Papermaking And Products Made Thereby With High Solids Glyoxalated-Polyacrylamide And Silicon-Containing Microparticle

Abstract

Enhancement of papermaking drainage and retention properties of aqueous cellulosic suspensions used for production of paper or paper board with a retention/drainage additive system including high solids glyoxalated polyacrylamide polymers in combination with silicon-containing microparticles is described.

1 . A process for making paper comprising adding silicon-containing microparticles and a glyoxalated polyacrylamide polymer comprising at least about 25% by weight cationic monomer to an aqueous suspension containing cellulosic fibers, and forming said suspension into a water-laid web and drying said web to form paper, wherein the added amount of silicon-containing microparticles is effective to increase fiber retention and de-watering rate as compared to paper made with the suspension absent the silicon-containing microparticles. 
     
     
         2 . The process of  claim 1 , wherein the glyoxalated polyacrylamide polymer is a reaction product of glyoxal and a base polymer comprising the acrylamide monomer and the cationic monomer. 
     
     
         3 . The process of  claim 2 , wherein said base polymer has an average molecular weight range from 500 Daltons to 20,000 Daltons. 
     
     
         4 . The process of  claim 2 , wherein said base polymer has a charge density of 1 meg/g or greater. 
     
     
         5 . The process of  claim 2 , wherein said base polymer has a charge density of from 1 meg/g to 4.5 meg/g. 
     
     
         6 . The process of  claim 2 , wherein said base polymer has a charge density of from 1.5 to 3.5 meg/g. 
     
     
         7 . The process according to  claim 1 , wherein the paper comprises from about 0.05 to about 2.5 pounds said silicon-containing microparticles/ton dry fiber. 
     
     
         8 . The process according to  claim 1 , wherein the silicon-containing microparticles are selected from silica microparticles and bentonite microparticles. 
     
     
         9 . The process according to  claim 1 , wherein the silicon-containing microparticles comprise amorphous silica microparticles. 
     
     
         10 . The process according to  claim 1 , wherein said silicon-containing microparticles comprise colloidal silica comprising a surface area from 300 m 2 /g to 1000 m 2 /g and an S-value of from 80% to 20%. 
     
     
         11 . The process according to  claim 1 , wherein said silicon-containing microparticles comprise bentonite microparticles. 
     
     
         12 . The process according to  claim 1 , wherein the microparticles have an absolute particle size of not greater than about 750 nm. 
     
     
         13 . The process according to  claim 1 , wherein at least 90% of the microparticles have an absolute particle size of not greater than about 750 nm. 
     
     
         14 . The process according to  claim 1 , wherein the paper comprises from about 0.5 to about 12 pounds said polymer/ton dry fiber. 
     
     
         15 . The process according to  claim 1 , wherein said adding comprises introducing an aqueous polymer composition comprising said glyoxalated polyacrylamide polymer, wherein the polymer composition comprises (a) at least 10%, by weight, said glyoxalated polyacrylamide polymer, and (b) water, wherein the glyoxalated polyacrylamide polymer comprises a reaction product between glyoxal and a cationic polyacrylamide base polymer, wherein the cationic polyacrylamide base polymer comprises from about 75% to about 10%, by weight, acrylamide monomer and from about 25% to about 90%, by weight, cationic monomer copolymerizable with said acrylamide monomer, and having sufficient glyoxal-reactive amide substituents and —CHOHCHO substituents to be thermosetting. 
     
     
         16 . The process according to  claim 15 , wherein said polymer composition comprising about 5% to about 30%, by weight, said glyoxalated polyacrylamide polymer. 
     
     
         17 . The process according to  claim 15 , wherein said polymer composition comprising about 7% to about 15%, by weight, said glyoxalated polyacrylamide polymer. 
     
     
         18 . The process according to  claim 15 , wherein the cationic monomer is 2-vinylpyridine, 2-vinyl-N-methylpyridinium chloride, (p-vinylphenyl) trimethyl ammonium chloride, diallyldimethylammonium chloride, 2-(dimethylamino)ethyl acrylate, trimethyl(p-vinylbenzyl)ammonium chloride, p-dimethylaminoethylstyrene, dimethylaminopropyl acrylamide, 2-methylacroyloxyethyltrimethyl ammonium methylsulfate, or 3-acrylamido-3-methylbutyl trimethyl ammonium chloride, or any combination thereof. 
     
     
         19 . The process according to  claim 15 , wherein the cationic monomer is diallyldimethyl-ammonium chloride. 
     
     
         20 . The process according to  claim 15 , wherein the acrylamide monomer is acrylamide, methacrylamide, ethylacrylamide, crotonamide, N-methyl acrylamide, N-butyl acrylamide, or N-ethyl methacrylamide, or any combination thereof. 
     
     
         21 . The process according to  claim 15 , wherein the cationic polyacrylamide base polymer comprises from about 70% to about 20%, by weight, acrylamide monomer and from about 30% to about 80%, by weight, cationic monomer copolymerizable with said acrylamide monomer. 
     
     
         22 . The process according to  claim 15 , wherein the polymer is a reaction product of glyoxal and a base polymer comprising the acrylamide monomer and the cationic monomer in a weight ratio ranging from about 0.01 to 0.6:1. 
     
     
         23 . The process according to  claim 22 , wherein the base polymer has a molecular weight ranging from about 500 Daltons to about 100,000 Daltons. 
     
     
         24 . The process according to  claim 1 , wherein the paper comprises a cellulosic fibrous non-woven web. 
     
     
         25 . A product comprising a paper made by the process of  claim 1  containing the glyoxalated polyacrylamide polymer and silicon-containing microparticles. 
     
     
         26 . A product according to  claim 25 , wherein the product is paper sheeting, paperboard, tissue paper, or wall board. 
     
     
         27 . A product according to  claim 25 , wherein the product is newsprint or linerboard.