Abstract: A method of preparing ethylene polymers which comprises polymerizing ethylene, or ethylene and one or more .alpha.-olefins other than ethylene in the presence of a composite catalyst which catalyst comprises:(A) a solid composition prepared by depositing one or more chromium compounds and one or more metal compounds other than said chromium compounds onto an inorganic oxide support material and then calcining the resulting solid; and(B) one or more organometallic compounds that are each independently represented by the following general formula:MR.sup.1 aR.sup.2 bR.sup.3 cwherein M is a metal of Group I, II or III of the periodic table and the R.sup.1, R.sup.2 and R.sup.3 moieties are each independently hydrogen, a hydrocarbon radical of C.sub.1 -C.sub.14, or an alkoxy group of C.sub.1 -C.sub.

Abstract: The present invention relates to a process for preparing aluminoxane which comprises reacting an organoaluminum compound and water in a solvent system containing solvent having a higher boiling point than that of the organoaluminum compound, or reacting an organoaluminum compound and water, and then adding a solvent system containing the solvent having a higher boiling point than that of the organoaluminum compound to the reaction mixture; and thereafter condensing the resulting reaction mixture under atmospheric pressure or reduced pressure.

Abstract: A process for producing styrene-based polymers having mainly syndiotactic configuration in the presence of a catalyst comprising (A) a titanium compound and (B) a contact product of a methyl group-containing organoaluminum compound and water, wherein the contact product (B) has a high magnetic field component of not more than 50% in the methyl proton signal region due to an aluminum-methyl group (Al--CH.sub.3) bond as determined by the proton nuclear magnetic resonance absorption method.According to this process, styrene-based polymers having mainly syndiotactic configuration can be efficiently and economically produced.