PREPARATION OF ISOBUTENE OLIGOMER

PURPOSE:To prepare the titled compound, in high conversion of isobutene and low conversion of 1-butene, in high yield, by the catalytic reaction of a 4C hydrocarbon mixture containing isobutene using a catalyst obtained by the calcination of a silica-alumina catalyst at a specific temperature. CONSTITUTION:Isobutene oligomer is prepared by the catalytic reaction of a 4C hydrocarbon mixture containing isobutene (a 4C hydrocarbon mixture containing isomers of butane and butene and obtained as the by-product of olefin preparation by the thermal cracking of a petroleum fraction such as naphtha) at 50- 150 deg.C, preferably 70-100 deg.C, using a catalyst obtained by the calcination of a silica-alumina catalyst in air at 600-950 deg.C for 1-10hr, preferably 800-900 deg.C for 3-5hr. USE:Raw material for the oxo synthesis of nonyl alcohol and p-octylphenol, additive of gasoline, intermediate of the solvent for wet-type copying and the solvent for the preparation of high-pressure polyethylene, etc.