Patent application number | Description | Published |
20110257350 | Polymer mitigation - Ethylene is selectively oligomerized in a continuously stirred tank reactor (CSTR) that is preferably operated in an isothermal manner using a chromium catalyst. The undesired formation of by-product polyethylene is mitigated by contacting the ethylene with hydrogen prior to adding the ethylene to the reactor and feeding the ethylene and hydrogen via a common feed port. | 10-20-2011 |
20110282016 | Oligomerization - The oligomerization of ethylene using a chromium catalyst having a phosphorus-nitrogen-phosphorus (“P—N—P”) ligand is typically activated with an aluminoxane. The addition of an alkyl zinc, particularly diethyl zinc, has been fund to improve the productivity of certain oligomerization reactions. In particular, the addition of diethyl zinc to an oligomerization reaction that is activated by methylaluminoxane (MAO) improves the productivity of the reaction. | 11-17-2011 |
20120101321 | Ethylene oligomerization - The oligomerization of ethylene using a chromium catalyst having a bridged diphosphine ligand can produce a selective product distribution (to predominantly hexene or predominantly octene/hexene) when activated with an aluminoxane. The oligomerization reaction also produces polymer by product—particularly when the aluminoxane is provided in a non-aromatic solvent. The present invention mitigates this problem. | 04-26-2012 |
20120142989 | HEAT MANAGEMENT IN ETHYLENE OLIGOMERIZATION - The oligomerization of ethylene using a chromium catalyst having a heteroatomic ligand may be used to provide oligomerization products that are selective towards hexene and/or octene. However, such processes also typically produce some polymer as an undesirable by product. The present invention is directed towards improvements in the selective oligomerization of ethylene. | 06-07-2012 |
20120271087 | Activation for Oligomerization - The oligomerization of ethylene using a chromium catalyst and an aluminoxane activator is well known. The undesired formation of polyethylene as a by-product is also known to occur during prior oligomerization processes. We have discovered that the use of an aluminoxane that is prepared by non-hydrolytic means provides a highly productive activator (co-catalyst) for ethylene oligomerization and mitigates the undesired formation of by-product polyethylene. | 10-25-2012 |
20130053524 | Feeding Highly Active Phosphinimine Catalysts to a Gas phase reactor - A highly active, supported phosphinimine catalyst is fed to a gas phase reactor as a slurry in a liquid hydrocarbon. Feeding the catalyst to a gas phase reactor in a viscous liquid hydrocarbon modifies catalyst initiation kinetics. | 02-28-2013 |
20130225743 | BARRIER FILM FOR FOOD PACKAGING - Barrier films are prepared from a blend of two high density polyethylene blend components and a high performance organic nucleating agent. The two high density polyethylene blend components have substantially different melt indices. Large reductions in the moisture vapor transmission rate of the film are observed in the presence of the nucleating agent when the melt indices of the two blend components have a ratio of greater than 10/1. The resulting barrier films are suitable for the preparation of packaging for dry foods such as crackers and breakfast cereals. | 08-29-2013 |
20140142360 | BULK ETHYLENE OLIGOMERIZATION USING A LOW CONCENTRATION OF CHROMIUM CATALYST AND THREE-PART ACTIVATOR - This invention enables the “bulk” oligomerization of ethylene (i.e. the oligomerization of ethylene in the presence of the oligomer product) using a catalyst system comprising 1) a very low concentration of a chromium catalyst and 2) a three part activator. The chromium catalyst contains a diphosphine ligand, preferably a so called P—N—P ligand. The activator includes an aluminoxane, trimethyl aluminum, and triethyl aluminum. | 05-22-2014 |
20140272366 | MULTILAYER FILMS - A multilayer film is prepared from a high impact strength polyethylene (HI polyethylene); a Ziegler Natta catalyzed polyethylene (Z/N polyethylene) and a high pressure low density polyethylene (LD polyethylene) with i) at least one skin layer consists essentially of HI polyethylene and ii) at least one core layer comprises a blend of Z/N polyethylene and said LD polyethylene. The HI polyethylene has a density of from 0.915 to about 0.930 g/cc and a normalized impact strength of at least about 300 g/mil. The amount of HI polyethylene is from about 30 to about 55 weight % (based on the combined weights of the HI+Z/N+LD polyethylenes). The films described herein are readily prepared on blown film equipment and provide an excellent balance of mechanical properties. | 09-18-2014 |
20140275302 | POLYETHYLENE ADDITIVE - A new additive for plastics (for example, polyethylene) is prepared by reacting a fatty acid ester of glycerol (such as glycerol monostearate) with a source of a reactive divalent metal selected from zinc, calcium, and magnesium. In an embodiment, Zinc oxide is the reactive divalent metal and the reaction is conducted in the presence of an acid such as zinc acetate. In one embodiment, a molar excess of zinc oxide (compared to the fatty acid ester) is used. The additive is suitable for use in the preparation of injection molded parts, rotomolded parts, and films. | 09-18-2014 |
20140309351 | BARRIER PROPERTIES OF HDPE FILM - A composition comprising high density polyethylene (HDPE), calcium phthalate and a metal stearate is provided. Film that is prepared from this composition has excellent barrier properties—especially a low water vapor transmission rate (WVTR)—and is suitable for the preparation of packaging for dry foods such as crackers and cereals. | 10-16-2014 |