摘要:
Silica sols with a high content of microgel and particles with a specific surface area within the range 300 to 700 m.sup.2 /g, preferably 400 to 650 m.sup.2 /g. The sols can be prepared by acidification or a water glass solution and alkalization at a certain dry content, alternatively to a certain pH. The sols are particularly suitable for use as additives in papermaking in combination with cationic polymers and especially in combination with cationic acrylamide based polymers.
摘要:
The invention relates to a pigment composition in the form of an aqueous dispersion or slurry comprising: (c) porous aggregates formed by aggregation of colloidal primary particles of silica, aluminosilicate or a mixture thereof in an aqueous sol, said porous aggregates having a mean diameter from about 0.03 to about 25 μm, and, (d) extender particles where the mean size of at least one dimension is larger than the mean diameter of the porous aggregates, wherein the weight ratio of porous aggregates to extender particles is from about 0.01:1 to about 3:1. The invention further relates to a process for its production, a composition for coating paper or paper board and a process for its production, and a process for coating paper or paper board and paper or paper board obtainable by the process.
摘要:
The present invention relates to a process for the production of coated paper or paperboard comprising a step of applying a pigment composition as a coating to at least one side of a paper or paperboard web, said pigment composition being an aqueous dispersion comprising as pigment particles optionally aggregated colloidal particles of silica or aluminosilicate prepared from alkali metal silicate by ion exchange or pH-reduction and having a surface area from about 30 m2/g to about 450 m2/g, and at least one cationic component selected from the group consisting of water soluble aluminium salts and cationic polymers with a molecular weight from about 2000 to about 1000000 and a charge density from about 0.2 meq/g to about 12 meq/g, wherein at least about 0.4 g pigment particles from the pigment composition are applied per m2 coated side of the paper or paper board web.
摘要:
Aqueous suspensions of colloidal particles which particles are both silica based anionic particles and swollen particles of clays of smectite type which are expandable in water and a process for the preparation thereof. The suspensions are useful as flocculating agents and particularly in combination with polymers in the production of paper.
摘要:
The present invention relates to a pigment composition in the form of an aqueous dispersion comprising: (d) pigment particles of synthetic amorphous silica or aluminosilicate; (e) at least one water soluble aluminium salt; and, (f) at least one cationic polymer having a molecular weight from about 2000 to about 1000000 and a charge density from about 0.2 to about 12 meq/g. The invention further relates to a process for its production, use thereof, a process for coating paper or paper board and paper or paper board obtainable by the process.
摘要:
The present invention relates to a method of treating polyaluminium compounds comprising contacting at least one polyaluminium compound in an aqueous solution with an anion exchange material capable of accepting anions or anionic groups and donating hydroxyl ions for a time necessary to obtain a polyaluminium compound having a higher molar ratio of hydroxide to aluminium than the polyaluminium compound had before contacting it with the anion exchange material.
摘要:
The invention relates to a process for the production of paper from a suspension of cellulose containing fibres, and optional fillers, which comprises adding a water-soluble cationic or amphoteric branched acrylamide-based polymer and an anionic aluminium-containing silica sol to the suspension and forming and draining the suspension on a wire.
摘要:
The invention relates to an aqueous dispersion containing a dispersant and a disperse phase containing a hydrophobic material, the dispersant comprising an anionic compound having a molecular weight less than 50,000 and being selected from the group consisting of carbon-containing compounds and silicon-containing compounds, and a cationic organic compound having a molecular weight less than 50,000. The invention further relates to the preparation and use of the dispersion in the production of paper. The invention also relates to a substantially water-free composition containing a hydrophobic material, an anionic compound having a molecular weight less than 50,000 and being selected from carbon-containing compounds and silicon-containing compounds, and a cationic organic compound having a molecular weight less than 50,000, as well as it use in the preparation of an aqueous dispersion.
摘要:
The invention relates to a process for producing board which comprises providing an aqueous suspension comprising cellulosic fibres; adding hydrotalcite to the suspension; dewatering the obtained suspension to provide a (i) single ply board. The invention further relates to board comprising one or more plies containing cellulosic fibres, wherein the board further comprises hydrotalcite distributed throughout at least one of said one or more plies.
摘要:
A process for sizing paper comprising adding to an aqueous suspension containing cellulosic fibers, and optional fillers, an anionic or cationic sizing dispersion, and a sizing promoter comprising a cationic organic polymer having an aromatic group; and an anionic polymer having an aromatic group selected from step-growth polymers, polysaccharides and naturally occurring aromatic polymers, wherein the sizing dispersion and sizing promoter are added separately to the aqueous suspension.