Patent ID: 7208435

Claim:
A solid catalyst component (A1) prepared by contacting (a1) a dialkoxy magnesium compound, (b) a tetravalent titanium halide, and (c) an electron donor compound of the following formula (1), R 1 R 2 C(COOR 3 ) 2 (1) wherein R 1 and R 2 individually represent a branched alkyl group having 3–20 carbon atoms including one or more secondary, tertiary, or quaternary carbon atoms, and R 3 individually represents a linear or branched alkyl group having 1–20 carbon atoms, cycloalkyl group, phenyl group, vinyl group, allyl group, or aralkyl group, by suspending components (a1), (b) and (c) in (d) an aromatic hydrocarbon having a boiling point in the range of 50–150° C.; wherein said catalyst component (A1) is suitable for polymerization of olefins.