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:
Apr. 06, 1993
Filed:
Dec. 31, 1991
Shujiro Shiga, Oita, JP;
Yasuyoshi Sawaguri, Chiba, JP;
Koji Kabasawa, Chiba, JP;
Tatsuya Momobayashi, Chiba, JP;
Sumitomo Chemical Co., Ltd., Osaka, JP;
Abstract
A process for purifying a hydrogen peroxide solution is disclosed, comprising treating a 10 to 60% by weight hydrogen peroxide solution having a pH between 1.5 and 5.0 and containing anionic impurities with a hydrogencarbonate type or carbonate type anion exchange resin while adding an acid or a salt thereof having an acid dissociation constant pKa in water of not more than 5 to the hydrogen peroxide solution to be treated continuously or semi-continuously in an amount of from 0.5 to 5 milli-equivalents per liter of hydrogen peroxide solution. The hydrogen peroxide decomposing activity of the anion exchange resin can be inhibited without decreasing a rate of removal of strong acid radicals in the anionic impurities thereby minimizing oxygen evolution due to decomposition of hydrogen peroxide.