Abstract: A continuous polymerization device is equipped with a stirring mechanism which possesses a drive shaft parallel to the direction of flow, a multiple number of polymerization precursor supply ports in the direction of flow, and at least one polymerization product output port at its latter portion, and possessing mixing capability with respect to the radial direction while possessing no actual mixing capability with respect to the direction of flow, in a continuous polymerization device which functions by piston flow.

Abstract: A proteinaceous emulsifier can be obtained by reacting an amino acid ester with a hydrophilic protein in the presence of an endopeptidase to form decomposition products of the hydrophilic protein having a carboxyl end group joined to the amino group of the amino acid ester by amide linkage.This proteinaceous emulsifier has a typical surfactant structure in which a hydrophobic portion consisting of the amino acid ester is attached to the rear end of a hydrophilic portion consisting of the protein, and is characterized by causing little irritation to the skin, exhibiting strong emulsifying power and possessing moisture retention properties. Thus, it is very suitable for use as an emulsifier in various cosmetics such as creams, milky lotions and the like.