Dispersion comprising cerium oxide and sheet silicate

Abstract

A dispersion comprising particles of cerium oxide and sheet silicate, where -the zeta potential of the sheet silicate 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 sheet silicate 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 sheet silicate particles is from 0.01 to 10% by weight and - the pH of the dispersion is from 3.5 to <7.5.

Description

technical field [0001] The invention relates to a dispersion containing cerium dioxide and sheet silicate, its preparation and use. Background technique [0002] It is known that ceria dispersions can be used to polish glass surfaces, metal surfaces and dielectric surfaces, and can be used for both rough polishing (high material removal, irregular contours, scratches) and fine polishing (low material removal, smooth surface, very few scratches, if any). The disadvantage is that it is often found that the ceria particles and the surface to be polished are charged differently and therefore attract each other. As a result, it is difficult to remove the ceria particles from the polished surface again. [0003] US 7112123 discloses a dispersion for polishing glass surfaces, metal surfaces and dielectric surfaces, which comprises 0.1 to 50% by weight of cerium oxide particles and 0.1 to 10% by weight of clay abrasive particles as abrasives, 90 % of the clay abrasive particles h...

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Problems solved by technology

However, this dispersion results in a high defect rate

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