The present invention relates to a copolymer comprising at least one hydrophilic monomer; at least one hydrophobic monomer and at least 10% by weight of methyl styrene, particularly suitable to be used as detackifying agent for reducing negative effects caused by natural pitch and/or adhesive contaminants in both pulping and papermaking operations.

The invention relates to a UV-initiated RAFT-type polymerization for producing hydrophobically associative terpolymers in an aqueous solution. The terpolymers produced by this method can be used as aqueous rheological modifiers. Specifically, the invention relates to a hydrophobically associating terpolymers and a method to produce same using a light initiated iniferter. The monomers used in the present invention are selected from: a monomer having a water-soluble monoethylenically unsaturated group; a monomer having an ionic water-soluble monoethylenically unsaturated group; and a monomer having a monoethylenically unsaturated monomer capable of forming hydrophobically associative bonds in aqueous medium. The iniferter is initiated with light of wavelength between 250-400 nm. The resultant terpolymer is produced in a cost-effective, simple, and one-step process and can be used to thicken aqueous mediums with less or equal amounts of polymer than currently available.

The invention relates to a UV-initiated RAFT-type polymerization for producing hydrophobically associative terpolymers in an aqueous solution. The terpolymers produced by this method can be used as aqueous rheological modifiers. Specifically, the invention relates to a hydrophobically associating terpolymers and a method to produce same using a light initiated iniferter. The monomers used in the present invention are selected from: a monomer having a water-soluble monoethylenically unsaturated group; a monomer having an ionic water-soluble monoethylenically unsaturated group; and a monomer having a monoethylenically unsaturated monomer capable of forming hydrophobically associative bonds in aqueous medium. The iniferter is initiated with light of wavelength between 250-400 nm. The resultant terpolymer is produced in a cost-effective, simple, and one-step process and can be used to thicken aqueous mediums with less or equal amounts of polymer than currently available.

The invention relates to a use of a water-soluble polymer product comprising amphoteric polyacrylamide, which has neutral or cationic net charge at pH 7, a weight-average molecular weight of 2 500 000-18 000 000 g/mol and a total ionicity of 4-28 mol-%. The polymer product is used for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres. The invention relates also to a method for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres, as well as to produced paper or board.

A method for producing dried multilayer paper is provided comprising (A) Dewatering a first aqueous fibrous suspension, thereby creating a first fibrous web, (B) Dewatering a second aqueous fibrous suspension, thereby creating a second fibrous web, (C) Spraying one or more of a first fibrous web and a second fibrous web with a spray solution or spray suspension, thereby producing at least one sprayed fibrous web, (D) Assembling the first fibrous web with the second fibrous web, (E) Dehydrating the resulting layer compound by pressing, then (F) Dehydrating by supplying heat, which creates the dried multilayer paper, wherein the spray solution or spray suspension contains (c-a) Water (c-b) at least one water-soluble polymer P obtained by polymerizing 40 to 85 mol % of a monomer of Formula I

##STR00001## in which R.sup.1=H or C.sub.1-C.sub.6-Alkyl, 15 to 60 mol % of one or more ethylenically unsaturated monomers.

A method for producing dried multilayer paper is provided comprising (A) Dewatering a first aqueous fibrous suspension, thereby creating a first fibrous web, (B) Dewatering a second aqueous fibrous suspension, thereby creating a second fibrous web, (C) Spraying one or more of a first fibrous web and a second fibrous web with a spray solution or spray suspension, thereby producing at least one sprayed fibrous web, (D) Assembling the first fibrous web with the second fibrous web, (E) Dehydrating the resulting layer compound by pressing, then (F) Dehydrating by supplying heat, which creates the dried multilayer paper, wherein the spray solution or spray suspension contains (c-a) Water (c-b) at least one water-soluble polymer P obtained by polymerizing 40 to 85 mol % of a monomer of Formula I

##STR00001## in which R.sup.1=H or C.sub.1-C.sub.6-Alkyl, 15 to 60 mol % of one or more ethylenically unsaturated monomers.

Embodiments of the present invention relate to a method of making a paper comprising the steps of: a) providing a cationic wet strength resin comprising a polyamidoamine epihalohydrin, a condensation copolymer of epihalohydrin and amine, or combination thereof; b) providing an anionic polymer; c) co-mixing the cationic wet strength resin and the anionic polymer to provide a composition comprising polyelectrolyte complexes; d) providing an aqueous pulp slurry, draining the aqueous pulp slurry on a screen to form a wet fiber web, and drying the wet fiber web to obtain the paper, wherein said co-mixed composition is introduced to the aqueous pulp slurry or on the formed wet fiber web. Embodiments of the present invention further relates to a paper wet strength composition, its use in paper making and a paper obtainable therefrom.

Embodiments of the present invention relate to a method of making a paper comprising the steps of: a) providing a cationic wet strength resin comprising a polyamidoamine epihalohydrin, a condensation copolymer of epihalohydrin and amine, or combination thereof; b) providing an anionic polymer; c) co-mixing the cationic wet strength resin and the anionic polymer to provide a composition comprising polyelectrolyte complexes; d) providing an aqueous pulp slurry, draining the aqueous pulp slurry on a screen to form a wet fiber web, and drying the wet fiber web to obtain the paper, wherein said co-mixed composition is introduced to the aqueous pulp slurry or on the formed wet fiber web. Embodiments of the present invention further relates to a paper wet strength composition, its use in paper making and a paper obtainable therefrom.

The invention relates to a method for producing anionic polymers that are hydrosoluble in an aqueous solution, comprising at least the following successive steps: b) polymerisation, in an aqueous solution, of anionic monomers containing at least 5 mol % of 2-acrylamido-2-methylpropane sulfonic acid and/or one of the salts thereof and optionally non-ionic monomers up to a mass concentration of polymer A of between 5 and 40%, b) addition of at least one aldehyde into the solution produced in step a), and c) acidification to a pH of between 3 and 4 of the solution produced in step b). The invention also relates to the use thereof in a paper-making method.

The invention relates to a method for producing anionic polymers that are hydrosoluble in an aqueous solution, comprising at least the following successive steps: b) polymerisation, in an aqueous solution, of anionic monomers containing at least 5 mol % of 2-acrylamido-2-methylpropane sulfonic acid and/or one of the salts thereof and optionally non-ionic monomers up to a mass concentration of polymer A of between 5 and 40%, b) addition of at least one aldehyde into the solution produced in step a), and c) acidification to a pH of between 3 and 4 of the solution produced in step b). The invention also relates to the use thereof in a paper-making method.