Polímero y su preparación y uso

Un polímero catiónico basado en acrilamida soluble en agua que tiene uno o más grupos acetoacetato, en el que el polímero se obtiene polimerizando monómeros etilénicamente insaturados en una fase acuosa, en el que los monómeros comprenden: (a) (met)acrilamida, (b) monómero catiónico etilénicamente insaturado, (c) monómero etilénicamente insaturado que tiene uno o más grupos acetoacetato, y (d) opcionalmente otro monómero etilénicamente insaturado. The present invention relates to a water-soluble cationic acrylamide-based polymer having one or more acetoacetate groups. The invention also relates to a method for producing the water-soluble polymer which comprises polymerizing ethylenically unsaturated monomers in an aqueous phase, wherein the monomers comprise (a) (meth)acrylamide, (b) ethylenically unsaturated cationic monomer, (c) ethylenically unsaturated monomer having one or more acetoacetate groups, and (d) optionally other ethylenically unsaturated monomer. The invention further relates to the use of the water-soluble polymer as a strength agent in the production of paper and board. The invention further relates to a process for producing paper and board which comprises providing an aqueous cellulosic suspension, adding to the suspension water-soluble polymer having one or more ketone groups, and dewatering the obtained suspension. The invention further relates to paper and board comprising the water-soluble polymer of the invention, as well as paper and board produced by the process of the invention.