A dcor paper is prepared from a dispersion having improved optical performance, wherein the dispersion contains a TiO.sub.2 particle slurry; paper pulp; and a cationic polymer. The TiO.sub.2 particle slurry has a treated TiO.sub.2 particle with a surface area of at least about 30 m.sup.2/g and a cationic polymer; the treatment is an oxide of silicon, aluminum, phosphorus or mixtures thereof; and the treatment is present in the amount of at least 15% based on the total weight of the treated titanium dioxide particle. Comparable dispersions not using the TiO.sub.2 particle slurry described would require about 10% more treated TiO.sub.2 particle than a dispersion made with the described TiO.sub.2 particle slurry, paper pulp, and cationic polymer to achieve equivalent optical performance. These dcor papers are useful in preparing paper laminates.

A dcor paper is prepared from a dispersion having improved optical performance, wherein the dispersion contains a TiO.sub.2 particle slurry; paper pulp; and a cationic polymer. The TiO.sub.2 particle slurry has a treated TiO.sub.2 particle with a surface area of at least about 30 m.sup.2/g and a cationic polymer; the treatment is an oxide of silicon, aluminum, phosphorus or mixtures thereof; and the treatment is present in the amount of at least 15% based on the total weight of the treated titanium dioxide particle. Comparable dispersions not using the TiO.sub.2 particle slurry described would require about 10% more treated TiO.sub.2 particle than a dispersion made with the described TiO.sub.2 particle slurry, paper pulp, and cationic polymer to achieve equivalent optical performance. These dcor papers are useful in preparing paper laminates.

Disclosed is a pitch control agent including a (meth)acrylamide-based amphoteric polymer. The (meth)acrylamide-based amphoteric polymer contains 50 mol % or more of (meth)acrylamide, 0.5 to 20 mol % of a diallyldialkylammonium salt; and 0.1 to 14 mol % of an anionic monomer, as copolymerizable monomer components. This pitch control agent is less likely to be affected by a change in a surrounding environment, and therefore can exhibit excellent pitch controllability under various environments in paper production process.

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.

There is provided a method of making white sack paper having a grammage of 50-140 g/m2 and a Gurley porosity (ISO 5636/5) of 2-10 s, comprising the steps of: a) providing bleached pulp, such as bleached sulphate pulp; b) subjecting the pulp to high consistency (HC) refining and optionally low consistency (LC) refining to the extent that the sack paper obtains the Gurley porosity; c) adding cationic polymer, such as cationic starch, to the pulp in an amount of 1.5-5.0 kg/ton paper; and d) adding size to the pulp in an amount of 0.4-2.0 kg/ton paper; and e) forming the sack paper from the pulp, wherein less than 2 kg/ton paper of anionic starch is added to the pulp.

A method of increasing paper strength is provided. The method includes adding a lignin-based compound to a pulp slurry: and adding a cationic polymer to the pulp slurry. When added to a pulp slurry. the combination of a lignin-based compound and a cationic polymer produce a comprehensive paper strength increase.

The present invention relates to a crumple-resistant security sheet comprising fibers; an anionic polymer in a proportion lying in the range 5% to 45% by dry weight relative to the total dry weight of the fibers, and presenting a glass transition temperature greater than 40 C.; and a main cationic flocculation agent in a quantity lying in the range 1% to 5% by dry weight relative to the total dry weight of the fibers.

The present invention relates to a crumple-resistant security sheet comprising fibers; an anionic polymer in a proportion lying in the range 5% to 45% by dry weight relative to the total dry weight of the fibers, and presenting a glass transition temperature greater than 40 C.; and a main cationic flocculation agent in a quantity lying in the range 1% to 5% by dry weight relative to the total dry weight of the fibers.

An absorbent towel paper product having a machine direction and a cross-machine direction orthogonal to the machine direction, wherein the absorbent towel paper product comprises two plies of absorbent towel paper webs, wherein each paper web comprises from about 20% to about 90% by weight of the dry fiber basis of the towel paper web of a refined long fiber soft wood pulp fiber mixture comprising from about 18.5% to about 88.5% by weight of the dry fiber basis of the towel paper web of long fiber soft wood pulp fiber, wherein the long fiber soft wood pulp fiber is optionally refined before being added to the mixture; from about 0.25% to about 5.0% by weight of the dry fiber basis of the tissue paper web of cationic strengthening polymer, from about 10% to about 55% by weight of the dry fiber basis of the tissue paper web of a hard wood pulp fiber mixture; and not more than about 10% by weight moisture; wherein the two-ply paper product has a Mean Square Tensile Index value ranging from about 10 N.Math.m/g to about 18 N.Math.m/g; and wherein the two-ply paper product has a Cross-directional Wet Tensile Strength to Cross-directional Dry Tensile Strength Ratio value ranging from about 0.295 to about 0.33.