GB560980A - Improvements relating to polymerisation processes - Google Patents

Abstract

A polymerization mixture comprising one or more olefinic hydrocarbons and a catalyst-quenching agent which is in the solid inactive condition at the low polymerization temperature is prepared at a temperature at or near the polymerization temperature, a Friedel-Crafts catalyst is added, the mixture is polymerized and then warmed up to a temperature at which the catalyst-quenching agent melts and becomes active, so as to destroy the activity of the catalyst at that temperature. The olefin may comprise isobutylene, propylene, methyl ethyl ethylene, 3 - methylbutene - 1 or 2 - methylpentene-1, with or without a diolefin such as butadiene, isoprene, 2,3-dimethyl butadiene-1,3 or 1,3-pentadiene. The catalyst-quenching agent may be ammonia, methylamine, ethylamine, n-propylamine, tert-butylamine, methyl alcohol, ethyl alcohol, isopropyl alcohol or tertamyl alcohol. Examples describe polymerizing: (1) iso-butylene in liquid ethylene using gaseous boron fluoride as catalyst and ammonia as quenching agent; (2) isobutylene in solid carbon dioxide using as catalyst gaseous boron trifluoride and as quenching agent ammonia; (3) isobutylene and butadiene in liquid ethylene, using as catalyst aluminium chloride in methyl chloride and as quenching agent ammonia; (4) isobutylene and 2,3-dimethyl butadiene-1,3 in liquid ethylene using aluminium chloride in carbon disulphide as catalyst and ammonia as quenching agent. The residual reaction products of the catalyst and quenching agent are removed from the polymer by washing with water. Specifications 513,521, 523,248 and 565,974 as open to inspection under Sect. 91, are referred to.