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Abstract

A process for the production of propylene/1-butene copolymers comprising: reacting propylene and 1-butene monomers in the presence of a catalyst system comprising: (a) a solid supported catalyst component is prepared by the method comprising: (i) co-comminuting magnesium halide support base and aluminum trihalide in a molar ratio from about 8:0.5 to about 8:3 in the absence of added electron donor; and (ii) then co-comminuting the product of step (i) in the absence of added electron donor with sufficient titanium tetrahalide to provide a molar ratio of magnesium halide to titanium tetrahalide from about 8:0.1 to about 8:1.0. (b) a trialkylaluminum co-catalyst, having from 1 to 9 carbon atoms in each alkyl group in an amount such that the Al/Ti ratio is between about 50:1 and about 500:1. (c) an alkoxy silane component of the formula R.sub.n Si(OR').sub.4-n where n=1-3, R=aryl or alkyl and R'=C.sub.1-3 alkyl in a sufficient quantity such that the molar ratio of organoaluminum co-catalyst to alkoxy silane is in the range from about 20:1 to about 45:1. said copolymer being characterized by a propylene content of 25 to 50 wt%, a 1-butene content of 75 to 50 wt% and a tensile strength of at least 300 psig.

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First Claim