| abstract |
Oriented poly(chlorotrifluoroethylene) based films comprising up to 1 pourcent by weight of copolymerizable comonomers as well as oriented poly(chlorotrifluoroethylene) films formed essentially of a homopolymer comprising no copolymerizable comonomers are provided; all of the films are formed from low zero strength time film forming resin compositions which are highly amorphous in nature, and which are subjected to a process which includes the steps of: preheating the film above its glass transition temperature, stretching the film to provide a film having a stretched:unstretched ratio of between about 2:1 to about 5:1, followed by annealing the film. The films feature excellent resistance to vapor transmission, particularly water vapor, and feature good physical strength characteristics. |