Abstract: The invention relates to a papermaking agent system in liquid form, which comprises (i) cationic starch solution, prepared by cooking a starch mixture comprising a starch component and a water component, and (ii) polymer composition, which has anionic and cationic groups and a cationic net charge of >0.1 meq/g. The polymer composition comprises or originates from at least one of constituents a), b) or c). Constituent a) contains an amphoteric polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic and cationic groups attached to the copolymer. Constituent b) contains a first polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic or cationic groups attached to the copolymer, as well as a second polymer, which comprises groups with opposite charge than the first polymer.

Abstract: The invention relates to a composition for sizing of a surface of paper, board or the like and its use for increasing strength properties of paper, board or the like. The composition has a solids content of 3-30%, and it comprises degraded non-ion is starch, and at least 0.5 weight-% of anionic polyacrylamide, which has a molecular weight, MW, >500 000 g/mol and <2 500 000 g/mol and an anionicity in the range of 4-35 mol-%. The invention further relates also to a method for producing paper, board or the like, which comprises addition of a first strength composition, which comprises a cationic agent, to a fibre stock, formation of a fibrous web from the fibre stock, drying of the fibrous web to dryness of at least 60%, and application of a second strength com position, which comprises an anionic hydrophilic polymer and a starch component, on the surface of the fibrous web.

Abstract: The invention provides new water soluble polymers for the use in industrial processes, where large quantities of water is handled, such as sludge dewatering and papermaking. These new polymers are water soluble cross-linked block copolymers, wherein the block copolymers are cross-linked together using a cross-linking agent. Each of the block copolymers contain two different blocks, and these blocks are formed from different monomers. The blocks are linked together with a molecular spacer derived from a bifunctional initiator used during the polymerization of the blocks. The monomers used in polymerizing the blocks are different with each other and they are selected from a group consisting of N-vinylformamide, acrylic acid, acrylamide and water-soluble derivatives thereof.

Abstract: The present invention relates to a process for producing microcellulose comprising a) acidifying fibrous cellulosic material, b) washing the acidified cellulosic material, c) optionally dewatering the washed cellulosic material, and d) hydrolyzing the washed or washed and dewatered cellulosic material under acidic conditions at a temperature of at least 120° C. and at a consistency of at least 8% on dry weight of the cellulose.

Abstract: The invention relates to a method for dissolving cationic starch. In the method is obtained an aqueous polyelectrolyte solution comprising a synthetic cationic polymer, which has a charge density value of at least 0.1 meq/g, determined at pH3, the concentration of the cationic polymer in the polyelectrolyte solution being >2.5 weight-%, and the aqueous polyelectrolyte solution is brought together with cationic starch having a degree of substitution, DS, >0.1. The cationic starch is dissolved to the polyelectrolyte solution by heating and/or mixing. The invention relates also to a papermaking agent comprising 2-40 weight-% of synthetic cationic polymer which has a charge density value of at least 0.1 meq/g, determined at p H 3, and 2.5-25 weight-% cationic starch having degree of substitution, DS, >0.1. The papermaking agent is in slurry form and has a viscosity of 50-20 000 m Pas, measured at 25° C. with Brookfield DVI+ viscometer.

Abstract: The invention relates to a papermaking agent system in liquid form, which comprises (i) cationic starch solution, prepared by cooking a starch mixture comprising a starch component and a water component, and (ii) polymer composition, which has anionic and cationic groups and a cationic net charge of >0.1 meq/g. The polymer composition comprises or originates from at least one of constituents a), b) or c). Constituent a) contains an amphoteric polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic and cationic groups attached to the copolymer. Constituent b) contains a first polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic or cationic groups attached to the copolymer, as well as a second polymer, which comprises groups with opposite charge than the first polymer.

Abstract: The invention relates to a method for making of paper, tissue, board or the like by using recycled fiber material as a raw material. The method comprises following steps: pulping recycled paper, board or the like in a pulper and obtaining a pulp flow comprising (i) an aqueous phase and (ii) at least recycled fibers and starch having low molecular weight, which are dispersed in the aqueous phase; adding a coagulant agent to the pulp flow or to an aqueous process flow comprising starch having low molecular weight; allowing the coagulant agent to interact with the starch having low molecular weight and optionally forming aggregates; and adding at least one flocculating agent, after the addition of the coagulant agent, to any flow, which comprises interacted coagulant agent, and forming a treated flow with starch comprising agglomerate(s); retaining at least part of the said aggregates and/or the said agglomerates to the fibers or to a web, which is formed.

