A method for obtaining a fibrous preparation for manufacturing a paper having significant water repellency and opacity in the dry or wet state. Fibres are suspended in water; calcium salts are added to the fibres; a source of carbonate salts in the form of an aqueous solution are added and the resulting mixture is stirred for a time sufficient to allow calcium carbonate particles to be precipitated. A solution of fatty acid salts heated to a temperature which corresponds to the micellisation temperature of said fatty acid salts is added and takes into account the critical micellar concentration of the fatty acid salts. The mixture is stirred thus obtained for a time sufficient to allow the fatty acids to be absorbed at the surface of the calcium carbonate particles and to obtain the desired fibrous preparation.

The present disclosure provides for a paper product. The paper product has: (a) from about 20% to about 90% by weight of the dry fiber basis of the paper product of a refined soft wood pulp fiber mixture, (b) pulp fibers selected from the group consisting of hard wood fibers, non-wood fibers, recycled fibers, synthetic polymer fibers, bleached eucalyptus kraft fibers, and combinations thereof; and, (c) not more than about 10% by weight moisture.

The present disclosure provides for a paper product. The paper product has: (a) from about 20% to about 90% by weight of the dry fiber basis of the paper product of a refined soft wood pulp fiber mixture, (b) pulp fibers selected from the group consisting of hard wood fibers, non-wood fibers, recycled fibers, synthetic polymer fibers, bleached eucalyptus kraft fibers, and combinations thereof; and, (c) not more than about 10% by weight moisture.

A process for flocculating filler particles in water is provided. The process comprises adding a flocculant to a mixture comprising filler particles and water, wherein the flocculant has a reduced specific viscosity (“RSV”) of from about 5 dL/g to about 16 dL/g, a viscosity average molecular weight of from about 1,200,000 to about 7,500,000, and a cationic charge of from about 5 mol % to about 50 mol %. Flocs formed by flocculation of the filler particles and the flocculant have a median particle size of from about 10 um to about 150 um. The filler is not precipitated calcium carbonate alone. The flocs provided by the process are useful in increasing ash content of a paper product.

A process for flocculating filler particles in water is provided. The process comprises adding a flocculant to a mixture comprising filler particles and water, wherein the flocculant has a reduced specific viscosity (“RSV”) of from about 5 dL/g to about 16 dL/g, a viscosity average molecular weight of from about 1,200,000 to about 7,500,000, and a cationic charge of from about 5 mol % to about 50 mol %. Flocs formed by flocculation of the filler particles and the flocculant have a median particle size of from about 10 um to about 150 um. The filler is not precipitated calcium carbonate alone. The flocs provided by the process are useful in increasing ash content of a paper product.

Provided is a printing coated paper which is advantageous not only in that the coated paper has offset printability and causes no mottling in the printed area even in ink jet printing, but also in that the coated paper exhibits excellent rubbing resistance with respect to the printed area and excellent print density of a dye ink. The task of the present invention is achieved by a printing coated paper having a coating layer comprised mainly of a pigment and a binder formed on at least one side of a base paper, wherein the base paper is a treated base paper which has been subjected to size press using a treatment solution containing at least one member selected from a cationic resin and a water-soluble multivalent cation salt, wherein the total applied amount per each side of the at least one member selected from a cationic resin and a water-soluble multivalent cation salt, in terms of the solids content, is in the range of from 0.1 to 5.0 g/m.sup.2, and wherein the at least one pigment in the coating layer is ground calcium carbonate having an average particle diameter of 0.1 to 0.28 μm, wherein the amount of the ground calcium carbonate having an average particle diameter of 0.1 to 0.28 μm contained in the coating layer is in the range of 60 parts by mass or more, relative to 100 parts by mass of the total of the pigment(s) in the coating layer.

Provided is a printing coated paper which is advantageous not only in that the coated paper has offset printability and causes no mottling in the printed area even in ink jet printing, but also in that the coated paper exhibits excellent rubbing resistance with respect to the printed area and excellent print density of a dye ink. The task of the present invention is achieved by a printing coated paper having a coating layer comprised mainly of a pigment and a binder formed on at least one side of a base paper, wherein the base paper is a treated base paper which has been subjected to size press using a treatment solution containing at least one member selected from a cationic resin and a water-soluble multivalent cation salt, wherein the total applied amount per each side of the at least one member selected from a cationic resin and a water-soluble multivalent cation salt, in terms of the solids content, is in the range of from 0.1 to 5.0 g/m.sup.2, and wherein the at least one pigment in the coating layer is ground calcium carbonate having an average particle diameter of 0.1 to 0.28 μm, wherein the amount of the ground calcium carbonate having an average particle diameter of 0.1 to 0.28 μm contained in the coating layer is in the range of 60 parts by mass or more, relative to 100 parts by mass of the total of the pigment(s) in the coating layer.

Methods of producing a multi-ply paper product are provided. The methods comprise applying coagulant and/or hybrid coagulant-flocculant composition to an upper ply substrate disposed adjacent and above a lower ply substrate in an amount such that a portion of the coagulant and/or the hybrid coagulant-flocculant composition passes through the upper ply substrate. Preferably, the lower ply substrate has a greater freeness than the upper ply substrate. The methods of the present disclosure preferably allow for efficient use of RDF chemicals while making use of the innate freeness differences between the upper and lower ply substrates.

A strength additive system for manufacturing paper, board, tissue or the like includes preferably as separate components, a cationic strength agent, such as a cationic polymer with aldehyde functional groups, and an anionic copolymer obtained by polymerization of a reaction mixture including (meth)acrylamide and anionic monomers, the standard viscosity of the obtained copolymer being in a range of 1.5-5.0 mPas. A method for manufacturing of a paper, board, tissue or the like is further disclosed.

A polymeric structure, which is obtained by polymerisation of (meth) acrylamide and at least one charged monomer in a polymerisation medium comprising at least a first host polymer, which first host polymer comprises polyvinyl alcohol. The polymeric structure may be used in making of paper, board, tissue or the like as a strength agent, or in dewatering of sludge.