HIGH TENSILE STRENGTH AMORPHOUS 1-BUTENE/PROPYLENE COPOLYMERS

摘要

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 8:10; (b) a trialkylaluminum co-catalyst, having from 1 to 9 carbon atoms in each alkyl group in an amount such that the AI/Ti ratio is between about 50:1 and about 500:1; (c) an alkoxy silane component of the formula R n Si(OR')4-n where n = 1-3, R = aryl or alkyl and R' = C1-3 alkyl in a sufficient quantity such that the molar ratio of organoaluminum co-catalyst to alkoxy silane is in the range from about20:1 to about 45 :1. Said copolymer being characterized by a propylene content of 25 to 50 wt %, a 1-butene content of 50 to 75 wt % and a tensile strength of at least 300 psig.