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. 18, 1989
Filed:
Jun. 07, 1988
Alexander Ruhs, Rheinfelden, DE;
Degussa Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Particulate, active-oxygen compounds, especially sodium percarbonate, tend to cake during storage, which makes it more difficult to handle them. The invention reduces this caking tendency while the active-oxygen content remains essentially unchanged. The method of achieving this comprises bringing the active-oxygen compound in contact with such an amount of an aqueous solution containing one or more phosphonic acid compounds capable of chelate complex formation that the weight ratio of active-oxygen compound to phosphonic acid compound is 100:0.1 to 100:10, preferably 100:1 to 100:3, and subsequent drying. Sodium percarbonate is used in particular as active-oxygen compound and 1-hydroxyethane-1,1-diphosphonic acid as a 3 to 30% by weight aqueous solution is used as phosphonic acid compound. Sodium percarbonate wet salt is preferably washed with this solution, freed of excess solution and dried. Percarbonate treated in this manner hardly tends to cake at all and exhibits a greater active-oxygen stability.