Polyethylene Materials: Titles
Patents with Abstracts
8. U.S. Patent 8,524,844 (September 3, 2013), “Method of Controlling Polymer Architecture,” Yves Lacombe, Victoria Ker, Peter Phung Minh Hoang, and Patrick Evans (Nova Chemicals, International S.A., Fribourg, Switzerland).
Mixtures of polyethylenes with different molecular weights and even different structures are used for improved polyethylene materials for specific applications from low density film to high density pressure pipe. These bimodal or multimodal resins are produced during polymerization with catalyst mixtures. Control during polymerization is not precise and can lead to undesirable products. Lacombe et al found that carbon dioxide can be used to control polyethylene compositions during polymerization with a catalyst mixture such as a chromium catalyst, a single site catalyst and one or more activators. Carbon dioxide has little effect on the average molecular weight produced but does control the relative amounts of high and low molecular weight components and/or high and low comonomer content without significantly affecting the relative molecular weights of the polymer components.
Polyethylene composition for pressure pipes with enhanced flexibility
Backman et al of Borealis Technology Oy, Finland, developed a polyethylene material for piping consisting of a base resin with (a) an ethylene homo- or copolymer fraction (A); and (b) an ethylene homo- or copolymer fraction (B), wherein (i) fraction (A) has a lower average molecular weight than fraction (B); (ii) the base resin has a density of 940 to 947 kg/m3; (iii) the polyethylene composition has an MFR5 of 0.1 to 0.5 g/10 min; and (iv) the polyethylene composition has an SHI 2.7/210) of 10 to 49. SHI is the ratio of the viscosity of the polyethylene composition at different shear stresses (RDC 2/13/2013)
Polyolefin resin composition and uses thereof
Abe et al of Mitsui Chemicals, Inc, Japan, developed a polyolefin resin composition which is excellent in mechanical properties and dimensional stability and is particularly excellent in heat resistance. This polyolefins consists of 85 to 50% by mass of ultrahigh-molecular weight polyethylene (A) and 15 to 50% by mass of a polymer (B) containing a repeating unit derived from 4-methyl-1-pentene. (RDC 1/22/2013)
Polyethylene and poly(hydroxyl carboxylic acid) blends
Brusson and De Groof of Total Petrochemicals Research Feluy, Belgium, developed a A resin consisting of at least 0.1% by weight of poly(hydroxy carboxylic acid and at least 50% by weight of polyethylene prepared with a single-site catalyst, preferably a metallocene. (RDC 10/17/2012)
Stabilized medium and high voltage insulation composition
Herbst and Kolb of BASF, Germany, developed cable insulation with improved water tree resisistance consisting of a) a crosslinked polyethylene, b) a sulfur-containing phenolic antioxidant, c) a migrating antistatic agent, and d) an organic peroxide. Migrating antistatic agents include ethoxylated alkylamines, ethoxylated dialkylamines, fatty acid esters, polyethylene glycol esters, polyglycerol esters, glycidyl ester, alkyl sulfonates, pentaerythritol esters, sorbitan esters and diethanol amides of fatty acids. (RDC 7/27/2012)
Silicon-containing ethylene-based polymer blends, methods for making same, and articles made therefrom
Vigan , Allermann and Ohlsson of ExxonMobil, Texas, developed polyethylene blends consisting of (a) 5 to 95 wt% HDPE with a density from 0.941 g/cm3 to 0.980 g/cm3 and an I22 of 10 dg/min or more; and (b) 95 to 5 wt% of a grafted mPE with a density from 0.860 g/cm3 to 0.935 g/cm3 and an I2 from 0.7 to 5.0 dg/min, and a silicon-containing grafting component, wherein the blend exhibits a high-temperature creep after extrusion that is at least 20% lower than a blend of the HDPE and the mPE that has not been grafted with a silicon-containing grafting component. These blends can advantageously comprise at least one layer of a film, e.g., made via extrusion. (RDC 7/10/2012)
Radiation-proof sheath material and radiation-proof cable
Sorimachi et al of Hitachi Cable, Japan, developed a radiation-proof sheath material including a polymer material containing molecular chains of ethylene units as a main component in which side chain groups are randomly distributed and cross-linked, an antioxidant, a processing aid, and a flame retardant. The polymer material includes chlorinated polyethylene containing chloro groups in the side chain groups. (RDC 5/29/2012)
Protective sheet made from a blend of ethylene vinyl acetate (EVA) and polyethylene (PE)
May of Trimaco, North Carolina, developed a protective sheet and method for protecting an object is disclosed. The protective sheet or drop cloth is made from a blend comprising ethylene vinyl acetate (EVA) and polyethylene (PE), making it naturally liquid impervious and slip resistant. The protective sheet includes a top side having a raised surface design configured for retaining fluid, and a bottom side that is smoother than the top side for added slip resistance. The method comprises the steps of providing the protective sheet and positioning it over the object, wherein the top side faces away from the object, and the bottom side faces the object and the top side is available for a workman to walk on. (RDC 5/17/2012)
Roger D. Corneliussen
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Copyright 2012 by Roger D. Corneliussen.
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** Date of latest addition; date of first entry is 5/17/2012.