FIELD: paper manufacturing.
SUBSTANCE: invention relates to a method for the manufacture of paper or cardboard. The method includes the steps of adding the final polymer A to the first aqueous fibrous material suspension to obtain a second aqueous fibrous material suspension comprising the final polymer A, dewatering the second aqueous fibrous material suspension comprising the final polymer A on a water-permeable substrate to obtain a wet paper structure, dehydrating the wet paper structures to obtain paper or cardboard. The final polymer A is a polymer obtained by radical polymerization of: (i) 30-90 mol.% N-vinylformamide, (ii) 3-60 mol.% C1 -C4 -acrylic acid alkyl ester or C1 -C4-alkyl ester of methacrylic acid, (iii) 0-45 mol.% monoethylenically unsaturated carboxylic, sulfonic or phosphonic acids or their salt forms, (iv) 0-9 mol.% acrylonitrile or methacrylonitrile, (v) 0-35 mol. % ethylenically unsaturated monomers other than monomer (i), (ii), (iii) and (iv) to form the starting polymer V, and hydrolyzing the starting polymer V to form the final polymer A.
EFFECT: improved dry strength.
10 cl, 1 dwg, 4 tbl
