MgCl₂ supported titanium catalyst prepared by mechanical pulverization

Summary

MgCl₂ supported titanium catalysts were prepared by mechanical pulverization or MgCl₂ with titanium compounds using two types of machines, rotatory mill and vibratory mill. Both methods gave substantially the same results, although vibratory mill much saved the milling time. The nature of the fixed titanium compounds was not homogeneous, and the titanium compounds fixed at an earlier stage of milling, which could be located at exposed “active” edge positions of MgCl₂ particles, showed higher activity in ethylene polymerization. On the other hand, those fixed at the later stage showed lower activity and caused reaggregation of the particles. Furthermore, chlorine-free titanate compounds, Ti(OBu)₄ and Ti(OEt)₄, also could be fixed on MgCl₂ which showed high activity in ethylene polymerization.