The invention relates to a method for dissolving cationic starch. In the method is obtained an aqueous polyelectrolyte solution comprising a synthetic cationic polymer, which has a charge density value of at least 0.1 meq/g, determined at pH3, the concentration of the cationic polymer in the polyelectrolyte solution being >2.5 weight-%, and the aqueous polyelectrolyte solution is brought together with cationic starch having a degree of substitution, DS, >0.1. The cationic starch is dissolved to the polyelectrolyte solution by heating and/or mixing. The invention relates also to a papermaking agent comprising 2-40 weight-% of synthetic cationic polymer which has a charge density value of at least 0.1 meq/g, determined at p H 3, and 2.5-25 weight-% cationic starch having degree of substitution, DS, >0.1. The papermaking agent is in slurry form and has a viscosity of 50-20 000 m Pas, measured at 25 C. with Brookfield DVI+ viscometer.

The invention relates to a method for dissolving cationic starch. In the method is obtained an aqueous polyelectrolyte solution comprising a synthetic cationic polymer, which has a charge density value of at least 0.1 meq/g, determined at pH3, the concentration of the cationic polymer in the polyelectrolyte solution being >2.5 weight-%, and the aqueous polyelectrolyte solution is brought together with cationic starch having a degree of substitution, DS, >0.1. The cationic starch is dissolved to the polyelectrolyte solution by heating and/or mixing. The invention relates also to a papermaking agent comprising 2-40 weight-% of synthetic cationic polymer which has a charge density value of at least 0.1 meq/g, determined at p H 3, and 2.5-25 weight-% cationic starch having degree of substitution, DS, >0.1. The papermaking agent is in slurry form and has a viscosity of 50-20 000 m Pas, measured at 25 C. with Brookfield DVI+ viscometer.

Process for manufacturing a sheet of paper and/or of paperboard and the like, according to which, the cellulosic material is brought into contact with at least one dry strength aid, characterized in that said dry strength aid is a cationic or amphoteric (co)polymer derived from the reaction between at least one aldehyde and at least one base (co)polymer comprising at least one nonionic monomer, said base copolymer being modified with at least one polyfunctional compound comprising at least three heteroatoms chosen from N, S, O and P, in which at least three of these heteroatoms each have at least one mobile hydrogen.

One or more embodiments include paper, methods of making paper, compositions, and the like, are provided. In various exemplary embodiments described herein, a paper material may be formed by treating a cellulosic fiber or an aqueous pulp slurry, with a strength including a polyamine resin.

One or more embodiments include paper, methods of making paper, compositions, and the like, are provided. In various exemplary embodiments described herein, a paper material may be formed by treating a cellulosic fiber or an aqueous pulp slurry, with a strength including a polyamine resin.

Compositions that can be used in a paper material, which may include an anionic polymer, a polyamidoamine epihalohydrin resin, and a stabilizer, are disclosed. Methods for adding the compositions to a paper material are also disclosed.

Compositions that can be used in a paper material, which may include an anionic polymer, a polyamidoamine epihalohydrin resin, and a stabilizer, are disclosed. Methods for adding the compositions to a paper material are also disclosed.

Disclosed is a treatment agent for paper comprising a fluorine-containing copolymer having a repeat unit (a) derived from a fluorine-containing monomer represented by general formula (I): CH.sub.2C(X)C(O)Y[CH.sub.2).sub.mZ].sub.p(CH.sub.2).sub.nRf; a repeat unit (b) derived from at least one amino monomer represented by general formula (II-1): ##STR00001##
or a derivative thereof; and a repeat unit (c) derived from a pyrrolidone monomer represented by general formula (III): ##STR00002##
The treatment agent for paper provides paper having high oil resistance and high water resistance.

Disclosed is a treatment agent for paper comprising a fluorine-containing copolymer having a repeat unit (a) derived from a fluorine-containing monomer represented by general formula (I): CH.sub.2C(X)C(O)Y[CH.sub.2).sub.mZ].sub.p(CH.sub.2).sub.nRf; a repeat unit (b) derived from at least one amino monomer represented by general formula (II-1): ##STR00001##
or a derivative thereof; and a repeat unit (c) derived from a pyrrolidone monomer represented by general formula (III): ##STR00002##
The treatment agent for paper provides paper having high oil resistance and high water resistance.