公开(公告)号：DE3931681A1

公开(公告)日：1991-04-04

申请号：DE3931681

申请日：1989-09-22

Applicant: BASF AG

Inventor： POTTHOFF-KARL BIRGIT DR ,  NUBER ADOLF DR ,  HINZ WILLY DR ,  SANNER AXEL DR

IPC: C08F6/10 ,  C08F2/04 ,  C08F2/10 ,  C08F6/00 ,  C08F26/10 ,  C08F218/02 ,  C08F218/04 ,  C08F226/10

Abstract: Preparation of copolymers which are clear in water from A) 45 to 90% by weight of N-vinylpyrrolidone, B) 10 to 55% by weight of a vinyl ester and C) 0 to 10% by weight of further copolymerisable monomers by free radical polymerisation in an organic solvent in the presence of a free radical initiator and separation of the organic solvent and other volatile components by distillation, by carrying out the polymerisation until the N-vinylpyrrolidone content of the reaction mixture corresponds to 5 to 1% by weight of the amount of N-vinylpyrrolidone used, substantially separating off the organic solvent and other volatile components by distillation, adding water to the mixture, leaving the aqueous solution for 1 to 10 hours at 50 to 100 DEG C with further addition of free radical initiators and then virtually completely removing volatile organic components by steam distillation.