GB509463A - Improvements relating to the production of olefin polymers - Google Patents

Abstract

509,463. Polymerizing olefines. STANDARD OIL DEVELOPMENT CO. Aug. 4, 1938, No. 23049. Convention date, Oct. 2, 1937. [Class 2 (iii)] . Linear polymers of olefines, especially isobutylene, iso-amylene and like iso-olefines, of molecular weight above 3,000 are produced by mixing the olefine with a preformed solution of a solid metal halide of the Friedel-Crafts' type in a saturated halogenated aliphatic hydrocarbon having less than 5 carbon atoms, and at least 1 hydrogen atom, and which is liquid at the reaction temperature, the latter being kept below - 10‹ C. Alkyl halides, e.g. methyl and ethyl bromides, iodides, and especially chlorides are preferably used. The catalyst solution is preferably prepared at low temperatures, below 0‹ C., and contains .1-2 per cent of the metal halide. It may be precooled to the reaction temperature, e.g. to about -100‹ C. by dilution with liquid ethylene, and added to the liquid olefine in an amount of about .01 to 2 per cent. Cooling may be effected by addition of solid CO2 or liquefied inert hydrocarbons which evaporate under a predetermined pressure. The catalyst is hydrolysed, the polymer dissolved, e.g. in naphtha, and recovered. Examples contrast the treatment of isobutylene with aluminium chloride alone or dissolved in the known solvents (ethyl ether, pyridine, benzoyl chloride, trichlorbenzene, and nitromethane) with the polymerization using solutions of aluminium chloride in methyl, ethyl, isopropyl, butyl or secondary butyl chlorides, ethylene dichloride, chloroform, ethyl bromide, and methyl iodide, or of aluminium bromide in chloroform. Temperatures down to about - 100‹ C. are used, the polymers having molecular weights up to 115,000. Specification 472,553 is referred to.