Patent · US Expired

Preparation of copolymers which form clear aqueous solutions

US5122582A · kind A · utility

16Cited by

5References

4Claims

0Family size

Assignee

BASF SE

Inventors

Birgit Potthoff-Karl · Weinheim, DE
Adolf Nuber · Böhl-Iggelheim, DE
Willy Hinz · Mannheim, DE
Axel Sanner · Bischofswerda, DE

Key dates

Filing date	Sep 21, 1990
Grant date	Jun 16, 1992
Priority date	—
Expiry date	Sep 21, 2010

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08F218/04
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

The preparation of copolymers which form clear aqueous solutions from PA0 A) 45 to 90% by weight N-vinylpyrrolidone, PA0 B) 10 to 55% by weight of a vinyl ester and PA0 C) 0 to 10% by weight of other copolymerizable monomers by radical polymerization in an organic solvent in the presence of a radical initiator, and removal of the organic solvent and other volatiles by distillation, entails allowing the polymerization to proceed until the N-vinylpyrrolidone content in the reaction mixture is from 5 to 1% by weight of the N-vinylpyrrolidone amount employed, substantially removing the organic solvent and other volatiles by distillation, adding water to the mixture, again adding a radical initiator and leaving the aqueous solution at from 50.degree. to 100.degree. C. for from 1 to 10 hours, and then removing volatile organic constituents virtually completely by a steam distillation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.