JP2810661B2 - Method for producing polyamic acid copolymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polyamic acid which is a precursor of a polyimide resin. More specifically, in a method for producing a polyamic acid which is a precursor of a novel polyimide resin having extremely excellent dimensional stability, and having excellent mechanical properties, as well as a conventionally known polyimide resin. It is related. (Description of the prior art, problems to be solved by the invention) It is known that polyimide resin has high heat resistance, chemical resistance, electrical properties, mechanical properties, and other excellent properties. In particular, it is very useful and widely used for various applications, particularly for heat-resistant electric insulating films and electric wire coatings. However, in recent years, demands for polyimide resins having more excellent dimensional stability and more excellent mechanical properties such as elongation have been increasing, and various studies have been made for this purpose. For example, the general formula (I) [In the formula, R ₀ is a tetravalent organic group.] A polyimide film composed of a repeating unit represented by the formula is excellent in mechanical properties such as elongation, but generally has a large coefficient of linear expansion and a coefficient of humidity expansion. It is known that the dimensional stability is poor. On the other hand, the general formula (II) [Wherein, R is hydrogen or a monovalent substituent, n is an integer of 1-3, R ₀
Is the same as the above.] A polyimide film comprising a repeating unit represented by the formula (1) has a small linear expansion coefficient and a low humidity expansion coefficient and is excellent in dimensional stability, but is very fragile and lacks practicality as a film. However, it has a disadvantage that it cannot be used industrially. In addition, a random copolymerized polyimide film composed of repeating units of the general formulas (I) and (II) does not necessarily have satisfactory physical properties. The present inventors have made intensive studies to find a novel polyimide film having better dimensional stability and more excellent mechanical properties, and have reached the present invention. (Means for Solving the Problems) That is, the present invention relates to an organic solvent in which 10 to 90 mol% of an aromatic diamine component (A) based on the total diamine component and 40% based on the diamine component (A). 9999 mol% of an aromatic tetracarboxylic dianhydride is reacted to obtain an amic acid prepolymer, and then 90 to 10 mol% of an aromatic diamine component (B ) After the addition, in the method for producing a polyamic acid copolymer by adding and reacting a shortage of aromatic tetracarboxylic dianhydride so as to be equimolar to all diamine components,
The diamine component (A) is 4,4'-diaminodiphenyl ether, and the diamine component (B) is represented by the general formula (II)
I) Wherein R is at least one selected from the group consisting of hydrogen or a halogen atom, a nitro group, a hydroxyl group, a methyl group and a methoxy group, and n is 2 when R is hydrogen.
And R is an integer of 1 to 3 when R is a halogen atom, a nitro group, a hydroxyl group, a methyl group or a methoxy group. Or the diamine component (A) is an aromatic diamine represented by the general formula (III), and the diamine component (B) is 4,4'-diaminodiphenyl ether. A method for producing a polyamic acid copolymer characterized by the following: This polyamic acid solution is cast or coated to form a film, the film is dried, and the polyamic acid copolymer is thermally or chemically dehydrated and ring-closed (imidized) to obtain dimensional stability and mechanical stability. Can be obtained. The aromatic diamine component (A) used in the present invention includes:
4,4'-diaminodiphenyl ether, paraphenylenediamine, dimethylbenzidine, dimethoxybenzidine, diaminoparaterphenyl and the like can be mentioned. The same diamine can be used as the aromatic diamine component (B), but the diamine component (A) and the diamine component (B)
