Method for producing high dry-strength paper, pulpboard and cardboard
AssigneeBASF SE
InventorsRainer Dyllick-Brenzinger, Primoz Lorencak, Hubert Meixner, Peter Baumann, Ellen Krüger, Andreas Stange, Martin Rübenacker
Life of this patent
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Abstract
Paper, board and cardboard having high dry strength are produced by the addition of cationic, anionic and/or amphoteric starch as dry strength agents to the paper stock and drainage of the paper stock with sheet formation in the presence of cationic polymers as retention aids for starch, and cationic polymeric retention aids are used for increasing the retention of dry strength agents comprising cationic, anionic and/or amphoteric starch in the production of paper, board and cardboard.
Claims18
A process for the production of paper, board and cardboard comprising addition of cationic, anionic or amphoteric starch as a dry strength agent to paper stock and drainage of the paper stock in the presence of retention aids with sheet formation, wherein one of the following is used as a retention aid for starch:
- polymers containing vinylamine units
- polyethyleneimines
- crosslinked polyamidoamines
- ethyleneimine-grafted and crosslinked polyamidoamines
- polydiallyldimethylammonium chlorides
- polymers containing N-vinylimidazoline units
- polymers containing dialkylaminoalkyl acrylate or dialkylaminoalkyl methacrylate
- polymers containing dialkylaminoalkylacrylamide units or dialkylaminoalkylmethacrylamide units and
- polyallylamines.
A method for increasing the retention of dry strength agents comprising cationic, anionic or amphoteric starch in the production of paper, board or cardboard, comprising carrying out said production in the presence of a cationic polymeric retention aid selected from the group consisting of
- polymers containing vinylamine units
- polyethyleneimines
- crosslinked polyamidoamines
- ethyleneimine-grafted and crosslinked polyamidoamines
- polydiallyldimethylammonium chlorides
- polymers containing N-vinylimidazoline units
- polymers containing dialkylaminoalkyl acrylate or dialkylaminoalkyl methacrylate
- polymers containing dialkylaminoalkylacrylamide units or dialkylaminoalkylmethacrylamide units and polyallylamines.
Dependencies are inferred from the claim text.