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:
Sep. 20, 1977
Filed:
Sep. 17, 1975
Mitsui Petrochemical Industries, Ltd., Tokyo, JA;
Abstract
A method for separating and recovering hydroquinone which comprises distilling a by-product-containing acid-cleavage product, which is obtained by acid-cleavage of an oxidation product of para-diisopropyl benzene in a solvent, in the presence of an aromatic hydrocarbon, thereby removing low-boiling fractions including the solvent, bringing the resulting hydroquinone-containing distillation bottoms into contact with water, and crystallizing and separating hydroquinone; characterized in that A. the distilling off of the low-boiling fractions is effected without the addition of water and in the absence of an azeotropic amount of water and also in the presence of an aromatic hydrocarbon containing 9 to 10 carbon atoms, and B. the contacting of the distillation bottoms with water is effected under conditions which do not induce crystallization of hydroquinone in the distillation bottoms.