Methods for Increasing Retention and Drainage in Papermaking Processes

Abstract

Disclosed herein are methods of increasing retention and drainage in papermaking processes using high molecular-weight, water-soluble polymers.

1 . A method for improving retention and drainage in a papermaking process, comprising:
 providing a first composition comprising a water-soluble polymer having hydrolyzable cross-linked monomer units, the polymer comprising about 1 mol % to about 100 mol % acrylamide monomers;   activating the composition to hydrolyze the cross-linked monomer units to provide an activated polymer composition, wherein the activated polymer composition has a viscosity that is greater than the aqueous composition; and   adding the activated polymer composition to the papermaking process.   
     
     
         2 . The method of  claim 1 , wherein the hydrolyzable cross-linked monomer units are ionically cross-linked via an ionic interaction between two monomer units. 
     
     
         3 . The method of  claim 2 , wherein the water-soluble polymer comprises from about 1 mol % to about 25 mol % ionically cross-linked monomer units. 
     
     
         4 . The method of  claim 2 , wherein the water-soluble polymer comprises at least one monomer unit having the following formula (I): 
       
         
           
           
               
               
           
         
       
       wherein:
 R is selected from the group consisting of —H, C 1 -C 24  alkyl, C 2 -C 24  alkenyl and C 2 -C 24  alkynyl; 
 each R a  is independently selected from the group consisting of —H, optionally substituted C 1 -C 50  alkyl, optionally substituted C 2 -C 50  alkenyl, optionally substituted C 2 -C 50  alkynyl and optionally substituted aryl; 
 A is selected from the group consisting of O, S and NR b ; 
 R b  is selected from the group consisting of —H, optionally substituted C 1 -C 24  alkyl, optionally substituted C 2 -C 24  alkenyl and optionally substituted C 2 -C 24  alkynyl; 
 B is selected from the group consisting of optionally substituted C 1 -C 24  alkylenyl, optionally substituted C 2 -C 24  alkenylenyl, optionally substituted C 2 -C 24  alkynylenyl and optionally substituted C 2 -C 24  heteroalkylenyl; 
 Z θ  is an anion; and 
 each   represents a point of attachment to the polymer backbone. 
 
     
     
         5 . The method of  claim 4 , wherein the monomer unit of formula (I) is derived from a monomer selected from the group consisting of N,N-dimethylaminoethyl acrylate methyl chloride quaternary salt, N,N-dimethylaminoethyl methacrylate methyl chloride quaternary salt, N,N-dimethylaminopropyl acrylamide methyl chloride quaternary salt, and N,N-dimethylaminopropyl methacrylamide methyl chloride quaternary salt. 
     
     
         6 . The method of  claim 4 , wherein the water-soluble polymer further comprises at least one anionic monomer unit derived from a monomer selected from the group consisting of an acrylic acid salt, a methacrylic acid salt, a 2-acrylamido-2-methylpropane sulfonic acid salt and a styrene sulfonic acid salt. 
     
     
         7 . The method of  claim 1 , wherein the hydrolyzable cross-linked monomer units are covalently cross-linked. 
     
     
         8 . The method of  claim 7 , wherein the covalently cross-linked monomer units have the following formula (II): 
       
         
           
           
               
               
           
         
       
       wherein:
 each X is selected from the group consisting of O, S and NR b ; 
 each R b  is independently selected from the group consisting of —H, optionally substituted C 1 -C 24  alkyl, optionally substituted C 2 -C 24  alkenyl and optionally substituted C 2 -C 24  alkynyl; 
 each R is independently selected from the group consisting of —H, optionally substituted C 1 -C 24  alkyl, optionally substituted C 2 -C 24  alkenyl and optionally substituted C 2 -C 24  alkynyl; 
 Y is selected from a group consisting of a bond and a linker comprising 1 to about 1000 member atoms; and 
 each   represents a point of attachment to a first polymer backbone, and each   represents a point of attachment to the first polymer backbone or to a second polymer backbone. 
 
     
     
         9 . The method of  claim 7 , wherein the covalently cross-linked monomer units have the following formula (IIa): 
       
         
           
           
               
               
           
         
       
       wherein:
 each R is independently selected from the group consisting of —H and —CH 3 ; 
 Z is selected from the group consisting of a bond and a C 1 -C 12  alkylenyl group; and 
 each   represents a point of attachment to a first polymer backbone, and each   represents a point of attachment to the first polymer backbone or to a second polymer backbone. 
 
     
     
         10 . The method of  claim 7 , wherein the covalently cross-linked monomer units have the following formula (IIb): 
       
         
           
           
               
               
           
         
       
     
     
         11 . The method of  claim 7 , wherein the water-soluble polymer comprises about 0.1 ppm to about 20000 ppm covalently cross-linked monomer units. 
     
     
         12 . The method of  claim 1 , wherein the water-soluble polymer comprises about 0.1 ppm to about 100 ppm covalently cross-linked monomer units. 
     
     
         13 . The method of  claim 1 , wherein the aqueous composition comprises about 100 ppm to about 10000 ppm of the water-soluble polymer. 
     
     
         14 . The method of  claim 1 , wherein the aqueous composition further comprises an additional retention aid, a filler, an optical brightening agent, a dye, a sizing agent, cationic starch, a fixative, a detackifier, a dispersant, a wet or dry strength additive, or any combination thereof. 
     
     
         15 . The method of  claim 1 , wherein prior to activation, the first composition has a viscosity of about 0 cPs to about 100 cPs. 
     
     
         16 . The method of  claim 1 , wherein after activation, the activated polymer composition has a viscosity of about 1 cPs to about 5000 cPs. 
     
     
         17 . The method of  claim 1 , wherein the activating step comprises heating the first composition, increasing the ionic strength of the first composition, or increasing the pH of the first composition. 
     
     
         18 . The method of  claim 1 , comprising adding the activated polymer composition to a wet end of a papermaking machine. 
     
     
         19 . The method of  claim 1 , comprising adding the activated polymer composition to a pulp slurry.