反应详情

A vinyl acetate-methyl acrylate copolymer containing 43% by mole of the latter monomer units was obtained by polymerizing 0.8 mole of vinyl acetate and 0.2 mole of methyl acrylate in benzene at 80° C. for 2 hours in the presence of benzoyl peroxide. Then, 10 g of the copolymer was dissolved by heating in 500 ml of methanol and saponified by adding 20 ml of 40% aqueous NaOH and heating at 60° C. for 15 hours. The saponified product was thoroughly washed with acetone to remove free NaOH, and dried at 60° C. under reduced pressure for 20 hours, thus giving a powdery sodium salt of vinyl alcohol-acrylic acid copolymer. The saponification degree thereof determined from the alkali consumption was 93% by mole.