| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water-soluble polyvinyl acetal resin excellent in mechanical strength and flexibility. <P>SOLUTION: The water-soluble polyvinyl acetal resin includes a structural unit of formula (2) based on a partial acetalization product of polyvinyl alcohol and a copolymerized unit of formula (3) and has an acetalization rate of ≥50 mol%. In formula (2), R<SP POS="POST">1</SP>represents H or 1C-20C alkyl. In formula (3), R<SP POS="POST">2</SP>represents carboxyl, ethylene oxide, amide or sulfo. <P>COPYRIGHT: (C)2012,JPO&INPIT |
