Patent ID: 7488769
Filing Date: 2009-02-10
Classification: B82Y,C08F,C08J

Abstract:
1. An aqueous dispersion, comprising: (A) at least one swellable polymer and/or oligomer comprising at least one functional group that is at least one of an anionic functional group, a potentially anionic functional group, and/or a nonionic hydrophilic functional group; (B) surface-modified, cationically stabilized, inorganic nanoparticles of at least one kind; and (C) at least one amphiphile; wherein the at least one swellable polymer and/or oligomer (A) comprises a copolymer prepared by two-stage or multistage controlled free-radical copolymerization in an aqueous or an organic medium; wherein in a first stage, at least one olefinically unsaturated monomer (a) is copolymerized with at least one non-(a) olefinically unsaturated monomer of the general formula (I): wherein R 1 , R 2 , R 3 , and R 4 are each independently one of a hydrogen atom, an unsubstituted alkyl radical, an unsubstituted cycloalkyl radical, an unsubstituted alkylcycloalkyl radical, an unsubstituted cycloalkylalkyl radical, an unsubstituted aryl radical, an unsubstituted alkylaryl radical, an unsubstituted cycloalkylaryl radical, an unsubstituted arylalkyl radical, an unsubstituted arylcycloalkyl radical, a substituted alkyl radical, a substituted cycloalkyl radical, a substituted alkylcycloalkyl radical, a substituted cycloalkylalkyl radical, a substituted aryl radical, a substituted alkylaryl radical, a substituted cycloalkylaryl radical, a substituted arylalkyl radical, and a substituted arylcycloalkyl radical, with the proviso that at least two of R 1 , R 2 , R 3 , and R 4 are at least one of an unsubstituted aryl radical, an unsubstituted arylalkyl radical, an unsubstituted arylcycloalkyl radical, a substituted aryl radical, a substituted arylalkyl radical, and a substituted arylcycloalkyl radical; wherein in a second stage, at least one further monomer (a) is (co)polymerized in the presence of a copolymer formed in the first stage, following the addition of small amounts, or without the addition, of free-radical initiators; and wherein the dispersion has a pH of from 2 to 7.