GB1104665A - Polymer moulding compositions - Google Patents

Abstract

A solid polymer moulding composition comprising a copolymer of propylene comprises at least 55% by weight of propylene monomer units, monomer units of a second component which is a linear 1-olefine having 4 to 18 carbon atoms in an amount up to 35% by weight, and having dispersed throughout the composition units of a third component which is an alpha-olefine, which as a homopolymer has a crystalline melting point above 180 DEG C., and is present in the composition in an amount of up to 10% by weight. The composition is made by bringing propylene, the second and third components into contact with an alpha-olefin polymerization catalyst, preferably stereospecific. The catalyst is preferably "pretreated" i.e. a catalyst which has been treated with one or more monomers at high catalyst concentration and subsequently used at lower catalyst concentration for a further polymerization. The third component may be polymerized before or subsequent to the polymerization of the other monomers. The catalyst is preferably TiCl3 activated by an organoaluminium compound. The TiCl3 may be obtained by reducing TiCl4 with an aluminium alkyl sesquichloride. The second monomer may be butene-1, octene-1, or ecened-1. The third component may be 3-methyl-pentene-1, 4,4-dimethylpentene-1, vinylcyclohexane, or 3-methyl-butene-1. The polymeric compositions may be recovered from the polymerization reaction by conventional techniques. The compositions may be compounded with heat and light stabilizers, fillers, antioxidants, antistatic agents, carbon black, pigments, flame retardant materials and other polymers such as high or low density polythene, polypropylene and butyl rubber.