Surface-treated TiO 2, BaSO 4, ZnS, and/or lithopone particle obtainable by a process for the surface treatment of primary particles, characterized in that during the treatment the primary particles are brought into contact with at least one compound of the formula where R identically or differently is R 1, methyl, or hydroxy R 1 identically or differently is a polyether moiety of the formula -Z-(O-C m H 2m - (n-1)) o -[O- -R 3] n where Z is a branched or unbranched alkylene moiety having from 2 to 4 carbon atoms, preferably 3 carbon atoms, m is from 2 to 4, preferably 3, n is from 1 to 3, preferably 1 or 2, with particular preference 1, o is 0 or 1, preferably 0, AO identically or differently is an oxyalkylene moiety comprising oxyethylene, oxypropylene, and/or oxybutylene moieties, R 3 identically or differently is hydrogen or an alkyl moiety having from 1 to 4 carbon atoms, with the proviso that in R 1 the total number of carbon atoms and oxygen atoms is at least 70, a is from 20 to 200, preferably from 30, from 40, from 50, or from 60 to 170, to 160, to 150, to 140, to 130, to 120, or to 110, and with particular preference from 70 to 100, b is from 1 to 50, preferably from 2, from 3 or from 4 to 30, to 25, or to 20, and with particular preference from 5 to 15, with the proviso that if none of the moieties R is R 1, b is at least 3, where the proportion used of the compounds of the formula is from 0.01 to 2% by weight, preferably from 0.05 to 1% by weight, more preferably from 0.1 to 0.8% by weight, still more preferably from 0.2 to 0.6% by weight, and with particular preference from 0.3 to 0.5% by weight, based on the mass of the primary particles to be treated. R identically or differently is R 1, methyl, or hydroxy R 1 identically or differently is a polyether moiety of the formula -Z-(O-C m H 2m - (n-1)) o -[O- -R 3] n where Z is a branched or unbranched alkylene moiety having from 2 to 4 carbon atoms, preferably 3 carbon atoms, m is from 2 to 4, preferably 3, n is from 1 to 3, preferably 1 or 2, with particular preference 1, o is 0 or 1, preferably 0, AO identically or differently is an oxyalkylene moiety comprising oxyethylene, oxypropylene, and/or oxybutylene moieties, R 3 identically or differently is hydrogen or an alkyl moiety having from 1 to 4 carbon atoms, Z is a branched or unbranched alkylene moiety having from 2 to 4 carbon atoms, preferably 3 carbon atoms, m is from 2 to 4, preferably 3, n is from 1 to 3, preferably 1 or 2, with particular preference 1, o is 0 or 1, preferably 0, AO identically or differently is an oxyalkylene moiety comprising oxyethylene, oxypropylene, and/or oxybutylene moieties, R 3 identically or differently is hydrogen or an alkyl moiety having from 1 to 4 carbon atoms, with the proviso that in R 1 the total number of carbon atoms and oxygen atoms is at least 70, a is from 20 to 200, preferably from 30, from 40, from 50, or from 60 to 170, to 160, to 150, to 140, to 130, to 120, or to 110, and with particular preference from 70 to 100, b is from 1 to 50, preferably from 2, from 3 or from 4 to 30, to 25, or to 20, and with particular preference from 5 to 15, with the proviso that if none of the moieties R is R 1, b is at least 3, where the proportion used of the compounds of the formula is from 0.01 to 2% by weight, preferably from 0.05 to 1% by weight, more preferably from 0.1 to 0.8% by weight, still more preferably from 0.2 to 0.6% by weight, and with particular preference from 0.3 to 0.5% by weight, based on the mass of the primary particles to be treated.