JPH03181511A - Production of polyamide-imide polymer and varnish thereof - Google Patents

Abstract

PURPOSE:To obtain the subject polymer capable of providing varnishes, excellent in heat resistance and mechanical characteristics, soluble in low-boiling solvents and curable at low temperatures by successively reacting an aromatic tricarboxylic acid anhydride with an ether bond-containing diamine and diisocyanate. CONSTITUTION:The objective polymer obtained by initially reacting an aromatic tricarboxylic acid anhydride (preferably trimellitic anhydride) with an ether bond-containing diamine expressed by formula I [R1 is -C(CH3)2- or -SO2-] {e.g. bis[4-(4-aminophenoxy)phenyl]propane} in a state of the excessive acid component, then reacting the resultant reaction product with a diisocyanate expressed by formula II (R2 is formula III, IV, etc.) (preferably diphenylmethane 4,4'- diisocyanate). Furthermore, the ratio of the aforementioned acid component : diamine component is preferably 100 : 60. The ratio of the diamine component : diisocyanate component is preferably 60 : 40.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing a polyamide-imide polymer and a varnish thereof, and more specifically, a method for producing a polyamide-imide polymer that is soluble in an organic solvent and can be cured at low temperatures, and a varnish thereof. It is related to. (Prior art) Conventionally, flexible printed circuit boards have been manufactured using the film coverlay method, in which a film is fused to the circuit surface in order to protect the conductor surface from moisture, dirt, and damage, or by applying and curing a liquid coating agent. It is used after being protected by an ink cover coating method. When protecting the conductor surface using the ink cover coating method, it is dried at high temperature to remove the solvent of the coating agent.
This flexible circuit board is made by bonding polyimide and metal foil together with an adhesive, and since the adhesive originally has poor heat resistance, it deteriorates after high-temperature firing and dimensional changes occur at high temperatures. However, the currently synthesized polyamideimide polymer is N-methyl-2-
It is soluble in high-boiling aprotic polar solvents such as pyrrolidone, but hardly soluble in organic solvents such as 1,4-dioxane, diethylene glycol dimedyl ether, and cyclohexanone. Furthermore, attempts have been made to improve solubility by introducing ether bonds or siloxane into the polyamide-imide polymer skeleton, but these methods are not sufficient in terms of mechanical properties and reactivity. (Problems to be Solved by the Invention) The present invention was obtained as a result of research aimed at efficiently obtaining a low-temperature curable polyamide-imide polymer varnish that is soluble in low-boiling solvents and has excellent heat resistance and mechanical properties. It is something that That is, by using a diamine having an ether bond, the solubility is improved, and by using a diisocyanate, a polyamide-imide polymer varnish with excellent mechanical properties can be efficiently produced. (Means for Solving the Problems) The present invention provides aromatic tricarboxylic acid anhydrides and general formula (T) (wherein R1 is -C(CH3)!- or -8O□-
In the first step, the general formula (n) OCN Rz NCO...(IT) (in the formula R2 represents a divalent group containing an aromatic ring shown in OcH, e. or 2,4.-tolylene dimer).
