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:
Jan. 14, 2014
Filed:
May. 19, 2010
Frank Mrzena, Mutterstadt, DE;
Hans-juergen Kinder, Speyer, DE;
Michael Schoenherr, Frankenthal, DE;
Gerhard Cox, Bad Duerkheim, DE;
Thomas Schmidt, Neustadt, DE;
Volker Huett, Hockenheim, DE;
Frank Mrzena, Mutterstadt, DE;
Hans-Juergen Kinder, Speyer, DE;
Michael Schoenherr, Frankenthal, DE;
Gerhard Cox, Bad Duerkheim, DE;
Thomas Schmidt, Neustadt, DE;
Volker Huett, Hockenheim, DE;
BASF SE, Ludwigshafen, DE;
Abstract
A process is proposed for the preparation of a powder comprising one or more derivatives of glycine-N,N-diacetic acid and/or one or more derivatives of glutamine-N,N-diacetic acid with a degree of crystallinity of ≧30%, starting from an aqueous solution comprising the one or more derivatives of glycine-N,N-diacetic acid and/or the one or more derivatives of glutamine-N,N-diacetic acid in a concentration range from 20 to 60% by weight, based on the total weight of the aqueous solution, wherethe aqueous solution is concentrated in a first process step in an evaporator with rotating internals, which are arranged at a distance relative to the inside wall of the evaporator of ≦1% of the diameter of the evaporator, to give a crystal slurry with a solids concentration in the range from 60 to 85% by weight, based on the total weight of the crystal slurry, and wherein a second process step the crystal slurry is left to ripen in a paste bunker and then in a thin-film contact dryer, and where the residence time in the paste bunker and in the thin-film contact dryer is in total ≧15 minutes.