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:
Nov. 02, 1982
Filed:
Sep. 11, 1980
Jacques D Hanotier, Saint-Lambert, BE;
Jacques F Dauby, Groot-Bijgaarden, BE;
Labofina, S.A., Brussels, BE;
Abstract
The reaction mixture obtained by oxidizing p-xylene in the presence of water as diluent, at a temperature comprised between 140.degree. and 220.degree. C., and consisting of terephthalic acid crystals in suspension in an aqueous solution comprising unreacted p-xylene, intermediate oxidation products thereof, the heavy-metal catalyst and water is introduced in the upper part of a sedimentation column wherein the acid is separated by gravity and is washed with a counter current of water introduced near the bottom of said column, the temperature of the washing zone being higher than the minimum value T.sub.w given by the equation T.sub.w =144+0.225 T.sub.R, wherein T.sub.R is the oxidation temperature.