procedures for the separation of mixtures of different aluminiumtrialkyle with different chain length alkylresten or disproportionierung, at least one of aluminum alkylverbindung with mutually different alkylresten

摘要

Mixtures of trialkyl aluminium compound (the term alkyl includes alkenyl) are separated by taking up at least a part thereof into an inert atmosphere under super-critical conditions, and separating compounds therefrom by depressurization and/or increase in temperature. Specified gases are ethylene and ethane which may be used at temperatures up to 50 DEG C. above their critical temperatures. The mixture may be fractionated in the gas phase in an exchange zone, and separated on leaving the zone. An apparatus is described. The process is similar to that of Specification 1,057,911. Trialkyl aluminium compounds with identical groups may be separated from those having different groups, e.g. tributyl- and trioctenyl-aluminium from dibutyloctenyl aluminium by the process. Compounds having C4-C9 groups may be removed from growth reactions by the process, enabling compounds of anti-statistical chain length distribution to be obtained. The separated C4-C9 compounds may be returned to an earlier stage of the growth reaction.