Rutgerswerke Aktiengesellschaft

Wolfgang Jaumann

Siegfried Peter

Herbert Beneke

Arnold Alscher

Rudolf Oberkobusch

Franz Dietrich Oeste

Manfred Meinbreckse

Joachim R Kempfert

Wolfgang Fexer

A method of removing salts from coal tar and coal pitches comprising washing coal tar or coal pitch in a pressure container with water and a carbon dioxide containing gas at a temperature and pressure near the critical point of the gas in the optional presence of at least one member of the group consisting of a solvent and an entraining agent, removing the liquid or dissolved tar or pitch to obtain tar or pitch with a low salt content and removing the aqueous phase whereby all the resins remain in the tar or pitch.

Novel method for extraction of salts from coal tar and pitches

A method for the production of a carbon fiber precursor from coal tar pitch comprising extracting coal tar pitch at elevated temperatures and pressures with a mixture of a supercritical gas and an entraining agent to obtain a solution free of quinoline-insoluble components, recovering from the solution by lowering the pressure and/or raising the temperature to obtain at least one fraction selected from the group consisting of quinoline-soluble fraction and toluene-soluble fraction, treating the said fraction(s) at 380.degree. to 450.degree. C. under a non-oxidizing atmosphere at atmosphere pressure until 40 to 65% by volume of the product is converted into pitch containing mesophase, extracting the latter pitch with a mixture of supercritical gas and an entraining agent to remove isotropic pitch and recovering isotropic pitch with a mesophase content of at least 75% by volume, a pyridine-insoluble matter content of 20 to 50% by weight, a mean molecular weight of 900 to 1200 and a melting point of 330.degree. to 360.degree. C. and the isotropic pitch product produced therefrom and carbon fibers made from the isotropic pitch.

A method for the production of a carbon fiber precursor

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Nuremberg, Germany

Wolfgang Jaumann