The Dow Chemical Company

Illinois Tool Works Inc.

Gene A Cochran

Alan W Weimer

Glenn A Eisman

John P Henley

Stephen D Dunmead

Donald R Beaman

Kevin J Nilsen

Daniel F Carroll

David W Susnitzky

George J Quarderer, Jr

David A Dunn

Rex R Stevens

Craig B Murchison

William G Moore

Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

Silicon nitride/silicon carbide composite densified materials prepared

Carbothermally reduce a metal oxide to its corresponding metal nitride or metal carbide powder in a vertical gravity flow reactor by adding precursor pellets containing the metal oxide, a thermally decomposed binder material and carbon or a source of carbon directly to a heated reaction zone within the reactor. The pellets form a pellet bed, the top of which must be maintained within the heated reaction zone. The binder material is a blend of wheat and corn starches, optionally in conjunction with another binder such as melamine. The binder material thermally decomposes to a carbonaceous residue which functions both as an additional source of carbon and as a binder for the precursor pellets. The reactor may be modified by adding an internal vent line to remove volatile materials from the heated reaction zone before they have an opportunity to condense on internal reactor surfaces.

Moving bed process for carbothermally synthesizing nonoxide ceramic

Silicon carbide/silicon nitride composites are prepared by carbothermal reduction of crystalline silica powder, carbon powder and optionally crsytalline silicon nitride powder. The crystalline silicon carbide portion of the composite has a mean number diameter less than about 700 nanometers and contains nitrogen.

Method for producing silicon nitride/silicon carbide composite

Silicon nitride/silicon carbide composite powders

Rapidly heat powdered aluminum, an admixture of powdered aluminum and a compatible solid material, a powdered admixture of alumina and carbon, or aluminum nitride powder having a surface area lower than desired in the presence of a source of nitrogen at a temperature of 2473 to 3073K to produce aluminum nitride, then promptly quench the aluminum nitride product. The product has a surface area of greater than 10 m.sup.2 /g, preferably greater than 15 m.sup.2 /g.

Process for preparing ultrafine aluminum nitride powder

An easy-open container includes guide strips to limit tearing to areas adjacent to the intended line of tearing with a tear strip. The guide strips protect zipper elements and bag walls from distortion or tearing due to deviating tear lines. In a second embodiment, the guide strips are included with one or more tear strips on a membrane which may be attached to a container.

Tear-open bag having guide strips

Rapidly heat powdered aluminum in the presence of a source of nitrogen at a temperature of 1873 to 2373 K. to produce aluminum nitride, then promptly quench the aluminum nitride product. The product has a surface area between 2 and 8 square meters per gram and an oxygen content of less than 1.2 weight percent.

Process for preparing aluminum nitride powder via controlled combustion

A process for forming an alcohol fraction boiling in the range of motor gasoline that is enriched in higher alcohols, comprises contacting a mixture of hydrogen, carbon monoxide and a lower alkanol with a catalyst comprising:

Preparation of ethanol and higher alcohols from lower carbon number

A Fischer-Tropsch reaction to form alcohols from hydrogen and carbon monoxide, using a catalyst containing:

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Midland, MI, United States of America

Gene A Cochran