E.i. Dupont De Nemours and Company

Frederick N Tebbe

John D Bolt

Leo E Manzer

Walter Mahler

Robert J Young, Jr

Steven Dale Ittel

Ralph Thomas Baker

Ulrich Klabunde

William G Peet

Edward J Newitt

Patricia L Watson

Shaped articles of polycrystalline aluminum nitride are disclosed having a tensile strength of at least about 100 Kpsi. The shaped articles are preferably fibers. Composites of polycrystalline AlN fibers in a matrix of organic or inorganic polymer, metal, glass or ceramic are also disclosed herein. The process for the preparation of polycrystalline aluminum nitride fibers is covered.

High strength aluminum nitride fibers and composites and processes for

Borides and boride precursors deposited from solution

A catalyst composition is disclosed which consists essentially of an aluminum fluoride prepared by the reaction of aluminum hydroxide and HF. Also disclosed is a process for preparing 1,1,-dichloro-1,2,2,2-tetrafluoroethane by chlorofluorination which comprises the step of contacting a gaseous mixture comprising at least one tetrahaloethylene having the formula C.sub.2 Cl.sub.4-x F.sub.x wherein x is an integer from zero to 3 and both Cl.sub.2 and HF with said catalyst composition at an elevated temperature; and a process for producing 2-chloro-1,1,1,2-tetrafluoroethane and/or 1,1,1,2-tetrafluoroethane by hydrodechlorinating 1,1-dichloro-1,2,2,2-tetrafluoroethane prepared by said chlorofluorination.

Aluminum fluoride catalyst compositions and use thereof in a

A process is disclosed for transforming a saturated reactant (e.g. 1,1,2-trichloro-1,2,2-trifluoroethane) into a saturated product (e.g. 1,1-dichloro-1,2,2,2-tetrafluoroethane) by contacting a gaseous mixture comprising said reactant with an aluminum fluoride catalyst at an elevated temperature, which is characterized using a catalyst composition consisting essentially of an aluminum fluoride prepared by the reaction of aluminum hydroxide and HF. Also disclosed is a process for producing 2-chloro-1,1,1,2-tetrafluoroethane and/or 1,1,1,2-tetrafluoroethane by hydrodechlorinating 1,1-dichloro-1,2,2,2-tetrafluoroethane produced by said transformation.

Processes using aluminum fluoride catalyst compositions for preparing

A process for preparing chemically stable compositions of tetra(hydrocarbyl)metallic compounds in solution, and an improved process for the preparation of active 1-olefin polymerization catalysts.

Stable solutions of tetra(hydrocarbyl)metal compounds and use thereof

Methods are described for preparing aluminum nitride of controllable morphology for ceramic and heat conduction applications. The methods comprise forming spherical particles or flakes of an intermediate, RAlNH, followed by heating the spheres or flakes of RAlNH at elevated temperatures to produce high purity aluminum nitride of corresponding morphology. Spheres of RAlNH are formed by (i) freezing a suspension of RAlNH in a liquid medium and thawing, by (ii) aging the suspension, or by (iii) dissolving RAlNH in a liquid medium and precipitating it. Flakes are formed by freezing a suspension of RAlNH in a liquid medium and removing frozen medium from the frozen suspension.

Aluminum nitride flakes and spheres

Shaped articles of polycrystalline AlN and AlN-containing composites; the AlN articles having thermal conductivities of at least about 70 W/mK (watts/meter .degree.K); the AlN component effecting good thermal conductivity in the composited articles.

AlN and AlN-containing composites

An organoaluminum polymer formed from R.sub.3 A1 and dialkylaluminum amide that is useful for forming shaped articles of inorganic aluminum nitride alone or with nitrides (other than AlN), oxides, borides, carbides or combinations thereof; R being selected from hydrogen; C.sub.1 to C.sub.10 alkyl; halogen; and substituted or unsubstituted phenyl, naphthyl and biphenyl; no more than two of the R groups being alkyl.

Melt-formable organoaluminum polymer

A method of producing coatings of boron nitride on substrates by the application of solutions containing boron compounds.

Method for coating substrates with boron nitride

A process for forming polysilanes from silicon hydrides by contacting the silicon hydride with catalytic amounts of selected scandium, yttrium and rare earth metal hydrides, and a process for hydrosilation of alpha-olefins in which an alpha-olefin is contacted with a silicon hydride in the presence of catalytic amounts of selected scandium, yttrium and rare earth metal compounds.

Hydrosilation, and dehydrocondensation of silicon hydrides, catalyzed by

Methods are described for preparing aluminum nitride of controllable morphology for ceramic and heat conduction applications. The methods comprise forming spherical particles or flakes of an intermediate, RA1NH, followed by heating the spheres or flakes of RA1NH at elevated temperatures to produce high purity aluminum nitride of corresponding morphology. Spheres of RA1NH are formed by (i) freezing a suspension of RA1NH in a liquid medium and thawing, by (ii) aging the suspension, or by (iii) dissolving RA1NH in a liquid medium and precipitating it. Flakes are formed by freezing a suspension of RAINH in a liquid medium and removing frozen medium from the frozen suspension.

Admixing an aluminum alkyl, and optionally a boron compound, with a hydride of nitrogen in the gas phase and maintaining a gas phase temperature, optionally in the presence of a carrier gas, and producing aluminum nitride alone or in admixture with a precursor thereof or boron nitride or both.

Gas phase preparation of aluminum nitride

Cross-linked organosilazane polymers which are useful as ceramic precursors and film casting are disclosed.

Cross-linked organosilazane polymers

An organoaluminum polymer formed from R.sub.3 Al and R.sub.2 AlNH.sub.2 that is useful for forming shaped articles of inorganic aluminum nitride along or with other nitrides, oxides, carbides or combinations thereof; R being selected from C.sub.x H.sub.2x+1 wherein x is 1 to 10.

Alkali-metal tetraorganylborate compounds of formula MBR.sub.4 are prepared by reacting triorganylboranes R.sub.3 B with alkali-metal hydroxide or alkoxide compounds of the formula MOR.sup.1.

Growing community of inventors

Hockessin, DE, United States of America

Frederick N Tebbe