To provide a new inorganic particle composite fiber including a large amount of adhering inorganic particles, An inorganic particle composite fiber includes: fiber; and inorganic particles fixed to the fiber, the fiber being thread-like in shape, the inorganic particles being fixed to the fiber via an ionic polymer.

To provide a new inorganic particle composite fiber including a large amount of adhering inorganic particles, An inorganic particle composite fiber includes: fiber; and inorganic particles fixed to the fiber, the fiber being thread-like in shape, the inorganic particles being fixed to the fiber via an ionic polymer.

N-vinyllactam-containing polyvinylamine-based polymers, methods for producing N-vinyllactam-containing polyvinylamine-based polymers, and methods for papermaking are provided. An exemplary method for producing an N-vinyllactam-containing polyvinylamine-based polymer includes performing radical polymerization of a vinylamide monomer, a vinyl monomer containing an amide functional group, and, optionally, a vinyl monomer that contains a carboxylic acid group, to obtain a prepolymer. Further, the method includes hydrolyzing the prepolymer under alkaline conditions to obtain the N-vinyllactam-containing polyvinylamine-based polymer.

N-vinyllactam-containing polyvinylamine-based polymers, methods for producing N-vinyllactam-containing polyvinylamine-based polymers, and methods for papermaking are provided. An exemplary method for producing an N-vinyllactam-containing polyvinylamine-based polymer includes performing radical polymerization of a vinylamide monomer, a vinyl monomer containing an amide functional group, and, optionally, a vinyl monomer that contains a carboxylic acid group, to obtain a prepolymer. Further, the method includes hydrolyzing the prepolymer under alkaline conditions to obtain the N-vinyllactam-containing polyvinylamine-based polymer.

This invention relates to a method for manufacturing a sheet of paper or cardboard, according to which, before forming said sheet, at least one N-vinylformamide polymer that is partially hydrolyzed in the form of an inverse emulsion is added, at one or more injection points, to a fibrous suspension in the presence of an anti-gelling agent, and having a cationic regain between 30 and 150%, the inverse emulsion having a weight ratio of partially hydrolyzed N-vinylformamide polymer to anti-gelling agent in the range between 1,000,000/5000 and 1,000,000/50,000.

This invention relates to a method for manufacturing a sheet of paper or cardboard, according to which, before forming said sheet, at least one N-vinylformamide polymer that is partially hydrolyzed in the form of an inverse emulsion is added, at one or more injection points, to a fibrous suspension in the presence of an anti-gelling agent, and having a cationic regain between 30 and 150%, the inverse emulsion having a weight ratio of partially hydrolyzed N-vinylformamide polymer to anti-gelling agent in the range between 1,000,000/5000 and 1,000,000/50,000.

A method for producing dried multilayer paper is provided comprising dewatering a first aqueous fibrous suspension, thereby creating a first fibrous web; dewatering a second aqueous fibrous suspension, thereby creating a second fibrous web; spraying one or more of a first fibrous web and a second fibrous web with a spray solution or spray suspension, thereby producing at least one sprayed fibrous web; assembling the first fibrous web with the second fibrous web; dehydrating the resulting layer compound by pressing; then dehydrating by supplying heat, which creates the dried multilayer paper. The spray solution or spray suspension contains water and at least one water-soluble polymer P. The polymer P is obtained by polymerizing: 40 to 85 mol % of a monomer of Formula I ##STR00001##
in which R.sup.1=H or C.sub.1-C.sub.6-Alkyl; and 15 to 60 mol % of one or more ethylenically unsaturated monomers.

A method for producing dried multilayer paper is provided comprising dewatering a first aqueous fibrous suspension, thereby creating a first fibrous web; dewatering a second aqueous fibrous suspension, thereby creating a second fibrous web; spraying one or more of a first fibrous web and a second fibrous web with a spray solution or spray suspension, thereby producing at least one sprayed fibrous web; assembling the first fibrous web with the second fibrous web; dehydrating the resulting layer compound by pressing; then dehydrating by supplying heat, which creates the dried multilayer paper. The spray solution or spray suspension contains water and at least one water-soluble polymer P. The polymer P is obtained by polymerizing: 40 to 85 mol % of a monomer of Formula I ##STR00001##
in which R.sup.1=H or C.sub.1-C.sub.6-Alkyl; and 15 to 60 mol % of one or more ethylenically unsaturated monomers.

The present disclosure describes a treated cellulosic material comprising: a cellulosic material having a porous structure defining a plurality of pores, at least a portion of the pores containing a treating agent comprising: a polymer comprising an olefin-carboxylic acid copolymer; and a modifying agent comprising a hydrophobic amine.

The present disclosure describes a treated cellulosic material comprising: a cellulosic material having a porous structure defining a plurality of pores, at least a portion of the pores containing a treating agent comprising: a polymer comprising an olefin-carboxylic acid copolymer; and a modifying agent comprising a hydrophobic amine.