Henkel Kommanditgesellschaft Auf Aktien

Herbert Saran, Deceased

Martin Witthaus

Herbert Reuter

Coated granular bleach activators and a process for their preparation comprising spray drying an aqueous slurry containing 1 to 1.7 parts by weight of water per part of a mixtue of (A) a powdery bleach activator and (B) at least one water soluble cellulose ether, starch, or starch ether in a ratio of A:B of from 99:1 to 90:10. The process utilizes a current of a drying gas having an entrance temperature of 100.degree.-200.degree. C. and an exit temperature of 40.degree.-120.degree. C.

Method of making coated granular bleach activators by spray drying

In the production of a spray-dried detergent containing a silicone/silica mixture as an antifoaming agent, the aqueous silicone-free detergent slurry (A) is combined in the range of the spray nozzle or in the pressure line leading to the spray nozzle under conditions whereby substantial mixing is avoided in order to avoid loss of the antifoaming action, with an aqueous dispersion (B) which contains the liquid antifoaming silicone agent, which is present in a particle size of from 0.5 to 40 .mu.m, as well as a film-forming, high-molecular-weight polymer which is soluble or swellable in water, and which is suitable for the formation of microcapsules, preferably a cellulose ether. The microcapsules are formed during the combination of the mixture (A) with the dispersion (B) at the time of spraying, or in the dispersion itself, if electrolyte salts were added to the latter before spraying.

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Herbert Saran, Deceased