CATALYST FOR PRODUCING POLYOLEFIN HAVING NARROW MOLECULAR WEIGHT DISTRIBUTION AND METHOD FOR PRODUCING POLYOLEFIN USING THE SAME

摘要

Provided are a Ziegler-Natta catalyst for the preparation of a polyolefin having a narrow distribution of molecular weight and a desired level of melt index, and a method for preparing a polyolefin by using the catalyst. The Ziegler-Natta catalyst is prepared by reducing a transition metal compound having an oxidation number of 4 or more containing at least two aryloxy-based ligands with an organomagnesium compound to a trivalent transition metal compound, thereby supporting it; and reacting the obtained one with an alkoxysilane compound. Preferably, the transition metal compound having an oxidation number of 4 or more containing at least two aryloxy-based ligands is represented by M(OAr)_n X_(a-n), wherein M is a transition metal of group IV, V or VI in the periodic table; Ar is a C6-C30 substituted or unsubstituted aryl group; X is a halogen atom; 2<=n<=a; and a is an oxidation number of M and an integer of 4 or more.