申请人:Kuraray Co., Ltd.
公开号:EP3753959A1
公开(公告)日:2020-12-23
An object of the present invention is to provide a modified vinyl alcohol polymer having a sulfonic acid or a salt thereof, the polymer having notably improved water solubility as compared with a pre-modified vinyl alcohol polymer. A modified vinyl alcohol polymer (A) has in a side chain thereof a sulfonic acid group or a salt thereof, and in the modified vinyl alcohol polymer (A), a degree of modification with the sulfonic acid group or the salt thereof is 0.01 mol% or more and 10 mol% or less, and a block character of residual vinyl ester units is 0.55 or more and 1 or less.
本发明的目的是提供一种具有磺酸或其盐的改性乙烯醇聚合物,与预改性乙烯醇聚合物相比,该聚合物的水溶性显著提高。改性乙烯醇聚合物(A)的侧链中含有磺酸基团或其盐,在改性乙烯醇聚合物(A)中,磺酸基团或其盐的改性程度为 0.01 摩尔%或以上,10 摩尔%或以下,残余乙烯基酯单元的嵌段特性为 0.55 或以上,1 或以下。