Patent ID: 6110454
Filing Date: 2000-08-29
Classification: A61K,A61Q,C08F,Y10S

Abstract:
A process for making clear, low viscosity aqueous solutions of a homogeneous copolymer of vinyl pyrrolidone (VP) and N-3,3-dimethylaminopropyl methacrylamide (DMAPMA), in the compositional range of 20-99% VP and 1-80% DMAPMA, by weight, having a weight average molecular weight of about 200,000 to about 1,500,000, a solids content of about 5-20%, and a viscosity of about 5,000 to 80,000 cps, by polymerization of the monomers in water in the presence of a radical initiator, which comprises:(a) precharging a reactor with a predetermined amount of VP, and water, at a polymerization temperature of about 50-90.degree. C., and(b) introducing DMAPMA into said reactor at a predetermined rate corresponding to the rate of disappearance of VP, over a given period of time.