Method for improving printability and coatability of paper and board

Abstract

The printability and coatability of calendered paper and board is improved by adding a polysaccharide and, as a hydrophobic agent, at least one polymer dispersion comprising at least one dispersed polymer obtained from monomers comprising hydrophobic monomers to the fiber stock in the production of said paper or board.

What is claimed:  
     
         1 . A method for improving the printability of calendered paper and board and produced at least partly from lignin containing fiber composition which comprises adding to the fiber stock in the production of said paper or board; 
 a polysaccharide selected from the group consisting of starch, mannan and carboxymethylcellulose (CMC); and a    at least one polymer dispersion comprising at least one dispersed polymer wherein said at least one polymer is obtained from monomers comprising hydrophobic monomers; and a stabilizing agent.    
     
     
         2 . The method according to  claim 1 , wherein at least a part of the polysaccharide is added simultaneously with the polymer dispersion either as an admixture or at the same addition point.  
     
     
         3 . The method according to  claim 1 , wherein said polysaccharide comprises a cationic, nonionic and/or anionic starch.  
     
     
         4 . The method according to  claim 3 , wherein said polysaccharide comprises a cationic starch having a degree of substitution of 0.02 to 2 in the starch chain.  
     
     
         5 . The method according to  claim 3 , wherein said polysaccharide comprises a cationic starch having a degree of substitution of 0.02 to 0.4 in the starch chain.  
     
     
         6 . The method according to  claim 1 , wherein said polysaccharide comprises a cationic, nonionic and/or anionic mannan.  
     
     
         7 . The method according to  claim 6 , wherein said mannan comprises a cationic mannan having a degree of substitution of 0.02 to 2 in the mannan chain.  
     
     
         8 . The method according to  claim 1 , wherein said dispersed polymer is obtained from at least one monomer selected from the group consisting of styrene, butadiene, vinyl-acetate, acrylonitrile, and/or acrylates.  
     
     
         9 . The method according to  claim 1 , wherein said dispersed polymer comprises a cationic, nonionic and/or anionic polymer and/or is obtained from a cationic, nonionic and/or anionic monomer.  
     
     
         10 . The method according to  claim 1 , wherein said stabilizing agent comprises a cationic, nonionic, and/or anionic polysaccharide.  
     
     
         11 . The method according to  claim 10 , wherein said stabilizing agent comprises a cationic, nonionic and/or anionic starch.  
     
     
         12 . The method according to  claim 10 , wherein said stabilizing agent comprises a cationic, nonionic and/or anionic mannan.  
     
     
         13 . The method according to  claim 1 , wherein said dispersed polymer is obtained from at least one vinyl monomer.  
     
     
         14 . The method according to  claim 1 , wherein said dispersed polymer is produced by emulsion polymerization.  
     
     
         15 . The method according to  claim 1 , wherein the polymer dispersion is used in an amount of 0.5 to 20 kg/ton of paper or board calculated as the dispersion dry matter and the dry matter of the total fiber composition.  
     
     
         16 . The method according to  claim 15 , wherein the polymer dispersion is used in an amount of 0.5 to 10 kg/ton of paper or board calculated as the dispersion dry matter and the dry matter of the total fiber composition.  
     
     
         17 . The method according to  claim 15 , the polymer dispersion is used in an amount of 0.5 to 5 kg/ton of paper or board calculated as the dispersion dry matter and the dry matter of the total fiber composition.  
     
     
         18 . The method according to  claim 1 , wherein the fiber composition used in the production of the paper or board comprises lignin containing, chemically treated fiber or de-inked fiber or mixtures thereof.  
     
     
         19 . The method according to  claim 1 , which comprises using filler material in the production of the paper or board in an amount of over 5% by weight calculated as dry matter on the total dry matter of the total fiber composition.  
     
     
         20 . The method according to  claim 1 , which comprises using filler material in the production of the paper or board in an amount of over 10% by weight calculated as dry matter on the dry matter of the total fiber composition.  
     
     
         21 . The method according to  claim 1 , which comprises using filler material in the production of the paper or board in an amount of over 15% by weight calculated as dry matter on the dry matter of the total fiber composition.  
     
     
         22 . The method according to  claim 1 , which comprises using filler material in the production of the paper or board in an amount of over 20% by weight calculated as dry matter on the dry matter of the total fiber composition.  
     
     
         23 . The method according to  claim 1 , which further comprises adding to the fiber stock in addition to the polymer dispersion a further hydrophobic agent.  
     
     
         24 . The method according to  claim 23 , which comprises adding alkenyl-succinic acid as the further hydrophobic agent.  
     
     
         25 . The method according to  claim 23 , which comprises adding a rosin size as the further hydrophobic agent.  
     
     
         26 . The method according to  claim 23 , which comprises adding an alkyl-ketene-dimer as the further hydrophobic agent.  
     
     
         27 . The method according to  claim 1 , which comprises adding the polysaccharide to the fiber stock in an amount of 0.1 to 20 kg/ton of fiber.  
     
     
         28 . The method according to  claim 26 , which comprises adding the polysaccharide to the fiber stock in an amount of 0.1 to 15 kg/ton of fiber.  
     
     
         29 . The method according to  claim 27 , which comprises adding the polysaccharide to the fiber stock in an amount of 0.5 to 6 kg/ton of fiber.  
     
     
         30 . The method according to  claim 27 , which comprises adding the polysaccharide to the fiber stock in an amount of 0.1 to 3 kg/ton of fiber.  
     
     
         31 . The method according to  claim 27 , which comprises adding the polysaccharide to the fiber stock in an amount of over 1.5 kg/ton of fiber.  
     
     
         32 . A calendered or super-calendered paper or board produced in accordance with the method of  claim 1 .  
     
     
         33 . The paper or board according to  claim 32  for off-set and gravure printing.  
     
     
         34 . The method of  claim 1 , wherein said stabilizing agent comprises starch with a degree of substitution relative to the cationic or anionic substituents from 0.01 to 1 and an intrinsic viscosity, when cationized and/or anionized of greater than 1.0 dl/g; and wherein the amount of said polymer is 50 to 95% by weight and said starch is 5 to 50% by weight of the solid contents of said polymer dispersion.  
     
     
         35 . The method of  claim 34 , wherein the amount of said polymer is 60 to 95% and the amount of starch is 5 to 40%.  
     
     
         36 . The method of  claim 34 , wherein said starch is cationic with a degree of substitution from 0.04 to 1.0 and has an intrinsic viscosity of 12.5 to 1.5 dl/g.  
     
     
         37 . The method of  claim 1 , wherein said polymer dispersion has a solid content of from 10 to 60%.