PARTICLE FOR PREVENTING ULTRAVIOLET LIGHT

摘要

PROBLEM TO BE SOLVED: To obtain the particles having high biocompatibility and low irritation and not lowering the effect by providing a core part of a polymer containing an ultraviolet light-protecting agent and a shell part comprising a specific compound not containing the ultraviolet light protecting agent on the surface. SOLUTION: The particles are obtained by providing a core part comprising a polymer containing an ultraviolet light protecting agent and a shell part comprising a polyamino acid not containing ultraviolet light formed on the surface. For example, 4-t-butyl-4'-methoxy-dibenzoylmethane or titanium oxide is preferably used as the ultraviolet light protecting agent. For exmaple, styrene or vinyl acetate is used as the monomer forming the polymer of the core part. The ultraviolet light protecting agent is preferably used in an amount of 5-500 pts.wt., especially about 10-200 pts.wt. based on 100 pts.wt. polymer forming the core part. The shell part is obtained by carrying out emulsion polymerization ofα-amino acid-N-carbonic acid anhydride in the presence of ultraviolet light- protecting agent-containing polymer particles forming the core. A weight ratio of the core part with the shell part is preferably about (1,000:1) to (2:1).