DE1545048

1,051,391. Polymerization catalysts. UNION CARBIDE CORPORATION. Sept. 3, 1963, No. 34673/63. Headings C3P and C3S. Mono-unsaturated olefins having from 2 to 10 carbon atoms are polymerized using as a catalyst a silylchromate containing a group having the formula:- wherein R is a hydrocarbon radical containing from 1 to 14 carbon atoms. Specified olefins are ethylene, propylene, butene-1, pentene-#, 3-methyl butene-1, hexene-1, 4-methyl pentene- 1, 3-ethyl butene-1, heptene- 1, octene-1, decene- 1, 4,4-dimethyl pentene-1, 3,4-dimethyl hexene- 1, 4-butyl octene-1, and 5-ethyl docene-1. A number of catalysts are specified of which those exemplified are bis-triphenylsilylchromate, polydiphenylsilylchromate, and bis-trimethylsilylchromate, the latter two being prepared by the condensation using chromium trioxide of diphenylsilanediol and hexamethylsiloxane respectivoly. Alkyl aluminium compounds may be used in conjunction with the silyl chromates and those exemplified are triethyl aluminium and diethyl aluminium chloride. The catalyst may be absorbed on a conventional insoluble inorganic carrier. Polymerization may be effected in an inert organic liquid or in bulk. Conventional polymer purification methods are used.