| 摘要 |
The present invention relates to a novel process for the preparation of heat-stable copolymers which contain, in their structure, recurring units formed of imide-amide groups and diorganopolysiloxane groups. …<??>More precisely, these copolymers are obtained by direct reaction, in a solvent medium, of a diisocyanate of the formula …<IMAGE>… with A = a valency bond or a divalent radical, a monoanhydride of a tricarboxylic acid of the formula …<IMAGE>… (II) with B = an aromatic trivalent radical, and a siloxane diisocyanate of the formula …<IMAGE>… with D = a divalent hydrocarbon radical of alkylaromatic nature, which can contain one or more heteroatoms, R1 to R8 = hydrocarbon radicals and x + y = a number ranging from 0 to 100. |
