摘要 |
An aqueous polishing composition comprising (A) abrasive ceria particles and (B) amphiphilic nonionic surfactants selected water-soluble and water-dispersible, linear and branched polyoxyalkylene blockcopolymers of the general formula I: R[(B1)m/(B2)nY]p (I), wherein the indices and the variables have the following meaning: m, n, and p integers>1; R hydrogen atom or monovalent or polyvalent organic residue, except C5-C20 alkyl groups; (B1) block of oxyethylene monomer units; (B2) block of substituted oxyalkylene monomer units wherein the substituents are selected from two methyl groups, alkyl groups of more than two carbon atoms and cycloalkyl, aryl, alkyl-cycloalkyl, alkyl-aryl, cycloalkyl-aryl and alkyl-cycloalkyl-aryl groups; and Y hydrogen atom or monovalent organic residue, except C5-C20 alkyl groups; with the proviso that when (B) contains more than one block (B1) or (B2) two blocks of the same type are separated by a block of the other type. |