Catalyst and process for the polymerization of alpha-olefins

A process for the polymerization of propylene or a mixture of propylene and ethylene or propylene and another C.sub.4 to C.sub.8 alpha-olefin to form a highly crystalline polymeric substance, said process involving contacting under polymerizing conditions said propylene or said mixture with a catalyst comprising:

• (a) an alkylaluminum compound selected from the group consisting of a trialkylaluminum, a mixture of a trialkyl aluminum and an alkylaluminum dichloride or dibromide, a mixture of a trialkyl aluminum and a dialkylaluminum chloride or bromide and a dialkylaluminum chloride or bromide;
• (b) an effective amount up to about 10 mol percent hydrogen sulfide based upon the amount of alkylaluminum compound present;
• (c) an activated titanium trichloride;
• and
• (d) an effective amount of an additive which is selected from the group consisting of trihydrocarbylphosphites, sterically hindered, lower alkyl substituted, cyclic, tertiary amines and sterically hindered, lower alkyl substituted, cyclic, amine oxides;
• said amounts effective to result in a substantial reduction of alkane solubles while not seriously affecting the total yield of said polymeric substance.

A process for the polymerization of propylene or a mixture of propylene and ethylene or propylene and another C.sub.4 to C.sub.8 alpha-olefin to form a highly crystalline polymeric substance, said process involving contacting under polymerizing conditions said propylene or said mixture with a catalyst comprising:

• (a) an alkylaluminum compound selected from the group consisting of a trialkyl aluminum, a mixture of a trialkyl aluminum and an alkylaluminum dichloride or dibromide, a mixture of a trialkyl aluminum and a dialkylaluminum chloride or bromide and a dialkylaluminum chloride or bromide, said alkylaluminum compound having been treated with an effective amount, up to about 10 mol percent based on the amount of said alkylaluminum compound, of hydrogen sulfide;
• (b) an activated titanium trichloride;
• and
• (c) an effective amount of an additive which is selected from the group consisting of trihydrocarbylphosphites, sterically hindered, lower alkyl substituted, cyclic, tertiary amines, and sterically hindered, lower alkyl substituted, cyclic, amine oxides;
• said amounts effective to result in a substantial reduction of alkane solubles while not seriously affecting the total yield of said polymeric substance.