Hoechst Aktiengesellschaft

Katharina Seitz

Andreas Roosen

Friedrich Hessel

Gerhard Wegner

Wolfgang Meyer

Christine Kostler

Rainer Buckpesch

Hans-Michael Guther

Christine Koestler

Frank Schroeder

Hans-Michael Guether

Jurgen Rudolph

Wolfgang Sigmund

A process is proposed for producing non-oxidic ceramic having a thermal conductivity in a predetermined range. A shaped body of non-oxidic ceramic material is heated to remove organic constituents, and is subsequently thermally treated in an oxygen-containing atmosphere to incorporate oxygen atoms into the crystal lattice of the non-oxidic ceramic, with the temperature and/or the hold time at this temperature being selected as a function of the predetermined thermal conductivity range, and the shaped body is finally sintered in a non-oxidizing atmosphere.

Process for producing non-oxidic ceramic having a defined thermal

A composition of inorganic powders comprises inorganic powder, dispersant and binder. The dispersant and/or binder used is a block copolymer of the units methacrylic acid and alkyl methacrylate in which the alkyl radical can comprise from 1 to 8 carbon atoms. The individual blocks of alkyl methacrylate possess an average molecular weight of at least 4000 and the total block copolymer has an average molecular weight of up to 150,000, in each case expressed as number average (M.sub.n).

Inorganic powder composition containing polymeric auxiliaries and use

The invention relates to a casting composition comprising a ceramic powder, an organic solvent, binder, plasticizer and a dispersant, which composition is suitable for producing green ceramic sheets by the tape casting process. The dispersant present in the casting composition of the invention is a polyvinyl alcohol/fatty acid ester having a degree of conversion in the range from 50 to 100%. The invention also relates to the use of such a casting composition for producing ceramic green sheets and a process for producing ceramic substrates using a green sheet thus produced.

Casting composition for producing green ceramic sheets containing

A method of processing water-sensitive ceramic powders, particularly carbothermically produced aluminum nitride, whereby the ceramic powder is deagglomerated in a dry milling step with addition of an alkylamine which is liquid at room temperature is disclosed. The alkylamine is added in an amount sufficient to produce a monomolecular layer on the surface of the ceramic powder. The deagglomerated powder subsequently is vigorously stirred with a concentrated aqueous solution or dispersion of binder and rapidly and gently dried, preferably by freeze drying. Aluminum nitride powder prepared by this process can be further processed into shaped parts with a high thermal conductivity.

Process for converting water-sensitive ceramic powders into a

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Frankfurt am Main, Germany

Katharina Seitz