Importance

Loading Importance Indicators...

Abstract

Polyamide-polyimide block copolymers having an average molecular weight M.sub.n of 1,000-50,000 and containing recurring units of the formula I --(PA)-(PI)--. (I) in which (PA) is a polyamide block having an average molecular weight M.sub.n of 300-20,000 and containing at least one (recurring) unit of the formula II ##STR1## in which R.sup.1 is ##STR2## and R.sup.2 is ##STR3## in which Q is a direct bond, --CH.sub.2 --, --CH.sub.2 CH.sub.2 --, ##STR4## --O--, --S--, --SO.sub.2 -- or --C(O)--, and n is 2-12, and Y.sub.a, Y.sub.b, Y.sub.c and Y.sub.d independently of one another are hydrogen, halogen or C.sub.1 -C.sub.4 alkyl, and (PI) is a polyimide block having an average molecular weight M.sub.n of 300-20,000 and containing at least one (recurring) unit of the formula III ##STR5## in which R.sup.3 is ##STR6## and Q and R.sup.2 are as defined above, with the proviso that 25-100 mol % of all the bridge members R.sup.2 are ##STR7## and the (cyclo)aliphatic proportion of bridge members R.sup.2 does not make up more than 10 mol %. These polymers are soluble in aprotic dipolar solvents, which leads to various advantages for practical applications, for example in the production of laminates or coating agents.

Loading the Abstract Image...

First Claim