Polymerization of propylene with a catalyst prepared in situ
AssigneeE. I. Du Pont de Nemours and Company
InventorsEdward G. Howard, Jr., Christos Sarafidis
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Abstract
In the production of elastomeric polypropylene by polymerizing propylene in the presence of a catalyst system which is the reaction product of a metal oxide and and an organometallic compound of Zr, Ti or Hf under conditions such that the reaction medium contains liquid propylene, a fluid, mobile slurry of polypropylene in propylene is formed by mixing the components of the catalyst system together in the presence of the propylene to be polymerized.
Claims10
In the method of producing elastomeric polymers of propylene and up to about 5 mole % of another .alpha.-olefin by the polymerization of propylene in the presence of a catalyst system which is the reaction product of a metal oxide and an organometallic compound of the formula (RCH.sub.2).sub.4 M, where M is Zr, Ti or Hf;
- R is aryl, aralkyl, tertiary alkyl or trialkylsilyl;
- the aforementioned alkyl groups are C.sub.1 -C.sub.12 ;
- and the RCH.sub.2 group has no hydrogen bonded to the carbon which is beta to M;
- at a temperature of 20.degree. to 100.degree. C. and a pressure of 147 psi up to 5000 psi (0.1-34.5 MPa) such that the reaction medium contains liquid propylene, the improvement which comprises mixing the components of the catalyst system together, whereby they react to form said catalyst system, in a solvent consisting principally of liquid propylene and the elastomeric polymer is produced as a mobile slurry in said liquid propylene.
Dependencies are inferred from the claim text.