Akzo Nobel N.v.

Ciba-geigy Corporation

Eka Chemicals Ab

Akzo Nobel Pulp and Performance Chemicals Ab

Johan Nyander

Erik Sanne

Glenn Mankin

Rune Kjell Andersson

Fredrik Solhage

Hans Erik Johansson-Vestin

Jan Nordin

Annika Viola Pal

Jan-Erik Nystrom

Sonny Jonsson

Bjorn Elman

Ann-Britt Pettersson

Per-Erik Sundell

Hans Johansson-Vestin

Kjell Andersson

The present invention relates to a filler comprising clay and cellulose derivative having a degree of substitution of net ionic groups up to about 0.65.

Filler for paper making process

The present invention relates to a process for producing paper which comprises: (i) providing an aqueous suspension comprising cellulosic fibers, (ii) adding to the suspension after the last point of high shear subsequent a centri-screen: (a) a first anionic component which is a water-soluble anionic anionic polysaccharide; (b) a second anionic component which is a water-dispersible or branched acrylamide-based polymer; and (c) a third anionic component which is an anionic siliceous material comprising an anionic silica-based polymer comprising anionic silica-based particles having a specific surface area within the range of from 100 to 1700 m2/g (iii) dewatering the obtained suspension to form paper.

Process for the production of paper

The present invention relates to a drainage and retention aid composition which comprises:

A process for producing an aqueous silica-based sol is disclosed wherein a cationic ion exchange resin having part of its ion exchange capacity in hydrogen form is contacted with an aqueous alkali metal silicate to form a slurry having a pH from 5.0 to 11.5 and/or having particle aggregation or microgel formation corresponding to a S value up to 45%; adjusting the pH using a material comprising an aluminum compound; and separating the resin from the slurry. Silica-based sols having an S value from 15 to 25%, mole ratio Si:Al from 20:1 to 50:1, mole ratio Si:X, where X=alkali metal, from 5:1 to 17:1, SiOcontent of at least 5% by weight and containing silica-based particles having a specific surface area of at least 300 m/g, as well as the use of such silica-based sols in producing paper are disclosed.

Silica-based sols and their production and use

A process for producing aqueous silica-based sols, having an S value from 15 to 25%, mole ratio Si:Al from 20:1 to 50:1, mole ratio Si:X, where X=alkali metal, from 5:1 to 17:1, SiO2 content of at least 5% by weight and containing silica-based particles having a specific surface area of at least 300 m2/g, are disclosed wherein a cationic ion exchange resin having part of its ion exchange capacity in hydrogen form is contacted with an aqueous alkali metal silicate to form a slurry having a pH from 5.0 to 11.5 and/or having particle aggregation or microgel formation corresponding to a S value up to 45%; adjusting the pH using a material comprising an aluminium compound; and separating the resin from the slurry. Further, the use of such silica-based sols in producing paper is disclosed.

A process for producing an aqueous silica-based soils disclosed wherein a cationic ion exchange resin having part of its ion exchange capacity in hydrogen form is contacted with an aqueous alkali metal silicate to form a slurry having a pH from 5.0 to 11.5 and/or having particle aggregation or microgel formation corresponding to a S value up to 45%; adjusting the pH using a material comprising an aluminum compound; and separating the resin from the slurry. Silica-based sols having an S value from 15 to 25%, mole ratio Si:Al from 20:1 to 50:1, mole ratio Si:X, where X=alkali metal, from 5:1 to 17:1, SiOcontent of at least 5% by weight and containing silica-based particles having a specific surface area of at least 300 m/g, as well as the use of such silica-based sols in producing paper are also disclosed.

The present invention refers to a process for the production of paper from a suspension containing cellulosic fibers, and optionally fillers, comprising adding to the suspension at least one cationic organic polymer and an aqueous silica-containing composition comprising an anionic naphthalene sulphonate formaldehyde condensate and anionic silica-based particles, the composition having a weight ratio of naphthalene sulphonate formaldehyde condensate to silica-based particles within the range of from 0.2:1 to 99:1, and containing naphthalene sulphonate formaldehyde condensate and silica-based particles in an amount of at least 0.01% by weight, based on the total weight of the aqueous silica-containing composition, and with the proviso that the composition contains substantially no cellulose-reactive sizing agent. The invention also encompasses an aqueous silica-containing composition and a method for preparation of an aqueous silica-containing compound.

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Sollentuna, Sweden

Johan Nyander