Akzo Nobel N.v.

Akzo N.v.

Eka Nobel Ab

Eka Chemicals Ab

Marek Gorzynski

Andreas Pingel

Oliver Struck

Horst Schurmann

Hans Wallenius

Arne Andersson

Sussan Sandberg

Heribert J Macherey

Christian Biermann

Tissue paper having a bulk between 2 and 8 cm/g and containing an amount of a wet strength agent, wherein the tissue paper contains a wet strength agent in the form of a nitrogen-containing polymer having hydrophobic side-chains. Said tissue paper before converting has a relative wet strength value (RWS) of at least 45%.

Wet strong tissue paper

A method for preparing a wet strength agent comprising a first step of reacting a nitrogen-containing polymer with a hydrophobic compound to form hydrophobic side-chain substituents on the polymer, a second step of reacting the hydrophobised nitrogen-containing polymer obtained with a crosslinker to form a cationic nitrogen-containing resin, and a third step comprising forming of particles by emulsion polymerisation of one or more ethylenically unsaturated monomers in the presence of the wet strength resin formed. The invention further relates to a wet strength agent and resin. It further relates to the use of said agent and resin in cellulosic suspensions, the production of paper, preferably tissue paper, and paper, preferably tissue paper comprising a wet strength resin or agent.

Wet strength agent and method for production thereof

The invention comprises an aqueous solution comprising a water-soluble, polyamidoamine- epichlorohydrin resin, said solution having a reduced halogen content and effective wet strength agent properties, obtained by subjecting an aqueous solution comprising a water-soluble polyamido-amine-epichlorohydrin resin to an organic halogen content reducing after-treatment wherein the total halogen content is below 1% by weight, calculated on solid resin and the halogen content is below 0.1% by weight.

Epihalohydrin-based resins having a reduced halogen content

A process for reducing the content of organic and inorganic halogen in an aqueous solution of a nitrogen-containing epihalohydrin-based resin, in which process the aqueous resin solution is subjected to an electrodialysis treatment. The aqueous resin solutions obtained by the process are used as additives in the production of paper, board and paper board, in particular as wet-strength agents.

Electrodialysis treatment

Anionic polyurethanes are produced by reacting an aliphatic dihydroxy compound, which has an aliphatic substituent with at least 10 carbon atoms, with a polyisocyanate to form a prepolymer with an NCO end group, and for the purpose of chain lengthening, by reacting the prepolymer with an aliphatic diol, which carries an acid group capable of salt formation, and by converting the said acid group totally or partially into a salt. In the production of the polyurethane, polyether compounds with at least one OH group, particularly polyalkylene glycols such as polyethylene glycol, are used additionally. The resulting anionic polyurethanes are particularly suitable as a sizing agent for paper and permit sizing in the acid pH region as well; the sizing agent is furthermore less sensitive to polyvalent cations such as calcium and aluminum ions.

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Duren, Germany

Marek Gorzynski