METHOD OF DETERMINING STORAGE TIME OF COMMERCIAL TOILET SOAP IN ORDER TO CONTROL AND/OR PREDICT ITS QUALITY Russian patent published in 2003 - IPC

FIELD: detergents. SUBSTANCE: invention, in particular, relates to detergents based on saturated and unsaturated aliphatic acid alkali metal salts. Storage time of soap is determined by oxidation of samples being analyzed by air oxygen at heating in presence of test additive. Current concentrations of the latter are measured, kinetic parameter reflecting oxidation rate calculated, and calibration graph is then plotted. Oxidation reaction is conducted in autooxidation mode and test additive is selected from aromatic or condensed aromatic diamine, for example N,N'-di-beta-naphthyl-p-phenylenediamine. Concentration of additive is measured using electron-spectroscopy technique and kinetic parameter is computed in terms of the following formula: wherein α is kinetic parameter, l/mole*s; ε molar extinction of test additive conversion product, l/mole*cm; D₁, D₂ optical density of solution of toilet soap oxidized during time τ₁, τ₂; D₀ optical density of reference solution; [O₂] concentration of oxygen dissolved in substrate being oxidized, mole/l; [Mc_m] concentration of toilet soap in solution, mole/l; τ₁, τ₂ experiment time, sec; and l thickness of cuvette, cm. Calibration graph represents logarithm of kinetic parameter α as function of storage time of toilet soap samples. Proposed express method is low expensive, informative, allows prediction of toilet soap storage time, and enables, in the toilet soap composition development stage or in stripped soap base partial modification stage, recommendations concerning optimization of additive formula. EFFECT: facilitated soap production control and reduced expenses on selection of optimum antioxidant concentrations. 1 dwg, 1 tbl, 9 ex