Abstract: The present invention relates to compositions comprising conductive particles and one or more polymers, particularly acid copolymer resins or derived ionomers, which can be extruded or heat formed into films or articles. More specifically, the method of the present invention is directed to a novel, non-uniform heating process, wherein the edge portions of a material is heated about 3-50 degrees Celsius hotter than the center or middle portions of the article or film during fabrication to thereby provide improved and substantially uniform electrostatic dissipative ("ESD") properties.
Abstract: The present invention relates to poly(ethylene terephthalate)("PET") polymer resins having high melt strength and advantageous non-Newtonian behavior; the resins can be foamed to produce closed cell structures with advantageous densities, cell sizes, cell size distributions, mechanical properties and thermal properties. More specifically, the PET resins of the present invention are highly branched due to the inclusion of one or more branching agents, and these resins can be advantageously used with environmentally friendly blowing agents.
Abstract: A film comprising alternating layers of polyvinylidene chloride resin and a solvent barrier such as polyvinyl alcohol provides superior barrier properties. Barrier and mechanical properties are enhanced when formulation additives are present at customary levels only in the outermost layers.
Type:
Grant
Filed:
May 21, 1992
Date of Patent:
July 6, 1993
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Charles L. Beeson, Raymond T. Cole, Gedeon I. Deak, Herbeson H. Leidolf, Jr.
Abstract: A multiple layer article of a thermoformable structural polymeric layer which is susceptible to damage upon exposure to hydrohalocarbon blowing agents and a polymeric layer which is a barrier to such hydrohalocarbon blowing agents provides a useful refrigerator liner. Related structures are useful for preventing the migration of hydrohalocarbons.
Abstract: A blend of 5 to 95 percent of an ethylene vinyl alcohol copolymer and 95 to 5 percent of an amorphous polyamide having fewer than about 0.100 equivalents of carboxyl end groups per kilogram of polyamide exhibits improved oxidative and thermal stability. The blend is useful for preparing films and multiple layered structures including thermoformed structures and oriented shrink films.
Abstract: A blend consisting essentially of a major portion of an amorphous polyamide and a minor portion of an ethylene vinyl alcohol copolymer exhibits gas barrier properties which are less dependent on humidity than are those of either of the component polymers. Films and laminated structures which incorporate the material of these blends are suitable for use as packaging materials.