| 摘要 |
Films prepared by melt extrusion or aqueous casting from compositions consisting essentially of a (i) resin mixture containing a low molecular weight polyvinyl alcohol and a medium molecular weight polyvinyl alcohol, and optionally, a copolymer of vinyl alcohol and an ethylenically unsaturated ester and (ii) as a plasticizer a polyethylene glycol. The films are suitable for use as packaging film in automatic packaging equipment. They can be used to package pulverulent materials, and the film package containing the pulverulent material can be charged directly to water in which the film will dissolve, thus eliminating the problem of user contact and exact measuring of the package contents, as well as disposal of containers in which the pulverulent materials would otherwise be packaged. Moreover, the films provide enhanced resistance to breakage of packages made therefrom when such packages are handled or shipped, even under cold or dry conditions.
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