GB887544A - Process for polymerising propylene - Google Patents

Abstract

Propylene is polymerized in the presence of a catalyst comprising a component consisting of the part insoluble in hydrocarbons of the reaction product formed between a hydride or an organo-metallic compound of a metal of Group IV, V, or VI, of the Mendeleeff Periodic Table of Elements, an inorganic compound of a polyvalent metal of Group IV, or VI, and a halide of an element of Group III or V, and a second component consisting of an organo-metallic compound of an element of Group III, or Group V. The three substances used in the formation of the first component of the catalyst are preferably selected respectively from alkyl compounds of tin, lead, antimony, and tellurium, halides of titanium, zirconium, and chromium, and halides of aluminium, boron, vanadium, and antimony D. The second component of the catalyst is preferably selected from aluminium boron, or antimony. The polymerization reaction is generally effected in an inert solvent, at a temperature between 0 DEG C. and 120 DEG C., and under a partial pressure of propylene below 40 kgr./sq. cm. In Example 1, the catalyst is formed by reacting aluminium chloride, tetrabutyl tin, and titanium tetrachloride, separating the precipitate and mixing it with aluminium triethyl. In Example 2, the catalyst is made in a similar manner to Example 1, but the substances are used in different proportions. The polypropylene may be separated into fractions by solvent extraction. Specifications 789,781 and 795,182 are referred to.