Patent ID: 6610800
Filing Date: 2003-08-26
Classification: C08F,C08L,Y10S

Abstract:
An ethylene-based polymer blend made with a mixed catalyst system comprising a first and a second catalyst, the blend having (a) a molecular weight distribution (i) of at least about 2, and (ii) at least about ten percent greater than that of a polymer prepared in a single reactor with either the first or second catalyst alone under similar polymerization conditions, and (b) a uniform molecular architecture, the blend made by a process comprising contacting under polymerization conditions and in a single reaction vessel:A. ethylene B. at least one C3-C20 &agr;-olefin, and C. the mixed catalyst system comprising the first catalyst and the second catalyst, and each catalyst comprising: 1. a metal complex of formula I ZLMXpXâ€²qâ€ƒâ€ƒ(I) â€ƒwherein M is a metal of Group 4 of the Periodic Table of the Elements having an oxidation state of +2, +3 or +4 bound in an &eegr;5 bonding mode to L; L is a cyclopentadienyl-, indenyl-, tetrahydroindenyl-, fluorenyl-, tetrahydrofluorenyl-, or octahydrofluorenyl-group covalently substituted with at least the divalent moiety, Z, and L further may be substituted with from 1 to 8 substituents independently selected from the group consisting of hydrocarbyl, halo, halohydrocarbyl, hydrocarbyloxy, dihydrocarbylamine, dihydrocarbylphosphino or silyl groups containing up to 20 nonhydrogen atoms; Z is a divalent moiety, or a moiety comprising one &sgr;-bond and a neutral two electron pair able to form a coordinate-covalent bond to M, Z comprising boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprising nitrogen, phosphorus, sulfur or oxygen; X is a anionic ligand group having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalized, &pgr;-bound ligand groups; Xâ€² independently each occurrence is a neutral ligating compound having up to 20 atoms; p is 0, 1 or 2, and is two less than the formal oxidation state of M, with the proviso that when X is a dianionic ligand group, p is 1; and q is 0, 1 or 2; and 2. an activating cocatalyst; with the provisos that D. the first catalyst is different from the second catalyst, and E. the weight ratio of the first catalyst to the second catalyst, based on the weight of the metal M in each catalyst, is between about 90:10 and 10:90.