To obtain a highly active catalyst excellent in dimer selectivity, useful esp. for propylene dimerization, by mutual contact between a specific nickel compound, a specific phosphorus compound, an organoaluminum compound and a sulfonic acid compound.
This catralyst is obtained by mutual contact between (A) a nickel compound, i.e., an organic acid nickel salt (e.g. nickel acetate, nickel naphthenate), inorganic acid nickel salt (e.g. nickel chloride, nickel nitrate) or nickel complex compound [e.g. bis (acetylacetonato)nickel, bis(1,5- cyclooctadiene)nickel], (B) an organophosphorus compound of the formula, PX1X2X3 (X1-X3 are each H, a halogen or 1-12C hydrocarbon resideue) (e.g. trimethylphosphine), (C) an organoaluminum compound (e.g. diethylaluminum chloride), and (D) a shlfonic acid compound [e.g. (thifluoro)methanesulfonic acid].
NAKANO TAKASHI
TAJIMA YOSHIO
MATSUURA KAZUO
