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, 1999
Filed:
Apr. 15, 1998
Shoichiro Kajiwara, Yamakita-machi, JP;
Hirokazu Serizawa, Yamakita-machi, JP;
Kazunori Nagai, Yamakita-machi, JP;
Mitsubishi Gas Chemical Company, Inc, Tokyo, JP;
Abstract
A process for purifying an aqueous solution of hydrogen peroxide comprising bringing the aqueous solution of hydrogen peroxide into contact with a cation exchange resin or an anion exchange resin, aging the obtained intermediately purified aqueous solution of hydrogen peroxide by standing alone for 1 hour or more, and bringing the aged aqueous solution of hydrogen peroxide into contact with an ion exchange resin of the same type. The process provides a high purity aqueous solution of hydrogen peroxide and can advantageously be used in the field of production of semiconductors.