GB799850A - Improvements in or relating to the polymerization of alpha olefins - Google Patents

Abstract

<PICT:0799850/III/1> A catalyst for polymerizing olefines is made by mixing a titanium compound and a vanadium compound dissolved in an inert hydrocarbon solvent with a metal hydride or metal compound containing a hydrocarbon radical directly attached to the metal. The metal hydride or alkyl effects a reducing action. compounds specified are: TiCl4, Ti(O-alkyl)2Cl2; UO(O-isopropyl)3, ammonium vanadate; UCl4, UOCl3; aluminium tri-hexyl or tri-isobutyl lithium aluminium tetra heptyl or tri-isobutyl chloride, tri-tetra butyl. Hydrocarbon solvents are decahydronaphthalene, cyclohexane, benzene, or toluene. Preferably the metal hydride or alkyl is added to the solution containing both vanadium and titanium compounds at 0 DEG to 300 DEG C. Olefines polymerized include ethylene, vinyl and vinylidene hydrocarbons, and may be effected at 0 DEG to 300 DEG C. or below 0 DEG C., and at 1 to 200 atmospheres. In the flow sheet, vessels band 7 containing respectively the titanium and vanadium compounds dissolved in cyclohexane feed together into a mixing tube 10 to which the aluminium compound, also dissolved in cyclohexane, added from a vessel 8. The reaction product enters a pressure vessel 1, to which ethylene and cyclohexane is admitted through an inlet 2. Polymerization is carried out continuously and the product is mixed with methanol and flows through a valve 5 to a receiver 14 where the methanol is recovered. The polyethylene is then re-plurried with methanol to wash out catalyst ash, the content of which is the air-dried product is reduced to a few hundred pacts per million. A further reduction may be effected by melting the polymer in the presence of methanol under pressure. No references made to co-polymers or cross-linking.ALSO:A catalyst for polymerizing olefines is made by mixing a titanium compound and a vanadium compound dissolved in an inert hydrocarbon solvent, with a metal hydride or metal compound containing a directly linked hydrocarbon radical. The metal hydride or alkyl effects a reducing action. Compounds specified are TiCl4, Ti (O alkyl)2Cl2; VCl4, VOCl3, VO (O isopropyl)3, ammonium vanadate; lithium alkyls aluminium tri-hexyl or triisobutyl, lithium aluminium tetra heptyl or triisobutyl chloride, lithium aluminium hydride with cyclohexene and tin tetra butyl. Hydrocarbon solvents are deca hydronaphthalene, benzene, toluene or cyclohexane. Preferably an aluminium compound is added to the solution of <PICT:0799850/IV (a)/1> mixed vanadium and titanium compounds at 0 DEG to 300 DEG C. Olefines polymerized include ethylene and vinyl and vinylidene hydrocarbons, and polymerization may be effected at 0 DEG to 300 DEG C. or below 0 DEG C., and at 1 to 200 atmospheres. In the flow sheet, vessels 6 and 7 containing respectively the titanium and vanadium compounds dissolved in cyclohexane feed together into a mixing tube 10 to which the aluminium compound also dissolved in cyclohexane, is added from a vessel 8. The reaction product enters a pressure vessel 1, to which ethylene and cyclohexane is admitted through an inlet 2. Polymerization is carried out continuously and the product is mixed with methanol and flows through a valve 5 to a receiver 14 where the methanol is recovered. The polymer is re-slurred with methanol to wash out the catalyst ash, the content of which in the air-dried product is reduced to a few hundred parts per million. A further reduction may be effected by re-melting the polymer in the presence of methanol under pressure. No references made to copolymers or cross linking.