UN PROCEDIMIENTO PARA OLIGOMERIZAR ETILENO A ALFA-OLEFINAS NORMALES

摘要

Ethylene is oligomerized by reacting ethylene in methanol under oligomerization conditions in contact with a nickel ylide defined by the following Formula I: wherein R1, R2, R3, R4, R5, R6, R7 and R8 are either alike or different members selected from the group consisting of hydrogen, alkyl radicals having from about one to about 24 carbon atoms, preferably from about one to about 10 carbon atoms; aryl radicals having from about six to about 20 carbon atoms, preferably from about six to about 10 carbon atoms; alkenyl radicals having from about two to about 30 carbon atoms, preferably from about two to about 20 carbon atoms; cycloalkyl radicals having from about three to about 40 carbon atoms, preferably about three to about 30 carbon atoms; aralkyl and alkaryl radicals having from about six to about 40 carbon atoms, preferably from about six to about 30 carbon atoms; a halogen radical selected from the group consisting of fluorine, chlorine, bromine and iodine, preferably chlorine; a hydroxyl group; an alkoxy or aryloxy group; and a hydrocarbyl group, such as defined above, carrying halogen, hydroxyl or alkoxy or aryloxy; provided that at least one, preferably from about one to about four, of each of R1 to R8 is a sulfonato group (-SO3-) or an alkyl, aryl, alkenyl, cycloalkyl, aralkyl or alkaryl group carrying a sulfonato group; M is sulfur or oxygen, preferably oxygen; E is phosphorus, arsenic, antimony or nitrogen, preferably phosphorus; and F is phosphorus, arsenic or antimony, preferably phosphorus. There is thus obtained a reaction product containing (A) a methanol phase having dissolved therein the nickel ylide catalyst and (B) an alpha olefin phase. These two phases are then separated from each other to recover the alpha olefin phase. The use of methanol as the solvent medium causes the reaction product to resolve itself into two phases, an upper phase containing most of the oligomer product and a lower methanol phase carrying the catalyst dissolved therein. This permits easy separation of the product from the reaction mixture and also permits effective recycle of methanol with dissolved catalyst. The product obtained contains normal alpha olefins having from about four to about 100 carbon atoms, generally from about four to about 50 carbon atoms.