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 paper suitable for use as a separator or thermal or fire insulation for use in or with electrochemical cells, and an electrochemical cell comprising the same, the paper having 90 to 99 weight percent aramid fibrous pulp comprising aramid polymer fibrils and 1 to 10 weight percent polyvinylpyrrolidone present as a coating on the surface of the fibers, the paper having a thickness of 10 to 40 micrometers and a tensile strength of at least 15 megapascals or greater.

A paper suitable for use as a separator or thermal or fire insulation for use in or with electrochemical cells, and an electrochemical cell comprising the same, the paper having 90 to 99 weight percent aramid fibrous pulp comprising aramid polymer fibrils and 1 to 10 weight percent polyvinylpyrrolidone present as a coating on the surface of the fibers, the paper having a thickness of 10 to 40 micrometers and a tensile strength of at least 15 megapascals or greater.

The present invention relates to multi-layer fiber products and a method of manufacturing these kinds of products. The present product comprises a first layer consists mainly of natural fibers and a second, heat-sealing layer located on top of the first layer. The heat-sealing layer consists mainly of synthetic thermoplastic fibers or particles. According to the present method, the heat-sealing layer is brought onto the first layer already during the web forming process, the first and the second layers being formed and joined together in a foam forming process. With the present invention, it is possible to decrease the amount of plastic materials in packaging materials having heat-sealing properties.

The present invention relates to multi-layer fiber products and a method of manufacturing these kinds of products. The present product comprises a first layer consists mainly of natural fibers and a second, heat-sealing layer located on top of the first layer. The heat-sealing layer consists mainly of synthetic thermoplastic fibers or particles. According to the present method, the heat-sealing layer is brought onto the first layer already during the web forming process, the first and the second layers being formed and joined together in a foam forming process. With the present invention, it is possible to decrease the amount of plastic materials in packaging materials having heat-sealing properties.

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.

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.

The present invention relates to a water-soluble polymer obtained by polymerization of at least a 2-dimethylaminoethyl acrylate monomer and/or its salts, in presence of at least a tocopherol and/or its derivatives, or a tocotrienol and/or its derivatives, and its uses.

This invention relates to a method for manufacturing a sheet of paper or cardboard, comprising the addition of a water-soluble polymer P with a weight-average molecular weight greater than 750,000 Dalton to a fibrous suspension. This method comprises the following successive steps: preparing an aqueous solution A containing at least one water-soluble polymer P at a concentration C of between 0.1 and 0.5% by weight, said polymer P having a factor F(C) strictly greater than 4, with F.sub.(C)=Δ600/C, Δ600 being the slope to reach 90% of the viscosity developed by aqueous solution A at 600 seconds at 25° C., obtained from the viscosity curve of aqueous solution A as a function of time, at the given concentration C, at 25° C., adding aqueous solution A to the fibrous suspension, at one or more injection points, forming a sheet of paper or cardboard.