Patent application number | Description | Published |
20090061135 | Polyolefin resin blends for crack-resistant pipe - Resin blends useful for pipe and blow-molded articles are disclosed. The blends comprise a low-molecular-weight, high-density polyethylene and a high-molecular-weight, low-density ethylene copolymer. The high-molecular-weight component is made with a bridged indenoindolyl Group 4 metal complex having open architecture. Blends of the invention uniquely have high molecular weight (M | 03-05-2009 |
20090275711 | Olefin polymerization process - A slurry process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in a first reactor in the presence of hydrogen and a catalyst comprising an activator and a supported dimethylsilyl-bridged indeno[1,2-b]indolyl zirconium complex to produce an ethylene homopolymer, removing some of the unreacted hydrogen, and reacting the homopolymer slurry in a second reactor with ethylene and a C | 11-05-2009 |
20090304966 | Bimodal polyethylene process and products - Bimodal polyethylene resins having reduced long-chain branching and suitable for use in pipe resin applications as a result of their improved SCG and RCP resistance are provided. The improved resins of the invention are produced in a two-reactor cascade slurry polymerization process using a Ziegler-Natta catalyst system and wherein an alkoxysilane modifier is present in both reactors. | 12-10-2009 |
20100092709 | Multimodal polyethylene pipe resins and process - Multimodal polyethylene resins having improved stress crack resistance and melt strength rendering them useful for the manufacture of thick-walled pipe are produced in a process wherein the second stage of the process is a copolymerization conducted at a high temperature with a low comonomer to ethylene ratio and a low hydrogen to ethylene ratio. | 04-15-2010 |
20100221561 | Polyolefin composition having improved oxidative stability - Disclosed is a pipe resin composition. The composition comprises a polyethylene pipe resin, a primary antioxidant, and an acid. The composition of the invention has an increased oxidative induction time (OIT) and environmental stress cracking resistance (ESCR). | 09-02-2010 |
20100272937 | Polyethylene pipe resins - Disclosed is a pipe resin composition. The composition comprises a polyethylene pipe resin, a primary antioxidant, and an acid. The composition of the invention has an increased oxidative induction time (OIT) and environmental stress cracking resistance (ESCR). | 10-28-2010 |
20120123067 | BIMODAL POLYETHYLENE PROCESS AND PRODUCTS - Bimodal polyethylene resins having reduced long-chain branching and suitable for use in pipe resin applications as a result of their improved SCG and RCP resistance are provided. The improved resins of the invention are produced in a two-reactor cascade slurry polymerization process using a Ziegler-Natta catalyst system and wherein an alkoxysilane modifier is present in both reactors. | 05-17-2012 |
20140127438 | STABILIZED HIGH-DENSITY POLYETHYLENE COMPOSITION WITH IMPROVED RESISTANCE TO DETERIORATION AND STABILIZER SYSTEM - The disclosure relates to a high-density polyethylene (HDPE) composition with resistance to deterioration in the presence of chlorinated and non-chlorinated water at temperatures in the range of about 0° C. to about 100° C., due to a particular stabilizer system which is composed of a hindered phenol antioxidant, a phosphonite or phosphine antioxidant, and a natural or synthetic hydrotalcite. The stabilizer system is specifically tailored to protect the HDPE as well as other polyolefins against deterioration and degradation. | 05-08-2014 |