| 摘要 |
Provided is a Ziegler-Natta/metallocene catalyst supported on a silica carrier, which has a plurality of catalytic active sites, and allows control of the branch distribution and molecular weight distribution of a linear low-density polyethylene polymer. The Ziegler-Natta/metallocene catalyst supported on a silica carrier for preparing linear low-density polyethylene is obtained by successively supporting methyl aluminoxane, a titanium compound having ethylene polymerization activity as a Ziegler-Natta catalyst, and a metallocene catalyst having zirconium as a central metal, successively onto the silica carrier. The Ziegler-Natta/metallocene catalyst supported on a silica carrier has a surface structure represented by the following reaction scheme 1(C). In reaction scheme 1, L represents a ligand of the metallocene, X is a halogen bound thereto, and each of n and m is a number of 0-4 with the proviso that n+m=4.
|
