Abstract
Soap has been the most popular surfactant, because of its low price, rich foam, and refreshed feeling after washing. However, it is sometimes said that soap feels squeaky in rinsing and stretched after dried.
We searched mild surfactants to solve these problems, while preserving good points of soap. As a result, lysine salt of fatty acid is found to be a good surfactant with features as below;
(1) It shows as low primary irritations to both skin and eye mucosa as popular mild surfactants.
(2) It shows better biodegradability than other salts of fatty acid.
(3) It has excellent foaming power under various conditions, i.e. low concentration, weak alkaline region.
(4) In sensory test, it shows rapid foaming, rich foam volume, long lasting foam at washing, and refreshed, moisturized, smooth feeling after dried.
