Verfahren zur Herstellung von linearen alpha-Olefinen des Wachsbereiches

摘要

1288793 Preparation of wax range olefins ESSO RESEARCH & ENG CO 24 Nov 1969 [5 Dec 1968] 57363/69 Heading C3P Wax range (i.e. C 22 -C 200 ) linear alpha olefins are prepared by polymerizing ethylene, in the presence of a diluent, at a temperature and pressure sufficient to oligomerize the ethylene while suppressing copolymerization reactions, the temperature being below 75‹ C., by contact with a pi base-modified catalyst system comprising the reaction product of a transition metal halide of the formula TiX 4 , TiX 3 OR1 or TiX 3 OOCR1 wherein X is Cl or Br and R1 is alkyl, aryl, aralkyl, or cycloalkyl; an aluminium alkyl halide chosen so that the organoaluminium component of the reaction product is a compound of the formula AlR n X 3-n wherein n is less than 2, X is Cl, Br or I and R is alkyl, aralkyl or cycloalkyl; and a pi base compound to increase the number average molecular weight of the product olefins over and above that attributable to the use of the unmodified catalyst at otherwise identical conditions. The pi base modifier is preferably an aromatic hydrocarbon containing substituents selected from alkyl, aryl, alkaryl, aralkyl, cycloalkyl and alkoxy or may be a heterocyclio analogue e.g. pyridine or thiophene. In the examples the catalysts used are prepared by reaction in n-heptane of TiCl 4 , a mixture of AlEtCl 2 and AlEt 2 Cl and a pi base modifier selected from benzene, xylene, naphthalene, anthracene, mesitylene, durene, isodurene, hexamethyl benzene, and thiophene. Ethylene is oligomerized using these catalysts and n-heptane, chlorobenzene or xylene as a diluent and the reaction is stopped by addition of isopropanol.