Method for producing paper, paperboard and cardboard

Abstract

Paper, board and cardboard are produced by adding (i) at least one retention aid and (ii) ionic, water-insoluble, uncrosslinked, organic microparticles which have an average particle size of less than 500 nm and a content of polymerized ionic monomers of less than 1% by weight or water-insoluble, uncrosslinked, organic microparticles having an average particle size of less than 500 nm and a content of polymerized ionic monomers of not more than 10% by weight, which are obtainable by polymerizing the monomers in the presence of silica, waterglass, bentonite and/or mixtures thereof, to a paper stock and draining the paper stock over a wire.

1 . A process for the production of paper, board and cardboard comprising: 
 adding ionic, water-insoluble, uncrosslinked, organic microparticles and at least one retention aid to a paper stock; and    draining the paper stock over a wire,    wherein the organic microparticles used are water-insoluble, uncrosslinked, organic polymers having an average particle size of less than 500 nm and a content of polymerized ionic monomers of less than 1% by weight of water-insoluble, uncrosslinked, organic polymers having an average particle size of less than 500 nm and a content of polymerized ionic monomers of not more than 10% by weight, which are obtainable by polymerizing the monomers in the presence of silica, waterglass, bentonite and/or mixtures thereof.    
   
   
       2 . The process according to  claim 1 , wherein the average particle size of the water-insoluble, uncrosslinked, organic polymers is from 10 to 100 nm; and the content of polymerized ionic monomers is from 0.1 to 0.95% by weight.  
   
   
       3 . The process according to  claim 1 , wherein the average particle size of the water-insoluble, uncrosslinked, organic polymers is from 10 to 80 nm; and the content of polymerized ionic monomers is from 0.2 to 0.7% by weight.  
   
   
       4 . The process according to  claim 1 , wherein the average particle size of the water-insoluble, uncrosslinked, organic polymers is from 15 to 50 nm.  
   
   
       5 . The process according to  claim 1 , wherein the water-insoluble, uncrosslinked, organic polymers comprise at least one anionic monomer incorporated in the form of polymerized units.  
   
   
       6 . The process according to  claim 1 , wherein the water-insoluble, uncrosslinked, organic polymers comprise at least one cationic monomer incorporated in the form of polymerized units.  
   
   
       7 . The process according to  claim 1 , wherein water-insoluble, uncrosslinked, organic polymers which are obtainable by free radical aqueous emulsion polymerization of a monomer mixture comprising: 
 (a) from 30 to 55 parts by weight of at least one monomer whose homopolymer has a glass transition temperature T g  of <20° C.;    (b) from 45 to 70 parts by weight of at least one monomer whose homopolymer has a glass transition temperature T g  of >50° C.; and    (c) from 0.01 to less than 1 part by weight of a monomer having ionic groups, the sum of the parts by weight of (a) and (b) always being 100, are used.    
   
   
       8 . The process according to  claim 7 , wherein the monomer (a) is selected from at least one C 1 - to C 10 -alkyl acrylate, C 5 - to C 10 -alkyl methacrylate, C 5 - to C 10 -cycloalkyl(meth)acrylate, C 1 - to C 10 -dialkyl maleate and/or C 1 - to C 10 -dialkyl fumarate; and the monomer (b) is selected from at least one vinylaromatic monomer and/or one α,β-unsaturated carbonitrile or carbodinitrile.  
   
   
       9 . The process according to  claim 7 , wherein the monomer (c) is selected from α,β-unsaturated C 3 - to C 6 -carboxylic acids, α,β-unsaturated C 4 - to C 8 -dicarboxylic acids, anhydrides thereof, monoethylenically unsaturated alkanesulfonic acids, monoethylenically unsaturated phosphonic acids and/or monoethylenically unsaturated arylsulfonic acids.  
   
   
       10 . The process according to  claim 9 , wherein the monomer (c) is used in the polymerization in the form partly or completely neutralized with alkali metal, alkaline earth metal and/or ammonium bases.  
   
   
       11 . The process according to  claim 7 , wherein the water-insoluble, uncrosslinked, organic polymers are composed of: 
 from 35 to 50 parts by weight of monomer units (a);    from 50 to 65 parts by weight of monomer units (b); and    from 0.01 to 0.95 part by weight of monomer units (c),    the sum of the monomer units (a) and (b) always being 100.    
   
   
       12 . The process according to  claim 7 , wherein the water-insoluble, uncrosslinked, organic polymers are obtainable by polymerizing the monomers in the presence of silica, waterglass, bentonite and/or mixtures thereof.  
   
   
       13 . The process according to  claim 1 , wherein at least one fixing agent, strength agent for paper and/or an engine size are also added to the paper stock.  
   
   
       14 . The process according to  claim 13 , wherein the fixing agent used is a polymer comprising vinylamine units, polydiallyldimethylammonium chloride, polyethylenimine, polyalkylenepolyamine and/or dicyandiamide polymer.  
   
   
       15 . The process according to  claim 1 , wherein water-insoluble, uncrosslinked, organic polymers having an average particle size of less than 500 nm and a content of polymerized ionic monomers of less than 1% by weight are metered together with at least one cationic, anionic, amphoteric or neutral synthetic organic polymer and/or cationic starch as a retention aid to the paper stock before the final shear stage upstream of the headbox.  
   
   
       16 . The process according to  claim 1 , wherein water-insoluble, uncrosslinked, organic polymers having an average particle size of less than 500 nm and a content of polymerized ionic monomers of less than 1% by weight are metered together with at least one retention aid and one finely divided inorganic component to the paper stock after the final shear stage upstream of the headbox; or wherein the retention aid is metered before the final shear stage upstream of the headbox and water-insoluble, uncrosslinked, organic polymers having an average particle size of less than 500 nm and a content of polymerized ionic monomers of less than 1% by weight are metered alone or together with the finely divided inorganic component after the final shear stage upstream of the headbox.