Abstract: Methods for producing paper or cardboard are provided that comprise the steps (A) adding a final polymer A to a first aqueous fibrous material suspension, whereby a second aqueous fibrous material suspension containing final polymer A is created, wherein the final polymer A is obtainable by radical polymerisation of the monomers (i), (ii), (iii), (iv), and (v) as described herein in the amounts provided herein; and hydrolysing the starting polymer V in order to obtain the final polymer A, (B) dewatering the second aqueous fibrous material suspension containing final polymer A on a water-permeable substrate to form a wet paper structure, (C) dewatering the wet paper structure, whereby the paper or the cardboard is formed.

Abstract: A method for producing dried multilayer paper is provided comprising dewatering a first aqueous fibrous suspension, thereby creating a first fibrous web; dewatering a second aqueous fibrous suspension, thereby creating a second fibrous web; 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; assembling the first fibrous web with the second fibrous web; dehydrating the resulting layer compound by pressing; then dehydrating by supplying heat, which creates the dried multilayer paper. The spray solution or spray suspension contains water and at least one water-soluble polymer P. The polymer P is obtained by polymerizing: 40 to 85 mol % of a monomer of Formula I in which R1=H or C1-C6-Alkyl; and 15 to 60 mol % of one or more ethylenically unsaturated monomers.

Abstract: A method to produce dried single-layer or multi-layer paper is disclosed. The method comprises, for a single-layer paper, preparing and spraying a partially dehydrated first fibrous web with a spray solution or suspension to give a sprayed partially dehydrated first fibrous web, and dehydrating the sprayed partially dehydrated first fibrous web by applying heat to form a dried single-layer paper; or, for a multi-layer paper, preparing and spraying a partially dehydrated layer compound with a spray solution or suspension to form a sprayed layer compound, and dehydrating the sprayed layer compound by applying heat to form a dried multi-layer paper. The spray solution or suspension comprises water and at least one water-soluble polymer P, which is obtained by polymerizing: (i) a monomer of formula H2CCHNHC(0)R1, where R1 is H or C1-C6- alkyl; and (ii) one or more ethylenically unsaturated monomers different from monomer (i).

Abstract: Methods for producing final polymer A are provided that comprise the following steps: (A) providing a starting polymer V, the starting polymer V being obtainable by radical polymerization of the monomers (i), (ii), (iii), and (iv) as described herein in the amounts provided herein; and (B) hydrolyzing the provided starting polymer V under alkaline conditions to obtain the final polymer A, wherein the N—C(?O)R1 groups of formula (I) at least partially hydrolyze the monomers (i) polymerized into the starting polymer V to form primary amino groups. Certain final polymers A obtained are useful for a method for producing paper or cardboard comprising adding certain final polymers A to a first aqueous pulp suspension, dewatering the obtained second aqueous pulp suspension containing certain final polymers A on a water-permeable substrate to a wet paper structure, and further dewatering of the wet paper structure into a paper or cardboard.

Abstract: Methods for producing paper or cardboard are provided that comprise the steps (A) adding a final polymer A to a first aqueous fibrous material suspension, whereby a second aqueous fibrous material suspension containing final polymer A is created, wherein the final polymer A is obtainable by radical polymerisation of the monomers (i), (ii), (iii), (iv), and (v) as described herein in the amounts provided herein; and hydrolysing the starting polymer V in order to obtain the final polymer A, (B) dewatering the second aqueous fibrous material suspension containing final polymer A on a water-permeable substrate to form a wet paper structure, (C) dewatering the wet paper structure, whereby the paper or the cardboard is formed.

