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:
Jul. 01, 2003
Filed:
Feb. 20, 2001
The Gillette Company, Boston, MA (US);
Abstract
A process for manufacture of manganese dioxide comprising subjecting an aqueous bath comprising manganese sulfate (MnSO ) and sulfuric acid (H SO ) to electrolysis in a closed cell wherein the electrolysis bath is maintained at an elevated temperature above 110° C., preferably above 115° C. and at superatmospheric pressure. Desirably the bath can be maintained at an elevated temperature between about 115° C. and 155° C. The electrolysis is carried out preferably at elevated current density of between about 12.5 and 37 Amp/sq. ft (135 and 400 Amp/sq. meter) which allows for smaller or fewer electrolysis units. An MnO product having a specific surface area (SSA) within desired range of between 18-45 m /g can be obtained. A doping agent, preferably a soluble titanium dopant is employed to help obtain the desired specific surface area (SSA) of the MnO product. The manganese dioxide product in zinc/MnO alkaline cells gives excellent service life, particularly in high power application.