Abstract: This method for treating the surface of paper and/or one of the layers thereof, comprises the following successive steps: i) Supplying an aqueous suspension S of polysaccharide; ii) Supplying an aqueous dispersion D comprising (a) particles of at least one anionic water-swellable polymer P and (b) at least one compound selected from a mineral salt, an organic salt, an organic dispersing polymer and the mixtures thereof; iii) Mixing the suspension S and the dispersion D to obtain a mixture M; iv) Applying the mixture M to the surface of the paper and/or to at least one of the layers thereof.

Abstract: The present invention relates to a polymer complex obtained by inverse emulsion polymerization of water-soluble monomers: in the presence of a cationic water-soluble host polymer comprising amine functions.

Abstract: This invention relates to an additive based on (co)polymers resulting from the reaction between at least one dialdehyde compound and at least one complex (co)polymer obtained by polymerization of water-soluble monomers in the presence of at least one host (co)polymer comprising vinylamine functions.

Abstract: The present invention relates to a complex of polymers and to the use thereof in a method of making paper, cardboard or the like. This complex of polymers is obtained by polymerizing water-soluble monomers: in the presence of a host polymer that comprises vinylamine functions and of a non-polymeric transfer agent, and in the absence of a branching or crosslinking agent of the ethylenic polyfunctional type. It is obtained as from a mass ratio of anionic monomer to water that is greater than 0.035.

Abstract: This invention relates to a method for manufacturing a sheet of paper or cardboard, according to which, before forming said sheet, at least one N-vinylformamide polymer that is partially hydrolyzed in the form of an inverse emulsion is added, at one or more injection points, to a fibrous suspension in the presence of an anti-gelling agent, and having a cationic regain between 30 and 150%, the inverse emulsion having a weight ratio of partially hydrolyzed N-vinylformamide polymer to anti-gelling agent in the range between 1,000,000/5000 and 1,000,000/50,000.

Abstract: This method for treating the surface of paper and/or one of the layers thereof, comprises the following successive steps: i) Supplying an aqueous suspension S of polysaccharide; ii) Supplying an aqueous dispersion D comprising (a) particles of at least one anionic water-swellable polymer P and (b) at least one compound selected from a mineral salt, an organic salt, an organic dispersing polymer and the mixtures thereof; iii) Mixing the suspension S and the dispersion D to obtain a mixture M; iv) Applying the mixture M to the surface of the paper and/or to at least one of the layers thereof.

Abstract: The present invention relates to a complex of polymers and to the use thereof in a method of making paper, cardboard or the like. This complex of polymers is obtained by polymerizing water-soluble monomers: in the presence of a host polymer that comprises vinylamine functions and of a non-polymeric transfer agent, and in the absence of a branching or crosslinking agent of the ethylenic polyfunctional type. It is obtained as from a mass ratio of anionic monomer to water that is greater than 0.035.

Abstract: 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.

Abstract: This invention relates to an additive based on (co)polymers resulting from the reaction between at least one dialdehyde compound and at least one complex (co)polymer obtained by polymerization of water-soluble monomers in the presence of at least one host (co)polymer comprising vinylamine functions.

Abstract: The present invention relates to a process for manufacturing a sheet of paper and/or board from a fibrous suspension, according to which, before the formation of said sheet, added to the fibrous suspension, at one or more injection points, are at least two retention aids respectively: (a) at least one water-soluble organic cationic polymer P1 having a cationicity greater than 2 meq·g?1, and (b) at least one water-soluble amphoteric polymer P2 of at least one anionic monomer and of at least one cationic monomer. The polymer P2 is added to the fibrous suspension after dissolving, in aqueous solution, the polymer P2 previously obtained by one of the following polymerization techniques: gel polymerization, suspension polymerization, inverse emulsion polymerization, dispersion polymerization. The polymer P2 has a factor F>2, said factor F being defined by the formula: F=UL2×[(100?A)/(100?C)] with UL: Brookfield viscosity of the polymer P2 at 0.

Abstract: The present invention relates to a process for manufacturing a sheet of paper and/or board from a fibrous suspension, according to which, before the formation of said sheet, added to the fibrous suspension, at one or more injection points, are at least two retention aids respectively: (a) at least one water-soluble organic cationic polymer P1 having a cationicity greater than 2 meq·g?1, and (b) at least one water-soluble amphoteric polymer P2 of at least one anionic monomer and of at least one cationic monomer. The polymer P2 is added to the fibrous suspension after dissolving, in aqueous solution, the polymer P2 previously obtained by one of the following polymerization techniques: gel polymerization, suspension polymerization, inverse emulsion polymerization, dispersion polymerization. The polymer P2 has a factor F>2, said factor F being defined by the formula: F=UL2×[(100?A)/(100?C)] with UL: Brookfield viscosity of the polymer P2 at 0.

