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:
Oct. 12, 1976
Filed:
Jun. 06, 1975
Gerd Knippschild, Rheinfelden-Beuggen, DT;
Hubert Schuster, Rheinfelden-Karsau, DT;
Abstract
Abrasion resistant and coarser sodium perborate tetrahydrate is prepared by reacting an aqueous sodium metaborate solution with aqueous hydrogen peroxide while avoiding free active oxygen and free alkali in the reaction medium. A strongly supersaturated perborate tetrahydrate solution having 200 to 700 grams/liter of perborate tetrahydrate is introduced into a previously prepared suspension of mother liquor and innoculant crystals which contains 100 to 500 grams/liter of suspension of seed crystals at such a rate that not more than 30 grams of perborate tetrahydrate grow as crystals per minute per square meter apparent innoculant surface area at 20 to 40.degree. C. and a rate of crystallization growth of not more than 100% whereupon the temperature is reduced to 15.degree. C. within 15 to 30 minutes, in a given case in a subsequent step. In another aspect of the invention the perborate is added at a point not earlier than the crystallizer.