Vinyl alcohol copolymers, water-soluble films containing such vinyl alcohol copolymers, their use as packaging material and process of their preparation

摘要

In the present invention, there are disclosed vinyl alcohol copolymers that can be prepared by the acid-catalyzed acetalization reaction of polyvinyl alcohols with a degree of saponification within the range of 80 to 99.5 mole percent and preferably between 88 and 99.5 mole percent with natural substances or their derivatives containing carbonyl or presumptive carbonyl groups. The description also relates to water-soluble films containing such vinyl alcohol copolymers, the solubility of which can be adjusted to the desired dissolution temperature. Said water-soluble films are used as packaging materials and auxiliaries, for example in the form of sealing lacquers. Further described is a process for preparing the invented vinyl alcohol copolymers as well as water-soluble lacquers produced therefrom.