METALLOCENE CATALYSTS HAVING MULTI-NUCLEAR CONSTRAINED GEOMETRY AND ETHYLENE/AROMATIC VINYL COMPOUND CO-POLYMERS PREPARED BY USING THE SAME

摘要

The metallocene catalyst according to the present invention contains in one molecule 2 to 4 transition metals that are bonded with ligands. The metallocene catalyst is used for preparing an ethylene/vinyl aromatic compound copolymer. The metallocene catalyst is employed with a cocatalyst such as organometallic compound or amixture of non-coordinated Lewis acid and alkyl aluminum. The ethylene/vinyl aromatic compound copolymer prepared by using the metallocene catalyst shows an isotacticity of at least 60%, and especially an alternating index of at least 80% measured by <13>C NMR analysis.