Abstract: A process for preparing a predispersed fiber composition useful for dispersing discontinuous fibers into a rubber or plastic polymer compound is disclosed which comprises mixing at least about 15 percent by weight of a pourable binder composition with up to about 85 percent by weight of discontinuous fibers at a temperature of from about 40.degree. C. to about 150.degree. C. until a homogeneous predispersed fiber composition is obtained. The binder composition comprises from about 50 to 100 percent by weight of a rubber or plastic polymer, from 0 to about 50 perecnt by weight of a plasticizer or peptizer for the polymer, and from 0 to about 45 percent by weight of critical chemical additives, and is pourable at ambient tmeperature or becomes pourable upon being heated to a temperature of up to about 135.degree. C. and has a Brookfield viscosity of less than about 1,300,000 centipoises at the temperature at which it is pourable.

Abstract: A rubber composition comprising a highly unsaturated rubber, a magnesium compound capable of donating electrons and a carboxylated cobalt oxy metal complex comprising at least one metal atom selected from Groups IIIA, IIIB, IVA, IVB, VA and VB of the Periodic Table, at least one cobalt atom, said metal and cobalt atoms being linked through oxygen atoms, at least one acyloxy radical attached to a cobalt atom, and any residual valences of said complex being satisfied by acyloxy, aryloxy or alkoxy radicals.