Michael Bruce Thomas - Pasadena MD Michael Vance Ernest - Catonsville MD Sandra Joan Kempske - Baltimore MD
Assignee:
W. R. Grace Co. -Conn. - Columbia MD
International Classification:
A61K 716
US Classification:
424 49, 424401, 424484, 423339, 423335, 423338
Abstract:
Silica compositions for abrasive systems in dentifrice formulations are disclosed. The silica abrasive system comprises (a) silica gels having a median particle size below 7 microns, a pH of from about 6 to about 11 and powder RDAs of from 100 to about 200 and (b) silica gels or precipitates having a median particle size of 7 microns or greater and powder RDAs of from 50 to about 180. Silica (a) is preferably prepared by contacting a hydrous silica gel with an alkaline medium. Dentifrice compositions comprising the abrasive system has an RDA of 150 or less and PCRs of at least 80 and up to about 150, and an REA of less than about 30 (as measured on the IU scale).
Abrasive Silica Compositions And Dentifrice Compositions Prepared Therefrom
Michael Bruce Thomas - Pasadena MD Michael Vance Ernest - Catonsville MD Sandra Joan Kempske - Baltimore MD
Assignee:
W. R. Grace Co.-Conn. - Columbia MD
International Classification:
A61K 716
US Classification:
424 49, 424484
Abstract:
Silica compositions for abrasive systems in dentifrice formulations are disclosed. The silica abrasive system comprises (a) silica gels having a median particle size below 7 microns, a pH of from about 6 to about 11 and powder RDAs of from 100 to about 200 and (b) silica gels or precipitates having a median particle size of 7 microns or greater and powder RDAs of from 50 to about 180. Silica (a) is preferably prepared by contacting a hydrous silica gel with an alkaline medium. Dentifrice compositions comprising the abrasive system has an RDA of 150 or less and PCRs of at least 80 and up to about 150, and an REA of less than about 30 (as measured on the IU scale).
Process For Preparing Spheroidal Alumina Particles
Moises G. Sanchez - Severna Park MD Michael V. Ernest - Baltimore MD Norman R. Laine - Rockville MD
Assignee:
W. R. Grace & Co. - New York NY
International Classification:
B01J 2104 B01J 3700
US Classification:
252448
Abstract:
Spheroidal alumina particles have a combination of high macroporosity, surface area, crush strength and low attrition loss and bulk density. The particles are prepared by an improved external gelation oil-drop process. In the process a slurry of alumina, preferably a microcrystalline boehmite-pseudoboehmite intermediate, is prepared in an acidic aqueous medium and droplets of the slurry are passed through air into a column containing an upper body of water-immiscible liquid and ammonia and a lower body of aqueous coagulating agent. Catalysts employing the particles as a support and having catalytic agents distributed at controlled depths in the particle have excellent initial and sustained activity and durability, especially for eliminating pollutants in automotive exhaust streams.
Auto Exhaust Catalyst Composition Having Low H.sub.2 S Emissions And Method Of Making The Catalyst
A catalyst suitable for use as a three-way catalyst having low H. sub. 2 S emissions for emission control and with substantially no ceria present is made with a refractory oxide particle or powder support having deposited thereon about 0. 5-20% by weight of a non-rate earth oxide stabilizer, at least 0. 5 to about 5% by weight of an alkali metal oxide as a promoter, and a catalytically-effective amount of one or more platinum group metals. The preferred refractory oxide is alumina and the non-rare earth oxide stabilizer can be an oxide such as ZrO. sub. 2, MgO, CaO, SnO, CaO, Y. sub. 2 O. sub. 3, TiO. sub. 2, ZnO, B. sub. 2 O. sub. 3, P. sub. 2 O. sub. 5, SnO. sub. 2, Bi. sub. 2 O. sub. 3, or SiO. sub. 2 with the preferred oxide being zirconia.
Catalyst Composition For Ultra High Temperature Operation
A high temperature stable catalyst is made with fine particles of a base metal such as chromium, hafnium and niobium or their oxides dispersed throughout a matrix made of composite particles having at least one platinum group metal on a ceria promoted, high temperature chemically stabilized refractory oxide powder. The refractory oxide powder can be either alumina, alumina powder which has been calcined at a temperature near incipient alpha alumina formation, silica-alumina or zirconia. The base metal or base metal oxide comprises about 15% to 90% by weight of the total weight and the platinum group metal comprises 0. 05% to 10% by weight of the total weight. The catalyst composition can be applied as a washcoat to conventional substrates or it can be formed into shaped catalysts. The washcoat is made by mixing together one slip containing the composite particles with a second slip containing the base metal or base metal oxide particles.
Rare Earth And Platinum Group Metal Catalyst Compositions
Michael V. Ernest - Baltimore MD James M. Maselli - Columbia MD
Assignee:
W. R. Grace & Co. - New York NY
International Classification:
B01J 2104 B01J 2310 B01J 2340
US Classification:
252462
Abstract:
A catalyst composition comprising a composite of ceria, lanthana, and alumina and a catalytically-effective amount of one or more platinum group metals deposited on the composite is disclosed. The composite is prepared by depositing a cerium compound on a calcined admixture of the lanthana and the alumina and calcining the composite. The catalyst is capable of operating in the combustion of carbonaceous fuel at high temperatures, e. g. , greater than 2400. degree. F. (1317. degree. C. ), for extended periods of time such as 20 hours with low emissions of carbon monoxide and nitrogen oxides.
Michael V. Ernest - Baltimore MD James M. Maselli - Columbia MD
Assignee:
W. R. Grace & Co. - New York NY
International Classification:
B01D 5336
US Classification:
4232132
Abstract:
Suspended particles in exhaust gases, such as carbon and lead particles in internal combustion engine exhaust gases, are removed by passing the gases through a coarse filter and then through a fine filter. The filters may comprise a ceramic foam material and a catalyst material effective for the conversion of the carbon particles and/or gaseous pollutants in the exhaust gases to innocuous entities may be deposited on the filters.
Michael V. Ernest - Baltimore MD James M. Maselli - Columbia MD
Assignee:
W. R. Grace & Co. - New York NY
International Classification:
B01J 2104 B01J 2364 B01J 2372 B01J 3504
US Classification:
502313
Abstract:
Suspended particles in exhaust gases, such as carbon and lead particles in internal combustion engine exhaust gases, are removed by passing the gases through a coarse filter and then through a fine filter. The filters may comprise a ceramic foam material and a catalyst material effective for the conversion of the carbon particles and/or gaseous pollutants in the exhaust gases to innocuous entities may be deposited on the filters.