Abstract: The invention relates to a process for producing an aqueous polymer dispersion by means of radically initiated aqueous emulsion polymerisation by polymerising, in an aqueous medium, in accordance with a monomer feed process: (a) 40 to 75 parts by weight styrene; (b) 24.9 to 59.9 parts by weight butadiene; (c) 0.1 to 10 parts by weight of at least one ethylenically unsaturated carboxylic acid; and (d) 0 to 15 parts by weight other monomers, wherein the parts by weight of monomers (a) to (d) add up to 100 parts by weight, which process comprises the following steps: a) creating a template of a seed latex and 1 to 10 parts by weight monomers, based on the total monomer amount; b) starting the polymerisation at a temperature ?80° C.

Abstract: The invention relates to a coating slip comprising (i) an aqueous dispersion of one or more vinyl acetate polymers, obtainable by free-radically initiated emulsion polymerization of 77% to 99% by weight of vinyl acetate, 1% to 13% by weight of ethylene and 0% to 10% by weight of one or more monoethylenically unsaturated monomers that are neither vinyl acetate nor ethylene, where the amounts of the monomers add up to 100% by weight, (ii) an aqueous dispersion of one or more styrene copolymers, obtainable by free-radically initiated emulsion polymerization of a monomer composition comprising 35% to 70% by weight of styrene, 20% to 60% by weight of one or more esters of acrylic and/or methacrylic acid with alkanols having 1 to 12 carbon atoms, or of one or more conjugated aliphatic dienes, 1% to 10% by weight of one or more monomers comprising acid groups, where the amounts of the monomers add up to 100% by weight, (iii) inorganic pigments and (iv) optionally further auxiliaries, where the total amount of

Abstract: The present invention concerns a composition being an inverse emulsion comprising cross-linked anionic, organic polymeric microparticles, said microparticles having an unswollen z-average particle size diameter of less than 0.75 ?m, wherein the organic polymeric microparticles are formed from a monomer mixture comprising (a) an ethylenically unsaturated carboxylic acid, or a salt thereof; (b) an ethylenically unsaturated non-ionic monomer; and (c) from 1 to 10 mole % of 2-acrylamido-2-methylpropanesulphonic acid, or a salt thereof. The invention also provides a process for preparing the composition, the use of the composition in a paper or paperboard making process and methods of making paper or paperboard employing said composition.

Abstract: Finely divided, cationic, aqueous polymer dispersion which is obtainable by emulsion polymerisation of ethylenically unsaturated monomers in an aqueous liquid containing a cationic prepolymer as a dispersant, wherein the cationic prepolymer is prepared in the presence of at least one polymerisation initiator by polymerisation of (a) from 15 to 45% by weight of at least one ethylenically unsaturated monomer comprising at least one quaternary ammonium group; (b) from 5 to 80% by weight of at least one optionally substituted styrene; (c) from 0 to 50% by weight of at least one C 1-12 alkyl (meth) acrylate; (d) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising an acid group; (e) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising an amine group; and (f) from 0 to 20% by weight of at least one non-ionic ethylenically unsaturated monomer differing from (b), (c) and (e), the sum of (a)+(b)+(c)+(d)+(e)+(f) being 100% by weight, in a first emulsion po

Abstract: The present invention concerns a composition being an inverse emulsion comprising cross-linked anionic, organic polymeric microparticles, said microparticles having an unswollen z-average particle size diameter of less than 0.75 ?m, wherein the organic polymeric microparticles are formed from a monomer mixture comprising (a) an ethylenically unsaturated carboxylic acid, or a salt thereof; (b) an ethylenically unsaturated non-ionic monomer; and (c) from 1 to 10 mole % of 2-acrylamido-2-methylpropanesulphonic acid, or a salt thereof. The invention also provides a process for preparing the composition, the use of the composition in a paper or paperboard making process and methods of making paper or paperboard employing said composition.

