Impact copolymer in single reactor

1. 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.

2. The method of claim 1 wherein the first metallocene component is dimethylsilyl-bis(2-methyl,4-naphtyl-indenyl) zirconium dichloride.