Abstract: Process for manufacturing a sheet of paper and/or of paperboard and the like, according to which, the cellulosic material is brought into contact with at least one dry strength aid, characterized in that said dry strength aid is a cationic or amphoteric (co)polymer derived from the reaction between at least one aldehyde and at least one base (co)polymer comprising at least one nonionic monomer, said base copolymer being modified with at least one polyfunctional compound comprising at least three heteroatoms chosen from N, S, O and P, in which at least three of these heteroatoms each have at least one mobile hydrogen.

Abstract: The present invention relates to a process for the preparation of an aqueous polymer solution containing at least one cationic or amphoteric (co)polymer, comprising the following steps: Hofmann degradation reaction on a (co)polymer based on at least one non-ionic monomer chosen from the group including acrylamide, methacrylamide, N,N-dimethylacrylamide, and acrylonitrile; post-processing of the resulting aqueous polymer solution of viscosity V1; characterized in that the post processing comprises the following successive steps: obtaining of an aqueous polymer solution containing at least one cationic or amphoteric (co)polymer derived from the Hofmann degradation reaction; post-processing of this aqueous polymer solution; characterized in that the post processing comprises the following successive steps: (a) adjustment of the pH of the aqueous polymer solution to a value greater than or equal to 5.5; (b) decrease of the pH of the aqueous polymer solution to a value between 2 and 5.

Abstract: Process for manufacturing a sheet of paper and/or of paperboard and the like, according to which, the cellulosic material is brought into contact with at least one dry strength aid, characterized in that said dry strength aid is a cationic or amphoteric (co)polymer derived from the reaction between at least one aldehyde and at least one base (co)polymer comprising at least one nonionic monomer, said base copolymer being modified with at least one polyfunctional compound comprising at least three heteroatoms chosen from N, S, O and P, in which at least three of these heteroatoms each have at least one mobile hydrogen.

Abstract: Polymer complex obtained by polymerization of water-soluble monomers: in the presence of a host polymer comprising vinylamine functions and of a non-polymeric transfer agent, and in the absence of branching or crosslinking agent of ethylenic polyfunctional type.

Abstract: Process for manufacturing a sheet of paper and/or of paperboard and the like, according to which, the cellulosic material is brought into contact with at least one dry strength aid, characterized in that said dry strength aid is a cationic or amphoteric (co)polymer derived from the reaction between at least one aldehyde and at least one base (co)polymer comprising at least one nonionic monomer, said base copolymer being modified with at least one polyfunctional compound comprising at least three heteroatoms chosen from N, S, O and P, in which at least three of these heteroatoms each have at least one mobile hydrogen.

Abstract: The present invention relates to a process for the preparation of an aqueous polymer solution containing at least one cationic or amphoteric (co)polymer, comprising the following steps: Hofmann degradation reaction on a (co)polymer based on at least one non-ionic monomer chosen from the group including acrylamide, methacrylamide, N, N-dimethylacrylamide, and acrylonitrile; post-processing of the resulting aqueous polymer solution of viscosity V1; characterized in that the post processing comprises the following successive steps: obtaining of an aqueous polymer solution containing at least one cationic or amphoteric (co)polymer derived from the Hofmann degradation reaction; post-processing of this aqueous polymer solution; characterized in that the post processing comprises the following successive steps: (a) adjustment of the pH of the aqueous polymer solution to a value greater than or equal to 5.5; (b) decrease of the pH of the aqueous polymer solution to a value between 2 and 5.

Abstract: Process for manufacturing a sheet of paper and/or board, according to which, in a plant comprising a fan pump and a head box: a cellulose fiber suspension is prepared; the white waters are introduced into the thick stock; the mixture is homogenized in the fan pump; the thin stock is transferred to the head box; the sheet is formed and then dried, characterized in that, before homogenization of the mixture in the fan pump, a cationic copolymer obtained by Hofmann degradation reaction is introduced into the white waters and/or the thick stock and/or the mixture formed by the white waters and the thick stock.

Abstract: Process for manufacturing a sheet of paper and/or board, according to which, in a plant comprising a fan pump and a head box: a cellulose fibre suspension is prepared; the white waters are introduced into the thick stock; the mixture is homogenized in the fan pump; the thin stock is transferred to the head box; the sheet is formed and then dried, characterized in that, before homogenization of the mixture in the fan pump, a cationic copolymer obtained by Hofmann degradation reaction is introduced into the white waters and/or the thick stock and/or the mixture formed by the white waters and the thick stock.

Abstract: Process for manufacturing a sheet of paper and/or of paperboard and the like, according to which, the cellulosic material is brought into contact with at least one dry strength aid, characterized in that said dry strength aid is a cationic or amphoteric (co)polymer derived from the reaction between at least one aldehyde and at least one base (co)polymer comprising at least one nonionic monomer, said base copolymer being modified with at least one polyfunctional compound comprising at least three heteroatoms chosen from N, S, O and P, in which at least three of these heteroatoms each have at least one mobile hydrogen.