Patent ID: 9540597
Date: 2017-01-10
CPC Classifications: C07C,C11D

Claim:
1. A process for preparing a powder comprising at least one methylglycine-N,N diacetic acid complexing agent salt of formula (I): wherein R′ is and R″ is methyl; M is, independently, hydrogen, an alkali metal, an alkaline earth metal, ammonium or a substituted ammonium in corresponding stoichiometric amounts, provided that at least one M is not hydrogen; comprising: (a) atomizing an aqueous solution comprising a first complexing agent salt of formula (I) in the presence of a crystalline fine dust of a second complexing agent salt of formula (I), to produce a powder, and (b) drying the powder, wherein a concentration of the first complexing agent salt in the aqueous solution is from 10 to 80% by weight, based on a total weight of the aqueous solution; an upper limit for an average particle diameter of the crystalline fine dust is lower by at least a factor of 2 than a lower limit of an average particle diameter of the powder obtained by the process; a fraction of the crystalline fine dust is from 0.1 to 20% by weight, based on a weight of the powder obtained in the process; and the residual moisture of the powder after drying is 6.5 to 14% by weight.