The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 22, 1979
Filed:
Aug. 11, 1978
Robert D Wysong, Talleyville, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
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, are used for preparing films by melt extrusion. The compositions, in the form of powder or granules, or preferably pellets, are melted, extruded through a slit or annulus, quenched by air and then drawn down and/or blown to form a thin film. Such drawing or blowing can impart orientation to the film. 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.