| 摘要 |
This invention relates to a process to produce propylene polymer using a bridged hafnium transition metal metallocene catalyst compounds having two indenyl ligands substituted at the 4 positions with a C1 to C10 alkyl, where the 3 positions are hydrogen (assuming the bridge position is counted as the one position) and the bridging atom is carbon or silicon which is incorporated into a cyclic group comprising 3, 4, 5, or 6 silicon and/or carbon atoms that make up the cyclic ring, where the propylene polymer has 1) greater than 40% vinyl chain ends, relative to the total unsaturated chain ends, 2) a Tm of 70° C. or more; an Mw of 3000 to 300,000 g/mol, and 4) a g′vis of 0.90 or less. |
| 主权项 |
1. A process for polymerization, comprising:
(i) contacting one or more monomers comprising propylene and optionally ethylene, with a catalyst system comprising a metallocene catalyst compound and an activator, wherein the metallocene catalyst compound is represented by the formula: where each R3 is hydrogen; each R4 is independently a C1-C10 alkyl; each R2 and R7 is independently hydrogen or C1-C10 alkyl; each R5 and R6 is independently hydrogen, C1-C50 substituted or unsubstituted hydrocarbyl, or C1-C50 substituted or unsubstituted halocarbyl; and R4 and R5, R5 and R6 and/or R6 and R7 are optionally bonded together to form a ring structure; J is a bridging group represented by the formula Ra2J′, where J′ is C or Si, and each Ra is, independently, C1 to C20 substituted or unsubstituted hydrocarbyl, and the two Ra form a cyclic structure incorporating J′ and the cyclic structure is optionally a saturated or partially saturated cyclic or fused ring system; and each X is a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand; and (ii) obtaining a polymer having: 1) greater than 40% vinyl chain ends, relative to the total unsaturated chain ends, 2) a Tm of 70° C. or more; 3) an Mw of 3000 to 300,000 g/mol, and 4) a g′vis of 0.90 or less. |
