GB710777A - Improvements in washing and cleaning agents containing alkali salts of carboxyalkylcellulose - Google Patents

Abstract

An alkali salt of a carboxyalkyl cellulose for use in detergent compositions (see Group III) has a degree of substitution of 0.49 to 0.60, a fibre content of 6 to 16 per cent. and a viscosity of 20 to 30 cP. when measured in a standard Höppler viscometer at 20 DEG C. as a 1 per cent. aqueous solution, buffered by the addition of 2.5 per cent. by weight of anhydrous sodium carbonate and 2.5 per cent. by weight of sodium bicarbonate. In an example, sodium carboxymethyl cellulose with a degree of substitution of 0.55, a fibre content of 14 per cent. and a viscosity measured as above of 21 cP. is made by steeping 1 kg. of pulp in 20 per cent. sodium hydroxide at 20 DEG C. for two hours, pressing, shredding, and adding 276 g. of sodium hydroxide in 414 g. of water, followed by 750 g. of monochloracetic acid; the mixture is heated at 45 DEG C. for 20 hours, neutralized with HCl in ethanol, washed, dried and ground.ALSO:A detergent composition comprises one or more alkali salts of a carboxyalkyl cellulose and one or more other detergents, the carboxyalkyl cellulose salt having a degree of substitution of 0.49 to 0.60, a fibre content of 6 to 16 per cent. and a viscosity of 20 to 30-cP when measured in a standard Hoppler viscometer at 20 DEG C. as a 1 per cent. solution in water, buffered by the addition of 2.5 per cent. by weight of anhydrous sodium carbonate and 2.5 per cent by weight of sodium bicarbonate. The other detergent may be soap, a sodium alkyl-aryl sulphonate or a sodium salt of a primary or secondary alkyl sulphate. Sodium carbonate or sodium metasilicate may also be present in the compositions.