Abstract: Finely divided, cationic, aqueous polymer dispersion which is obtainable by emulsion polymerisation of ethylenically unsaturated monomers in an aqueous liquid containing a cationic prepolymer as a dispersant, wherein the cationic prepolymer is prepared in the presence of at least one polymerisation initiator by polymerisation of (a) from 15 to 45% by weight of at least one ethylenically unsaturated monomer comprising at least one quaternary ammonium group; (b) from 5 to 80% by weight of at least one optionally substituted styrene; (c) from 0 to 50% by weight of at least one C 1-12 alkyl (meth) acrylate; (d) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising an acid group; (e) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising an amine group; and (f) from 0 to 20% by weight of at least one non-ionic ethylenically unsaturated monomer differing from (b), (c) and (e), the sum of (a)+(b)+(c)+(d)+(e)+(f) being 100% by weight, in a first emulsion po

Abstract: Process for the Manufacture of Paper and Paperboard The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of from 0.

Abstract: The invention relates to a finely divided, starch-containing aqueous polymer dispersion which is obtainable by free radical emulsion polymerization of ethylenically unsaturated monomers in the presence of at least one redox initiator and starch, wherein the ethylenically unsaturated monomers comprise (a) from 30 to 65% by weight of acrylonitrile and/or methacrylonitrile, (b) from 35 to 60% by weight of at least one C1-C12-alkyl acrylate and/or at least one C1-C12-alkyl methacrylate, (c) from 0 to 35% by weight of at least one other ethylenically unsaturated copolymerisable monomer, in which the sum of (a), (b) and (c) totals 100%, and in which the aqueous polymer dispersion comprises, (d) from 10 to 55% by weight of an ionic tapioca starch, in which the weight of (d) is based on the total solids of components (a), (b), (c) and (d) of the aqueous polymer dispersion.

Abstract: A pulp making process in which fibrous cellulosic material is pulped to form an aqueous suspension of cellulosic material, the suspension is drained through a screen to form a pulp sheet and that the pulp sheet is dried to form a dry market pulp, in which a water soluble cationic polymer is added to the suspension as the sole drainage aid wherein the water-soluble cationic polymer is either, i) a copolymer comprising (a) between 1 and 70 mole % (meth) acrylamide and (b) between 30 and 99 mole % (meth) acryloyloxyethyltrimethyl ammonium chloride with an intrinsic viscosity between 5 and 9 dl/g; or ii) a hydrolysed homopolymer of vinylformamide comprising between 1 and 100 mole % vinyl amine units and having a K value of between 45 and 240. The process of the invention provides improved drainage time and solids content of the dewatered pulp.

Abstract: The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of at least 3 mEq per gram and a molar mass of greater than 700,000 Da, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.

Abstract: Process for the Manufacture of Paper and Paperboard The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of from 0.

Abstract: The present invention relates to a process of making paper or paperboard, the process including introducing a dual retention system into a cellulosic thin stock, subjecting the cellulosic thin stock to one or more shear stages, and then draining the cellulosic thin stock on a moving screen to form a dried sheet, wherein the dual retention system consists of a first polymeric retention aid and a second polymeric retention aid, the first polymeric retention aid is a water-soluble cationic polymer exhibiting an intrinsic viscosity of at least 6 dl/g, the second polymeric retention aid is a water-soluble cationic polymer exhibiting an intrinsic viscosity of from 4 to 9 dl/g, and the second polymeric retention aid has a greater cationic charge density than the first polymeric retention aid.

Abstract: A pulp making process in which fibrous cellulosic material is pulped to form an aqueous suspension of cellulosic material, the suspension is drained through a screen to form a pulp sheet and that the pulp sheet is dried to form a dry market pulp, in which a water soluble cationic polymer is added to the suspension as the sole drainage aid wherein the water-soluble cationic polymer is either, i) a copolymer comprising (a) between 1 and 70 mole % (meth) acrylamide and (b) between 30 and 99 mole % (meth) acryloyloxyethyltrimethyl ammonium chloride with an intrinsic viscosity between 5 and 9 dl/g; or ii) a hydrolysed homopolymer of vinylformamide comprising between 1 and 100 mole % vinyl amine units and having a K value of between 45 and 240. The process of the invention provides improved drainage time and solids content of the dewatered pulp.

