Process for producing olefin polymers

A supported catalyst component prepared by a process comprising

• (1) forming a solid product carrier in an inert atmosphere by
• (I) reacting (a) an organomagnesium compound of the formulae R.sup.6 MgX or R.sup.6.sub.2 Mg wherein R.sup.6 is an alkyl group, an aryl group, an aralkyl group, or an alkenyl group each having up to 8 carbon atoms and X is a halogen atom with (b) (i) an aluminum halide compound of the formula R.sub.n AlX.sub.3-n wherein R is an alkyl group, an aryl group, an aralkyl group, or an alkenyl group each having up to 8 carbon atoms, X is a halogen atom, and n is a number defined by 0.ltoreq.n<3 and/or (ii) a silicon halide compound of the formula R.sup.1.sub.m SiX.sub.4-m wherein R.sup.1 is an alkyl group, an aryl group, an aralkyl group, or an alkenyl group each having up to 8 carbon atoms, X is a halogen atom, and m is a number defined by 0.ltoreq.m<4 in a hydrocarbon solvent and/or an etherial solvent at a temperature of 0.degree. to 100.degree. C., in a former-to-latter molar ratio of 1:10 to 10:1 to form a solid product,
• (II) separating the resulting solid product from the reaction system and
• (III) washing the solid product with a hydrocarbon solvent to form a solid product carrier,
• (2)
• (I) heating a liquid ether complex of titanium trichloride in a hydrocarbon solvent at a temperature of about 25.degree. to about 150.degree. C. in the presence of said carrier to deposit titanium trichloride on the carrier, the amount of trivalent titanium atoms contained in the solid product being 3 to 20% by weight,
• (II) separating the resulting titanium trichloride-containing solid product form the reaction system, and
• (III) washing the solid product with a hydrocarbon solvent, and
• (3)
• (I) further reacting the titanium trichloride-containing solid product obtained above with titanium tetrachloride at a temperature of about 20.degree. to 150.degree. C.,
• (II) separating the resulting supported catalyst component from the reaction system, and
• (III) washing the supported catalyst component with a hydrocarbon solvent.