The invention relates to a water-soluble polymer product in particle form, comprising amphoteric polyacrylamide, which is obtained by gel polymerisation of acrylamide together with anionic and cationic monomers. The amphoteric polyacrylamide has a mass average molecular weight MW of 1500000-6000000 g/mol, and a total ionicity of 4-15 mol-%, whereby the polymer product has a polymer content of at least 60 weight-%. The invention relates also to uses of the polymer product in paper and board making.

The invention relates to a transfer material for dye sublimation processes, comprising a base paper, which is coated on one side with a color-receiving layer, wherein the base paper contains at least 1.5% by weight, based on the mass of the pulp, of a polymer dispersion selected from the group consisting of polyacrylates, polyesters, polyolefins or mixtures thereof. The invention further relates to a process for producing a transfer material according to the invention, comprising the steps of: (a) producing a base paper on a paper machine, wherein at least 1.5% by weight, based on the mass of the pulp, of a polymer dispersion selected from the group consisting of polyacrylates, polyesters, polyolefins or mixtures thereof are added to the pulp suspension during production of the base paper; (b) drying and smoothing the base paper; (c) applying the color-receiving layer to a surface of the base paper; and (d) drying the transfer material obtained in step (c). The invention further relates to a process for transferring an image onto a receiving material by sublimation, wherein a transfer material according to the invention is printed with an image by way of the inkjet printing process, and the image is transferred onto a receiving material by sublimation.

The invention relates to a transfer material for dye sublimation processes, comprising a base paper, which is coated on one side with a color-receiving layer, wherein the base paper contains at least 1.5% by weight, based on the mass of the pulp, of a polymer dispersion selected from the group consisting of polyacrylates, polyesters, polyolefins or mixtures thereof. The invention further relates to a process for producing a transfer material according to the invention, comprising the steps of: (a) producing a base paper on a paper machine, wherein at least 1.5% by weight, based on the mass of the pulp, of a polymer dispersion selected from the group consisting of polyacrylates, polyesters, polyolefins or mixtures thereof are added to the pulp suspension during production of the base paper; (b) drying and smoothing the base paper; (c) applying the color-receiving layer to a surface of the base paper; and (d) drying the transfer material obtained in step (c). The invention further relates to a process for transferring an image onto a receiving material by sublimation, wherein a transfer material according to the invention is printed with an image by way of the inkjet printing process, and the image is transferred onto a receiving material by sublimation.

Wet strengthened fiber products, wet strengthening resins, and methods for making such wet strengthened fiber products and wet strengthening resins. The wet strengthened fiber product can include a fiber web and an at least partially cured wet strengthening resin, which prior to at least partially curing, the wet strengthening resin can include a polyamide-epihalohydrin (PAE) resin and a cationic styrene maleimide (SMI) resin. The PAE resin can include a reaction product of a polyamidoamine and an epihalohydrin and the cationic SMI resin can include a reaction product of a styrene maleic anhydride (SMA) copolymer and an amine. The wet strengthened fiber product can include the wet strengthening resin in an amount of about 0.05 wt % to about 5 wt %, based on a dried weight of the wet strengthened fiber product.

Wet strengthened fiber products, wet strengthening resins, and methods for making such wet strengthened fiber products and wet strengthening resins. The wet strengthened fiber product can include a fiber web and an at least partially cured wet strengthening resin, which prior to at least partially curing, the wet strengthening resin can include a polyamide-epihalohydrin (PAE) resin and a cationic styrene maleimide (SMI) resin. The PAE resin can include a reaction product of a polyamidoamine and an epihalohydrin and the cationic SMI resin can include a reaction product of a styrene maleic anhydride (SMA) copolymer and an amine. The wet strengthened fiber product can include the wet strengthening resin in an amount of about 0.05 wt % to about 5 wt %, based on a dried weight of the wet strengthened fiber product.

