Other

Hercules Corporation

Lanxide Technology Company, LP

Cerametec, Inc.

Roger L Matsumoto

Alexander Lukacs, Iii

Joanne M Schwark

Allan B Rosenthal

Anil Vasudeo Virkar

Raymond Ashton Cutler

The present invention relates to coated optical devices, such as optical fibers and optical wave guides, and methods for forming coated optical devices. Methods for forming coated optical devices comprise providing at least one optical device and contacting at least a portion of at least one optical device with at least one coating composition comprising at least one metal-nitrogen polymer. The at least one coating composition may further comprise at least one multifunctional organic electrophile comprising at least one monomer, oligomer, or polymer comprising a plurality of organic electrophilic substituents. The coating composition contacting at least a portion of an optical device is at least partially crosslinked, thereby forming coated optical devices which exhibit enhanced resistance to, for example, deterioration resulting from, among other things, exposure to chemicals and environmental factors.

Coated optical devices and methods of making the same

The present invention relates to a process of depositing metals onto various substrates. Applications for which the present invention may be useful include the formation of catalysts such as those used in electrochemical applications, including fuel cells and the like, refining applications such as oil refining, automotive applications such as automotive catalytic converters, and other similar applications.

Catalyst formation techniques

Crystallization of grain boundery phases in silicon carbide ceramics

A sintered, Si.sub.3 N.sub.4 -containing ceramic article is prepared by a reaction injection molding process comprising (1) injecting into a heated mold a fluid, nondilatant mixture of (a) at least 40% by volume of a powder mixture of (i) Si.sub.3 N.sub.4, (ii) a silicate glass-forming sintering aid and (iii) a high metal content silicide, and (b) a curable Si.sub.3 N.sub.4 precursor binder, to cure the binder and produce a hardened molded article, and (2) heating the molded article under a suitable atmosphere to convert the cured binder to a Si.sub.3 N.sub.4 -containing ceramic. The molded article is then sintered under a vacuum to crystallize the silicate glass phase by deoxygenation.

Reaction injection molding of silicon nitride ceramics having

The present invention relates to preceramic polymers incorporating boron and their application in the sintering of SiC ceramics. The present invention is also directed to a process for preparing a boron-substituted polysilazane which involves preparing a silazane ammonolysis product by reacting ammonia with a halogenated silicon compound selected from the group consisting of RSiX.sub.3, RR'SiX.sub.2, RR'R'SiX, SiX.sub.4 and mixtures thereof, wherein X is selected from the group consisting of Cl, Br and I; and R, R' and R' are the same or different and are selected from the group consisting of H, substituted or unsubstituted 1-6 carbon alkyl groups, aryl groups, 2-6 carbon alkenyl groups and 2-6 carbon alkynyl groups, wherein at least one of the halogenated silicon compounds may comprise at least one member selected from the group consisting of alkenyl groups and alkynyl groups; and reacting the silazane ammonolysis product with a borane containing at least one B-H group per molecule under conditions and for a time sufficient to form a boron-substituted polysilazane containing boron-carbon bonds.

Shape sintered articles derived from boro-containing polysilazanes

A silicon nitride ceramic having crystalline grain boundary phases is prepared by heating a composition comprising silicon nitride, a silicate glass-forming sintering aid and a high metal content transition metal silicide, to a temperature of 1300.degree. to 1800.degree. C. under vacuum until a glass forms, oxygen is removed from the glass, and the glass crystallizes. Alternatively, the grain boundaries of a sintered composition comprising silicon nitride, a silicate glass and a high metal content transition metal silicide can be crystallized by heating to at least 1300.degree. C. under a vacuum.

Silicon nitride ceramics containing crystallized grain boundary phases

A silicon carbide ceramic having crystalline grain boundary phases is prepared by heating a composition comprising silicon carbide, a silicate glass and a high metal content transition metal silicide, to a temperature of 1300.degree. to 2100.degree. C. under vacuum until oxygen is removed from the glass as SiO gas, and the glass that remains within the silicon carbide ceramic crystallizes.

Crystallization of grain boundary phases in SiC ceramics through

The present invention relates to preceramic polymers incorporating boron and their application in the sintering of SiC ceramics. The present invention is also directed to a process for preparing a boron-substituted polysilazane which involves preparing a silazane ammonolysis product by reacting ammonia with a halogenated silicon compound selected from the group consisting of RSiX.sub.3, RR'SiX.sub.2, RR'R'SiX, SiX.sub.4 and mixtures thereof, wherein X is selected from the group consisting of Cl, Br and I; and R, R' and R' are the same or different and are selected from the group consisting of H, substituted or unsubstituted 1-6 carbon alkyl groups, aryl groups, 2-6 carbon alkenyl groups and 2-6 carbon alkynyl groups, wherein at least one of the halogenated silicon compounds may comprise at least one member selected from the group consisting of alkenyl groups and alkynyl groups; and reacting the silazane ammonolysis product with a borane containing at least one B--H group per molecule under conditions and for a time sufficient to form a boron-substituted polysilazane containing boron-carbon bonds.

Preceramic polymers incorporating boron and their application in the

A sintered silicon carbide product having improved fracture toughness contains from 1% to 80% by weight of (a) a uniformly dispersed, nonagglomerated, high metal content silicide of iron, nickel, cobalt or molybdenum in which the metal/silicon ratio is equal to or greater than 1. The silicon carbide starting material can be alpha-phase, beta-phase or a mixture of the two.

Silicon carbide ceramics containing a dispersed high metal content

Disclosed is a wear resistant sintered ceramic product comprising (a) 40-98 weight percent silicon nitride having a high alpha-phase content, (b) 2-60 weight percent of a silicide of iron, cobalt or nickel and (c) up to 20 weight percent of at least one oxide, nitride, or silicate of an element of IUPAC groups 2, 3, 4, 13 or the lanthanide series. A method for making such a product is also disclosed.

Wear resistant ceramic with a high alpha-content silicon nitride phase

Disclosed is a sintered ceramic product comprising (a) 20-98 percent by weight silicon nitride, (b) 1-80 percent by weight of a silicide of iron, cobalt or nickel and (c) 0.02-20 parts by weight of at least one oxide, nitride, or silicate of an element of IUPAC groups 2, 3, 4, 13 or the lanthanide series. A method for making such a product is also disclosed.

Silicon nitride ceramics containing a metal silicide phase

A ceramic comprising a matrix of Al.sub.2 O.sub.3, ZrO.sub.2 (partially or fully stabilized) or mixtures of Al.sub.2 O.sub.3 and ZrO.sub.2 with strontium aluminate plate-shaped grains distributed throughout the matrix results in a ceramic with high toughness, high strength and good hardness. SrO/Al.sub.2 O.sub.3 molar ratios between 0.02 and 0.20 result in in-situ formation of plate-shaped grains approximately 0.5 .mu.m in thickness and 5.0 .mu.m in breadth in tetragonal zirconia polycrystalline ceramic matrices. The in-situ formation of strontium aluminates allows high volume loading of platelets to occur and high toughness is achieved without the loss of strength. High alumina compositions have the added benefit of higher strength, lower thermal expansion, higher modulus and higher thermal conductivity than zirconia ceramics with comparable toughness.

Growing community of inventors

Newark, DE, United States of America

Roger L Matsumoto