| abstract |
A process is described for making substantially homogeneous copolymers comprising 20-99 % of vinyl pyrrolidone (VP) and 1-80 % of N-3,3-dimethylaminopropyl methacrylamide (DMAPMA), preferably 50-95 % VP and 5-50 % DMAPMA, and, most preferably, about 80:20, by weight, having a weight average molecular weight of about 200,000 to 1,500,000, as a clear, low viscosity aqueous solution of the homogeneous copolymer, at a 5-20 % solids level, preferably about 10-15 %, by weight of the solution, having a viscosity of about 5,000 to 80,000 cps, preferably about 10,000 to 70,000 cps. The solution obtained herein has lower viscosity and better clarity, and provides hair care products with enhanced curl retention (hold), when compared to non-homogeneous copolymers of the same composition, or related existing commercial products. |