| 摘要 |
<p>A process for producing an emulsion of an ultraviolet-absorbent water-base vinyl resin or a fine particle thereof, which can be blended with a cosmetic base, etc., at high concentration, is highly safe and can exhibit sufficiently the effect as an ultraviolet absorber. An ultraviolet-absorbent self-dispersible water-base vinyl resin is obtained by conducting the solution polymerization of a monomer mixture containing as the essential components 20 to 95 wt % of a polymerizable monomer having a molar extinction coefficient of 10,000 or above and bearing an ultraviolet-absorbent group, such as a (meth)acrylamide monomer, a (meth)acrylate monomer or a substituted vinylbenzene monomer, respectively represented by general formulae (I), (II) or (III), and 80 to 5 wt % of a monomer bearing a salt-forming group, adding, if necessary, a neutralizing agent to the reaction mixture to ionize the salt-forming group, adding water to the resulting system, and distilling off the solvent to thereby cause phase inversion into a watery system. In formulae (I), (II), (III), R1 represents hydrogen or methyl; R2 represents hydrogen or C1 to C4 alkyl; and Y represents an ultraviolet-absorbent group. An ultraviolet-absorbent fine resin particle is obtained by dehydrating the above resin.</p> |
