| abstract |
Abstract of the Disclosure: Paper, board and cardboard are produced by draining a paper stock in the presence of a nonhydrolyzed copolymer which contains, as polymerized units, a) from 99 to 1 mol % of N-vinylformamide and (b) from 1 to 99 mol % of one or more water-soluble basic monomers of the formula (I) or (II) where R1 is H, CH3 or C2H5, R2, R3 and R4 are each H, CH3, C2H5 or (-CH2-CH2-O-)nH, R5 and R6 are each C1-C10-alkyl, A is C1-C6-alkylene, n is from 1 to 6 and Y6 is an anion, in an amount of from 0.01 to 3.5% by weight, based on dry paper stock. |