This is a method for producing a polyamideimide polymer, which is characterized by a two-step reaction in which 1. Moreover, the reduced viscosity of the present invention is 0.4 dl! (Function) The aromatic tricarboxylic acid anhydride used in the present invention is related to a polyamide-imide polymer varnish prepared by dissolving the polyamide-imide polymer having a boiling point of 170° C. or less in a solvent with a boiling point of 170° C. Mellitic acid anhydride, 3,4.4'-diphenyl ether tricarboxylic anhydride, 3,4.4'-benzophenone tricarboxylic anhydride, 1.2.4-11.4
．． These include 5- or 2,3.6-naphthalenetricarboxylic anhydride, 2,3.5-pyridinetricarboxylic anhydride, and the like, and one type or a mixture of two or more of these can be used. In particular, trimellitic anhydride is preferably used. The diamine having an ether bond represented by the general formula (I) used in the present invention includes 2,2-bis[4-
(4-aminophenoxy)phenyl]propane, bis[
These are 4-(4-aminophenoxy)phenylcosulfone and bis[4-(3-aminophenoxy)phenylcosulfone.They can be used alone or in combination. The ratio of the aromatic tricarboxylic acid used in the first stage reaction to the diamine having an ether bond represented by the general formula (1) (acid component diamine component) is +00:50.
~100:80 is preferable, especially 100:
It is preferable to set it to 80. This is mainly related to the solubility of the polyamideimide polymer to be produced. If the diamine component is less than 50%, the solubility decreases, and similarly, the
This is because mechanical properties deteriorate when the content is 0% or more. Furthermore, in the present invention, the reason why the reaction is carried out in an excess acid state in the first step is to sufficiently react amino groups, which are less reactive than isocyanate groups, to generate acid-terminated oligomers. . Further, when adding isocyanate in the second stage reaction, if any amino groups remain, they will react with the isocyanate groups to form urea bonds. For these reasons, in the first stage reaction, it is necessary to fully react the amine in a state of excess acid.
It can be easily confirmed by IH-NMR that no primary amine remains. The diisocyanate represented by #I general formula (11) used in the present invention is diphenylmethane-4,4'
-diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 3.3°tolylene-4,4′-diisocyanate, naphthalene-1. 5-diisocyanate, 2.41 rylene dimer, etc., and they can be used alone or in combination of two or more. In particular, diphenylmethane-4,4'-diisocyanate is preferably used. The ratio of the diamine having an ether bond represented by the general formula (I) and the diisocyanate represented by the general formula (II) (diamine component diisocyanate component) is preferably 50:50 to 80:20, A ratio of 60:40 is particularly preferable, because as the diisocyanate component increases, mechanical properties and reactivity are excellent, but solubility decreases. The diisocyanate added in the second stage quickly reacts with the acid-terminated oligomer produced in the first stage to produce a polyamide-imide polymer. The polyamide-imide polymer in the present invention is represented by the following general formula (III) due to its two-step reaction characteristics:
(IV) and/or (V). (In the formula, R represents ○I3- R+-Q-O<Ge in the general formula (I) or -R2- in the general formula (H). ) The polyamide-imide polymer in the present invention has a reduced viscosity of 0.
．． 4d9. If it is less than /g, the mechanical properties will be poor;
It is preferable to use a polyamideimide polymer with a polyamide-imide polymer having a viscosity of 0.4 dfL/g or more.
Measurements were made using pyrrolidone at a concentration of 0.5 g/day at 30°C. Solvents with a boiling point of less than 170°C used in the present invention include:
Examples include 1,4-dioxane, diethylene glycol dimethyl ether, tetrahydrofuran, cyclohexanone, N,N-dimethylformamide, N,N-dimethylacetamide, and pyridine. deer

