GB796627A - Improvements in or relating to detergent bars - Google Patents

Abstract

A milled detergent bar comprises (a) a sodium soap generally present to the extent of at least 10 per cent, usually 10-35 per cent; (b) a solid anionic synthetic detergent comprising a watersoluble alkali-metal salt of an organic sulphuric reaction product, generally present to the extent of 15-40 per cent; and (c) 15-70 per cent, generally 15-45 per cent, of a non-waxy starch, preferably oxidized starch, which has been so gelatinized that anisotropy has disappeared. The soap is suitably a coconut or tallow soap or a mixture of such soaps, and may additionally incorporate potassium, ammonium or substituted ammonium soaps in amounts of 5-10 per cent by weight of the sodium soap. Particularly suitable anionic detergents are the sodium salts of the alkyl sulphates, the alkyl glyceryl ether sulphonates, and the sulphated reaction products of ethylene oxide with fatty alcohols, but others which may be used are the alkyl monoglyceride sulphates, the alkyl monoglycol sulphates, the alkyl monoglyceryl sulphonates, the acyl isothionates, the N-acyl methyltaurines, the alkyl sulphoacetates, the N-alkyl hydroxyacetamides, and the alkylbenzene sulphonates. Non-ionic detergents may also be included in limited amounts. The total amount of detergent and soap may be 25-65 per cent, preferably 35-65 per cent, and moisture may comprise 5-15 per cent. Small amounts of perfume, sodium tripolyphosphate, calcium or magnesium soap and also of a fatty alcohol (as a suds improver) may be incorporated, and additionally the compositions generally contain small quantities of sodium chloride and sulphate as impurities. The bars may be prepared by a process comprising heating and agitating the starch in a solution of the anionic detergent, rupturing the starch, for example in a homogenizer, and then further heating it, for instance in a spray tower, until anisotropy disappears and the excess water is driven off from the solution, and thereafter adding the other ingredients to the dried mix, followed by milling and extruding the mix into bars. Alternatively both the rupturing and further heating process may be performed on a steam-heated roll. Yet again, the starch may be gelatinized by pre-cooking before it is mixed with the other ingredients. The sodium soap may be added either to the solution of synthetic detergent, or to the dried mix, or partly to both. Specification 791,415 is referred to.