GB1012488A - Improvements in or relating to detergent compositions - Google Patents

Abstract

A method of preparing a dry, free-flowing detergent composition comprises dispersing a phosphoric acid in a body of dry, solid particles of an alkali metal carbonate containing material in a proportion in which the M2CO3 : H3PO4 mol. ratio is at least 1.5 : 1 (M being the alkali metal), agitating the mixture while maintaining it at a temperature not substantially in excess of 104 DEG C., and recovering the resulting dry, free-flowing product characterized by an M2O : P2O5 mol. ratio greater than 3 : 1 and a pH as a 1% w/v. aqueous solution, greater than 7.5. The composition contains at least one phosphate having the formula: MxHyPO4.aH2O where x and y are positive integers greater than 0, the sum of which is 3 and a is a number from 0 to 2, e.g. Na2HPO4, NaH2PO4 and at least one alkali metal carbonate, bicarbonate, sesquicarbonate or a mixture thereof. Specified phosphoric acids are ortho-, pyro-, meta-, and tripolyphosphoric acids, and phospholeum, a concentrated phosphoric acid having a P2O5 content equivalent to 105% H3PO4. When the latter is reacted with soda ash the product contains Na4P2O7. "Light" and "Dense" ash are the preferred alkali metal carbonate-containing materials reacted with phosphoric acid. Non-ionic, cationic and anionic organic surfactants, which may be either in liquid or in solid form, may be added to the detergent composition together with the phosphoric acid. Exemplified non-ionic surfactants are alkyl aryl polyether alcohol, alkyl aryl polyethylene glycol ether, polyoxyethylene ether, polyoxyethylenethioether, polyoxyethylene ester of mixed fatty and resin acids, fatty alkylol amine condensates, alkyl aryl polyethylene glycol, alkyl polyoxyethylene alcohol, polyethanolamine fatty acid condensate, amino fatty ester, aromatic polyglycol ether condensate, polyethylene glycol tert-dodecyl thioether, and a secondary amide of lauric acid. Specified anionic surfactants are alkyl aryl sulfonates, decyl benzene sodium sulfonate, sodium lorol sulfoacetate, alkyl sulfates, sodium lorol sulfate, triethanolamine salt of alcohol sulfates, N-octadecyl disodium sulfo-succinamate, fatty amide sulfate, sodium palmitoyl methylaurate, amidoalkane sulphonates, sodium oleyl p-anisidine sulfonate, a mixture of an alkyl aryl sulfonate and an alkanolamide, lauroyl imidazolene, sodium dodecyl toluene sulfonate, and the sodium salt of alkyl aryl polyether sulfate. Cationic surfactants exemplified comprise quaternary ammonium halides, alkyl imidazolenes, alkanol alkyl imidazolenes, CH3(CH2)n-COOCH2CH2 <FORM:1012488/C4-C5/1> and lauryl pyridinium chloride. Solid and liquid alkali metal silicates may also be added to the "light" ash after phosphoric acid has been added thereto. Specification 1,005,400 is referred to.ALSO:A method of preparing a dry, free-flowing detergent composition comprises dispersing a phosphoric acid in a body of dry solid particles of an alkali-metal-carbonate-containing material in a proportion in which the M2CO3: H3PO4 mole ratio (M being alkali metal) is at least 1.5 : 1, agitating the mixture while maintaining it at a temperature not substantially in excess of 104 DEG C., and recovering the resulting dry free-flowing product characterized by an M2O : P2O5 mole ratio greater than 3 : 1 and a pH, as a 1% w/v aqueous solution, greater than 7.5. The composition contains at least one phosphate having the formula MxHyPO4.aH2O, where x and y are positive integers greater than 0, the sum of which is 3 and a is a number from 0 to 2, e.g. Na2HPO4 or NaH2PO4, and at least one alkal metal carbonate, bicarbonate, sesquicarbonate or a mixture thereof. Specified phosphoric acids which may be used are ortho-, pyro-, meta-, and tripoly-phosphoric acids, and phospholeum, a concentrated phosphoric acid having a P2O5 content equivalent to 105% H3PO4. When the latter is reacted with soda ash, the product contains Na4P2O7, tetrasodium pyrophosphate. The preferred alkali-metal-carbonate-containing materials reacted with the phosphoric acid are sodium carbonates known as "light ash" and "dense ash." In a typical example (Example 20), phospholeum is added to granular light ash in a Na2CO3 : H3PO4 mole ratio o 2 : 1 to give a product having a Na2O : P2O5 ratio of 4 : 1. Specification 1,005,400 is referred to.