The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 21, 1989
Filed:
Jan. 07, 1987
Herbert Beneke, Castrop-Rauxel, DE;
Siegfried Peter, Uttenreuth-Weiner, DE;
Rutgerswerke AG, , DE;
Abstract
A process for the production of pitch raw materials having improved properties comprising extracting coal-tar pitch free of solids with a mixture of a supercritical gas extracting agent and an entrainer at elevated temperatures and pressures, passing the extraction mixture to a plurality of separation steps where the supercritical gas and entrainer are removed by lowering the pressure and/or raising the temperature, recycling the mixture of extracting agent and entrainer to the extraction step and recovering the pitch fractions from the separation step, the said pitch fractions being useful for diverse purposes such as soot production, electrode bonding agents, etc.