バニシングクリームのレオロジー的研究

抄録

Dispersions of stearic acid in an aqueous phase containing polyhydric alcohol, stabilized by sodium and potassium soaps, so-called vanishing cream, have been studied by measuring their flow and creep properties. The stearic acid was a commercially available mixture of the long chain acids of C₁₄, C₁₆, C₁₈ and C₂₀; the polyhydric alcohol was a member of the series glycerin, propylene glycol, etc. All the systems examined showed complex flow properties, e.g., hysteresis loops and spur points in the flow experiments. The creep behavior of all the systems could be represented by a mechanical model composed of a Voigt unit and a Maxwell unit in series. The observed total compliance was markedly dependent on the formulation and the aging time of the systems. However, the retardation time did not change appreciably, indicating that there was no essential difference in the nature of the secondary bonds in the systems, which was break and reform during creep tests. These rheological properties may be explained by the presence of a network structure of the soap micelles in which fatty acid was solubilize partially, in the aqueous phase.