Patent ID: 8748366
Filing Date: 2014-06-10
Classification: C11D

Abstract:
1. A process for the preparation of a spray-dried powder comprising at least one glycine-N,N-diacetic acid compound of formula (I) wherein R is a C the process comprising: concurrently passing air and an aqueous solution comprising the at least one glycine-N,N-diacetic acid compound into a spray-drying apparatus; atomizing the aqueous solution in the spray-drying apparatus, to obtain fine liquid droplets; and drying the fine liquid droplets, to obtain the spray-dried powder, wherein a temperature difference between the aqueous solution and the air is in a range from 70 to 350° C., wherein the atomization comprises feeding the aqueous solution onto at least one disk which rotates at a peripheral speed of ≧100 m/s, or compressing the aqueous solution with a pump to a pressure of ≧20 bar absolute and feeding the aqueous solution into the spray-drying apparatus via at least one jet, wherein a content of the at least one glycine-N,N-diacetic acid compound in the aqueous solution passed into the spray-drying apparatus is ≧84% by weight, based on a total weight of the dry mass, wherein the spray-dried powder has a fraction of hollow spheres or hollow sphere breakage of ≧60%, wherein the fraction is determined by a process comprising: dispersing a sample of the spray-dried powder in a silicone oil, to obtain a sample mixture; transmitting light through the sample mixture, to obtain a transmitted light print having 56 to 300-times magnification; counting any particle present as a hollow sphere or a hollow sphere breakage and a totality of the particles in the transmitted light print; and calculating a percentage fraction of the particles present as hollow spheres or hollow sphere breakage, based on the totality of the particles, and wherein the spray-dried powder, when subjected to compression agglomeration, produces a tensile strength of ≧1.45 MPas.