| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyimide having a high modulus and a low coefficient of linear thermal expansion by combining a polyimide precursor soln. formed from pyromellitic dianhydride and p-phenylenediamine with another polyimide precursor soln. SOLUTION: This novel polyimide comprises 70-95 wt.%, pref. 80-95 wt.%, structural units of formula I and 5-30 wt.%, pref. 5-20 wt.%, structural units of formula II. In the formulas, X is a tetracarboxylic acid residue derived from pyromellitic dianhydride; Y is a p-phenylenediamine residue; S is a tetracarboxylic acid residue derived from a 2,3,3',4'-biphenyltetracarboxylic dianhydride; T is a 4,4'-diaminodiphenyl ether residue; and (m) and (n) are each an integer. This polyimide is excellent also in heat resistance. A laminated substrate is prepd. by laminating, directly or through a heat-resistant adhesive, a substrate to at least one side of a layer comprising the polyimide. |
