A method for manufacturing a powdery paper-strengthening agent including a branched (meth)acrylamide-based polymer (A) which includes a step of obtaining (A) component by polymerizing (meth)acrylamide (a1), anionic vinyl monomer (a2), cationic vinyl monomer (a3) and crosslinkable vinyl monomer (a4) in a solvent in a presence of a polymerization initiator, a step of dropping or putting the above (A) component into an organic solvent to form a precipitate, and a step of drying and pulverizing (A) component obtained as the precipitate.

This invention relates to an additive based on (co)polymers resulting from the reaction between at least one dialdehyde compound and at least one complex (co)polymer obtained by polymerization of water-soluble monomers in the presence of at least one host (co)polymer comprising vinylamine functions.

The present invention provides a novel method and composition for enhancing the efficiency of starch adsorption (i.e., starch trapping) from starch-containing furnishes comprising high content of recycled fibers for use in paper making processes such as pulp, paper, or board production. A novel polymer coagulation system is disclosed in which two quick inversion cationic emulsion polymers (starch trapping polymers A and B) are co-mixed at optimal blend ratios to meet specific recycled fiber and process water requirements for different recycled fiber plants and added to furnishes prior to formation of paper or board in a paper machine. Co-mixed solutions of starch trapping polymers A and B provide synergistic enhancements in (i) starch trapping efficiency and (ii) starch retention in the produced paper or board over equivalent dosage levels of singly administered polymer A, polymer B, or conventional starch trapping products, without over-flocculation or formation of stickies.

An aqueous prepolymer composition, which comprises a polyacrylamide base polymer comprising 10 - 40 mol-% of cationic monomers and having a weight average molecular weight Mw in the range of 120 000 - 350 000 g/mol, 0.1 - 1 weight-% of glyoxal, calculated from the total weight of the aqueous prepolymer composition, and a buffering acid for adjusting pH of the composition in the range of 2 - 4. A prepolymer composition is used in a method for producing on-site glyoxylated polyacrylamide useful in paper or board manufacturing.

The present disclosure generally relates to glyoxalated polyacrylamide (GPAM) compositions, methods of preparation and methods of use thereof, particularly in the paper industry. Moreover, the present disclosure generally pertains to cationic GPAM compositions, methods of preparation and methods of use thereof in papermaking applications and in products such as paper-based products, wherein the cationic GPAM compositions may provide increased wet and/or dry strength to the paper-based products, and wherein such cationic GPAM compositions optionally require a reduced volume of an aqueous carrier for storage or transport compared to a volume of an aqueous carrier needed for conventional GPAMs used in papermaking.

The present invention concerns a process for preparing self-binding pigment particles from an aqueous suspension of calcium carbonate containing material, wherein an anionic binder and at least one cationic polymer are mixed with the suspension.

A papermaking agent exhibiting an excellent freeness and paper strength effect with little increase in viscosity after long-term storage. A papermaking agent including a (meth)acrylamide polymer containing two or more starches (a1) selected from the group consisting of unmodified starch, oxidized starch, esterified starch, etherified starch, amidated starch, cationic starch, amphoteric starch and crosslinked starch, a (meth)acrylamide (a2), a polymerizable monomer having an amino group (a3), a polymerizable monomer having a carboxy group (a4) and a polymerizable monomer having a sulfonate group (a5) as essential constituent components.

A process for producing paper or board, which process comprises ad-mixing (I) an aqueous composition of pH ≦6 and (II) at least one water-soluble polymeric anionic compound to a paper stock having a pH in the range from 6 to 8 and then dewatering the paper stock by sheet formation and drying, wherein the aqueous composition comprises (a) polymers having primary amino groups and/or amidine groups to a combined content for these groups of ≧1.5 meq/g of polymer, and (b) 0.01 to 50 mol % of 1,4-cyclohexanedione (b) based on the combined amount of primary amino groups and/or amidine groups of the polymers, and also to the paper or board thus obtained.

The invention provides an associative polymer, a powder, and a process for making a powder comprising, networking one or more associative polymer(s) and one or more optional surfactant(s) to form a wet gel, and forming a powder from the wet gel, wherein the associative polymer(s) have a weight average molecular weight of from about 10 kDa to about 2,000 kDa.

The invention relates to a novel sulfobetaine monomer and to a process for the preparation thereof, advantageously by reaction between a vinyl-amine compound and a vinyl-sulfonic acid compound, preferably in the presence of a solubilizing agent. The invention also relates to the (co)polymers obtained from this novel type of sulfobetaine monomer, and to the use thereof, for example as a flocculant, dispersing agent, thickening agent, absorbent agent or friction-reducing agent.