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 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: 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: 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.