Must be different from As a more preferable combination of the aromatic diamine components to obtain the effect of the present invention, 4,4′-diaminodiphenyl ether and the following formula: [Wherein, R and n are the same as those described above]. The aromatic diamine represented by the above formula can be used in combination of two or more kinds. In the above formula, R is a hydrogen atom or a monovalent substituent, and examples of the substituent include a halogen atom, a nitro group, a hydroxyl group or a monovalent organic group such as a methyl group or a methoxy group. As the aromatic tetracarboxylic anhydride used in the present invention, pyromellitic anhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid Acid dianhydride, naphthalene-1,2,5,6,-
Examples thereof include tetracarboxylic dianhydrides, and these can be used alone or as a mixture in the present invention. In the present invention, the method of adding the monomer during the polymerization is important, and 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 20 to 80 mol% of the aromatic diamine relative to the total diamine component is used. Component (A) and this aromatic diamine component (A)
With an aromatic tetracarboxylic dianhydride in an amount of from 40 to 99 mol% to obtain an amic acid prepolymer. Next, 90 to 10 mol%, preferably 85 to 15 mol%, more preferably 80 to 20 mol% of the aromatic diamine component (B) is added to the amic acid prepolymer solution based on the total diamine component, Insufficient aromatic tetracarboxylic dianhydride is added and reacted so as to be equimolar to all diamine components to obtain the polyamic acid copolymer of the present invention. Examples of the organic solvent used for the polyamic acid copolymer production reaction include, for example, dimethyl sulfoxide, sulfoxide solvents such as diethyl sulfoxide, NN-dimethylformamide, N, N-formamide solvents such as diethylformamide, N, N -Dimethylacetamide, N, N-
Acetamide solvents such as diethylacetamide, N-
Pyrrolidone solvents such as methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone; phenol solvents such as phenol, o-, m-, or p-cresol, xylenol, halogenated phenols, and catechol; or hexamethylphosphorol Organic polar solvents such as amide and γ-butyrolactone can be mentioned. It is desirable to use these alone or as a mixture, but it is also possible to add aromatic hydrocarbons such as xylene and toluene. The polyamic acid copolymer is preferably dissolved in the organic solvent in an amount of 5 to 40% by weight, preferably 5 to 30% by weight, more preferably 5 to 25% by weight, from the viewpoint of handling. . The reaction temperature is in the range of 0 to 100 ° C, preferably 5 to 80 ° C, more preferably 5 to 50 ° C. A polyimide can be obtained from the polyamic acid copolymer solution thus obtained, and two generally known methods can be used for the production. That is, there are (a) a method of thermally dehydrating a ring-closing (imidization) and (b) a method of chemically dehydrating a ring-closing (imidization). More specifically, (a) is to obtain a self-supporting film after, for example, casting a polyamic acid solution on a heating drum or an endless belt and drying it. Pull it off from the drum or endless belt, fix both ends, and further about 450-5
This is a method in which a polyimide film is obtained by gradually heating to a temperature of 00 ° C. and drying and imidizing. In (b), for example, after mixing a polyamic acid solution with a dehydrating agent such as acetic anhydride and a tertiary amine such as pyridine, pyricons and quinolines, a polyimide film is obtained in the same manner as in (a). The polyimide copolymer obtained in this way has extremely excellent dimensional stability, and is excellent in mechanical properties such as elongation like a conventionally known polyimide resin.
For example, it has better dimensional stability and mechanical strength than a polyimide or copolyimide having a repeating unit of the general formula (I) or (II). (Examples) In the examples, ODA indicates 4,4'-diaminodiphenyl ether, o-TLD indicates dimethylbenzidine, and PMDA indicates pyromellitic anhydride. The elongation was measured by a method based on JIS K-7113. The linear expansion coefficient was measured at 10 ° C./min using a thermomechanical analyzer [TMA-10, manufactured by Seiko Electronics Co., Ltd.] and expressed as a value at 200 ° C. The coefficient of humidity expansion is measured using a thermomechanical analyzer [TMA-3
0, manufactured by Shimadzu Corporation] to measure the relative humidity at 50 ° C.