Abstract: A method for the production of paper or cardboard is provide comprising the following steps: (A) Adding a water soluble polymer P to a first aqueous pulp suspension, wherein polymer P is obtainable by Polymerizing to a polymer V of (i) 33 to 83 mol % of a monomer of formula I in which R1?H or C1-C6 alkyl, (ii) 6 to 56 mol % of diallyl dimethyl ammonium chloride, diallyl diethyl ammonium chloride or a salt form of a monoethylenically unsaturated monomer, (iii) 11 to 61 mol % of a monoethylenically unsaturated carboxylic acid, sulfonic acid or phosphonic acid, or salt forms thereof, (iv) 0 to 50 mol % of one or more ethylenically unsaturated monomers, and hydrolyzing the N—C(?O)R1 groups to form primary amino or amidine groups, (B) dehydrating the second aqueous pulp suspension to a wet paper structure, (C) dehydrating the wet paper structure.

Abstract: 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 in which R1=H or C1-C6-Alkyl, 15 to 60 mol % of one or more ethylenically unsaturated monomers.

Abstract: The invention relates to a method for producing dried single-layer or multi-layer paper containing the steps for a single-layer paper (A) Dewatering a first aqueous fibrous suspension, thereby creating a first fibrous web having a dry content between 14% wt. and 25% wt., (D-1) Dehydrating the first fibrous web by pressing, thereby creating a partially dehydrated first fibrous web, (E-1) Spraying the partially dehydrated first fibrous web on at least one surface side with a spray solution or spray suspension, which results in a sprayed partially dehydrated first fibrous web, (F-1) Dehydrating the sprayed partially dehydrated first fibrous web by applying heat to form the dried single-layer paper, or containing the above step (A) and steps for a multi-layer paper (B) Dewatering a second aqueous fibrous suspension, thereby creating a second fibrous web having a dry content between 14% wt. and 25% wt.

Abstract: A method for the production of paper or cardboard is provide comprising the following steps: (A) Adding a water soluble polymer P to a first aqueous pulp suspension, wherein polymer P is obtainable by Polymerizing to a polymer V of (i) 33 to 83 mol % of a monomer of formula I in which R1?H or C1-C6 alkyl, (ii) 6 to 56 mol % of diallyl dimethyl ammonium chloride, diallyl diethyl ammonium chloride or a salt form of a monoethylenically unsaturated monomer, (iii) 11 to 61 mol % of a monoethylenically unsaturated carboxylic acid, sulfonic acid or phosphonic acid, or salt forms thereof, (iv) 0 to 50 mol % of one or more ethylenically unsaturated monomers, and hydrolyzing the N—C(?O)R1 groups to form primary amino or amidine groups, (B) dehydrating the second aqueous pulp suspension to a wet paper structure, (C) dehydrating the wet paper structure.

Abstract: A method of producing paper and board by using at least one water-soluble amphoteric polymer is provided. The water-soluble amphoteric polymer is obtained by copolymerizing a monomer mixture containing a) at least one N-vinylcarboxamide, b) at least one monoethylenically unsaturated monomer having at least one free acid group or at least one acid group in salt form, c) optionally at least one monoethylenically unsaturated monomer other than components (a) and (b), and d) optionally at least one compound having two or more ethylenically unsaturated double bonds, and then partly or wholly hydrolyzing the —CO—R1 groups of the polymer. The cationic monomer units and the anionic monomer units differ in their respective molar fractions, each based on the total number of moles of all monomer units, by not more than 10 mol % in absolute terms.

Abstract: A method of producing paper and board by using at least one water-soluble amphoteric polymer is provided. The water-soluble amphoteric polymer is obtained by copolymerizing a monomer mixture containing a) at least one N-vinylcarboxamide, b) at least one monoethylenically unsaturated monomer having at least one free acid group or at least one acid group in salt form, c) optionally at least one monoethylenically unsaturated monomer other than components (a) and (b), and d) optionally at least one compound having two or more ethylenically unsaturated double bonds, and then partly or wholly hydrolyzing the —CO—R1 groups of the polymer. The cationic monomer units and the anionic monomer units differ in their respective molar fractions, each based on the total number of moles of all monomer units, by not more than 10 mol % in absolute terms.

