GB860641A - Improvements in or relating to the polymerization of ethylenically unsaturated hydrocarbons and catalysts therefor - Google Patents

Abstract

Olefines are polymerized using a catalyst composition (see Group III) formed by mixing, in the presence of a liquid diluent, a Group IVa metal halide with a combination of reducing agents comprising (1) a Group IIIb, IVb or Vb alkyl metal halide containing at least one alkyl and two halide groups and (2) a Group Ia, IIa or IIIb metal alkyl or aryl. The term "halide" is defined as including oxychlorides. Preferred liquid diluents are those which can serve as polymerization media and as solvents for the catalyst components, e.g. an inert hydrocarbon or liquid monomer. Polymerization may be effected batchwise or continuously preferably in a diluent such as cyclohexane, decane, xylene or toluene at temperatures from below O DEG to above 300 DEG C. and 1 to 200 atmospheres using 0.001 to 10% of the catalyst based on the weight of the monomer. In examples, ethylene or propylene is polymerized using catalyst compositions obtained by mixing the following ingredients in decahydronaphthalene: (a) TiCl4, C2H5AlB62, Mg(C5H5)2; (b) TiCl4, C2H5AlBr2, LiAl(C7H15)4; (c) TiCl4, (C4H9)2SnCl2, Mg(C6H5)2; and (d) TiCl4; (C4H9)2SbCl3, Mg(C6H5)2.ALSO:Catalyst compositions suitable for olefin polymerization reactions are formed by mixing the following three components in a liquid diluent: (i) a halide of titanium, zirconium or hafnium (including oxychlorides); (ii) a metal alkyl halide containing at least two halogen atoms and one alkyl group wherein the metal is aluminium, gallium, indium, thallium, germanium, tin, lead, antimony or bismuth; and (iii) a metal alkyl or aryl wherein the metal is one or more of the metals of Group Ia, IIa, and IIIb. The diluent may be an inert hydrocarbon or a liquid monomer. Components (ii) and (iii) are reducing agents for component (i) and should be added in sufficient amount to reduce the metal thereof to a valency state below three. The molar ratio of components (ii) plus (iii): (i) is preferably between 0.3 and 10 : 1 and the molar ratio of component (iii) : (ii) preferably exceeds 1. In examples the following catalyst compositions are used: (a) TiCl4, C2H5AlBr2, Mg(C6H5)2; (b) TiCl4, C2H5AlBr2, LiAl(C7H15)4; (c) TiCl4, (C4H9)2SnCl2, Mg(C6H5)2; and (d) TiCl4, (C4H9)2SbCl3, Mg(C6H5)2.