Bicomponent strengthening system for paper

Abstract

The present invention is directed to a bicomponent strengthening system and the paper webs produced with the bicomponent strengthening system. Through use of the strengthening system, paper webs may be produced in which the strength characteristics of the web may be specifically tailored. The first component of the system comprises a polymer having at least about 1.5 m-eq primary amine functionality per gram of polymer and a molecular weight of at least about 10,000 Daltons. The second component may be either a polymeric anionic compound or a polymeric aldehyde functional compound. For example, the polyamine polymer component may be a polyvinylamine or polysaccharide having primary amine functionality. In one embodiment, the second component may be a cationic polymeric aldehyde functional compound. For example, the second component may be a cationic glyoxylated polyacrylamide. In another embodiment, the second component may be a polymeric anionic compound comprising carboxy functionality.

1 - 61 . (canceled)  
   
   
       62 . A paper product comprising: 
 a paper web formed from a slurry of papermaking fibers; and    a bicomponent strengthening system comprising a first component comprising a polymer having at least about 1.5 m-eq primary amine functionality per gram of polymer and a molecular weight of at least about 10,000 Daltons and a second component selected from the group consisting of polymeric anionic compounds and polymeric aldehyde functional compounds, wherein the first component and the second component are sequentially added to the slurry of papermaking fibers.    
   
   
       63 . The paper product of  claim 62 , wherein the paper web has a bulk greater than about 2 cc/g.  
   
   
       64 . The paper product of  claim 62 , wherein the first component comprises a polymer having at least about 10 m-eq primary amine functionality per gram of polymer and a molecular weight of at least about 20,000 Daltons.  
   
   
       65 . The paper product of  claim 62 , wherein the paper web has less than about 70% of the initial wet tensile index remaining after soaking in water for about one hour.  
   
   
       66 . The paper product of  claim 65 , wherein the paper web has a dry tensile index greater than about 22 Nm/g.  
   
   
       67 . The paper product of  claim 65 , wherein the paper web has a dry tensile index greater than about 25 Nm/g.  
   
   
       68 . The paper product of  claim 65 , wherein the paper web has a wet tensile index less than about 2 Nm/g after soaking in water for about one hour.  
   
   
       69 . The paper product of  claim 65 , wherein the paper web has less than about 60% of the initial wet tensile index remaining after soaking in water for about one hour.  
   
   
       70 . The paper product of  claim 62 , wherein the paper web has more than about 70% of the initial wet tensile index remaining after soaking in water for about one hour, wherein the paper web does not comprise any polyamine epichlorohydrin strengthening agents.  
   
   
       71 . The paper product of  claim 70 , wherein the paper web has a dry tensile index greater than about 20 Nm/g.  
   
   
       72 . The paper product of  claim 71 , wherein the paper web has a dry tensile index greater than about 25 Nm/g.  
   
   
       73 . The paper product of  claim 70 , wherein the paper web has more than about 80% of the initial wet tensile index remaining after soaking in water for about one hour.  
   
   
       74 . The paper product of  claim 62 , wherein the first component comprises a polyvinylamine.  
   
   
       75 . The paper product of  claim 62 , wherein the first component comprises a polysaccharide having primary amine functionality.  
   
   
       76 . The paper product of  claim 62 , wherein the second component comprises a cationic polymeric aldehyde functional compound.  
   
   
       77 . The paper product of  claim 76 , wherein the second component comprises a glyoxylated polyacrylamide.  
   
   
       78 . The paper product of  claim 62 , wherein the second component comprises a polymeric anionic compound having carboxy functionality.  
   
   
       79 . The paper product of  claim 62 , wherein the second component comprises carboxymethyl cellulose.  
   
   
       80 . The paper product of  claim 62 , wherein the paper product has a bulk greater than about 5 cc/g.  
   
   
       81 . The paper product of  claim 62 , wherein the paper product has a basis weight between about 5 and about 200 gsm.  
   
   
       82 . The paper product of  claim 62 , wherein the paper product comprises a multi-layered paper web, wherein the bicomponent strengthening system is added to one or more layers of the paper web.  
   
   
       83 . The paper product of  claim 82 , wherein the multi-layered paper web comprises a layer comprising soft wood pulp and a layer comprising hard wood pulp, wherein the bicomponent strengthening system is added to the layer comprising soft wood pulp.