PRODUCTION OF POLYOLEFIN

PURPOSE:To obtain a polyolefin excellent in powder properties, etc., by polymerizing an olefin in the presence of a catalyst comprising a solid catalyst component prepared in a specific manner and an organometallic compound. CONSTITUTION:A homogeneous solution containing (A) metallic magnesium and an organic hydroxy compound (e.g., methanol) or an oxygen-containing organic compound of magnesium (e.g., magnesium ethylate) and (B) an oxygen-containing organic compound of titanium is reacted with an organoaluminum compound, then with a silicon compound, and finally with an aluminum halide compound to prepare a solid catalyst component. An olefin is polymerized in the presence of a catalyst comprising the above solid catalyst component and a catalyst component selected from among organometallic compounds of a Group I a, IIa, IIb, IIIb, or IVb metal of the periodic table (e.g., ethylaluminum sesquichloride).