Heat-shrinkable polymeric barrier film
AssigneeE. I. Du Pont de Nemours and Company
InventorDan S. C. Fong
Life of this patent
Estimating the term…
Abstract
A heat-shrinkable barrier film comprised of an oriented polyolefin film coated on one side with a vinylidene chloride copolymer are disclosed. The films have excellent gas and vapor barrier properties, can surprisingly be made using conventional dispersion coating techniques, and retain acceptable optical properties even on shrinking up to as high as 35% in either transverse or machine directions or both.
Claims11
A process for making a heat-shrinkable barrier film comprising coating an oriented polyolefin film having a surface energy of at least 35 dynes/cm on at least one side with an aqueous dispersion of vinylidene chloride copolymer, exposing the coated film to heat at a temperature and for a period of time sufficient to raise the temperature of the film to about 50.degree. C. to about 100.degree. C. and sufficient to remove substantially all of the water, whereby a film is produced capable of shrinking at least about 10 percent upon heating to about 100.degree. to 120.degree. C.
Dependencies are inferred from the claim text.