摘要:
Process for the production of paper, board and cardboard having high dry strength by separate addition of a water-soluble cationic polymer and of an aqueous dispersion of a water-insoluble polymer having a content of acid groups of not more than 10 mol % or of an aqueous dispersion of a nonionic polymer, which dispersion has been made anionic, to a paper stock, draining of the paper stock and drying of the paper products. Preferably, the polymers are added to a paper stock which has a temperature of at least 40° C.
摘要:
Aqueous slurries of finely divided fillers which are at least partly coated with a composition comprising at least one water-soluble amphoteric copolymer and at least one latex.
摘要:
The invention relates to a process for the production of paper, card and board, including the steps of draining a filler-containing paper stock, having a certain fibrous concentration and containing at least one water-soluble amphoteric copolymer, with sheet formation in a wire section, then pressing the paper in a press section, diluting the paper stock to a fibrous concentration in the range from 5 to 15 g/l, draining the diluted paper stock to form a sheet, and then pressing the sheet in the press section to a solids content G(x) wt % or greater, such that G(x) computes according to: G(x)=48+(x−15)·0.4, where x is the numerical value of a filler content of the dry paper, card or board (in wt %), and G(x) is a numerical value of the minimal solids content (in wt %) to which the sheet is pressed.
摘要:
Process for treating aqueous slurries of finely divided fillers, an aqueous dispersion of at least one latex and an aqueous slurry of at least one starch being metered separately from one another into an aqueous slurry of at least one finely divided filler.
摘要:
Aqueous slurries of finely divided fillers which are at least partly coated with polymers and which are obtainable by treating aqueous slurries of finely divided fillers with at least one water-soluble amphoteric copolymer whose structures are identified in the specification are used as an additive to the paper stock in the production of filler-containing paper, filler-containing cardboard or filler-containing board by draining of the paper stock.
摘要:
Process for the production of paper, board and cardboard having high dry strength by separate addition of a water-soluble cationic polymer and of an aqueous dispersion of a water-insoluble polymer having a content of acid groups of not more than 10 mol % or of an aqueous dispersion of a nonionic polymer, which dispersion has been made anionic, to a paper stock, draining of the paper stock and drying of the paper products. Preferably, the polymers are added to a paper stock which has a temperature of at least 40° C.
摘要:
The use of water-soluble, amphoteric copolymers which are obtainable by copolymerization of a) at least one N-vinylcarboxamide of the general formula in which R1 and R2, independently of one another, are H or C1- to C6-alkyl, b) at least one monomer which is selected from the group consisting of (b1) monoethylenically unsaturated sulfonic acids, phosphonic acids, phosphoric acid esters and derivatives thereof, and (b2) monoethylenically unsaturated mono- and dicarboxylic acids, the salts thereof and dicarboxylic anhydrides, c) if appropriate, at least one monoethylenically unsaturated monomer differing from the components (a) and (b), and d) if appropriate, at least one compound which has at least two ethylenically unsaturated double bonds in the molecule, with the proviso that the monomer mixture comprises at least one monomer (b) having at least one free acid group and/or an acid group in salt form,and subsequent partial or complete hydrolysis of the groups —CO—R1 from the monomers (a) incorporated in the form of copolymerized units into the copolymer,as agents for increasing the initial wet web strength of paper.
摘要:
The use of water-soluble, amphoteric copolymers which are obtainable by copolymerization of a) at least one N-vinylcarboxamide of the general formula in which R1 and R2, independently of one another, are H or C1- to C6-alkyl, b) at least one monomer which is selected from the group consisting of (b1) monoethylenically unsaturated sulfonic acids, phosphonic acids, phosphoric acid esters and derivatives thereof, and (b2) monoethylenically unsaturated mono- and dicarboxylic acids, the salts thereof and dicarboxylic anhydrides, c) if appropriate, at least one monoethylenically unsaturated monomer differing from the components (a) and (b), and d) if appropriate, at least one compound which has at least two ethylenically unsaturated double bonds in the molecule, with the proviso that the monomer mixture comprises at least one monomer (b) having at least one free acid group and/or an acid group in salt form,and subsequent partial or complete hydrolysis of the groups —CO—R1 from the monomers (a) incorporated in the form of copolymerized units into the copolymer,as agents for increasing the initial wet web strength of paper.
摘要:
A process for treating aqueous slurries of finely divided fillers, wherein the treatment is carried out by heating an aqueous slurry of at least one finely divided filler and then by adding an aqueous dispersion of at least one latex.
摘要:
Process for treating aqueous slurries of finely divided fillers, an aqueous dispersion of at least one latex and an aqueous slurry of at least one starch being metered separately from one another into an aqueous slurry of at least one finely divided filler.