GB1013992A - Detergent composition - Google Patents

Abstract

Homogeneous, mechanically worked detergent bars comprise by weight (1) 12 to 30% of an alkali metal e.g. sodium or potassium, or alkaline earth metal, e.g. calcium or magnesium, alkyl-arylsulphonate, alkyletheylene oxide ether sulphate, acyl N-methyl tauride, alkyl sulphate, alkyl sulphonate or acyl monoglyceride sulphate and (2) 46 to 88% of inorganic material consisting of alkali metal and alkaline earth metal carbonates, bicarbonates, borates, chlorides, ortho, meta, pyro and tripolyphophates and sulphates, the weight percentages being calculated on the basis of anhydrous materials. Preferably the bar may contain by weight (i) 10 to 25% of sodium tripolyphosphate, (ii) 25 to 55% of sodium bicarbonate, (iii) up to 15% of trisodium orthophosphate, (iv) up to 5% of an amide foam builder, e.g. N-substituted amides mono and diethanolamides of fatty acids having 8 to 18 carbon atoms, (v) up to 5% of sodium silicate with a ratio of Na2O:SiO2 of 1.0:0.90 to 1.0:3.25, and (vi) 5 to 25% of water. The alkylarl sulphonates contain alkyl groups having 9 to 15 carbon atoms and may be derived from alcohols obtained from naturally occurring glycerides, e.g. coconut and palm oils and petroleum, e.g. sodium tetrapropylene benzene sulphonate and sodium n-dodecyl benzene sulphonate. The aryl group may also be derived from naphthalene. The alkyl sulphates, sulphonates and alkylethylene oxide ether sulphates contain C8 to C20 alkyl groups, the ether sulphates also containing 1 to 9 ethylene oxide units per molecule, e.g. sodium tallow alkyl sulphate, sodium coconut alkyl sulphate, sodium lauryl sulphate, sodium dodecyl sulphate and the sulphated condensation product of one mole coconut alcohol and three moles ethylene oxide. The acyl N-methyl taurides and acyl monoglyceride sulphates contain C8 to C20 acyl groups derived from tallow, coconut, palm, soybean oils and lard. Other additives include sodium carboxymethylcellulose, high molecular weight polymers of ethylene oxide and carboxyvinyl polymers, colouring material, optical brighteners, benztriazole and bleaching agents. The detergent bars are formed by extruding the homogeneous detergent mixture at 100 DEG to 170 DEG F. into rods and then slicing into bars. The mixture may be prepared by (1) mixing the ingredients and then adding water or sodium silicate solution as plasticizer, working and milled into flakes; (ii) mixing a paste of the surfactant constituent with the inorganic materials to give a slurry which can be spray dried; and (iii) spraying a liquid form of the free acid of the surfactant on to at least a stoichiometric amount, sufficient to neutralize the free acid, of an alkali metal or alkaline earth metal carbonate or bicarbonate, the remainder of the inorganic material comprising an alkali metal or alkaline earth metal borate, chloride, ortho, meta, pyro or tripolyphosphates and sulphate giving a neutral or to alkaline reaction, the amount of water being insufficient to destroy the particulate nature of the mixture, mechanically working to effect homogeneity and effect complete neutralization of the detergent acid. Specifications 645,129 and 823,653 are referred to.