Patent ID: 8426534

Claim:
A method for preparing impact polymers of propylene in a single reactor, that comprises the steps of: a) providing a support; b) depositing on the support a first metallocene catalyst component capable of producing an isotactic homopolymer of propylene having an isotactic index of at least 97% in order to produce a polypropylene matrix, wherein the first metallocene catalyst component is CMe 2 (3-t-butyl-5-methyl-cyclopentadienyl)(3,6-t-butyl-fluorenyl) zirconium dichloride or is represented by formula II R″(IndR 2 R 4 ) 2 MQ 2 (II) wherein Ind is an unsubstituted or substituted indenyl or tetrahydroindenyl ring and R 2 and R 4 are substituents in positions 2 and 4 respectively; each R 2 and R 4 is the same or different and is a hydrocarbyl containing from 1 to 20 carbon atoms; R″ is a structural bridge between two Cp rings; M is a metal group 4 of the Periodic Table; each Q is independently a hydrocarbyl radical having from 1 to 20 carbon atoms or halogen; and wherein the substituent in position 4 is a bulky substituent having 3 carbon atoms or more and the substituent in position 2 is a small substituent having 1 or 2 carbon atoms; c) depositing on the same, or another, support a second metallocene component in order to prepare a rubber phase, wherein the second metallocene catalyst component is Ph 2 C(3-SiMe 3 -cyclopentadienyl)(fluorenyl)zirconium dichloride; d) activating the loaded support(s) with an activating agent having an ionising action before or after steps b) and c); e) injecting the loaded and activated support(s) into the reactor; f) injecting propylene into the reactor; g) maintaining under polymerisation conditions; and h) retrieving an impact polymer of propylene devoid of ethylene comonomer.