摘要 |
A dispersion comprising particles of cerium oxide and particles of cerium oxide and colloidal silicon dioxide, where —the zeta potential of the silicon dioxide particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, —the mean diameter of the cerium oxide particles is not more than 200 nm silicon dioxide particles is less than 100 nm, —the proportion, based in each case on the total amount of the dispersion, of cerium oxide particles is from 0.1 to 5% by weight silicon dioxide particles is from 0.01 to 10% by weight and —the pH of the dispersion is from 3.5 to <7.5. |