To provide a solid titanium catalyst component which can polymerize ethylene with a high activity and can produce an ethylene polymer excellent in particulate properties; a polymerization catalyst containing the same; and an ethylene polymerization method.
This catalyst component [I] is prepared by contacting a liquid magnesium compound (b) containing an organosilicon compound (a) having no active hydrogen atom with a liquid titanium compound (c), elevating the temperature of the resultant product (i) to 90-120°C, and keeping the product at that temperature and contains Mg, Ti, a halogen, and Si, the molar ratio of (Mg/Ti) being 3.0-4.0 and the content of Ti being 7.8 wt.% or higher. Compound (b) containing compound (a) is prepared by contacting 1 mol of a liquid magnesium compound with 0.2-0.4 mol of compound (a) for a time(t) defined by t>(3-(temp-50)/5) when the contact temperature(Temp) is 55°C or lower and for at least 1 hr when the contact temperature is higher than 55°C. The polymerization catalyst comprises component [I] and an organometallic compound [II]. Ethylene is (co)polymerized by using the catalyst.
YAMAMOTO KUNIO
NAKAYAMA YASUSHI
TSUTSUI TOSHIYUKI
