GELLED OIL-IN-WATER ULTRAFINE EMULSION STABILIZED BY AT LEAST 90 NEUTRALIZED CROSSLINKED POLY(2-ACRYLAMIDE-2-METHYLPROPANESULFONIC ACID, ITS PREPARATION, AND ITS APPLICATION

摘要

PROBLEM TO BE SOLVED: To obtain cosmetics and/or dermatologic composition which are in pleasant and stabilized oil-in-water type emulsion by adding a crosslinked poly(2- acrylamide-2-methylpropanesufonic acid) polymer. SOLUTION: This composition is in an ultrafine oil-in-water type emulsion in which the average particle size of the small spheres constituting the oil phase is 50-1,000nm and contains at least a crosslinked poly(2-acrylamide-2- methylpropanesulfonic acid) polymer neutralized by at least 90%. The polymer swells with water and contains randomly dispersed the following units a) and b): a) 90-99.9wt.%, based on the whole weight of the polymer, of the unit represented by the formula (X+ is a cation or a mixture thereof; the cation X+ may be H+ in an amount of 10mol% at maximum); b) 0.01-10wt.% of the crosslinking units which originate from at least one monomer containing at least 2 olefinic double bonds. This composition is prepared through the emulsification technique utilizing the phase inversion.