GB902385A - Improvements in or relating to copolymerization process - Google Patents

Abstract

In a process of copolymerizing ethylene with a second linear 1-olefin ethylene and the second olefin are passed into an inert organic liquid solvent therefor and for the copolymer produced, at a temperature from 0 DEG to 125 DEG C., in the presence of a catalyst dissolved in the solvent and the ratio of ethylene to the second olefin dissolved in the solvent is maintained constant throughout the copolymerization reaction, the catalyst being formed by mixing an aluminium compound of formula R3Al where R is a hydrocarbon radical, with a vanadium compound having the formula VOYn in which Y is an alkoxide or acetylacetonate group and n is 3 when Y is an alkoxide group and 2 or 3 when Y is an acetylacetonate group. The preferred olefin comonomers are propylene and butene-1. Specified aluminium compounds are those in which R is methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert. butyl amyl, isoamyl, hexyl, isohexyl, octyl, 2-ethyl-hexyl, cyclohexyl, phenyl or benzyl, particularly triethyl and triisobutyl aluminium. Specified vanadium compounds are trimethyl, triethyl, tri(n-propyl), tri(n-butyl) and tri(tert. butyl) orthovanadates and vanadium oxy diacetylacetonate and triacetylacetonate. Specified solvents are hydrocarbons and chlorinated hydrocarbons such as hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, cyclohexane, methylcyclohexane, carbon tetrachloride, chlorobenzene and dichlorobenzene. The copolymerization may be effected continuously and the catalyst formed in situ by the addition of its components. Using carbon tetrachloride as diluent elastomeric ethylene-propylene copolymers may be prepared, which copolymers may be chlorinated or sulphochlorinated without isolation from the diluent.