E.i. Dupont De Nemours and Company

Lloyd Abrams

Robert D Shannon

David Richard Corbin

Robert Ray Burch

George C Sonnichsen

Lionel S Sandell

Timothy D Krizan

Jesus G Moralez

Polyimide resin compositions that contain an end-capped rigid aromatic polyimide, graphite and, optionally, a filler selected from sepiolite, attapulgite, kaolinite, or a mixture thereof, are found to exhibit low wear at high temperatures. Such compositions are especially useful in molded articles that are exposed to wear conditions at high temperatures such as aircraft engine parts.

Polyimide resins for high temperature wear applications

Improved acidic zeolite rho and ZK-5 catalysts for conversion of methanol and ammonia to dimethylamine are disclosed. The acidic zeolite rho catalyst is prepared by calcining zeolite NH.sub.4 -rho or H-rho in the presence of steam. The acidic zeolite ZK-5 catalyst is prepared by calcining zeolite NH.sub.4 -ZK-5 or H-ZK-5 in the presence of steam. An acidic zeolite rho which has been prepared by calcining zeolite NH.sub.4 -rho in a vertical furnace in the presence of ammonia is disclosed. Processes for producing dimethylamine with the specified catalysts are also disclosed.

Zeolite rho and ZK-5 catalysts for conversion of methanol and ammonia to

A process is provided for producing dimethylamine, comprising reacting methanol and/or dimethylether and ammonia in amounts sufficient to provide a carbon/nitrogen (C/N) ratio from about 0.2 to about 1.5, at a temperature from about 250.degree. C. to about 450.degree. C., in the presence of a catalytic amount of an acidic zeolite catalyst selected from the group consisting of natural, H-exchanged, and M-exchanged chabazites, each having a geometric selectivity index greater than about 3, wherein M is one or more alkali metal ions selected from the group consisting of Na, K, Rb, and Cs.

Selected chabazite zeolites as catalysts for conversion of methanol and

Process for preparing pigmented microporous silica microspheres by spraying an aqueous suspension of pigment in a solution of alkali metal silicate through the air into a medium consisting of from 20% to 100% by volume of a water miscible organic liquid, the balance being water. The resulting microspheres are highly effective opacifying agents.

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Hockessin, DE, United States of America

Lloyd Abrams