| 摘要 |
Polyimide moulding powders are prepared by mixing (a) an imide linkage containing precondensate of a tetracarboxylic acid and a polyamine, which still contains reactive groups, and (b) a reactive substance which is at least bifunctional relative to (a), in amount such that one amine group is available per two carboxylic acid, anhydride, or ester groups. Preferably, (a) is a precondensate of a tetracarboxylic acid and a diamine in a mol ratio of 2:1. This precondensate (a) is pref. mixed with either (b) a precondensate of a tetracarboxylic acid and a diamine in a mol. ratio of 1:2, or with a polyamine. Alternatively (a) a precondensate of a tetracarboxylic acid and a diamine in a mol. ratio of 1:2, is mixed with (b) a dianhydride of a tetracarboxylic acid. |
