GB966788A - Improvements in or relating to novel catalyst system and olefin polymerization therewith - Google Patents

Abstract

966,788. Polymerization catalysts for 1-alkenes. AVISUN CORPORATION. April 19, 1962 [April 19, 1961; July 14, 1961), No. 15370/62. Heading C3P. A polymerization catalytic composition consists essentially of an alkyl aluminium compound selected from alkyl aluminium dihalides and alkyl aluminium sesquihalides, TiCl 3 , and a silicon compound selected from alkoxy silanes of the formula R 1 R 2 R 3 R 4 Si where R 1 is an alkoxy radical, R 2 , R 3 , and R 4 , are selected from alkoxy and hydrocarbon radicals, and alkyl disiloxanes. In the composition the mol ratio of the alkyl aluminium compound to TiCl 3 is from 0À2:1 to 10:1, and the atomic ratio of Al to active silane oxygen is from 5:4 to 10:1. The TiCl 3 component of the catalyst is essentially amorphous, i.e. it has been ball-milled until its crystallinity is below about 10 % of the original TiCl 3 , as determined by X-ray analysis. The catalytic composition is used for polymerizing 1-alkenes in the presence of an inert solvent or diluent. The Al compound may be ethyl, propyl or butyl aluminium dichloride, dibromide, or di-iodide. The silicon component may be trimethylethoxysilane, diethyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, triphenylethoxysilane, hexaethyldisiloxane, or hexamethyldisiloxane. In the examples the polymerization of propylene, and 4-methylpentene-1, is described. The polymers are recovered by conventional techniques, e.g. addition of methanol, and subsequently fractionated by solvent extraction techniques such as treatment with heptane and pentane. The catalyst may be "aged" before use. U.S.A. Specification 2,967,206 is referred to.