[While N,N-dimethylformamide, N,
Since N-dimethylacetamide, pyridine, and the like have toxicity problems, preferred solvents include 1,4-dioxane, diethylene glycol dimethyl ether, tetrahydrofuran, and cyclohexanone. These may be used alone or in combination, but in consideration of film forming properties, N-methyl-2-pyrrolidone should be used in an amount of 10 to 30%.
Preferably, mixed solvents are used, which are 1.4-
This is because dioxane or cyclohexanone alone may cause foaming depending on the drying conditions, resulting in poor film-forming properties. However, when the content of N-methyl-2-pyrrolidone exceeds 30%, it becomes difficult to obtain a mixed solvent with a boiling point of less than 170°C. Taking these things into consideration, the ratio of mixed solvent (N-
Methyl-2-pyrrolidone: cyclohexanone: 1.4-
A ratio of 20:50:30 (dioxane) is particularly preferred. <Example 1) Trimellitic anhydride 2,2-bis[4-(4-aminophenoxy)phenyl]propane N-methyl-2-pyrrolidone phosphoric acid aqueous soluble M (85%) diphenylmethane-4,4゛-di Isocyanate 10.6 parts by weight 13.1 parts by weight 69.8 parts by weight 0.3 parts by weight 5.6 parts by weight Diphenylmethane-4,4'-diisocyanate and N-
The above components except for a portion of methyl-2-pyrrolidone were placed in a four-hole flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a moisture meter, and the temperature was raised to 190° C. under a nitrogen stream. fl
The temperature was further raised to 200°C while removing the water from the system, and the mixture was stirred at 200°C for 5 hours. After cooling to room temperature, diphenylmethane-4,4'-diisocyanate and the remaining N-methyl-2-pyrrolidone were added and heated again. The reaction was carried out at 80°C for 1 hour and at 200°C for 18 hours to obtain a polyamideimide polymer having a reduced viscosity of 0.50. The obtained polyamide-imide polymer solution was
The mixture was diluted approximately 3 times with methyl-2-pyrrolidone and reprecipitated in methanol to obtain a polyamideimide polymer powder. When the solubility of this polyamide-imide polymer powder was examined, it was dissolved in 1,4-dioxane, diethylene glycol dimethyl ether, tetrahydrofuran, and cyclohexanone. (Comparative Example 1) Trimellitic anhydride 13.0 parts by weight N-
Methyl-2-pyrrolidone 70.0 parts by weight Diphenylmethane-4,4'-di 17.0 parts by weight Isocyanate The above ingredients were placed in a four-necked flask equipped with a stirrer, thermometer, nitrogen inlet tube, and reflux condenser tube, and nitrogen The reaction was carried out at 80° C. for 1 hour and at 160° C. for 2 hours under air flow to obtain a polyamideimide polymer having a reduced viscosity of 0.50. The obtained polyamide-imide polymer solution was diluted approximately three times with N-methyl-2-pyrrolidone and reprecipitated in methanol to obtain a polyamide-imide polymer powder. When the solubility of this polyamide-imide polymer powder was examined, it was not dissolved in any of 1,4-dioxane, diethylene glycol dimethyl ether, tetrahydrofuran, and cyclohexanone. (Comparative Example 2) Trimellitic anhydride 9.5 parts by weight 2.2
-Bis[4-(4-aminophe 20.41i partsnoxy)phenyl]propane N-methyl-2-pyrrolidone 69.8 parts by weight Phosphoric acid aqueous solution (85%) 0.311
Quantity: Put the above ingredients into a four-loaf flask equipped with a stirrer, thermometer, nitrogen inlet tube, and moisture meter, and heat under a nitrogen stream.190
The temperature was raised to ℃. While removing outflow water from the system 2
The temperature was further raised to 10°C and the reaction was carried out at 210°C for 24 hours to obtain a polyamideimide polymer with a reduced viscosity of 0.49. The obtained polyazidoimide polymer solution was diluted with N-methyl-2-pyrrolidone to about 3 ffj and reprecipitated in methanol to obtain a polyamide-imide polymer powder. 15g of this powder was mixed with H-methyl-2-pyrrolidone/cyclohexanone 71.4-dioxane = 20/50/30
(TL t ratio) (1) 35 g of mixed solvent was used to prepare a di-soluble M ciborium amide-imide polymer varnish. (Example 2) Polyazidoimide polymer powder 15 obtained in Example 1
g was dissolved in 35 g of a mixed solvent of N-methyl-2-pyrrolidone/cyclohexanone/l and 4-dioxane = 20/50/30 (weight ratio) to obtain a polyamideimide polymer varnish. The polyamide-imide polymer varnish prepared in Example 2 and Comparative Example 2 was applied onto a circuit board, dried at 00°C for 1 hour and at 170°C for 1 hour, and then subjected to a folding durability test. The results are shown in Table 1. The product using the varnish of Example 2 had about twice the folding durability compared to the product using the varnish of Comparative Example 2. Table 1 (Effects) According to the present invention, it has become possible to obtain a polyamide-imide polymer varnish with excellent mechanical properties that can be treated at low temperatures.

Claims (2)

[Claims] (1) Aromatic tricarboxylic acid anhydride and general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼…(I) (In the formula, R_1 is -C(CH_3)_2- or -SO
_2- represents a divalent group. ) is reacted with a diamine having an ether bond in an excess amount of acid component,
In the following, the general formula (II) OCN-R_2-NCO...(II) (In the formula, R_2 is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲Mathematical formulas, chemical formulas, tables, etc.▼ Or, it represents a divalent group containing an aromatic ring as shown in 2,4-tolylene dimer. ) A method for producing a polyamide-imide polymer, which is characterized by a two-step reaction in which a diisocyanate represented by the following formula is reacted. (2) The polyamide-imide polymer according to claim 1, which has a reduced viscosity of 0.4 dl/g or more, has a boiling point of 17 dl/g or more.
A polyamide-imide polymer varnish that is dissolved in a solvent at a temperature below 0°C.