To obtain a polyolefin of improved stereoregularity by using a catalyst comprising a solid catalyst component containing a dialkoxymagnesium, a halogen-containing titanium compound, an aromatic dicarboxylic diester, a carbonyl compound and an aluminum compound, an organoaluminum compound and an organosilicon compound.
A halogen-containing titanium compound (e.g. TiCl4) is brought into contact with a dialkoxymagnesium (e.g. dimethoxymagnesium) to form a solid product. Next, an aromatic dicarboxylic acid diester (e.g. diethyl phthalate) and a carbonyl compound represented by formula I (A1 is R1-(O)x1; A2 is R2-(O)x2; A3-(O)x3; A4 is H or the like; R1 to R4 are each a 1-20C hydrocarbon group; and x1 to x4, y4 and z1 are each 0, 1 or the like) and an aluminum compound (e.g. AlCl3) are added to obtain a solid catalyst component. A highly crystalline olefin polymer is obtained by using the solid catalyst component, an organoaluminum compound (e.g. triethylaluminum) and an organosilicon compound (e.g. tetraalkoxysilane) in a specified molar ratio.
NISHIYAMA ISA
SAITO MASAYOSHI