Measured by changing from 20% to 80%, relative humidity 20% to 80%
It was represented by the average value between. Comparative Example 1 21.54 g of ODA was collected in a 500 ml four-necked flask, and 245.00 g
Of N, N-dimethylacetamide was added and dissolved. On the other hand, 1
23.46 g of PMDA was collected in a 00 ml eggplant flask and added as a solid to the ODA solution. Further, PMDA adhering and remaining on the wall surface in the 100 ml eggplant flask was poured into the reaction system (four-neck flask) with 10.00 g of N, N-dimethylacetamide. Stirring was further continued for 1 hour to obtain a 15% by weight polyamic acid solution (I). On the other hand, 22.20 g of o-TLD was collected in a 500 ml four-necked flask, 245.00 g of N, N-dimethylacetamide was added and dissolved, and reacted with 22.80 g of PMDA according to the same method as described above.
A weight% polyamic acid solution (II) was obtained. However, PMDA adhering and remaining on the final wall surface was poured into the reaction system (four-necked flask) with 10.00 g of N, N-dimethylacetamide.
In each case, the reaction temperature was maintained at 5 to 10 ° C., and the handling of PMDA and the inside of the reaction system were placed under a stream of dry nitrogen by the above operation. Next, separately, 98.58 g of the polyamic acid solution (I) obtained by the above method is collected in a 500 ml four-necked flask, and 101.42 g of the polyamic acid solution (II) is further mixed therein. Stirred at about 10 minutes. The obtained polyamic acid mixed solution was cast-coated on a glass plate and dried at about 100 ° C. for about 60 minutes.Then, the polyamic acid coating film was peeled off from the glass plate, and the coating film was fixed on a support frame. About 30 minutes at about 200 ° C, about 60 minutes at about 200 ° C, about 6 minutes at about 300 ° C
After heating for 0 minutes and dehydration ring closure drying, a polyimide film of 15 to 25 microns was obtained. These films exhibited the following properties: Linear expansion coefficient (at 200 ℃) 0.6 × 10 ^-5 (cm / cm / ℃) Humidity expansion coefficient (at 50 ℃) 1.0 × 10 ^-5 (cm / cm / RH%) Elongation 10% Comparative row 2 500ml 4 In a one-necked flask, 10.62 g of ODA and 11.26 g of o-TLD were collected, and dissolved by adding 245.00 g of N, N-dimethylacetamide. On the other hand, 23.12 g of PMDA was collected in a 100 ml eggplant flask, and added in a solid form to the diamine mixed solution. Furthermore, PMD adhering and remaining on the wall surface in this 100 ml eggplant flask
A was poured into the reaction system (four-necked flask) with 10.00 g of N, N-dimethylacetamide. Further, stirring was continued for 1 hour to obtain a copolyamic acid solution. Reaction temperature is 5-10
C. However, with the above operation, the handling of PMDA and the inside of the reaction system were placed under a stream of dry nitrogen. Next, a copolyimide film was obtained from this copolyamic acid solution according to the method of Comparative Example 1. This film exhibited the following properties: Linear expansion coefficient (at 200 ° C) 0.7 × 10 ^-5 (cm / cm / ° C) Humidity expansion coefficient (at 50 ° C) 1.0 × 10 ^-5 (cm / cm / RH%) Elongation 8% Example 1 500 ml 10.62 g of ODA as an aromatic diamine component (A) was collected in a one-necked flask, and 255.00 g of N, N-dimethylacetamide was added and dissolved. On the other hand, P
10.40 g of MDA was collected and added as a solid to the ODA solution,
Stirring was continued for 1 hour to obtain an amic acid prepolymer solution. Then, 11.26 g of o-TLD as an aromatic diamine component (B) was collected in a 50 ml eggplant flask, added in a solid state to this amic acid prepolymer solution, and sufficiently stirred until the added o-TLD was completely dissolved. After that, 12.72 g of the insufficient PMDA was separately collected in a 100 ml eggplant flask, and added as a solid to the reaction system (four-neck flask). Subsequently, stirring was continued for 1 hour to obtain a copolyamic acid solution. The reaction temperature is 5
