| 摘要 |
Water-soluble films are made of compositions comprising a water-soluble polyvinyl alcohol derivative selected from partially saponified polyvinyl esters, low acetalized polyvinyl alcohol, urethanized polyvinyl alcohol, hydroxyethylated polyvinyl alcohol, cyanoethylated polyvinyl alcohol, and sulphoacetalized polyvinyl alcohol, a water-soluble starch or starch degradation product, and optionally a nonionic or anionic surface-active agent. Specified starch degradation products are amino dextrin, dextrin white, dextrin yellow, British gum, erythrodextrin and achrodextrin. Examples describe the making of films by casting aqueous solutions of (1) urethanized polyvinyl alcohol and dextrin white; (2) urethanized polyvinyl alcohol, dextrin yellow and an alkyl phenol-ethylene oxide condensate; and (3) partially saponified polyvinyl alcohol, starch and an alkyl phenol-ethylene oxide condensate.
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