Process for preparing needle-shaped crystal growth modified burkeite detergent additive
AssigneeLever Brothers Company
InventorsColin Atkinson, Michael J. Heybourne, William J. Iley, Peter C. Knight, Peter J. Russell, Thomas Taylor, David P. Jones
Life of this patent
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Abstract
Powders prepared by drying a slurry and suitable for use as detergent powders or components thereof contain (or consist of) sodium carbonate and/or the sodium carbonate/sodium sulphate double salt Burkeite the crystal forms of which have been modified by means of a low level of an organic polycarboxylate. The powders are able to absorb and retain very high levels of liquid components such as nonionic surfactants.
Claims15
A process for the production of a powder suitable for use as a granular detergent composition or a component thereof, which comprises the steps of
- (i) preparing an aqueous slurry comprising from about 5 to 70% sodium carbonate, and from 0 to about 50% sodium sulphate,
- (ii) drying the slurry to form a powder,
- the total amount of sodium carbonate and sodium sulphate being at least 10% by weight based on the dried powder, the weight ratio of sodium carbonate to sodium sulphate in the slurry being at least 0.37:1, the process being characterised in that an effective amount of a crystal growth modifier which is a polymeric polycarboxylate selected from the group consisting of acrylic acid homopolymers, acrylic acid/maleic acid copolymers, acrylic phosphinates and mixtures thereof, is incorporated in the slurry not later than the sodium carbonate, whereby needle-shaped crystal-growth-modified Burkeite is formed in the slurry.
Dependencies are inferred from the claim text.