ° C. There is no limitation on the rate of temperature increase during heating, but it is preferable that the maximum temperature reaches the above temperature by gradually heating. The heating time varies depending on the film thickness and the maximum temperature, but in general, it is preferably in the range of 10 seconds to 1 hour after the maximum temperature is reached. When the film having the self-supporting property is heated, it is preferable to peel the film from the support and fix the end portion in this state and heat the film to obtain a copolymer having a small linear expansion coefficient.

In the method of chemically dehydrating and ring-closing (imidizing), a dehydrating agent in a stoichiometric amount or more and a catalytic amount of a tertiary amine are added to a solution of the polyamic acid copolymer to thermally dehydrate. A desired polyimide film is obtained by treating in the same manner.

Comparing the thermal imidization method and the chemical imidization method, a polyimide having a higher mechanical strength and a smaller linear expansion coefficient can be obtained by the chemical method.

To obtain the polyisoimide copolymer,
The reaction may be completed by adding commonly known dicyclohexylcarbodiimide (DCC).

The number m of repeating block units in the copolymer represented by the general formula (1) may be a positive integer of 1 or more, but is particularly preferably 15 or less. This is because when the number of repetitions m is 15 or more, the effect of uneven copolymerization of the polymerization ratio, that is, the effect of the third component added for increasing the molecular weight becomes small. The number n of repeating blocks in the copolymer may be a positive integer of 1 or more, and the molecular weight of the copolymer is not particularly limited, but in order to maintain the strength of the polyimide resin produced, Preferably has a number average molecular weight of 50,000 or more, more preferably 80,000 or more, especially 100,000 or more, and more preferably 120,000 or more.

By the way, it is often difficult to directly measure the molecular weight of the polyimide copolymer. In such a case, an indirect method is used to make a speculative measurement. For example, when the polyimide copolymer is synthesized from polyamic acid, the value corresponding to the molecular weight of polyamic acid is the molecular weight of polyimide.

In this way, the general formula (1)

[Chemical formula 22] (In the formula, R 1 is a divalent organic group, R 2 is a tetravalent organic group, and X is

[Chemical formula 23] It is a trivalent linking group selected from Further, m and n are positive integers. Thus, a copolymer of polyamic acid, polyimide, or polyisoimide represented by (4) can be obtained.

The polyimide copolymer, which is a novel copolymer of the present invention obtained by the above method, has excellent thermoplasticity, adhesiveness and low water absorption. That is, the polyimide copolymer according to the present invention has a composition of 10
It has a clear glass transition point between 0 ° C. and 250 ° C. and is laminated at a temperature close to or above the glass transition point to obtain an adherend such as an aluminum / titanium / iron plate. It can be bonded to a copper plate or the like without an adhesive layer interfering with the excellent heat resistance of polyimide. From these results, it can be understood that, for example, when a copper plate is used, a copper clad laminate can be produced relatively easily. Further, it shows a low water absorption rate of about 1% when immersed in pure water at 20 ° C. for 24 hours.

Although the examples of the novel copolymer according to the present invention have been described above, the present invention is not limited to the above-mentioned purpose and various improvements, modifications and variations are added based on the knowledge of those skilled in the art. It can be carried out in a different manner.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the scope of these examples.

Example 1 In a 500 ml three-necked flask equipped with a stirrer, 4
0.3 g (70 mmol) of 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ',
150 g of 4,4′-tetracarboxylic dianhydride (ESDA) and dimethylformamide (DMF) were taken, stirred using a stirrer, and sufficiently dissolved at an ambient temperature of 40 ° C. Further, 20.0 g (100 mmol) of 4,4′-diaminodiphenyl ether (ODA) measured in 50 ml of Mayel was introduced into the reaction system and sufficiently reacted. After agitating for about 30 minutes, 6.54 g (30 mm) from another 50 ml Mayel
ol) pyromellitic dianhydride (PMDA) was gradually charged into a three-necked flask while paying attention to the viscosity of the solution.
After reaching the maximum viscosity, the addition of PMDA powder was completed, and the mixture was left for one hour with stirring to obtain a polyamic acid solution. When the viscosity was measured with a B-type viscometer, it showed 3500 poise.

100 g of this polyamic acid solution was weighed and added with 11.37 g of acetic anhydride, 11.18 g of isoquinoline and 11.95 g of DMF as a chemical curing agent, which was cast-coated on a PET film. 2 at ℃
After heating for 5 minutes and peeling off the PET film, 150
25μ each at 25 ° C and 200 ° C for imidization, 25μ
A polyimide film of m was obtained. 17 by IR measurement
It was confirmed to be a polyimide film having characteristic absorption by an imide carbonyl group at 80 cm ^-1 .

About the obtained film, glass transition point (° C.), peel strength (kg / cm), water absorption rate (%), tensile elongation (%), tensile strength (kg / cm ² ), tensile elastic modulus (kg) / Cm ² ). The glass transition point was measured by the TMA method, and the peel strength was measured by applying copper foil (thickness: 35 μm) on both sides of the obtained polyimide film at 300 ° C. and 2.2 cm /
After laminating at a speed of min, JIS C- 64
81 was measured. The water absorption rate is ASTM D-
According to 570, the weight change rate after immersion in distilled water at 20 ° C. for 24 hours was measured. Also, tensile strength, tensile elongation,
The tensile modulus of elasticity was measured according to JIS K-2318. The results are shown in Tables 1 and 2.

