Composition for skin or hair

#This application claims the priority of Japanese Patent Application No. 2007-44764 filed on Feb. 23, 2007, which is incorporated herein by reference.

#The present invention relates to a composition for external use on skin or hair. Particularly, the present invention relates to the composition for skin or hair which achieves a highly excellent stability (photostability) and an excellent UV absorption over a wide UV wavelength range from UV-A to UV-B. The present invention is preferably applied to sunscreen cosmetics.

#UV absorbers are blended in cosmetics to protect human skin from UV radiation or to prevent degradation of components due to UV rays.

#FIG. 1 is a graph showing an absorbance of the compound obtained in Synthesis Example 1, that is, di(2-ethylhexyl)-4-methoxybenzalmalonate represented in formula (II).

#The present invention will be further detailed in the following.

#For component (a), one or more kinds of dibenzoylmethane derivatives known as UV absorbers are used. In the present invention, 4-tert-butyl-4′-methoxydibenzoylmethane is particularly preferred. 4-tert-butyl-4′-methoxydibenzoylmethane is, for example, commercially available from DSM Nutritional Products, Inc. under the commercial name of “Parsol 1789”, which can be used in the present invention.

#The blending amount of component (a) is preferably from 0.01 to 10% by mass with respect to the composition of the present invention, more preferably from 0.3 to 5% by mass. If the blending amount of component (a) is less than 0.01% by mass, it is difficult to achieve a sufficient UV absorption. On the other hand, for cosmetics or preparations for external use on skin, 10% by mass of component (a) is enough to achieve a sufficient UV absorption. If component (a) is blended in the amount of more than 10% by mass, the effect is not improved in proportion to the increase of blending amount, which is not economical.