| abstract |
Raspberry-type coated particles comprising a core selected from the group consisting of metal oxides of Si, Ti, Zr, Al, Zn and mixtures thereof with a core size of from 20 to 100 nm wherein the core is coated with CeO2 particles having a particle size below 10 nm; process for preparing raspberry type coated particles comprising the steps of (i) providing a mixture containing (a) core particles selected from the group of metal oxides of Si, Ti, Zr, Al, Zn and mixtures thereof, with a particle size of from 20 to 100 nm, (b) a water soluble Ce-salt and (c) water, (ii) adding an organic or inorganic base to the mixture of step (i) at temperatures of from 10to90 DEG C and (iii) aging the mixture at temperatures of from 10 to 90 DEG C; and polishing agents containing the particles and their use for polishing surfaces. |