摘要:
A method of preparing supported catalysts useful for olefin polymerization is described. The catalysts comprise a Group 4 metal complex that incorporates a tridentate dianionic ligand. An activator mixture is first made from a boron compound having Lewis acidity and an excess of an alumoxane. The activator mixture is then combined with a support and the Group 4 metal complex to give a supported catalyst. The method provides an active, supported catalyst capable of making high-molecular-weight polyolefins.
摘要:
A method for preparing a supported catalyst suitable for use in slurry and gas-phase olefin polymerizations is disclosed. An alumoxane-treated silica is combined with a monocyclopentadienyl Group 6 metal complex that comprises a chelating Cp moiety to give the supported catalyst. The method is simple to practice and provides catalysts having high activity. Polyolefins made using the catalysts have high molecular weight that is readily controlled by adding hydrogen.
摘要:
A method of preparing supported catalysts useful for olefin polymerization is described. The catalysts comprise a Group 4 metal complex that incorporates a tridentate dianionic ligand. An activator mixture is first made from a boron compound having Lewis acidity and an excess of an alumoxane. The activator mixture is then combined with a support and the Group 4 metal complex to give a supported catalyst. The method provides an active, supported catalyst capable of making high-molecular-weight polyolefins.
摘要:
Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-(2-aryloxy)quinoline or 2-(2-aryloxy)dihydroquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.
摘要:
Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise a transition metal complex, an optional activator, and an optional support. The complex is the reaction product of a Group 3-6 transition metal source, an optional alkylating agent, and a ligand precursor comprising a 2-imino-8-anilinoquinoline or a 2-aminoalkyl-8-anilinoquinoline. The catalysts, which are easy to synthesize by in-situ metallation of the ligand precursor, offer polyolefin manufacturers good activity and the ability to make high-molecular-weight ethylene copolymers that have little or no long-chain branching.
摘要:
Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-aryl-8-anilinoquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.
摘要:
Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-(2-aryloxy)quinoline or 2-(2-aryloxy)dihydroquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.
摘要:
A method for making ethylene polymers and copolymers is disclosed. The method uses a catalyst system comprising a low level of an aluminum-containing activator, a bridged indenoindolyl transition metal complex, and a treated silica support. The method enables economical preparation of ethylene copolymers having very low density. The silica-supported, bridged complexes incorporate comonomers efficiently and are valuable for a commercial slurry loop process. Use of a bridged indeno[2,1-b]indolyl complex provides exceptionally efficient comonomer incorporation, and gives polymers with a substantial and controlled level of long-chain branching. The method facilitates the production of a wide variety of polyolefins, from HDPE to plastomers.
摘要:
A catalyst system useful for polymerizing olefins is disclosed. The catalyst system comprises an activator and a complex that incorporates a Group 3 to 10 transition metal and at least one chelating dianionic bis(allyl) or bis(benzyl) ligand. The ligands are often easy to make, and they are readily incorporated into transition metal complexes. By modifying the structure of the dianionic ligand, polyolefin makers can control comonomer incorporation, catalyst activity, and polymer properties.
摘要:
Single-site catalyst systems useful for polymerizing olefins are disclosed. The catalyst systems comprise an organometallic complex and an activator. The complex includes a Group 3-10 transition metal, M, and at least one indenoindolyl ligand that is pi-bonded to M. The activator is a reaction product of an alkylaluminum compound and an organoboronic acid. Catalyst systems of the invention significantly outperform known catalyst systems that employ a metallocene complex and similar aluminoboronate activators.