[C:1]([O:4][CH:5]=[CH2:6])(=[O:3])[CH3:2].[CH2:7]([S:10]([O-:13])(=[O:12])=[O:11])[CH:8]=[CH2:9].[Na+:14].CC(N=NC(C#N)(C)C)(C#N)C>CO>[C:1]([O:4][CH:5]=[CH2:6])(=[O:3])[CH3:2].[CH2:7]([S:10]([O-:13])(=[O:12])=[O:11])[CH:8]=[CH2:9].[Na+:14]A 1,000 ml. glass polymerization vessel equipped with a reflux condenser, a dropping funnel, a thermometer and a stirrer was charged with 395 parts of vinyl acetate, 186 parts of methanol, 27 parts of sodium allylsulfonate and 0.23% by mole per the vinyl acetate of azobisisobutylonitrile. After carrying out the polymerization at a temperature of 60° to 65°C. for 8 hours, the residual vinyl acetate was removed by a conventional method to give vinyl acetate-sodium allylsulfonate copolymer containing 3.0% by mole of sodium allylsulfonate unit. Then the copolymer was hydrolyzed by a conventional method to give a modified PVA of which degree of hydrolysis in vinyl acetate unit was 99% by mole.
Wird geladen…