[0035]

[Table 1]

[Table 2]

Example 2 In Example 1, PM was used as the acid dianhydride as the third component.
After using 9.6 g (30 mmol) of benzophenonetetracarboxylic dianhydride (BTDA) in place of DA, a polyamic acid solution of 2350 poise was obtained in substantially the same manner as in Example 1, and then the polyimide I made a film. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

Example 3 In Example 1, PM was used as the acid dianhydride as the third component.
After using 9.2 g (30 mmol) of oxydiphthalic acid dianhydride (ODPA) in place of DA, a polyamic acid solution of 2000 poise was obtained by substantially the same operation as in Example 1, and then polyimide I made a film. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

Example 4 In Example 1, PM was used as the acid dianhydride as the third component.
Other than using 8.9 g (30 mmol) of biphenyltetracarboxylic dianhydride (BPDA) instead of DA,
A polyimide film was prepared after obtaining a 2050 poise polyamic acid solution by substantially the same operation as in Example 1. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

Example 5 Substantially the same as Example 1, except that 10.8 g (100 mmol) of para-phenylenediamine (PPDA) was introduced into the reaction system instead of ODA as the diamine component. After obtaining a polyamic acid solution of 3200 poise by operation, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 3 and 4.

[0040]

[Table 3]

[Table 4]

Example 6 In Example 5, PM was used as the acid dianhydride as the third component.
The procedure of Example 5 was repeated except that 9.6 g (30 mmol) of BTDA was used instead of DA.
After obtaining a 0 poise polyamic acid solution, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 3 and 4.

Example 7 In Example 5, PM was used as the acid dianhydride as the third component.
The procedure of Example 5 was repeated except that 9.2 g (30 mmol) of ODPA was used instead of DA.
After obtaining a 0 poise polyamic acid solution, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 3 and 4.

Example 8 In Example 5, PM was used as the acid dianhydride as the third component.
The procedure of Example 5 was repeated except that 8.9 g (30 mmol) of BPDA was used in place of DA.
After obtaining a 0 poise polyamic acid solution, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 3 and 4.

Example 9 Substantially the same as Example 1, except that 41.1 g (100 mmol) of bisaminophenoxyphenylpropane (BAPP) was introduced into the reaction system instead of ODA as the diamine component. After a 2600 poise polyamic acid solution was obtained by the same operation, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 5 and 6.

[0045]

[Table 5]

[Table 6]

Example 10 In Example 9, PM was used as the acid dianhydride as the third component.
The procedure of Example 9 was repeated except that 9.6 g (30 mmol) of BTDA was used instead of DA.
After obtaining a 0 poise polyamic acid solution, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 5 and 6.

Example 11 In Example 9, PM was used as the acid dianhydride as the third component.
The procedure of Example 9 was repeated except that 9.2 g (30 mmol) of ODPA was used instead of DA.
After obtaining a 0 poise polyamic acid solution, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 5 and 6.

Example 12 In Example 9, PM was used as the acid dianhydride as the third component.
The procedure is substantially the same as in Example 9 except that 8.9 g (30 mmol) of BPDA is used instead of DA.
After obtaining a 0 poise polyamic acid solution, a polyimide film was prepared. Physical properties of the obtained polyimide film were examined in the same manner as in Example 1, and the results are shown in Tables 5 and 6.

[0049]

As described above, the present invention provides 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ', 4,4' as an acid dianhydride having an aliphatic group.
-Using tetracarboxylic dianhydride, it was possible to increase the molecular weight of the polyimide polymer produced by adding the acid dianhydride as the third component. As a result, it was possible to obtain a good thermoplastic polyimide polymer having excellent mechanical strength. This polyimide polymer has an adhesive property at low temperature and has a lower water absorption rate as compared with conventional polyimide-based materials. The polyimide polymer having these characteristics can be realized only by the copolymerization method newly found this time.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-198319 (JP, A) JP-A-4-366131 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 73/00-73/26 CAPLUS (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A compound represented by the general formula (1): (In the formula, R 1 is a divalent organic group, and X is A trivalent linking group selected from, R2 is Formula 3 embedded image Is a tetravalent organic group, and m and n are positive
Is a number. ) And having a number average molecular weight of 50,000 or more, a novel copolymer. 2. In the general formula (1), R1 is represented by the following formula: The novel copolymer according to claim 1, which is any one selected from the group of divalent organic groups represented by: 3. In an organic polar solvent, 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride (bisphenol A bistrimellitic dianhydride: ESDA) represented by , Then, Any one selected from the group of diamine compounds represented by the following formula is added, and as the third component, the compound represented by the general formula (2): (In the formula, Ar3 is Is any one selected from the group of tetravalent organic groups represented by. ) The method for producing a novel copolymer obtained by adding the acid dianhydride represented by the formula (4) so that the molar amounts of the acid dianhydride and the diamine compound are substantially equimolar. 4. In an organic polar solvent, 2,2-bis (4-
Hydroxyphenyl) propanedibenzoate-3,
Dissolve 3 ', 4,4'-tetracarboxylic dianhydride,
Next, Is added, and the acid dianhydride represented by the general formula (2) is added as a third component, and the molar amount of the acid dianhydride and the diamine compound is added. Is added so as to be substantially equimolar, and then dehydrated and ring-closed to produce a novel copolymer.