| 摘要 |
<p>A film of polyvinyl alcohol which has improved characteristics of solubility in borate and perborate solutions. This film consists essentially either of a polyvinyl alcohol polymer containing 80 to 92 mol% of polyvinyl alcohol or of a copolymer of polyvinyl alcohol and acrylic acid containing 30 to 95 mol% of polyvinyl alcohol and contains 1 to 20% by weight of a sulphonated hydrotropic agent.</p> |
