The present invention is to provide a polyvinyl alcohol containing the structural unit (I) of the following formula (I) at a molar fraction of 0.05 to 0.50 and the structural unit (II) of the following formula (II) at a molar fraction of 0.0001 to 0.50;
wherein R1 is hydrogen atom or a mono-valent hydrocarbon group; and R2 and R3 are mono-valent hydrocarbon groups or R2 and R3 together form a ring; or R1, R2 and R3 together form a ring; X is a group represented by the formula -CO-Y, -Y or -CO-COOH (wherein Y represents a hydrocarbon group directly or indirectly bonded with carboxyl group, sulfo group, amino group and/or phosphonooxy group) or X forms phosphonooxy group together with the oxygen atom to which X is bonded.
本发明旨在提供一种聚
乙烯醇,含有摩尔分数为 0.05 至 0.50 的下式(I)结构单元和摩尔分数为 0.0001 至 0.50 的下式(II)结构单元;
其中 R1 是氢原子或单价烃基;R2 和 R3 是单价烃基或 R2 和 R3 共同形成一个环;或 R1、R2 和 R3 共同形成一个环;X 是由式 -CO-Y、-Y 或 -CO-COOH 所代表的基团(其中 Y 代表直接或间接与羧基、磺基、
氨基和/或
磷酰氧基键合的烃基)或 X 与 X 键合的氧原子共同形成
磷酰氧基。