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1. (WO2017149214) PROCESS FOR MANUFACTURING PAPER AND BOARD

Pub. No.:    WO/2017/149214    International Application No.:    PCT/FR2017/050167
Publication Date: Sat Sep 09 01:59:59 CEST 2017 International Filing Date: Thu Jan 26 00:59:59 CET 2017
IPC: D21H 17/41
D21H 21/10
D21H 21/18
Applicants: S.P.C.M. SA
Inventors: FAUCHER, Gatien
FOUGEROUSE, Damien
HUND, René
Title: PROCESS FOR MANUFACTURING PAPER AND BOARD
Abstract:
The present invention relates to a process for manufacturing a sheet of paper and/or board from a fibrous suspension, according to which, before the formation of said sheet, added to the fibrous suspension, at one or more injection points, are at least two retention aids respectively: (a) at least one water-soluble organic cationic polymer P1 having a cationicity greater than 2 meq.g- 1 , and (b) at least one water-soluble amphoteric polymer P2 of at least one anionic monomer and of at least one cationic monomer. The polymer P2 is added to the fibrous suspension after dissolving, in aqueous solution, the polymer P2 previously obtained by one of the following polymerization techniques: - gel polymerization, suspension polymerization, inverse emulsion polymerization, dispersion polymerization. The polymer P2 has a factor F > 2, said factor F being defined by the formula: F=UL² x [(100-A)/(100-C)] with UL: Brookfield viscosity of the polymer P2 at 0.1% by weight in a 1M aqueous solution of NaCl, at 23°C, with a UL module and at 60 rev.min-1, A and C corresponding respectively to the molar percentages of the anionic and cationic monomers of the polymer P2.