Alkyl phosphates are well known and commonly used for a long time in the cosmetic and detergent field as a mild surfactant. However, many of general industrial products of alkyl phosphate in the market are the mixtures of mono-, di- and tri-esters which do not have the specific features of mono ester. In this study, by increasing the mono alkyl content, we tried to discover the new functional behavior and structure using the highly purified hexadecyl alkyl phosphate.
Among the compounds studied, hexadecyl phosphate neutralized with L-arginine (R16MP-Arg) in an aqueous system showed characteristic solution properties and association behavior below Krafft temperature. Spontaneous swelling of R16MP-Arg was observed below the Krafft temperature, and a gel structures composed of R16MP-Arg and water was formed without heating and shaking. This gel was identified as a thermodynamically stable “α-gel” based on the results of DSC and SAXS measurements.
In this study, we revealed that highly purified mono hexadecyl phosphate with L-arginine organized stable α-gel structure. Cosmetics in which this α-gel is used as the base give a refreshing and smoothing sensation when applied to the skin. The unique property of R16MP-Arg is that it affords a stable gel structure even when mixed with fatty alcohol.

The haptic technologies corresponding to metrology and display of tactile sensations are in progress. It requires fundamental information of the physical mechanisms of tactile sensations. Tactile sensation is usually expressed as adjectives or onomatopoeias, but the physical phenomena during touch cannot be presumed by such sensuous words. We are trying to examine what kind of physical phenomena and microscopic interactions between human skin and materials cause the objective tactile sensations. In this paper, we describe some fundamental examples of the physical models that represent tactile sensations for fabrics and skin care products, and then discuss about application possibility of the models for material design of tactile sensation.

The acquisition of objective skin information by analytical techniques is essential for evaluation of the effects of cosmetics and pharmaceuticals to the skin. In addition, analytical approaches that target not only the skin surface, but also those that specifically evaluate skin layer features and skin constituents are long-awaited. The progress of non-invasive optical technologies in recent years enables us acquisition of the skin structural information at a molecular level as well as the evaluation of skin physical properties. In this article, we present our novel skin evaluation methods developed using optical techniques.