Wet strengthened fiber products, wet strengthening resins, and methods for making such wet strengthened fiber products and wet strengthening resins. The wet strengthened fiber product can include a fiber web and an at least partially cured wet strengthening resin, which prior to at least partially curing, the wet strengthening resin can include a polyamide-epihalohydrin (PAE) resin and a cationic styrene maleimide (SMI) resin. The PAE resin can include a reaction product of a polyamidoamine and an epihalohydrin and the cationic SMI resin can include a reaction product of a styrene maleic anhydride (SMA) copolymer and an amine. The wet strengthened fiber product can include the wet strengthening resin in an amount of about 0.05 wt % to about 5 wt %, based on a dried weight of the wet strengthened fiber product.

The present invention relates to a process for producing corrugated fiberboard from plies of paper which each have a grammage of 70 to 200 g/m.sup.2 and of which at least one ply of paper is obtained by a process comprising the addition of (A) 0.25 to 5 wt %, based on dry paper stock, of at least one cationic polymer comprising vinylamine units, and (B) 0 to 5 wt %, based on dry paper stock, of at least one polymeric anionic compound,

to a paper stock, draining the paper stock by sheet formation, coating the paper web obtained with (C) 0.1 to 3 wt %, based on dry paper stock, of at least one starch

and drying the coated paper web,

wherein the polymeric anionic compound is selected from a polymeric anionic compound (B1) and a polymeric anionic compound (B2),

wherein said polymeric anionic compound (B1) is obtainable by copolymerizing a monomer mixture comprising, preferably consisting of, (a) at least one monomer (a) selected from acrylamide and an N-vinylcarboxamide of the formula

##STR00001## where R.sup.1 and R.sup.2 are each H or C.sub.1 to C.sub.6 alkyl, (b) at least one acid-functional monoethylenically unsaturated monomer and/or its alkali metal, alkaline earth metal or ammonium salts (b), and (c) optionally one or more monoethylenically unsaturated compounds (c) other than said monomers (a) and (b), and (d) optionally one or more compounds having at least two ethylenically unsaturated double bonds in the molecule,

and said polymeric anionic compound (B2) is the hydrolysis product of said polymeric anionic compound (B1) whose carboxamide moieties have been partly or wholly hydrolyzed into amino groups,

and also the corrugated fiberboard thus obtained and its use in the manufacture of packaging boxes from corrugated fiberboard.

The invention relates to a method of making paper or paperboard comprising the steps of; a. providing a stock suspension; b. adding a mixture of alkali-metal silicate and precipitated calcium carbonate to said stock suspension; c. adding an acidic media to said stock suspension substantially directly before and/or after step (b) d. forming a web of the stock suspension obtained in step (d) e. drying said web. The addition of a mixture of alkali-metal silicate and PCC and of an acidic media to the stock suspension in accordance with the invention improves the bonding between the fibers and the filler (PCC), whereby problems related to dusting is decreased. Moreover, the method enables the addition of a higher amount of fillers to the paper without substantially affecting the strength.

The present invention concerns a process of making paper, board or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained on a moving screen to form a sheet which is dried, wherein the process employs a treatment system which is applied to the thin stock, said treatment system comprising as components, a) a cationic organic polymer of charge density of at least 3.0 meq/g with a molar mass Mw of up to 3 million Daltons or poly aluminum chloride (PAC), b) a cationic polymer having an average molar mass Mw of at least 500,000 Daltons and a charge density not exceeding 4.0 meq/g; c) a microparticulate material; in which components (b) and (c) are added to the cellulosic thin stock after the last shear stage before the head box and component (a) is added to the cellulosic thin stock before the said last shear stage.

The present invention concerns a process of making paper, board or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained on a moving screen to form a sheet which is dried, wherein the process employs a treatment system which is applied to the thin stock, said treatment system comprising as components, a) a cationic organic polymer of charge density of at least 3.0 meq/g with a molar mass Mw of up to 3 million Daltons or poly aluminum chloride (PAC), b) a cationic polymer having an average molar mass Mw of at least 500,000 Daltons and a charge density not exceeding 4.0 meq/g; c) a microparticulate material; in which components (b) and (c) are added to the cellulosic thin stock after the last shear stage before the head box and component (a) is added to the cellulosic thin stock before the said last shear stage.