Abstract: A process for producing paper or board, which process comprises ad-mixing (I) an aqueous composition of pH ?6 and (II) at least one water-soluble polymeric anionic compound to a paper stock having a pH in the range from 6 to 8 and then dewatering the paper stock by sheet formation and drying, wherein the aqueous composition comprises (a) polymers having primary amino groups and/or amidine groups to a combined content for these groups of ?1.5 meq/g of polymer, and (b) 0.01 to 50 mol % of 1,4-cyclohexanedione (b) based on the combined amount of primary amino groups and/or amidine groups of the polymers, and also to the paper or board thus obtained.

Abstract: The present invention relates to a process for producing paper, card and board. The present invention is based on the discovery that controlling solids content during the process in a specified manner provide enhanced initial web strength of the paper prior to drying and allows for higher machine speeds in the paper production process as compared to known processes.

Abstract: The invention relates to an aqueous composition comprising (a) polymers having primary amino groups and/or amidine groups to a combined content for these groups of ?1.5 meq/g of polymer, and (b) 0.01 to 50 mol % of 1,4-cyclohexanedione (b) based on the combined amount of primary amino groups and amidine groups of the polymers, wherein the pH of the aqueous composition is ?6, and further to its use as strength enhancer and to a method of producing paper and board, employment of the aqueous composition and also the paper and board thus obtained.

Abstract: Process for the production of paper, board and cardboard having high dry strength by addition of an aqueous composition comprising a nanocellulose and at least one polymer selected from the group consisting of the anionic polymers and water-soluble cationic polymers, draining of the paper stock and drying of the paper products.

Abstract: The present invention relates to a process for production of paper, card and board comprising draining a filler-containing paper stock comprising at least one water-soluble polymer with sheet formation in the wire section and then pressing the paper in the press section, wherein a paper stock having a fibrous concentration in the range from 20 to 40 g/l has the at least one water-soluble polymer added to it, then the paper stock is diluted to a fibrous concentration in the range from 5 to 15 g/l, the diluted paper stock is drained to form a sheet and the sheet is pressed in the press section to a solids content G(x) wt % or greater and G(x) computes according to G(x)=48+(x?15)·0.

Abstract: The present invention relates to a process for production of paper, card and board comprising draining a filler-containing paper stock comprising at least one water-soluble polymer with sheet formation in the wire section and then pressing the paper in the press section, wherein a paper stock having a fibrous concentration in the range from 20 to 40 g/l has the at least one water-soluble polymer added to it, then the paper stock is diluted to a fibrous concentration in the range from 5 to 15 g/l, the diluted paper stock is drained to form a sheet and the sheet is pressed in the press section to a solids content G(x) wt % or greater and G(x) computes according to G(x)=48+(x?15)·0.

Abstract: A process for producing paper, board and cardboard in the presence of an aqueous slurry of components comprising finely divided fillers coated at least partly with water-soluble amphoteric copolymers, which involves adding, further to the aqueous slurry of components comprising finely divided fillers, at least one cationic and/or amphoteric polymer comprising as structural element no esters of unsaturated carboxylic acids with quaternized amino alcohols to the fiber suspension prior to sheet forming.

Abstract: The invention relates to a process for the production of paper, card and board, including the steps of draining a filler-containing paper stock, having a certain fibrous concentration and containing at least one water-soluble amphoteric copolymer, with sheet formation in a wire section, then pressing the paper in a press section, diluting the paper stock to a fibrous concentration in the range from 5 to 15 g/l, draining the diluted paper stock to form a sheet, and then pressing the sheet in the press section to a solids content G(x) wt % or greater, such that G(x) computes according to: G(x)=48+(x?15)·0.4, where x is the numerical value of a filler content of the dry paper, card or board (in wt %), and G(x) is a numerical value of the minimal solids content (in wt %) to which the sheet is pressed.

Abstract: Process for the production of paper, board and cardboard having high dry strength by addition of an aqueous composition comprising a nanocellulose and at least one polymer selected from the group consisting of the anionic polymers and water-soluble cationic polymers, draining of the paper stock and drying of the paper products.