Patent ID: 7918933

Claim:
A dispersion comprising water and mixed potassium silicon oxide powder, wherein the mixed potassium silicon oxide powder is in the form of aggregates of pore-free primary particles contains 0.2% to 1.5% by weight of K 2 O, distributed in the core and on the surface of the primary particles, and possesses a BET surface area of 100 to 350 m 2 /g and a specific DBP number, expressed as the DBP number per square meter of specific surface area, which is greater than or equal to that of a fumed silica powder of equal BET surface area that does not contain the potassium component and the dispersion has a fraction of mixed oxide powder in the dispersion of 25% to 40% by weight, the sum of water and mixed oxide powder is at least 98% by weight and the pH is 9 to 11.5.