Patent ID: 7241505
Filing Date: 2007-07-10
Classification: B82Y,C01B,C03C,C09D,Y10T

Abstract:
1. Hybrid sol comprising: [SiO water and a solvent, wherein the sol is obtained by a process comprising: hydrolytic polycondensation of tetraalkoxysilanes in an aqueous, solvent-containing medium by addition of the tetraalkoxysilanes to the aqueous, solvent-containing medium, resulting in a hydrolysis mixture comprising silicon oxide hydroxide particles having a particle size of 4–15 nm, followed by addition to the hydrolysis mixture of a monodisperse silicon oxide hydroxide sol essentially in the form of discrete particles having a mean particle size of 20–60 nm and a maximum standard deviation of 20%, said addition being at least 5 minutes after addition of the tetraalkoxysilanes to the aqueous, solvent-containing medium.