| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject polyimide which can be dissolved in various kinds of solvents, can exhibit excellent heat resistance, excellent mechanical characteristics, and so on, and is useful as a material for electronics, by copolymerizing an aromatic tetracarboxylic acid dianhydride with isophoronediamine and a specific aromatic diamine in a specific ratio. SOLUTION: This soluble polyimide comprises structural units of formulas I and II (Ar1 is a tetravalent aromatic residue containing at least one carbon six-membered ring, wherein the four carbonyl groups are directly bound to different carbon atoms in the residue and form two pairs which are bound to the adjacent carbon atoms, respectively, in the carbon six-membered ring; Ar2 is a divalent aromatic residue having at least one carbon six-membered ring), wherein the structural units of formulas I and II are contained in a molar ratio of 20:80 to 95:5. It is preferable that the polyimide has an imidation rate of >=90%. The polyimide is soluble in aprotic polar solvents, and is useful for producing heat-resistant tapes, and so on.
|