Maintained at 10 ° C. However, in the above operation, the handling of PMDA and the inside of the reaction system were placed under a dry nitrogen stream. The resulting copolyamic acid mixed solution is cast on a glass plate and dried at about 100 ° C. for about 60 minutes.Then, the copolyamic acid coating film is peeled off from the glass plate, and the coating film is fixed to a support frame, and then After heating at about 150 ° C. for about 30 minutes and at about 300 ° C. for about 60 minutes, dehydration ring-closing and drying were performed to obtain a polyimide film of 15 to 25 μm. This film exhibited the following properties: Linear expansion coefficient (at 200 ° C) 0.3 × 10 ^-5 (cm / cm / ° C) Humidity expansion coefficient (at 50 ° C) 0.5 × 10 ^-5 (cm / cm / RH%) Elongation 35% Example 2 500 ml 4 11.26 g of o-TLD was collected as an aromatic diamine component (A) in a one-necked flask, and 255.00 g of N, N-dimethylacetamide was added and dissolved. On the other hand, 10.40 g of PMDA was collected in a 100 ml eggplant flask, added in a solid form to the o-TLD solution, and stirred for 1 hour to obtain an amic acid prepolymer solution. Then, 10.62 g of ODA as an aromatic diamine component (B) was collected in a 50 ml eggplant flask, added in a solid form to this amic acid prepolymer solution, and the added ODA was added.
After stirring thoroughly until completely dissolved, separate 100 ml
12.72 g of the insufficient PMDA was collected in an eggplant flask, and added in a solid state to the reaction system (four-neck flask). Continue 1
Stirring was continued for an hour to obtain a copolyamic acid solution. The reaction temperature was kept at 5-10 ° C. However, in the above operation, the handling of PMDA and the inside of the reaction system were placed under a dry nitrogen stream. The resulting copolyamic acid mixed solution is cast on a glass plate and dried at about 100 ° C. for about 60 minutes.Then, the copolyamic acid coating film is peeled off from the glass plate, and the coating film is fixed to a support frame, and then About 150 ° C for about 10 minutes, about 200 ° C for about 60 minutes, about 300 ° C
For about 60 minutes to obtain a copolyimide film of 15 to 25 microns after dehydration ring-closing and drying. This film exhibited the following properties: Linear expansion coefficient (at 200 ℃) 0.3 × 10 ^-5 (cm / cm / ℃) Humidity expansion coefficient (at 50 ℃) 0.5 × 10 ^-5 (cm / cm / RH%) Elongation 33%

   ────────────────────────────────────────────────── ─── Continuation of front page                   (56) References JP-A-61-111359 (JP, A)                 JP-A-60-161429 (JP, A)                 JP-A-63-254131 (JP, A)

Claims (1)

(57) [Claims] 10 to 90 mol% of all diamine components in organic solvent
Of the aromatic diamine component (A) and 40 to 99 mol% of an aromatic tetracarboxylic dianhydride with respect to the diamine component (A) to obtain an amic acid prepolymer. 90 to 10 mol% of the aromatic diamine component (B) is added to the solution, and then the insufficient amount of the aromatic tetracarboxylic dianhydride is added so as to be equimolar to the total diamine component. In the method for producing a polyamic acid copolymer to be reacted, the diamine component (A) is 4,4′-diaminodiphenyl ether,
And the diamine component (B) has the general formula (III) (Wherein, R is a group selected from the group consisting of hydrogen or a halogen atom, a nitro group, a hydroxyl group, a methyl group and a methoxy group, and n is 2-3 when R is hydrogen;
When R is a halogen atom, a nitro group, a hydroxyl group, a methyl group or a methoxy group, it is an integer of 1 to 3. Or the diamine component (A) is an aromatic diamine represented by the general formula (III), and the diamine component (B) is 4,4'-diaminodiphenyl ether. A method for producing a polyamic acid copolymer, characterized in that: 2. The aromatic tetracarboxylic dianhydride component is an acid dianhydride selected from the group consisting of pyromellitic dianhydride, biphenyl tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride. 2. The method for producing a polyamic acid copolymer according to item 1.