【摘要】 从光敏反应机理出发 ,用色差方法评估了各类化妆品用二氧化钛的光活性。结果表明 ,颜料级二氧化钛光活性不明显 ,而超细二氧化钛因其对UV线的吸收 ,有明显的光活性 ;通过对各种超细二氧化钛的防晒因子 (SPF)值的测定 ,证明SPF值与光活性之间无顺变关系 ,即高防晒性并不意味着高光活性 ,后者受粉体表面性质及周围环境的影响这为合理而又完全地利用超细二氧化钛的高防晒性提供了依据更多还原

【Abstract】 The photo-activities of different type of TiO 2 for cosmetics use had been measured by colorimetric method on the base of the mechanism of their photo-reaction.The result indicated that the pigment grade TiO 2 aimost has no obvious photo-activity,in contrast,the ultra-fine TiO 2 has obvious photo-activity because of its high absorption of UV radiation.The measuring SPF of various ultra-fine TiO 2 by SPF290 indicated the sun-protecting ability has independent of its photo-activity,so the high sun-protecting ability doesn’t mean high activity or unsafe because the photo-activity is effected by the surface properties of powders and the surrounding conditions. Its possible to diminish or eliminate photo-reaction of TiO 2 while ensuring high sun-protecting ability.更多还原