Abstract: A method for manufacturing of an improved attrition resistant catalyst having an oxide-rich surface layer involving forming a slurry comprising; catalyst, catalyst precursor or catalyst support particles (e.g., transition metal oxides), a colloidal oxide sol (e.g., colloidal silica), and a solution of a solvent and solute wherein the solute consist essentially of a precursor of said oxide-rich surface with particle size no greater than 5 nm (e.g., aqueous silicic acid or polysilicic acid) and then spray drying the slurry to form porous microspheres of attrition resistant catalyst; and, calcining the spray dried microspheres. Such a catalyst is particularly useful in oxidation processes wherein the oxidation is performed by an oxidized form of the catalyst and the resulting reduced form of the catalyst is separately regenerated (e.g., two-step vapor phase processes carried out in recirculating solids reactors, transport bed reactors or circulating fluidized bed reactors and the like).
Type:
Grant
Filed:
September 30, 1998
Date of Patent:
August 22, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Rashmikant Maganlal Contractor, William Joseph Letts
Abstract: The invention comprises a flat or shaped fabric structure of yarn groups each yarn group comprising a plurality of yarn subgroups, each group positioned for covering an area. The structure comprises at least a first group of flexible yarns densely covering an area , the yarns within the first group following substantially parallel paths in a first direction and forming a stack with at least a second group of flexible yarns densely covering substantially the same area, the yarns within the second group following substantially parallel paths in a second direction; the yarns in the first group arranged to cross the yarns in the second group, optionally containing other groups of yarn, the yarns in the upper-most subgroup of the stack are connected to the yarns in the bottom-most subgroup of the stack either directly of through the yarns in other subgroups providing an interlaced fabric structure.
Type:
Grant
Filed:
October 17, 1997
Date of Patent:
August 22, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Peter Popper, William Charles Walker, Albert S. Tam, Paul Wesley Yngve, James K. Odle, George Yeaman Thomson, Jr.
Abstract: Audio sources are coded by recognizing different classes of audio such as speech and music. The classes are used to select between coding algorithms and to provide object definitions. Objects have abstract and concrete classes which may further rely on parameters produced by linear prediction and subband filters to provide a frame-based bit stream of information. Each object in the bit stream has layers of information such as basic bit rate, coding parameters and enhancement parameters. The layers of information in each object allow altering selected parameters to manipulate audio signals.
Type:
Grant
Filed:
May 14, 1998
Date of Patent:
August 22, 2000
Assignees:
Cselt-Centro Studi E Laboratori Telecomunicazioni S.p.A., Robert Bosch GmbH
Abstract: A process for the production of aromatic hydroxycarboxylic acids such as salicylic acid comprising contacting an aromatic hydroxy compound such as phenol with carbon dioxide in the presence of fluoride ion. The products are useful as pharmaceuticals and chemical intermediates, and as monomers for polymers.
Abstract: Compounds of Formula I, and their agriculturally-suitable salts, are disclosed which are useful as arthropodicides ##STR1## wherein R.sup.1 -R.sup.5 and n are as defined in the disclosure. Also disclosed are compositions containing the compounds of Formula I and a method for controlling arthropods which involves contacting the arthropods or their environment with an effective amount of a compound of Formula I.
Type:
Grant
Filed:
July 15, 1998
Date of Patent:
August 22, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Jeffrey Keith Long, Thomas Martin Stevenson
Abstract: A fabric made using a para-aramid yarn is disclosed having increased cut resistance and maintained comfort wherein the yarn has low twist and the staple fibers in the yarn have high linear density.
Abstract: This invention concerns a method for recycling polyesters comprising the hydrolysis of polyesters containing repeat units derived from 2,6-naphthalene dicarboxylic acid in the presence of a carboxylic acid which gives pure 2,6-naphthalene dicarboxylic acid suitable for use as a monomer.
Type:
Grant
Filed:
September 18, 1998
Date of Patent:
August 15, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Michael Robert Samuels, Marion Glen Wagonner
Abstract: A combination of layered structures is disclosed for protection from both penetration and ballistic threats wherein the outer face is the penetration strike face and includes layers of fabrics tightly woven from aramid yarns of linear density less than 500 dtex; and the inner face includes ballistic layers.
Abstract: A process for producing unsaturated nitrogen containing compounds such as enamides, enamines and aryl amineslamides is disclosed. A vinyl halide or aryl halide is reacted with an --NH-- containing compound in the presence of a catalytic amount of a catalyst precursor composition comprising a zero-valent nickel and an organophosphine or carbene ligand. One step coupling of vinyl halides and aryl halides with --NH-- containing compounds is made possible by practice of the invention.
Type:
Grant
Filed:
December 29, 1998
Date of Patent:
August 15, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Ralph Thomas Baker, Sigridur Soley Kristjansdottir
Abstract: Polymerization of vinylidene fluoride in carbon dioxide media is effectively initiated by dialkyl(2,2-azobisisobutyrate). Methyl is a preferred alkyl.
