GB893336A - Process for the production of a polyolefin - Google Patents

Abstract

893,336. Olefin polymerization. RUHRCHEMIE A.G. July 16, 1958 [Aug. 12, 1957; March 24, 1958], No. 22888/58. Class 2(6) An olefin, e.g. ethylene, is polymerized at a pressure of below 100 Kg./squ. cm. and at a temperature up to 100‹C. in the presence of a catalyst consisting of or comprising a mixture of an organometallic compound and a compound of a metal of subgroups A of groups 4 to 6 of the Periodic Table, and in the presence of an inert liquid reaction medium, an organic peroxide being added to the catalyst before or during the polymerization. The organometallic compound may be an aluminium alkyl, e.g. triethyl or triisobutyl, or an aluminium alkyl halide, e.g. aluminium monoethyldichloride, while the other metal compound may be a titanium halide, e.g. the tri and/or tetrachloride. The peroxide may be lauroyl, benzoyl, diacetyl, t-butyl, di-t-butyl or cyclohexanone peroxides or cumene hydroperoxide. The inert liquid may be a Diesel oil obtained by the Fischer-Tropsch synthesis or a hydrogenated propylene tetramer. The peroxide may be added stepwise during the polymerization or may be added to all or individual components of the catalyst for a period prior to the polymerization. The peroxide may be added in a solution, e.g. in a mixture of aliphatic hydrocarbons and/or naphthenes and/or aromatics free from ethylenic unsaturation and may be treated before addition with a finely divided substance, e.g. calcium chloride, alumina, silica magnesium nitride or phosphorus pentoxide, capable of removing water and/or oxygencontaining organic compounds deleterious to the catalyst, while the ethylene and liquid medium used should be free from oxygen, a small controlled amount of air may be admitted to the polymerization reaction. Specifications 799,823 and 801,031 are referred to.