This invention provides novel titania fine grains complex having high transparency, high stability, high UV-absorbability, and re-dispersion ability. The UV-protect ability for skin care agent can be enhanced by admixing the titania fine grains complex with the skin care agent. The titania fine grains complex are manufactured as follows: to an acid aqueous dispersion of titania fine grains, adding one, two or more selected from carboxylic acid and carboxylic acid derivatives of represented by formula (1) and polymers consisted of the said carboxylic acid and/or carboxylic acid derivatives as units, neutralizing with alkalis to produce the carboxylic acid monomer or polymers, and then compounding the carboxylic acid monomer or polymers on core surface of the titania fine grains. The titania fine grains complex have high crystals in core of the titania fine grains, the molecular interaction between the titania fine grains and the carboxylic acid monomer or polymers is great therefore, the titania fine grains can uniformly disperse in media and have high transparency and stability. The skin care agent with high UV-protect ability can be manufactured by admixing the titania fine grains with the skin care agent.本發明係提供透明性、穩定性及紫外線吸收能高,且再分散性優異之新穎二氧化鈦微粒子複合體,將本二氧化鈦微粒子複合體攙合在皮膚外用劑,藉此提供紫外線防護效果高的皮膚外用劑。在二氧化鈦微粒子之酸性水分散液添加選自通式(1)所示之羧酸及羧酸衍生物、以及以前述羧酸及/或羧酸衍生物作為構成單體之聚合物中之一種或二種以上後,藉由鹼中和的方式,製造前述羧酸單體或聚合物等複合化於二氧化鈦微粒子的的核芯表面之二氧化鈦微粒子複合體。該二氧化鈦微粒子複合體係核芯之二氧化鈦微粒子之結晶化度高、二氧化鈦微粒子和前述羧酸單體或聚合物等之分子間相互作用大,因此均一地分散在分散媒,透明性及穩定性高。進而藉由攙合該二氧化鈦微粒子複合體之方式,可製造紫外線防護效果高的皮膚外用劑。