Abstract: A two-step process for the production of polyamides from .alpha.,.omega.-dinitriles and .alpha.,.omega.-diamines involving the catalytic hydrolysis of the .alpha.,.omega.-dinitrile by addition of water with simultaneous purging of the reactor (i.e., venting of ammonia and water vapor) in the first step followed by polymerization by addition of the .alpha.,.omega.-diamine to the hydrolysate in the second step. Such a process is particularly useful in the production of poly(hexamethylene adipamide), i.e., nylon 6,6, from adiponitrile and hexamethylene diamine using lower catalyst levels during hydrolysis and resulting in reduced levels of bis(hexamethylene)triamine, BHMT, in the polymer.
Type:
Grant
Filed:
December 22, 1998
Date of Patent:
August 15, 2000
Assignee:
E. I. Dupont de Nemours & Company
Inventors:
Richard Allen Hayes, David Neil Marks, Maria Van Eijndhoven
Abstract: The invention relates to thick film conductor paste compositions with which thick film technology can be applied to aluminum nitride substrates and which can form a conductor as a thick film on a substrate by printing or coating and then firing and paste compositions as dispersions, which are obtained by dispersing a conductive powder and a boride in an organic medium.
Abstract: A temperature control unit for independent control of a number of independent channels, as can exist with a cluster tool used for semiconductor fabrication, has high efficiency, long term life and reliability, and requires only a small floor area. To these ends, the unit employs a single high capacity refrigeration system and disposes a number of separate temperature control channels for the individual tools, with only some channels receiving refrigerant. Low temperature channels use high pressure, sub-cooled refrigerant for chilling the heat transfer fluid to selected levels controlled by proportional valves adjusting refrigerant flow through evaporator heat exchanger units which cool heat transfer fluid. Moderate temperature channels cool the heat transfer fluid for associated tools to an ambient temperature level.
Abstract: This invention provides an attrition resistant catalyst composition and method for producing such composition. The catalyst is comprised of an acidic zeolite, rho or chabazite, and a particulate binder, kaolin, bentonite, alpha-alumina, or titania, which can be optionally modified by treatment with a compound containing Si, Al, P or B. This invention further provides a process for producing methylamines, preferably dimethylamine, comprising reacting methanol and/or dimethyl ether and ammonia in the presence of a catalytic amount of an attrition resistant catalyst of the invention.
Type:
Grant
Filed:
May 26, 1995
Date of Patent:
August 15, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Konstantinos Kourtakis, Horacio Enrique Bergna, George Carl Sonnichsen, David Richard Corbin, Loren D. Brake
Abstract: Alpha-olefins are manufactured in high yield and with very high selectivity by contacting ethylene with an iron complex of a selected 2,6-pyridinedicarboxaldehyde bisimine or a selected 2,6-diacylpyridine bisimine, and in some cases a selected activator compound such as an alkyl aluminum compound. Novel bisimines and their iron complexes are also disclosed. The .alpha.-olefins are useful as monomers and chemical intermediates.
Type:
Grant
Filed:
January 12, 1998
Date of Patent:
August 15, 2000
Assignees:
E. I. du Pont de Nemours and Company, University of North Carolina
Inventors:
Maurice S. Brookhart, III, Brooke L. Small
Abstract: Protective hats having a crown and broad brim provide protection from the sun and by surfaces reflecting light and/or radar waves provide distress signalling means. The hats can be colored international orange for enhancing their usefulness as a distress signal. Due to stiffening means such as a springy hoop of suitable material contained within the peripheral binder of the hat's brim, it can be easily folded into a small package for storage or carrying on the person.
Abstract: A device and process for dividing a pneumatic flow of fiber into a plurality of streams of pneumatically-conveyed fiber which aid in distributing the fiber more uniformly across an area such as a fiber bin.
Type:
Grant
Filed:
September 30, 1998
Date of Patent:
August 15, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Kenneth Stephen Freund, Todd Arden McCoy
Abstract: This invention relates to an arrangement for sealing a closed chamber in which equipment is to be replaced and especially to a chamber in which equipment is to be replaced while the chamber is to be maintained closed. The arrangement includes a channel filled with a fluid, such as water, and a skirt arranged to extend into the fluid to form the seal. As the skirt extends down into the liquid, a portal space is formed at the opening in the chamber and the opening preferably includes a gate for closing the chamber from the portal space and the outside.
Type:
Grant
Filed:
April 21, 1997
Date of Patent:
August 15, 2000
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Tom Edward Estep, Ronald P. Hoffman, James R. Hunter, Jean Joseph Muller, Germain Schilz, Carl E. Vorhees, James M. Wiggins, Jean Francois Woll
Abstract: The present invention relates to a stiffened fabric for use in cartridge filters comprising flat fabric formed from entangled heat resistant staple fibers having a weight of from 4 to 8 oz/yd.sup.2 wherein the stiffened fabric is characterized by a flex modulus of at least 10 KSI measured at 200.degree. C.