公开(公告)号：DE19836992A1

公开(公告)日：2000-02-17

申请号：DE19836992

申请日：1998-08-14

Applicant: BASF AG

Inventor： NIESNER MANFRED ,  RUEBENACKER MARTIN ,  MAHR NORBERT

IPC: C08F6/00 ,  C08J11/02

Abstract: Process for removing formamide (I) from a polymer containing N-vinylformamide units comprises treating the polymer with an acid or base in an amount of 1-2 molar equivalents per molar equivalent of (I) under conditions such that the N-vinylformamide units undergo practically no hydrolysis.

公开(公告)号：DE102004056551A1

公开(公告)日：2006-05-24

申请号：DE102004056551

申请日：2004-11-23

Applicant: BASF AG

Inventor： ESSER ANTON ,  HAEHNLE HANS-JOACHIM ,  RUEBENACKER MARTIN ,  SCHALL NORBERT ,  DUPUIS JACQUES ,  NEUTZNER JOSEF ,  NIESNER MANFRED ,  STURM BERTHOLD

IPC: D21H17/37 ,  D21H21/18

Abstract: The invention relates to a process for producing paper, board and cardboard of high dry strength by separately adding a polymer comprising vinylamine units and a polymeric anionic compound to a paper pulp, dewatering the pulp and drying the paper products, which comprises using as polymeric anionic compound at least one copolymer obtainable by copolymerizing (a) at least one N-vinylcarboxamide of the formula in which R1 and R2 are H or C1- to C6 alkyl, (b) at least one monoethylenically unsaturated monomer comprising acid groups, and/or the alkali metal, alkaline earth metal or ammonium salts thereof, and if appropriate (c) other monoethylenically unsaturated monomers, and if appropriate (d) compounds having at least two ethylenically unsaturated double bonds in their molecule.