Patent ID: 8758501
Filing Date: 2014-06-24
Classification: A61K,A61Q,B82Y,C01P,C09C,Y10T

Abstract:
1. A process for preparing a nanoparticulate UV protectant, comprising a) subjecting a nanoparticulate titanium dioxide to hydrothermal treatment, and b) subsequently applying a silicon dioxide coating onto said nanoparticulate titanium dioxide by a sol-gel process, in which a water-glass solution is added to a suspension of the titanium dioxide, wherein the application of the silicon dioxide coating is carried out at a pH kept constant in the range of pH=2 to pH=11, or the application of the silicon dioxide coating is carried out without pH regulation after prior pH adjustment of the suspension of the titanium dioxide to a value of pH=7 to pH=11, and the pH is subsequently lowered to a pH=5 to pH=8, and wherein the resultant coating is matured for 1 h to 8 h at a temperature of 50° C. to 110° C.