Chevron Phillips Chemical Company LP

Jim B Askew

Qing R Yang

Errun Ding

Youlu Yu

Lloyd W Guatney

Joel L Martin

Max P McDaniel

Mark L Hlavinka

Albert P Masino

Vivek Rohatgi

Jeff F Greco

Carlton Edwin Ash

Randall S Muninger

Jeffrey F Greco

Zhou Chen

Qing Yang

Vivek Rohatghi

Catalyst systems containing a titanium alkoxymagnesium halide supported catalyst component can be used for the polymerization of olefins. The catalyst can be prepared from a microcrystalline solid alkoxymagnesium halide support having a lattice spacing in the 5 nm to 15 nm range.

Ziegler-Natta catalysts prepared from solid alkoxymagnesium halide supports

Disclosed are metallocene compounds, catalyst compositions comprising a metallocene compound, processes for polymerizing olefins, methods for making catalyst compositions, olefin polymers and articles made from olefin polymers. In an aspect, a metallocene compounds contain a fluorenyl ligand and a cyclopentadienyl ligand which are bridged by a linking group, in which the metallocene is characterized by [1] the cyclopentadienyl ligand being substituted with a C-Cheterohydrocarbyl group having an oxygen atom positioned 5 atoms distance or less from the cyclopentadienyl ligand and [2] the linking group having a pendant C-Calkenyl group having a terminal C&#x2550;C double bond. It has been discovered that a catalyst composition comprising a metallocene compound having these features can produce polyethylene having a low melt index in the absence of a second metallocene.

Metallocene catalysts for polyethylene

Methods for controlling the die swell of an olefin polymer produced using a dual catalyst system are disclosed. The die swell of the olefin polymer can be increased or decreased as a function of the catalyst weight ratio and the reactant molar ratio used during the olefin polymerization process.

Methods for controlling die swell in dual catalyst olefin polymerization systems

Disclosed herein are ethylene-based polymers generally characterized by a density greater than 0.954 g/cm, high load melt index ranging from 10 to 45 g/10 min, a ratio of high load melt index to melt index ranging from 175 to 600, a rheological slope parameter ranging from 0.15 to 0.30, and an ESCR in 10% igepal exceeding 800 hours. These polymers have the beneficial processability and die swell features of chromium-based resins, but with improved stiffness and stress crack resistance, and can be used in blow molding and other end-use applications.

Polymers with improved ESCR for blow molding applications

Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes can use a dual catalyst system containing a zirconium or hafnium based metallocene compound and a titanium based half-metallocene compound containing an indenyl group.

Metallocene and half sandwich dual catalyst systems for producing broad molecular weight distribution polymers

The present invention discloses catalyst compositions employing silicon-bridged metallocene compounds with bulky substituents. Methods for making these silicon-bridged metallocene compounds and for using such compounds in catalyst compositions for the polymerization of olefins also are provided.

High activity catalyst compositions containing silicon-bridged metallocenes with bulky substituents

Methods of controlling polymerization reactions using a synergistic amount of hydrogen and an organozinc compound are disclosed. The resulting polymers have lower molecular weights and higher melt flow indices.

Use of hydrogen and an organozinc compound for polymerization and polymer property control

The techniques disclosed provide a treatment method for passivating the interior surface of a polymerization reactor to minimize the formation of a polymer coating on the surface. The passivation is performed using a passivating agent that reacts with adsorbed water to form labile passivation products. Both the passivating agent and passivation products may be easily removed from the reactor prior to polymerization. Other embodiments provide a reactor system with a tank configured to automatically add a passivating agent to the reactor and processes for making polymers using a treated reactor.

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Barnsdall, OK, United States of America

Jim B Askew