Abstract: The invention relates to a method for dissolving cationic starch. In the method is obtained an aqueous polyelectrolyte solution comprising a synthetic cationic polymer, which has a charge density value of at least 0.1 meq/g, determined at pH3, the concentration of the cationic polymer in the polyelectrolyte solution being >2.5 weight-%, and the aqueous polyelectrolyte solution is brought together with cationic starch having a degree of substitution, DS, >0.1. The cationic starch is dissolved to the polyelectrolyte solution by heating and/or mixing. The invention relates also to a papermaking agent comprising 2-40 weight-% of synthetic cationic polymer which has a charge density value of at least 0.1 meq/g, determined at p H 3, and 2.5-25 weight-% cationic starch having degree of substitution, DS, >0.1. The papermaking agent is in slurry form and has a viscosity of 50-20 000 m Pas, measured at 25° C. with Brookfield DVI+ viscometer.

Abstract: The invention relates to a method for making of paper, tissue, board or the like by using recycled fibre material as a raw material. The method comprises following steps: pulping recycled paper, board or the like in a pulper and obtaining a pulp flow comprising (i) an aqueous phase and (ii) at least recycled fibres and starch having low molecular weight, which are dispersed in the aqueous phase; adding a coagulant agent to the pulp flow or to an aqueous process flow comprising starch having low molecular weight; allowing the coagulant agent to interact with the starch having low molecular weight and optionally forming aggregates; and adding at least one flocculating agent, after the addition of the coagulant agent, to any flow, which comprises interacted coagulant agent, and forming a treated flow with starch comprising agglomerate(s); retaining at least part of the said aggregates and/or the said agglomerates to the fibres or to a web, which is formed.

Abstract: The present invention relates to a fixative composition and process for reducing hydrophobic and/or anionic substances in fiber-containing stock for making of paper, board or the like. The composition comprises a synthetic cationic polymer, which has a charge density of 3.0-24 meq/g, and a cationic non-degraded starch, which has charge density of 0.5-3.0 meq/g. The invention relates also to thick stock composition comprising fibers and a fixative composition according to the invention.

Abstract: The present invention relates to a process for producing microcellulose comprising a) acidifying fibrous cellulosic material, b) washing the acidified cellulosic material, c) optionally dewatering the washed cellulosic material, and d) hydrolyzing the washed or washed and dewatered cellulosic material under acidic conditions at a temperature of at least 120° C. and at a consistency of at least 8% on dry weight of the cellulose.

Abstract: The present invention relates to a fixative composition and process for reducing hydrophobic and/or anionic substances in fibre-containing stock for making of paper, board or the like. The composition comprises a synthetic cationic polymer, which has a charge density of 3.0-24 meq/g, and a cationic non-degraded starch, which has charge density of 0.5-3.0 meq/g. The invention relates also to thick stock composition comprising fibres and a fixative composition according to the invention.

Abstract: The present invention relates to a process for producing microcellulose comprising subjecting fibrous cellulosic material to acid hydrolysis at a temperature from 10° C. to less than 140° C. and at a consistency of at least 8% on dry weight of the cellulose, wherein the amount of added acid is from 0.2 to 2%, preferably from 0.3 to 1.9%, more preferably from 0.5 to 1.5% on dry weight of the cellulose.

Abstract: The present invention relates to polysaccharide, preferably starch, of high purity having cationic degree of substitution over 0.50 and bound nitrogen index after cationization reaction stage over 0.75, and to preparation thereof as well as to its use in making of paper or paperboard.

Abstract: The present invention relates to polysaccharide, preferably starch, of high purity having cationic degree of substitution over 0.50 and bound nitrogen index after cationisation reaction stage over 0.75, and to preparation thereof as well as to its use in making of paper or paperboard.

Abstract: A method for internal sizing of paper using cationic starch is provided. The starch used is cationized with a mixture of epichlorhydrin, trimethylamine, and mono-or dimethylamine or N,N,N′,N′-tetramethylethylenediamine. Cationizing results in a higher molecular size of the starch, which has e.g. a beneficial effect on dewatering on the paper machine forming wire.