Patent ID: 7918965

Claim:
A process for the production of paper, board and cardboard by draining a paper stock with sheet formation in the presence of a retention aid system comprising at least one polymer comprising vinylamine units and at least one particulate, anionic, crosslinked, organic polymer, wherein said retention aid system comprises (i) at least one polymer comprising vinylamine units, in the form of the free bases, of the salts and/or in quaternized form, as the sole cationic polymer, (ii) at least one linear, anionic polymer having a molar mass M w of at least 1 million and/or at least one branched, anionic, water-soluble polymer and/or bentonite and/or silica gel, and (iii) at least one particulate, anionic, crosslinked, organic polymer having a mean particle diameter of at least 1 μm and an intrinsic viscosity of less than 3 dl/g.