| abstract |
A supported titanium catalyst is produced by cogrinding, in combination, a magnesium halide, tetravalent titanium halide, organic acid ester, and an organic halogen compound. The resulting supported titanium catalyst, when employed as a titanium component with an organo aluminum catalyst component for the catalyst system in a process for stereoregular polymerization of α-olefins, produces high polymerization activity and unexpectedly high stereoregular polymer yielding ratios. |