A vinyl amine containing polymer comprises randomly distributed repeating monomer units having at least two of the following formulae:

##STR00001## wherein, R1 is a hydrogen atom or a methyl group; and wherein the vinyl amine containing polymer comprises repeating monomer unit III and/or IV in a total amount of from about 1.5 weight percent to about 8 weight percent based on a total weight of the polymer.

A method for the production of paper or cardboard is provide comprising the following steps: (A) Adding a water soluble polymer P to a first aqueous pulp suspension, wherein polymer P is obtainable by Polymerizing to a polymer V of (i) 33 to 83 mol % of a monomer of formula I ##STR00001## in which R.sup.1═H or C.sub.1-C.sub.6 alkyl, (ii) 6 to 56 mol % of diallyl dimethyl ammonium chloride, diallyl diethyl ammonium chloride or a salt form of a monoethylenically unsaturated monomer, (iii) 11 to 61 mol % of a monoethylenically unsaturated carboxylic acid, sulfonic acid or phosphonic acid, or salt forms thereof, (iv) 0 to 50 mol % of one or more ethylenically unsaturated monomers, and hydrolyzing the N—C(═O)R.sup.1 groups to form primary amino or amidine groups, (B) dehydrating the second aqueous pulp suspension to a wet paper structure, (C) dehydrating the wet paper structure.

A method for the production of paper or cardboard is provide comprising the following steps: (A) Adding a water soluble polymer P to a first aqueous pulp suspension, wherein polymer P is obtainable by Polymerizing to a polymer V of (i) 33 to 83 mol % of a monomer of formula I ##STR00001## in which R.sup.1═H or C.sub.1-C.sub.6 alkyl, (ii) 6 to 56 mol % of diallyl dimethyl ammonium chloride, diallyl diethyl ammonium chloride or a salt form of a monoethylenically unsaturated monomer, (iii) 11 to 61 mol % of a monoethylenically unsaturated carboxylic acid, sulfonic acid or phosphonic acid, or salt forms thereof, (iv) 0 to 50 mol % of one or more ethylenically unsaturated monomers, and hydrolyzing the N—C(═O)R.sup.1 groups to form primary amino or amidine groups, (B) dehydrating the second aqueous pulp suspension to a wet paper structure, (C) dehydrating the wet paper structure.

The present invention relates to a process wherein microfibrillated cellulose (MFC) is mixed with at least two retention aids, selected from a cationic or amphoteric polymer and a microparticle or nanoparticle as a pre-mix before dosing it to the stock in a process for manufacture of a fiber based product.

The present invention relates to a process wherein microfibrillated cellulose (MFC) is mixed with at least two retention aids, selected from a cationic or amphoteric polymer and a microparticle or nanoparticle as a pre-mix before dosing it to the stock in a process for manufacture of a fiber based product.

A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

A foaming formulation is provided herein. The foaming formulation includes at least one foaming agent in an amount of from about 0.001% to about 10% by weight based on a total weight of the foaming solution. The foaming formulation further includes a synthetic strength additive having a cationic functional group in an amount from about 0.01% to about 50% by weight based on a total weight of the foaming solution. The foaming formulation further includes water.

A foaming formulation is provided herein. The foaming formulation includes at least one foaming agent in an amount of from about 0.001% to about 10% by weight based on a total weight of the foaming solution. The foaming formulation further includes a synthetic strength additive having a cationic functional group in an amount from about 0.01% to about 50% by weight based on a total weight of the foaming solution. The foaming formulation further includes water.

A treated article includes fibers, a sizing agent, and a retention aid. The sizing agent includes a wax or a component thereof having an acid value of from 10 mg to 220 mg, KOH/g as measured in accordance with USP 401. The retention aid includes a nitrogen-containing polymer independently selected from the group consisting of (i) a nitrogen-containing polymer of Formula I, (ii) a polyethyleneimine, (iii) a polyaminoamide, (iv) a copolymer formed from the reaction product of epichlorohydrin and dimethylamine, and (v) combinations thereof.