Preparation of an aqueous polymer dispersion

A process as claimed in claim 1 and 16 and 17, wherein the residual monomer mixture whose content is to be reduced comprises acrylic acid.

A process as claimed in claim 1 and 16 to 19, wherein the residual monomer mixture whose content is to be reduced comprises acrylic acid and acrylonitrile.

A composition, comprising an adduct of a ketone of 3-8 carbon atoms with a bisulfite anion or a conjugated acid of this adduct and an aqueous polymer dispersion containing from >0 to .gtoreq.1% by weight, based on the aqueous polymer dispersion, of at least two residual monomers which differ from one another and have at least one ethylenically unsaturated double bond wherein said polymer is comprised of at least two monomeric units A and B which differ from one another.

A process for the preparation of an aqueous polymer dispersion, in which an aqueous dispersion of a polymer, which contains at least two monomers A and B, which differ from one another, have at least one ethylenically unsaturated group, and are incorporated in chemically bonded form is produced, in a manner known per se, so that the total content of monomers which are free, ie. not chemically bonded, and have a least one ethylenically unsaturated double bond in the aqueous polymer dispersion is from >0 to .ltoreq.0.5% by weight, based on the aqueous polymer dispersion, and this residual monomer content is then reduced by the action of a free radical redox initiator system comprising at least one oxidizing agent and at least one reducing agent, wherein the redox initiator system comprises, as the reducing agent, the adduct of a ketone of 3 to 8 carbon atoms with the bisulfite anion or the conjugated acid of this adduct.

A process for the preparation of an aqueous polymer dispersion, in which an aqueous dispersion of a polymer, which contains at least two monomers A and B, which differ from one another, have at least one ethylenically unsaturated group, and are incorporated in chemically bonded form is produced, in a manner known per se, so that the total content of monomers which are free, ie. not chemically bonded, and have a least one ethylenically unsaturated double bond in the aqueous polymer dispersion is from >0 to .ltoreq.0.1% by weight, based on the aqueous polymer dispersion, and this residual monomer content is then reduced by the action of a free radical redox initiator system comprising at least one oxidizing agent and at least one reducing agent, wherein the redox initiator system comprises, as the reducing agent, the adduct of a ketone of 3 to 8 carbon atoms with the bisulfite anion or the conjugated acid of this adduct.