SOME PECULIAR ASPECTS OF A NEW CATALYST FOR PROPENE POLYMERIZATION

An investigation was carried out on the preparation of highly disorder ed samples of MgCl2 (in delta -form), starting from different Mg-alkyl s and chlorinating agents. Successively we studied which kind of silic a carrier had to be preferred and which treatment was strictly necessa ry to achieve a qualified catalyst Precursor showing outstanding perfo rmance. Different routes were investigated to support the active, diso rdered MgCl2 on the silica carrier 2 and then some following ways to c omplete the catalyst. The final result of this investigation was the s ynthesis of a catalyst showing the best performance with reference to the parameters of use in every polymerization process. It has to be e. g. mentioned: - high yield, referred to the residual content of Mg, Ti and Cl; - no activity decrease when operating at a very high hydrogen concentration; - possibility to polymerize also at elevated temperatu res; - very high isotactic index and stereoregular structure, as measu red by the NMR technique; - possibily to reach high MFR (Melt Flow Rat e) (up to 400 g IPP/10 min at 230 degrees C, 2,16 kg, ASTM D 1238L); - outstanding morphology and flowability.