Abstract: Process for the production of paper, board and cardboard having high dry strength by addition of (a) at least one trivalent cation in the form of a salt, (b) at least one water-soluble cationic polymer and (c) at least one water-soluble amphoteric polymer to the paper stock, draining of the paper stock with sheet formation and subsequent drying of the paper products, the water-soluble cationic polymer (b) being selected from the group consisting of the (i) polymers comprising vinylamine units and (ii) polymers comprising ethylenimine units.

Abstract: A pulp making process in which fibrous cellulosic material is pulped to form an aqueous suspension of cellulosic material, the suspension is drained through a screen to form a pulp sheet and that the pulp sheet is dried to form a dry market pulp, in which a water soluble cationic polymer is added to the suspension as the sole drainage aid wherein the water-soluble cationic polymer is either, i) a copolymer comprising (a) between 1 and 70 mole % (meth)acrylamide and (b) between 30 and 99 mole % (meth)acryloyloxyethyl-trimethyl ammonium chloride with an intrinsic viscosity between 5 and 9 dl/g; or ii) a hydrolysed homopolymer of vinylformamide comprising between 1 and 100 mole % vinyl amine units and having a K value of between 45 and 240. The process of the invention provides improved drainage time and solids content of the dewatered pulp.

Abstract: The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of at least 3 mEq per gram and a molar mass of greater than 700,000 Da, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.

Abstract: A pulp making process in which fibrous cellulosic material is pulped to form an aqueous suspension of cellulosic material, the suspension is drained through a screen to form a pulp sheet and that the pulp sheet is dried to form a dry market pulp, in which a water soluble cationic polymer is added to the suspension as the sole drainage aid wherein the water-soluble cationic polymer is either, i) a copolymer comprising (a) between 1 and 70 mole % (meth)acrylamide and (b) between 30 and 99 mole % (meth)acryloyloxyethyl-trimethyl ammonium chloride with an intrinsic viscosity between 5 and 9 dl/g; or ii) a hydrolysed homopolymer of vinylformamide comprising between 1 and 100 mole % vinyl amine units and having a K value of between 45 and 240. The process of the invention provides improved drainage time and solids content of the dewatered pulp.

Abstract: The process of the present invention concerns manufacturing paper and paperboard employing two polymeric retention aids. These two polymeric retention aids should be added to the low consistency suspension, often referred to as the thin stock. The first polymeric retention aid is a water-soluble cationic polymer exhibiting an intrinsic viscosity of at least 6 dl/g. The second polymeric retention aid is a water-soluble cationic polymer exhibiting an intrinsic viscosity of between 4 and 9 dl/g. The cationic charge density of the second polymeric retention aid should be higher than that of the first polymeric retention aid. The process is particularly suitable for the manufacture of fine paper or multiply packaging paper which often contains filler.

Abstract: A cationic copolymer is obtained by the Hofmann rearrangement (also referred to as the Hofmann degradation reaction) in aqueous solution in the presence of an alkaline-earth and/or alkali hydroxide and an alkaline-earth and/or alkaline hypohalide, on a base copolymer comprising at least one nonionic monomer selected from the group comprising acrylamide (and/or methacrylamide), N,N-dimethylacrylamide and/or acrylonitrile The copolymer is branched after the Hofmann rearrangement, in the presence of at least one polyfunctional branching agent, and is soluble in water.

Abstract: A pulp making process in which fibrous cellulosic material is pulped to form an aqueous suspension of cellulosic material, the suspension is drained through a screen to form a pulp sheet and that the pulp sheet is dried to form a dry market pulp, in which a water soluble cationic polymer is added to the suspension as the sole drainage aid wherein the water-soluble cationic polymer is either, i) a copolymer comprising (a) between 1 and 70 mole % (meth) acrylamide and (b) between 30 and 99 mole % (meth) acryloyloxyethyl-trimethyl ammonium chloride with an intrinsic viscosity between 5 and 9 dl/g; or ii) a hydrolysed homopolymer of vinylformamide comprising between 1 and 100 mole % vinyl amine units and having a K value of between 45 and 240. The process of the invention provides improved drainage time and solids content of the dewatered pulp.