| 摘要 |
The present invention generally relates to low amidine content polyvinylamine in fresh or aged formats, papermaking and paper sizing compositions containing them, and processes for making, providing and using them. Disclosed is a polymer comprising units of N-vinylformamide, vinyl amine, and amidine, wherein the polymer has an age of at least 21 days and an amidine content no greater than about 15 mole per cent, and a vinyl amine content of from 5 mole per cent to 49 mole per cent. Also disclosed is a process for providing vinylamine polymer having low amidine content, comprising: (a) polymerizing N-vinylformamide, and (b) partially hydrolyzing the poly(N-vinylformamide) formed in step (a) under acidic aqueous conditions at a temperature no greater than about 85 degrees C and for a period of time of no greater than about 4 hours to provide a polymer comprising units of N-vinylformamide, vinyl amine, and amidine, wherein the amidine content is no greater than about 15 mole per cent and the polymer having a degree of hydrolysis of no more than about 57 per cent. |
