Process for the production of paper
First Claim
1. A process for the production of paper from an aqueous suspension containing cellulosic fibers, and optional fillers, which comprises separately adding to the suspension(i) a cationic organic polymer having one or more aromatic groups and having at least one quaternary ammonium group, the cationic organic polymer being a cationic polysaccharide and being added in an amount of at least 0.001% by weight based on dry cellulosic fibers and optional fillers;
- and (ii) an anionic polymer having one or more aromatic groups, the anionic polymer being added in an amount of at least 0.001% by weight based on dry cellulosic fibers and optional fillers, and the anionic polymer being a formaldehyde-naphthalene sulfonate condensation polymer;
and forming and draining the obtained suspension on a wire.
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Accused Products
Abstract
The invention relates to a process for the production of paper from an aqueous suspension containing cellulosic fibers, and optional fillers, which comprises separately adding to the suspension a cationic organic polymer having one or more aromatic groups and an anionic polymer having one or more aromatic groups, the anionic polymer being selected from step-growth polymers, polysaccharides and naturally occurring aromatic polymers and modifications thereof, forming and draining the suspension on a wire, with the proviso that if the anionic polymer is a step-growth polymer it is not an anionic melamine-sulphonic acid condensation polymer. The invention further relates to a process for the production of paper from an aqueous suspension containing cellulosic fibers, and optional fillers, which comprises separately adding to the suspension a cationic organic polymer having one or more aromatic groups and an anionic polymer having one or more aromatic groups, forming and draining the suspension on a wire, with the proviso that the anionic polymer is not an anionic polystyrene sulphonate or anionic melamine-sulphonic acid condensation polymer.
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Citations
13 Claims
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1. A process for the production of paper from an aqueous suspension containing cellulosic fibers, and optional fillers, which comprises separately adding to the suspension
(i) a cationic organic polymer having one or more aromatic groups and having at least one quaternary ammonium group, the cationic organic polymer being a cationic polysaccharide and being added in an amount of at least 0.001% by weight based on dry cellulosic fibers and optional fillers; - and
(ii) an anionic polymer having one or more aromatic groups, the anionic polymer being added in an amount of at least 0.001% by weight based on dry cellulosic fibers and optional fillers, and the anionic polymer being a formaldehyde-naphthalene sulfonate condensation polymer;
and forming and draining the obtained suspension on a wire. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A process for the production of paper from an aqueous suspension containing cellulosic fibers, and optional fillers, which comprises separately adding to the suspension
(i) a cationic starch having one or more aromatic groups and having at least one quartemary ammonium group, the cationic starch being added in an amount of at least 0.005% by weight based on dry cellulosic fibers and optional fillers; - and
(ii) an anionic condensation polymer, the anionic condensation polymer being a formaldehyde-naphtalene sulfonate condensation polymer and being added in an amount of at least 0.001% by weight based on dry cellulosic fibers and optional fillers;
forming and draining the obtained suspension on a wire. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification