Provided by the present invention is a PVA having highly harmonized adequate water solubility, thickening property and coating film strength, and having superior storage stability in terms of the viscosity in an aqueous solution. A vinyl alcohol polymer having a ratio (Mw (A)/Mn (A)) of the weight average molecular weight (Mw (A)) to the number average molecular weight (Mn (A)) of 3 or greater and 8 or less, and being capable of giving a vinyl alcohol polymer having a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 2 or greater and less than 3 when treated at 40 °C for 1 hour in a sodium hydroxide solution.
本发明提供了一种 PVA,它具有高度协调的充分
水溶性、增稠性能和涂膜强度,并且在
水溶液中的粘度具有优异的储存稳定性。一种
乙烯醇聚合物,其重量平均分子量(Mw(A))与数均分子量(Mn(A))之比(Mw(A)/Mn(A))为 3 或 3 以上 8 或 8 以下,并且在
氢氧化钠溶液中于 40 °C 下处理 1 小时后,能得到重量平均分子量(Mw)与数均分子量(Mn)之比(Mw/Mn)为 2 或 2 以上 3 以下的
乙烯醇聚合物。