Lime soap dispersing agents

The ability to disperse the calcium soap formed from a given amount of sodium oleate has been studied for a number of a-sulfo fatty acid esters with 14-22 carbon atoms [28,30]. In principle, the lime soap dispersion property increases with the number of C atoms and the dissymmetry of the molecule. Esters with 14 C atoms have no dispersion power and in the case of esters with 15-17 carbon atoms the least symmetrical are the better lime soap-dispersing agents. However this property does not only depend on the symmetry but on the chain length of the fatty acid group. For example, methyl and ethyl a-sulfomyristate have better dispersing power than dodecyl propionate and butyrate. The esters with 18 and more carbon atoms are about equal in lime soap dispersion power. Isobutyl a-sulfopalmitate is the most effective agent under the test conditions. 

IV. Chemical Structure of Lime Soap-Dispersing Agents 637... 

IV. CHEMICAL STRUCTURE OF LIME SOAP-DISPERSING AGENTS... 

FIG. 1 Schematic representation of the action of a lime soap-dispersing agent according to Stirton et al. (From Ref. 25.)... 

TABLE 1 Lime Soap Dispersant Requirement (LSDR) of Various Types of Lime Soap-Dispersing Agents (LSDAs)... 

Lime soap dispersing agents (LSDA) are surfactants that enable soap to act as an effective laundry detergent in hard water without the deposition of insoluble calcium soap. For a surfactant to act as an LSDA, it must possess a bulky... 

Amidosulfonates. Amidosulfonates or A/-acyl-A/-alkyltaurates, are derived from taurine, H2NCH2CH2S02Na, and are effective surfactants and lime soap dispersants (Table 9). Because of high raw material cost, usage is relatively small. Technically, amidosulfonates are of interest because they are stable to hydrolysis, unaffected by hard water, and compatible with soap. They have been used in soap—surfactant toilet-bar formulations. With shorter, acyl groups, they make excellent wetting agents. 

Ether carboxylates are used not only in powdered detergents but in liquid laundry detergents for their hard water stability, lime soap dispersibility, and electrolyte stability they improve the suspension stability and rheology of the electrolyte builder [130,131]. Formulations based particularly on lauryl ether carboxylate + 4.5 EO combined with fatty acid salt and other anionic surfactants are described [132], sometimes in combination with quaternary compounds as softeners [133,163]. Ether carboxylates show improved cleaning properties as suds-controlling agents in formulations with ethoxylated alkylphenol or fatty alcohol, alkyl phosphate esters or alkoxylate phosphate esters, and water-soluble builders [134]. 

Hydroxysultaines find use in personal care products, where they function as secondary surfactants to enhance the properties of anionic-based formulations, in much the same way as betaines. They are also among the best lime soap dispersants known, so they are used effectively in natural soap based products where they make the use of hard water practical. They are also used in petroleum production chemicals were they serve as foaming agents for acid and foam fracturing procedures. 

POE Mercaptans, RS(C2H/))XH Unstable to oxidizing agents, such as chlorine, hypochlorites, per-oxides, and strong acids. (This may be an advantage when inactivation of surfactant after use is desired.) Stable in hot, strong alkali. Good lime soap dispersants. 

Alipal . [Rhone-Poulenc Surf.] Ethoxylated alcohol sulfate salt detergent emulsifier, stabilizer, lime-soap dispersant wetting agent foamer dishwashing formulations, scrub soaps, car washes, rug and hair shampoos, emulsion polymerization, concrete, petrol, waxes, textile wet processing, cosmetics, pesticides. 

Surfonic . [Texaco] Ethoxylates emulsifier, wetting agent dry cleaning detergent penetrant solubilizer, lime soap dispersant antifoamer used in agric., cosmetics, industrial cleaners, ceramics, concrete, film developing, emulsion polymerization, latexes. 

Classification Organic acid Formula R(OCH2CH2)nOCH2COOH, R = coconut oil fatty acids, avg. n = 6 Properties Anionic/nonionic Uses Surfactant, emulsifier in cosmetics, hair care, skin care coupling agent lime soap dispersant... 

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