Paper-Making Aid Composition and Process for Increasing Tensile Strength of Paper

Abstract

A paper-making aid composition, as well as processes for increasing tensile strength in paper and paper-making processes are provided. The paper-making composition comprises an anionic dialdehyde-modified polyacrylamide and a polyamide polyamine-epichlorohydrin (“PAE”) resin present in the paper-making aid composition at a weight ratio of PAE resin to anionic dialdehyde-modified polyacrylamide of from about 5:1 to about 1:1.6. The processes utilize an anionic dialdehyde-modified polyacrylamide and PAE resin at certain ratios. The anionic dialdehyde-modified polyacrylamide and PAE resin may be added to the pulp slurry as a composition or separately.

1 . A paper-making aid composition comprising an anionic dialdehyde-modified polyacrylamide and a polyamide polyamine-epichlorohydrin (“PAE”) resin present in the paper-making aid composition at a weight ratio of PAE resin to anionic dialdehyde-modified polyacrylamide of from about 5:1 to about 1:1.6. 
     
     
         2 . The paper-making aid composition of  claim 1 , wherein the PAE resin and the anionic dialdehyde-modified polyacrylamide are present at a weight ratio of PAE resin to anionic dialdehyde-modified polyacrylamide of from about 3.5:1 to about 1:1.6. 
     
     
         3 . The paper-making aid composition of  claim 1 , wherein the paper-making aid composition has active content of dialdehyde-modified polyacrylamide and the PAE resin of from about 10 wt % to about 50 wt %. 
     
     
         4 . The paper-making aid composition of  claim 1 , wherein, except for the anionic dialdehyde-modified polyacrylamide and the polyamide polyamine-epichlorohydrin resin, the amount of other chemical aids for paper-making in the paper-making aid composition is from about 0 wt % to about 50 wt %. 
     
     
         5 . The paper-making aid composition of  claim 1 , wherein the paper-making aid composition is free of cationic and amphoteric dialdehyde-modified polyacrylamide. 
     
     
         6 . The paper-making aid composition of  claim 1 , consisting of the PAE resin, the anionic dialdehyde-modified polyacrylamide, and water. 
     
     
         7 . The paper-making aid composition of  claim 1 , wherein the anionic dialdehyde-modified polyacrylamide is glyoxalated polyacrylamide. 
     
     
         8 . The paper-making aid composition of  claim 1 , wherein the paper-making aid composition is free of cationic polyacrylamide polymer. 
     
     
         9 . A process for increasing tensile strength of paper comprising adding an anionic dialdehyde-modified polyacrylamide and a polyamide polyamine-epichlorohydrin (“PAE”) resin at a weight ratio of PAE resin to anionic dialdehyde-modified polyacrylamide of from about 5:1 to about 1:1.6 to a slurry comprising pulp in a pulping process and/or a paper-making process. 
     
     
         10 . The process of  claim 9 , wherein the anionic dialdehyde modified polyacrylamide and the PAE resin are added separately to the paper-making process. 
     
     
         11 . The process of  claim 9 , wherein the pulp comprises softwood bleached kraft pulp and hardwood bleached kraft pulp. 
     
     
         12 . A paper-making process comprising:
 (a) adding an anionic dialdehyde-modified polyacrylamide and a polyamide polyamine-epichlorohydrin (“PAE”) resin at a weight ratio of PAE resin to anionic dialdehyde-modified polyacrylamide of from about 5:1 to about 1:1.6 into pulp slurry to obtain a treated stock;   (b) forming the treated stock obtained in step (a) to obtain a wet paper web;   (c) pressing and draining the wet paper web obtained in step (b) to obtain a wet paper sheet; and   (d) drying the wet paper sheet obtained in step (c) to obtain a paper sheet.   
     
     
         13 . The paper-making aid composition of  claim 1 , wherein, except for the anionic dialdehyde-modified polyacrylamide and the polyamide polyamine-epichlorohydrin resin, the amount of other chemical aids for paper-making in the paper-making aid composition is from about 0 wt % to about 20 wt %. 
     
     
         14 . The paper-making aid composition of  claim 1 , wherein, except for the anionic dialdehyde-modified polyacrylamide and the polyamide polyamine-epichlorohydrin resin, the amount of other chemical aids for paper-making in the paper-making aid composition is from about 0 wt % to about 5 wt %. 
     
     
         15 . The paper-making aid composition of  claim 1 , wherein the paper-making aid composition is free of amphoteric dialdehyde-modified polyacrylamide. 
     
     
         16 . The paper-making aid composition of  claim 1 , further comprising a retention aid. 
     
     
         17 . The process of  claim 9 , wherein the slurry is thick stock. 
     
     
         18 . The process of  claim 9 , wherein the slurry is carton board furnish. 
     
     
         19 . The paper-making process of  claim 12 , wherein the pulp slurry is thick stock. 
     
     
         20 . The paper-making process of  claim 12 , wherein the pulp slurry is carton board furnish.