CORROSION PATENTS Available to Purchase

Dielectric compositions with high dielectric constant, low electrical losses, high softening point and resistance to moisture and corrosive atmospheres are obtained by polymerising or copolymerising a vinyl compound containing sulphur, in a position where it is chemically and electrically stable, e.g. vinyl diphenyl sulphide, vinyl benzothiophene, vinyl oxazole, etc., or compounds in which there is oxygen present in a heterocyclic ring in which there is a vinyl substituted carbon atom, e.g. vinyl pyrane, vinyl furane, vinyl coumarone, etc. These substances are used for the production of wrapping materials, particularly for food packaging. Suitable plasticisers are given.—U.S. Pat. 2,636,022, Sprague Electric Co., L. A. Brooks, M. Markarian and M. Nazzewski.