Abstract: A finely divided, cationic or amphoteric, aqueous polymer dispersion which is obtainable by emulsion polymerization of ethylenically unsaturated monomers in the presence of a cationic or amphoteric protective colloid, wherein first the cationic or amphoteric protective colloid is prepared by polymerizing a monomer blend in the presence of at least one first polymerization initiator in an organic solvent, and is carried out in a pressurized reactor at a pressure of at least 1720 kPa and at a temperature of at least 150° C.

Abstract: Described is an aqueous polymer dispersion comprising a chain growth addition polymer obtainable via free-radically initiated emulsion polymerization from ethylenically unsaturated, free-radically polymerizable monomers, wherein the chain growth addition polymer is formed to an extent of not less than 60 wt % from primary monomers selected from vinylaromatic compounds, conjugated aliphatic dienes, vinyl esters of saturated C1- to C20-carboxylic acids, esters of acrylic acid or of methacrylic acid with monohydric C1- to C20-alcohols, aliphatic hydrocarbons having 2 to 8 carbon atoms and one or two double bonds, or mixtures thereof, wherein the monomers are polymerized in the presence of lignosulfonate and wherein the chain growth addition polymer is branched or crosslinked. Also described is a process for preparing the aqueous polymer dispersion. The polymer dispersion is useful for preparing paper coating compositions.

Abstract: A paper coating slip additive obtainable by free-radical polymerization, its preparation and its use in paper coating compositions are described. The additive is formed from (a) acid monomers selected from ethylenically unsaturated C3 to C8 carboxylic acids, (b) associative monomers of the general formula H2C?CR1—COO-(EO)n—(PO)m—R2 where R1 is hydrogen or methyl, n is at least two, m is from zero to 50, EO is an ethylene oxide group, PO is a propylene oxide group and R2 is a C8-C30 alkyl group or a C8-C30 alkaryl group, and (c) nonionic copolymerizable monomers other than a) and b), wherein said additive has a weight average molecular weight of below 200 000 and wherein tert-dodecyl mercaptan is used as chain transfer agent.

Abstract: A finely divided, cationic, aqueous polymer dispersion, obtained by (I) solution polymerizing a first mixture containing (a) 15-40% by weight of a mixture of (a1) a (meth)acrylate and (a2) a (meth)acrylamide, (b) 40-85% by weight of styrene, (c) 0.5-5% by weight of an ethylenically unsaturated monomer, and (d) 0-20% by weight of a nonionic, ethylenically unsaturated monomer differing from (b); (II) adding water; and (III) emulsion polymerizing a second monomer mixture containing (i) 0-29% by weight of styrene, (ii) 50-100% by weight of a C1- to C18-(meth)acrylate, (iii) 0-30% by weight of a vinyl ester of a C1-C30-carboxylic acid, and (iv) 0-30% by weight of a nonionic ethylenically unsaturated monomer differing from (i), (ii), and (iii), wherein at least one of the solution and emulsion polymerizing are performed in the presence of 0-10% by weight of a regulator.

Abstract: Described is an aqueous polymer dispersion comprising a chain growth addition polymer obtainable via free-radically initiated emulsion polymerization from ethylenically unsaturated, free-radically polymerizable monomers, wherein the chain growth addition polymer is formed to an extent of not less than 60 wt % from primary monomers selected from vinylaromatic compounds, conjugated aliphatic dienes, vinyl esters of saturated C1- to C20-carboxylic acids, esters of acrylic acid or of methacrylic acid with monohydric C1- to C20-alcohols, aliphatic hydrocarbons having 2 to 8 carbon atoms and one or two double bonds, or mixtures thereof, wherein the monomers are polymerized in the presence of lignosulfonate and wherein the chain growth addition polymer is branched or crosslinked. Also described is a process for preparing the aqueous polymer dispersion. The polymer dispersion is useful for preparing paper coating compositions.

Abstract: A paper coating slip additive obtainable by free-radical polymerization, its preparation and its use in paper coating compositions are described. The additive is formed from (a) acid monomers selected from ethylenically unsaturated C3 to C8 carboxylic acids, (b) associative monomers of the general formula H2C?CR1—COO-(EO)n—(PO)m—R2 where R1 is hydrogen or methyl, n is at least two, m is from zero to 50, EO is an ethylene oxide group, PO is a propylene oxide group and R 2 is a C8-C30 alkyl group or a C8-C30 alkaryl group, and (c) nonionic copolymerizable monomers other than a) and b), wherein said additive has a weight average molecular weight of below 200 000 and wherein tert-dodecyl mercaptan is used as chain transfer agent.

Abstract: Finely divided, starch-containing polymer dispersions which are obtainable by free radical emulsion polymerization of ethylenically unsaturated monomers in the presence of at least one redox initiator and starch, (a) from 30 to 60% by weight of at least one optionally substituted styrene, (b) from 1 to 60% by weight of at least one C1-C12-alkyl acrylate and/or C1-C12-alkyl methacrylate, (c) from 0 to 10% by weight of at least one other ethylenically unsaturated copolymerizable monomer, being used as ethylenically unsaturated monomers and (d) from 15 to 40% by weight of at least one degraded starch which has a molar mass Mw of from 1000 to 65 000 g/mol being used as the starch, the sum (a)+(b)+(c)+(d) being 100% and being based on the total solids content, and the polymerization being carried out in the presence of at least 0.

Abstract: A finely divided, cationic or amphoteric, aqueous polymer dispersion which is obtainable by emulsion polymerisation of ethylenically unsaturated monomers in the presence of a cationic or amphoteric protective colloid, wherein first the cationic or amphoteric protective colloid is prepared by polymerising a monomer blend in the presence of at least one first polymerisation initiator in an organic solvent, and is carried out in a pressurised reactor at a pressure of at least 1720 kPa and at a temperature of at least 150° C.

Abstract: Finely divided, starch-containing polymer dispersions which are obtainable by free radical emulsion polymerization of ethylenically unsaturated monomers in the presence of at least one redox initiator and starch, (a) from 30 to 60% by weight of at least one optionally substituted styrene, (b) from 1 to 60% by weight of at least one C1-C12-alkyl acrylate and/or C1-C12-alkyl methacrylate, (c) from 0 to 10% by weight of at least one other ethylenically unsaturated copolymerizable monomer, being used as ethylenically unsaturated monomers and (d) from 15 to 40% by weight of at least one degraded starch which has a molar mass Mw of from 1000 to 65 000 g/mol being used as the starch, the sum (a)+(b)+(c)+(d) being 100% and being based on the total solids content, and the polymerization being carried out in the presence of at least 0.

Abstract: Finely divided, cationic, aqueous polymer dispersions which are obtainable by emulsion polymerization of ethylenically unsaturated monomers in an aqueous solution of a cationic prepolymer as a dispersant, wherein first the cationic prepolymer is prepared in the presence of polymerization initiators by polymerization of (a) from 15 to 40% by weight of a mixture of at least two different (meth)acrylates which in each case have an amino group and/or quaternary ammonium group and/or (meth)acrylamides which in each case carry an amino group and/or quaternary ammonium group, (b) from 40 to 85% by weight of at least one optionally substituted styrene, (c) from 0.