Lever Brothers Company

Raymond J Wilde

Timothy David Finch

James F Davies

David E Clarke

John B Tune

A stable heavy metal adjunct, particularly manganese adjunct, for use as a peroxygen bleach catalyst is disclosed which comprises a matrix of a heavy meal salt provided with a surface powder coating of desiccant microsized powdered material having a mean particle size of less than 25 .mu.m. A process for preparing said adjunct and bleaching and detergent compositions containing said adjunct are also disclosed. Preferred heavy metal is manganese and preferred surface powder coating is with microsized silicon dioxide (silica).

Heavy metal adjuncts, their preparation and use

A stable manganese adjunct for use as a bleach catalyst is obtained by having a manganese (II) cation bound to a 'ligand' forming either a true complex compound, a water-insoluble salt compound, or an ion-binding compound by absorption, which compound is then protectively embedded in a matrix of water-soluble or water-dispersible material. The adjunct is particularly suitable for incorporation in fabric-washing powder compositions containing a peroxide bleach without causing instablity to the composition and brown discoloration due to MnO.sub.2 formation.

Manganese adjuncts, their preparation and use

Particulate detergent compositions comprising a detergent active compound, an alkali metal carbonate and finely divided calcium carbonate, are made by contacting the alkali metal carbonate in particulate form with a liquid or pasty detergent active compound or mixture thereof and admixing the calcium carbonate in powder form with the alkali metal carbonate particles so that the calcium carbonate adheres thereto.

Production of detergent compositions

The invention relates to the preparation of spray-dried powders of low bulk density. Fabric washing powders containing nonionic surfactants as the major or sole detergent-active species have unacceptably high natural bulk densities (about 0.6 g/l). It has been found that the incorporation of certain alkenyl succinate salts into the crutcher slurry can reduce the bulk density of the resultant spray-dried powder. There is also a need for absorbents of low bulk density for manufacturing nonionic-surfactant based powders by dry-mixing routes and it has been found that suitable absorbents can be prepared by adding alkenyl succinate to a slurry of the chosen ingredients and spray-drying.

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Wirral, United Kingdom

Raymond J Wilde