Patent ID: 8598280

Claim:
A process for preparing a stabilized molding composition, the molding composition comprising: a polymer comprising units of formula I: wherein R 1 and R 2 are each hydrogen or methyl and R 3 is hydrogen, optionally substituted C 1 -C 18 -alkyl, optionally substituted C 5 -C 8 -cycloalkyl, optionally substituted C 6 -C 10 -aryl, or optionally substituted C 6 -C 10 -aryl-C 1 -C 4 -alkyl, optionally substituted with up to trisubstituted by radicals selected from the group consisting of C 1 -C 4 -alkoxy and halogen, and at least one reducing organic phosphorous compound of formula II: wherein R 4 is hydrogen or an aromatic 6-membered ring optionally up to pentasubstituted by at least one of C 1 -C 4 -alkyl and C 5 -C 8 -cycloalkyl groups, R 5 is an aromatic 6-membered ring optionally up to pentasubstituted by at least one of C 1 -C 4 -alkyl and C 5 -C 8 -cycloalkyl groups, and R 6 is hydrogen, an alkali metal, an alkaline earth metal, aluminum, ammonium or ammonium optionally substituted with up to four of at least one selected from C 1 to C 4 alkyl and C 5 to C 8 cycloalkyl groups; the process comprising: adding the at least one reducing organic phosphorous compound to the polymer after completion of an imidation reaction from which the polymer is obtained.