Auxiliary Detergent Functions

Phosphate applications in relation to detergency are the stabilisation of suspensions, pH control, corrosion prevention and water softening (either by precipitation or by sequestration) (Section 12.6) (Chapter 5.3). Patent literature on these topics dates back 70-80 years, and that on the use of polyphosphates as surfactants and builders for traditional soaps covers about the same period. 

Sodium pyrophosphate, triphosphate and oligophosphates such as glassy metaphosphates are used frequently in conjunction with alkali metal carboxylate soaps. They soften hard water which would otherwise cause precipitation of insoluble calcium and magnesium soaps, and they increase lathering power. 

In laundry processes, small quantities of oligophosphates will sequester iron and other cations which might otherwise discolour the fabrics. In industrial bottle-washing operations, small quantities of oligophosphates will prevent deposition of salts in the machinery and also produce brighter bottles by improving the action of the detergents present. 

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Detergent formulas vary greatly, depending upon the intended end-use application. Differentialion by surfactant type as well as selection of auxiliary ingredients is involved. Some of the ingredients must commonly used in detergent formulas and their functions are as follows. 

Primary emulsifiers for a wide variety of personal care, household and Industrial formulations. Excellent detergents and wetting agents for heavy duty and light duty cleaner systems. Function as dispersants, solubilizers, couplers, and co-emulsifiers for specialty cosmetic and Industrial applications. Also used as primary and auxiliary surfactants for emulsion polymerization. 

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