Process for the production of homogeneous polyolefin rubber-oil mixtures

Claim 1

A process for preparing a homogeneous liquid mixture consisting essentially of i) a normally solid polyolefin rubber copolymer of 30-65% by weight ethylene and correspondingly 70-35% by weight of at least one monoolefinically unsaturated hydrocarbon of 3-8 carbon atoms, optionally further including at least one copolymerizable unconjugated diene hydrocarbon of 6-16 carbon atoms in an amount which provides 0.5- 30 olefinic double bonds per 100 carbon atoms in the copolymer, sad polyolefin rubber copolymer having a molecular weight (M n ) of 25,000-100,000 as determined by the osmometric method and a Mooney viscosity ML 1 +4 at 100° C. of 30-180, dissolved in ii) 3-6 parts by weight, per part by weight of the copolymer, of an extending oil having a viscosity of 50-5000 centistokes at 20° C., a specific gravity of 0.84- 0.98 and a boiling point of 120°-370° C. at 5 Torr, which comprises: a. adding the polyolefin rubber in the form of loose, freely movable crumbs having a density of 0.1-0.4 g/cm 3 to said extending oil at a temperature of 160-210° C; and b. admixing the polyolefin rubber crumbs with the hot extending oil at an agitation speed of 5-100 cm/sec. and a shear velocity of 1-50 sec. - 1 for a period of time less than about 45 minutes but which time is sufficient to form a homogeneous liquid mixture wherein less than 1% by weight of the polyolefin rubber remains in the solid state.