Chevron Phillips Chemical Company LP

International Paper Company

Vivek Rohatgi

Ashish M Sukhadia

Qing R Yang

Yongwoo Inn

Lili Cui

Paul J DesLauriers

Elizabeth Mary Lanier

Mark L Hlavinka

Jeffrey F Greco

David Verd Reed

Jim B Askew

Alfred E Brown, Jr

Ladislav Bednarik

Jeff F Greco

Youlu Yu

Jeremy M Praetorius

Bruce E Kreischer

Chung Ching Tso

Ronald D Knudsen

David A Soules

Mark E Lashier

R Kim Perry

Qing Yang

Ethylene-based polymers having a density from 0.94 to 0.96 g/cm, a Mn from 5,000 to 14,000 g/mol, a ratio of Mw/Mn from 18 to 40, and at least one of a PENT value at 2.4 MPa of at least 11,500 hr and/or a W90 from 7.5 to 15 wt. % are disclosed. Additional ethylene polymers can have the same density, Mn, and Mw/Mn values, as well as a relaxation time from 0.5 to 3.5 sec, a CY-a parameter from 0.48 to 0.68, a HLMI from 5 to 11 g/10 min, a viscosity at HLMI from 3,000 to 7,500 Pa-sec, and a higher molecular weight component (HMW) and a lower molecular weight (LMW) component, in which a ratio of the number of SCBs at Mp of the HMW component to the number of SCBs at Mp of the LMW component is from 3.5 to 8.

Dual metallocene bimodal HDPE resins with improved stress crack resistance

Disclosed herein are ethylene-based polymers generally characterized by a density of at least 0.94 g/cm, a high load melt index from 4 to 20 g/10 min, a zero-shear viscosity at 190&#xb0; C. from 20,000 to 400,000 kPa-sec, and a relaxation time at 190&#xb0; C. from 225 to 3000 sec. These ethylene polymers can be produced by peroxide-treating a broad molecular weight distribution Ziegler-catalyzed resin, and can be used in large diameter, thick wall pipes and other end-use applications.

Bimodal polyethylene resins and pipes produced therefrom

Disclosed herein are ethylene-based polymers having low densities and narrow molecular weight distributions, but high melt strengths for blown film processing. Such polymers can be produced by peroxide-treating a metallocene-catalyzed resin.

Peroxide treated metallocene-based polyolefins with improved melt strength

A crosslinked metallocene-catalyzed polyethylene copolymer having a higher molecular weight (HMW) component and lower molecular weight (LMW) component wherein the HMW component is present in an amount of from about 10 wt. % to about 30 wt. % and wherein the LMW component is present in an amount of from about 70 wt. % to about 90 wt. %.

Polymers with improved processability for pipe applications

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 ethylene-based polymers having a higher molecular weight component and a lower molecular weight component, and characterized by a density greater than 0.945 g/cm, a melt index less than 1.5 g/10 min, and a ratio of high load melt index to melt index ranging from 40 to 175. These polymers have the processability of chromium-based resins, but with improved stiffness and stress crack resistance, and can be used in blow molding and other end-use applications.

Disclosed herein are methods for recovering a by-product stream of an ethylene oligomerization process, and systematically processing this stream in order to form a polymer composition that can be pelletized conventionally. This polymer composition can have a bimodal molecular weight distribution, which can be characterized by a ratio of the respective peak molecular weights ranging from 400:1 to 2000:1, and further, a liquid component of the polymer composition is in a range from 1 to 35 weight percent.

Oligomerization processes and polymer compositions produced therefrom

Growing community of inventors

Owasso, OK, United States of America

Vivek Rohatgi