GB1172581A - Polymerisation of Ethylene and Alpha-Olefins - Google Patents

Abstract

1,172,581. Olefin polymerization. INTERNATIONAL SYNTHETIC RUBBER CO. Ltd. 2 Feb., 1968 [2 Feb., 1967], No. 5137/67. Addition to 1,077,397 and 1,127,590. Heading C3P. Ethylene and an α-olefin and optionally not more than 10% of a third monomer are copolymerized using a catalyst system comprising: (a) a siloxy compound of vanadium, titanium or zirconium; (b) an aluminium trihalide or dihalohydride; (c) an alkyl, aryl or aralkyl organo lithium compound; (c) being brought into contact with (b) when (a) or at least one monomer is also present. Preferred (a) components are tetrakis-(trimethylsiloxy) titanium (IV) and vanadyl tris-(trimethyl siloxane), and the other preferred components are aluminium tribromide and n-butyl lithium. The mole ratio of (b) to (a) may be 8-50: 1, and of (b) to (c), 0.25-5: 1. The α-olefin may be ethylene or propylene and the termonomer a non-conjugated diene such as dicyclopentadiene. Preferably, the reaction is carried out at - 30‹ to + 150‹ C. and in a hydrocarbon solvent. In the Examples, (1) ethylene and propylene are copolymerized, (2) ethylene, propylene and dicyclopentadiene are terpolymerized and (3) ethylene is homopolymerized, in cyclohexane/ hexane using as catalyst, vanadyl tris-(trimethyl siloxane), AlBr 3 and n-BuLi, this reaction being terminated using methanol. In a further example, (1) above is repeated using as the siloxy component tetrakis-(trimethylsiloxy) titanium (IV). The polymer is isolated using methanol containing an antioxidant.