Strength synergy between polymer and papermaking strength aid

Abstract

The disclosure provides compounds, compositions, and methods for improving a papermaking process. A method may include adding a strength aid to a cellulosic fiber suspension in the papermaking process and adding a dewatering agent to the cellulosic fiber suspension. The dewatering agent may comprise a polymer having a reduced specific viscosity from about 2.5 to about 5.5 dL/g. The polymer may include, for example, a solution polymer, a latex polymer, or both. The strength aid may be selected from, for example, a cationic GPAM polymer, an anionic GPAM polymer, an amphoteric polymer with an overall negative charge, an amphoteric polymer with an overall positive charge, a cationic polyacrylamide polymer, an anionic polyacrylamide polymer, an associative polymer, a treatment polymer embedded in a colloidal hydroxide complex, starch, or any combination of the foregoing.

What is claimed is: 
     
         1 . A method of improving a papermaking process, comprising:
 adding a strength aid to a cellulosic fiber suspension in the papermaking process, and   adding a dewatering agent to the cellulosic fiber suspension,   wherein the dewatering agent comprises a polymer having a reduced specific viscosity from about 2.5 to about 5.5 dL/g.   
     
     
         2 . The method of  claim 1 , wherein the polymer comprises a solution polymer, a latex polymer, a dry form polymer, or any combination thereof. 
     
     
         3 . The method of  claim 1 , wherein the polymer comprises from about 20 mol % to about 100 mol % of a cationic monomer. 
     
     
         4 . The method of  claim 1 , wherein the polymer comprises a non-ionic monomer selected from the group consisting of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-vinylformamide, N-vinylmethylacetamide, N-vinyl pyrrolidone, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-tert-butylacrylamide, N-methylolacrylamide, diallylamine, allylamine, and any combination thereof. 
     
     
         5 . The method of  claim 1 , wherein the polymer comprises an anionic monomer selected from the group consisting of acrylic acid, sodium acrylate, ammonium acrylate, methacrylic acid, sodium methacrylate, ammonium methacrylate, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), a sodium salt of AMPS, sodium vinyl sulfonate, styrene sulfonate, maleic acid, a sodium salt of maleic acid, an ammonium salt of maleic acid, sulfonate itaconate, sulfopropyl acrylate, sulfopropyl methacrylate, a sulphonic acid, sulfomethylated acrylamide, allyl sulfonate, sodium vinyl sulfonate, itaconic acid, acrylamidomethylbutanoic acid, fumaric acid, vinylphosphonic acid, vinylsulfonic acid, allylphosphonic acid, sulfomethylated acrylamide, phosphonomethylated acrylamide, and any combination thereof. 
     
     
         6 . The method of  claim 3 , wherein the cationic monomer is selected from the group consisting of a dialkylaminoalkyl acrylate or a salt thereof, a dialkylaminoalkyl methacrylate or a salt thereof, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate sulfuric acid salt, dimethylaminoethyl acrylate hydrochloric acid salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate sulfuric acid salt, dimethylaminoethyl methacrylate hydrochloric acid salt, a dialkylaminoalkyl acrylamide or a salt thereof, a dialkylaminoalkyl methacrylamide or a salt thereof, acrylamidopropyltrimethylammonium chloride, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, methacrylarnidopropyl trimethylammonium chloride, dimethylaminopropyl acrylamide methyl sulfate quaternary salt, dimethylaminopropyl acrylamide sulfuric acid salt, dimethylaminopropyl acrylamide hydrochloric acid salt, methacrylamidopropyltrimethylammonium chloride, dimethylaminopropyl methacrylamide methyl sulfate quaternary salt, dimethylaminopropyl methacrylamide sulfuric acid salt, dimethylaminopropyl methacrylamide hydrochloric acid salt, diethylaminoethylacrylate, diethylaminoethylmethacrylate, diallyldiethylammonium chloride, diallyldimethylammonium chloride, and any combination thereof. 
     
     
         7 . The method of  claim 1 , wherein the polymer comprises 2-dimethylaminoethyl acrylate (DMAEA) methyl chloride quaternary (MCQ) salt and acrylamide, 2-dimethylaminoethyl methacrylate (DMAEM) MCQ salt and acrylamide, diallyldimethylammonium chloride (DADMAC) and acrylamide, DMAEA and acrylamide, DMAEM and acrylamide, and any combination thereof. 
     
     
         8 . The method of  claim 1 , wherein the strength aid is selected from the group consisting of a cationic glyoxalated polyacrylamide (GPAM) polymer, an anionic GPAM polymer, an amphoteric polymer with an overall negative charge, an amphoteric polymer with an overall positive charge, a cationic polyacrylamide polymer, an anionic polyacrylamide polymer, an associative polymer, a treatment polymer embedded in a colloidal hydroxide complex, a starch, a synthetic strength aid, and any combination thereof. 
     
     
         9 . The method of  claim 1 , wherein the strength aid excludes starch. 
     
     
         10 . The method of  claim 1 , wherein the strength aid is added before, after, and/or with the dewatering agent. 
     
     
         11 . The method of  claim 1 , wherein the strength aid and the dewatering agent are added to a headbox, before the headbox, prior to a forming section, to a mixing chest, before a fan pump, between the fan pump and a pressure screen, after the pressure screen, to a thin stock, to a thick stock, or any combination thereof. 
     
     
         12 . The method of  claim 1 , wherein the cellulosic fiber suspension comprises a conductivity of at least about 1 mS/cm or a high charge, wherein the high charge is about −200 meq/L or less. 
     
     
         13 . A composition for improving a papermaking process, comprising:
 a strength aid and a dewatering agent, wherein the dewatering agent comprises a polymer having a reduced specific viscosity from about 2.5 to about 5.5 dL/g.   
     
     
         14 . The composition of  claim 13 , wherein the polymer comprises a solution polymer, a latex polymer, a dry form polymer, or any combination thereof. 
     
     
         15 . The composition of  claim 13 , wherein the polymer comprises from about 20 mol % to about 100 mol % of a cationic monomer. 
     
     
         16 . The composition of  claim 13 , wherein the polymer comprises a non-ionic monomer and/or an anionic monomer. 
     
     
         17 . The composition of  claim 13 , wherein the polymer comprises DMAEA.MCQ and acrylamide, DMAEM.MCQ and acrylamide, DADMAC and acrylamide, DMAEA and acrylamide, DMAEM and acrylamide, and any combination thereof. 
     
     
         18 . The composition of  claim 13 , wherein the strength aid is a synthetic strength aid. 
     
     
         19 . The composition of  claim 13 , wherein the strength aid is selected from the group consisting of a cationic GPAM polymer, an anionic GPAM polymer, an amphoteric polymer with an overall negative charge, an amphoteric polymer with an overall positive charge, a cationic polyacrylamide polymer, an anionic polyacrylamide polymer, an associative polymer, a treatment polymer embedded in a colloidal hydroxide complex, starch, and any combination thereof. 
     
     
         20 . The composition of  claim 13 , wherein the composition excludes starch.