Reduced shear cellulose reactive sizing agent for wet end applications

Abstract

The invention relates to a method for sizing a paper product that involves the steps of (a) providing a paper stock system; (b) forming, in the absence of high shearing forces, an aqueous sizing emulsion comprising an alkenylsuccinic anhydride component; (c) submitting the emulsion formed from step b to a post-dilution step in the presence of a cationic component under conditions, in the absence of high shearing forces, that produce a post-diluted emulsion having improved sizing efficacy; (d) adding the post-diluted emulsion to the paper stock; and (e) forming a paper web.

1 . A method for sizing a paper product comprising:
 (a) providing a paper stock system;   (b) forming, in the absence of high shearing forces, an aqueous sizing emulsion comprising an alkenylsuccinic anhydride component;   (c) submitting the emulsion formed from step b to a post-dilution step in the presence of a cationic component under conditions, in the absence of high shearing forces, that produce a post-diluted emulsion having improved sizing efficacy;   (d) adding the post-diluted emulsion to the paper stock; and   (e) forming a paper web.   
     
     
         2 . The method of  claim 1 , wherein the emulsion in step (b) further comprises a surfactant component. 
     
     
         3 . The method of  claim 1 , wherein the emulsion in step (b) comprises an alkenylsuccinic anhydride component comprising alkenylsuccinic anhydride particles suspended in a starch component, wherein the starch component comprises an containing emulsifying starch selected from the group consisting of non-ionic starches, anionic starches, cationic starches, and mixtures thereof. 
     
     
         4 . The method of  claim 3 , wherein the emulsion in step (b) further comprises a surfactant component. 
     
     
         5 . The method of  claim 1 , wherein the emulsion in step (b) comprises an emulsion comprising alkenylsuccinic anhydride component comprising alkenylsuccinic anhydride particles suspended in an aqueous polymer solution, wherein the aqueous polymer solution is selected from the group consisting of cationic polymers, nonionic polymers, anionic polymers, vinyl addition polymers, condensation polymers, and mixtures thereof. 
     
     
         6 . The method of  claim 5 , wherein the emulsion in step (b) further comprises a surfactant component. 
     
     
         7 . The method of  claim 1 , wherein the emulsion in step (b) comprises an alkenylsuccinic anhydride component comprising (i) alkenylsuccinic anhydride particles and (ii) a surfactant component suspended in water. 
     
     
         8 . The method of  claim 1 , wherein the alkenyl succinic anhydride component in step (b) comprises:
 a. from 80 to 97 parts of substituted cyclic dicarboxylic acid anhydride corresponding to the formula   
       
         
           
           
               
               
           
         
       
       wherein R represents a dimethylene or trimethylene radical and wherein R′ is a hydrophobic group containing more than 5 carbon atoms; 
       
         
           
           
               
               
           
         
       
       wherein R x  is an alkyl radical containing at least 5 carbon atoms and R y  is an alkyl radical containing at least 5 carbon atoms, and R x  and R y  are interchangeable; 
       
         
           
           
               
               
           
         
       
       wherein R x  is an alkyl radical containing at least 5 carbon atoms and R y  is an alkyl radical containing at least 5 carbon atoms and R x  and R y  are interchangeable; and
 b. from 3 to 20 parts of a polyoxyalkylene alkyl or polyoxyalkylene alkyl-aryl ether or the corresponding mono- or diester selected from the group consisting of: 
 
       
         
           
           
               
               
           
         
       
       wherein x and n are integers in the range of 8 to 20; R is an aryl radical; m is an integer in the range of 5 to 20; and i is 0, 1, or 2. 
     
     
         9 . The method of  claim 1 , wherein the cationic component in step (c) is selected from the group consisting of cationic starches, cationic polymers, cationic starch-grafted polymers, and mixtures thereof. 
     
     
         10 . The method of  claim 1 , wherein the cationic component in step (c) is selected from the group consisting of cationic vinyl addition polymers, cationic condensation polymers, and combinations thereof. 
     
     
         11 . The method of  claim 1 , wherein the emulsion contains alkenylsuccinic anhydride particles ranging from 0.5 microns to less than 3 microns. 
     
     
         12 . The method of  claim 1 , wherein the sizing emulsion is formed with a surfactant component selected from the group consisting of sulfosuccinates, alkyl and aryl amides and primary, secondary and tertiary amines and their corresponding quaternary salts, fatty acids, ethoxylated fatty acids, fatty alcohols, ethoxylated fatty alcohols, fatty esters, ethoxylated fatty esters, ethoxylated triglycerides, ethoxylated lanolins, sulfonated amines, sulfonated amides, ethoxylated polymers, propoxylated polymers, ethoxylated/propoxylated copolymers, polyethylene glycols, phosphate esters, phosphonated fatty acid ethoxylates, phosphonated fatty alcohol ethoxylates, alkyl sulfonates, aryl sulfonates, alkyl sulfates, aryl sulfates, and combinations thereof 
     
     
         13 . The method of  claim 1 , wherein the post-dilution step comprises mixing the emulsion with an additive selected from the group consisting of cationic starches, cationic polymers, cationic starch-grafted polymers, and mixtures thereof at autogenous conditions. 
     
     
         14 . The method of  claim 1 , wherein the temperature is less than 50° C. 
     
     
         15 . The method of  claim 1 , wherein the mixing in step (c) occurs less than one minute. 
     
     
         16 . The method of  claim 1 , wherein the mixing in step (c) occurs from 1 to 20 seconds. 
     
     
         17 . The method of  claim 1 , wherein the paper exhibits a sizing efficiency that is more than 20% higher, as compared to paper made with a composition that is not subjected to a post-dilution step. 
     
     
         18 . The method of  claim 17 , wherein the paper is selected from the group consisting of paperboard papers, fine papers, newsprint papers, and combinations thereof. 
     
     
         19 . The method of  claim 1 , wherein the post-diluted composition is stable from 1 to 6 hours. 
     
     
         20 . The method of  claim 1 , wherein the emulsion in step (b) is made by emulsifying alkenylsuccinic anhydride with a first starch component comprising a starch selected from the group consisting of non-ionic starches, ionic starches, and mixtures thereof and thereby forming an emulsion. 
     
     
         21 . The method of  claim 20 , wherein the emulsion contains a surfactant component. 
     
     
         22 . The method of  claim 1 , wherein the emulsion in step (b) is made by emulsifying an alkenylsuccinic anhydride component containing (i) alkenylsuccinic anhydride and (ii) a surfactant component, with water; and thereby fowling an emulsion having an alkenylsuccinic anhydride component containing (i) alkenylsuccinic anhydride particles and (ii) a surfactant component suspended in water. 
     
     
         23 . The method of  claim 1 , wherein the emulsion in step (b) is made by emulsifying an alkenylsuccinic anhydride component, optionally containing a surfactant, with an aqueous polymer solution, and thereby forming an emulsion. 
     
     
         24 . A paper made by the process of  claim 1 . 
     
     
         25 . The paper of  claim 24 , wherein the paper is selected from the group consisting of paperboard papers, fine papers, newsprint papers, and combinations thereof. 
     
     
         26 . A method for sizing a paper product comprising:
 (a) providing a paper stock system;   (b) forming, in the absence of high shearing forces, an aqueous sizing emulsion comprising an alkenylsuccinic anhydride component;   wherein the emulsion is made in the presence of a cationic component under conditions, in the absence of high shearing forces, that produce an emulsion having improved sizing efficacy;   (c) adding the emulsion to the paper stock; and   (d) forming a paper web.