Polyorganosilsesquioxane supported metallocene catalysts

A process for the preparation of a supported metallocene catalyst comprising:

• a. providing a particulate catalyst support material in the form of a polyorganosilsesquioxane powder having an average particle size within the range of 0.3–20 microns;
• b. contacting said particulate support material with an alumoxane cocatalyst;
• c. providing a dispersion in an aromatic hydrocarbon solvent of a stereospecific metallocene incorporating a metallocene ligand structure having two sterically dissimilar cyclopentadienyl ring structures coordinated with a central transition metal atom;
• at least one of said cyclopentadienyl ring structures being a substituted cyclopentadienyl group which provides an orientation with respect to said transition metal atom which is sterically different from the orientation of the other cyclopentadienyl ring structure with respect to said transition metal atom, and both of said cyclopentadienyl ring structure being in a relationship with each other providing a stereorigid relationship relative to said coordinating transition metal atom to prevent rotation of said ring structures;
• d. mixing said dispersion and the product produced by the reaction of said particulate catalyst support material and alumoxane co-catalyst for a period of time to allow said metallocene to become reactively supported on said particulate support support to form a supported catalyst;
• e. recovering said supported catalyst from said aromatic hydrocarbon solvent.

A process for the preparation of a supported metallocene catalyst comprising:

• a. providing a particulate catalyst support material in the form of polyalkylsilsesquioxane powder having an average particle size within the range of 0.3–20 microns;
• b. contacting said particulate support material with an alkyl alumoxane cocatalyst to produce a reaction product of said polyalkylsilsesquioxane powder and said alkyl alumoxane cocatalyst and a trialkyl aluminum;
• c. providing a dispersion in an aromatic hydrocarbon solvent of a stereospecific metallocene incorporating a metallocene ligand structure having two sterically dissimilar cyclopentadienyl ring structures coordinated with a central transition metal atom;
• at least one of said cyclopentadienyl ring structures being a substituted cyclopentadienyl group which provides an orientation with respect to said transition metal atom which is sterically different from the orientation of the other cyclopentadienyl ring structure with respect to said transition metal atom, and both of said cyclopentiadienyl ring structure being in a relationship with each other providing a stereorigid, relationship relative to said coordinating transition metal atom to prevent rotation of said ring structures;
• d. mixing said dispersion and the reaction product produced by the reaction of said particulate catalyst support material and alkyl alumoxane cocatalyst for a period of time to allow said metallocene to become reactively supported on said particulate support support to form a supported catalyst;
• and
• e. recovering said supported catalyst froin said aromatic solvent.

A supported metallocene catalyst composition comprising:

• a. a particulate support comprising spheroidal polyorganosilsesquioxane support particles having an average diameter within the range of 0.3–20 microns and having an alkylalumoxane co-catalyst supported on the surface of said polyorganosilsesquioxane support particles by reaction of said alkylalumoxane co-catalyst and said polyorganosilsesquioxane support;
• and
• b. a stereospecific metallocene supported on said particulate support and incorporating a metallocene ligand structure having two sterically dissimilar cyclopentadienyl ring structures coordinated with a central transition metal atom;
• at least one of said cyclopentadienyl ring structures being a substituted cyclopentadienyl group which provides an orientation with respect to said transition metal atom which is sterically different from the orientation of the other cyclopentadienyl ring structure with respect to said transition metal atom, both of said cyclopentadienyl ring structure being in a relationship with each other providing a stereorigid relationship relative to said coordinating transition metal atom to prevent rotation of said ring structures.