Bicomponent strengtheninig 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.

What is claimed is:  
     
         1 . A process for forming a paper web comprising: 
 providing a slurry of pulp fibers;    adding 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 to the slurry of pulp fibers;    adding a second component to the slurry of pulp fibers, the second component being selected from the group consisting of polymeric anionic compounds and polymeric aldehyde functional compounds, wherein the second component is added to the slurry of pulp fibers separately from the first component;    depositing the slurry of pulp fibers containing the first and second components on a forming fabric; and    drying the slurry of pulp fibers to form a paper web, wherein the first and second components form a bicomponent strengthening system in the paper web.    
     
     
         2 . A process as defined in  claim 1 , wherein the first and second components form a polyelectrolyte complex in the slurry of pulp fibers.  
     
     
         3 . A process as defined in  claim 1 , wherein the first and second components are bonded to each other in the bicomponent strengthening system.  
     
     
         4 . A process as defined in  claim 3 , wherein the first and second components are capable of forming covalent bonds with each other.  
     
     
         5 . A process as defined in  claim 1 , wherein the first component is a polyvinylamine.  
     
     
         6 . A process as defined in  claim 5 , wherein the polyvinylamine comprises vinylformamide units, at least about 50% of which have been hydrolyzed to offer amine functionality.  
     
     
         7 . A process as defined in  claim 5 , wherein the polyvinylamine comprises vinylformamide units, at least about 70% of which have been hydrolyzed to offer amine functionality.  
     
     
         8 . A process as defined in  claim 1 , wherein the first component is a polysaccharide having primary amine functionality.  
     
     
         9 . A process as defined in  claim 1 , wherein the first component is added to the slurry of pulp fibers before the second component.  
     
     
         10 . A process as defined in  claim 1 , wherein the first component is added to the slurry of pulp fibers after the second component.  
     
     
         11 . A process as defined in  claim 1 , wherein the second component comprises a cationic polymeric aldehyde functional compound.  
     
     
         12 . A process as defined in  claim 11 , wherein the second component comprises a glyoxylated polyacrylamide.  
     
     
         13 . A process as defined in  claim 1 , further comprising adjusting the pH of the slurry of pulp fibers to a pH of less than about 6.  
     
     
         14 . A process as defined in  claim 1 , wherein the first component comprises at least about 11 m-eq primary amine per gram of the polymer.  
     
     
         15 . A process as defined in  claim 1 , wherein the first component comprises at least about 15 m-eq primary amine per gram of the polymer.  
     
     
         16 . A process as defined in  claim 1 , wherein the paper web has less than about 70% of the initial wet tensile index remaining after soaking in water for about one hour.  
     
     
         17 . A process as defined in  claim 1 , wherein the paper web has more than about 70% of the initial wet tensile index remaining after soaking in water for about one hour.  
     
     
         18 . A process as defined in  claim 1 , wherein the first and second components are added to the slurry of pulp fibers in a ratio of between about 5:1 to about 1:5.  
     
     
         19 . A process as defined in  claim 1 , further comprising adjusting the pH of the slurry of pulp fibers to a pH greater than about 6.  
     
     
         20 . A process as defined in  claim 1 , wherein the second component comprises a polymeric anionic compound having carboxy functionality.  
     
     
         21 . A process as defined in  claim 1 , 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.  
     
     
         22 . A bicomponent strengthening system for a paper web 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 bicomponent strengthening system develops in a slurry of pulp fibers after the first component and the second component are sequentially added to the slurry.  
     
     
         23 . A bicomponent strengthening system as defined in  claim 22 , wherein the first component comprises a polyvinylamine.  
     
     
         24 . A bicomponent strengthening system as defined in  claim 22 , wherein the first component comprises a polysaccharide having primary amine functionality.  
     
     
         25 . A bicomponent strengthening system as defined in  claim 22 , wherein the first component is added to the slurry of pulp fibers before the second component.  
     
     
         26 . A bicomponent strengthening system as defined in  claim 22 , wherein the first component is added to the slurry of pulp fibers after the second component.  
     
     
         27 . A bicomponent strengthening system as defined in  claim 22 , wherein the second component comprises a cationic polymeric aldehyde functional compound.  
     
     
         28 . A bicomponent strengthening system as defined in  claim 27 , wherein the second component comprises a glyoxylated polyacrylamide.  
     
     
         29 . A bicomponent strengthening system as defined in  claim 22 , wherein the bicomponent strengthening system develops in the slurry of pulp fibers at a pH less than about 6.  
     
     
         30 . A bicomponent strengthening system as defined in  claim 22 , wherein the first and second components form a polyelectrolyte complex in the slurry of pulp fibers.  
     
     
         31 . A bicomponent strengthening system as defined in  claim 22 , wherein the first and second components are bonded to each other.  
     
     
         32 . A bicomponent strengthening system as defined in  claim 31 , wherein the first and second components are capable of forming covalent bonds with each other.  
     
     
         33 . A bicomponent strengthening system as defined in  claim 22 , wherein the first component has greater than about 11 m-eq primary amine per gram of polymer.  
     
     
         34 . A bicomponent strengthening system as defined in  claim 22 , wherein the first component has greater than about 15 m-eq primary amine per gram of polymer.  
     
     
         35 . A bicomponent strengthening system as defined in  claim 22 , comprising the first and second components in a ratio to each other of between about 5:1 and about 1:5.  
     
     
         36 . A bicomponent strengthening system as defined in  claim 22 , wherein second component comprises a polymeric anionic compound having carboxy functionality.  
     
     
         37 . A bicomponent strengthening system as defined in  claim 22 , wherein the second component comprises carboxymethyl cellulose.  
     
     
         38 . A bicomponent strengthening system as defined in  claim 22 , wherein the bicomponent strengthening system develops in the slurry of pulp fibers at a pH greater than about 6.  
     
     
         39 . A bicomponent strengthening system as defined in  claim 22 , wherein the bicomponent strengthening system provides temporary wet strength to the paper web.  
     
     
         40 . A bicomponent strengthening system as defined in  claim 22 , wherein the bicomponent strengthening system provides permanent wet strength to the paper web.  
     
     
         41 . A bicomponent strengthening system as defined in  claim 22 , 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.  
     
     
         42 . A bicomponent strengthening system as defined in  claim 22 , wherein the first component comprises a polyvinylamine polymer comprising partially hydrolyzed polyvinylformamide.  
     
     
         43 . A bicomponent strengthening system as defined in  claim 42 , wherein the degree of hydrolyzation of the polyvinylformamide is about 50% or greater.  
     
     
         44 . A bicomponent strengthening system as defined in  claim 42 , wherein the degree of hydrolyzation of the polyvinylformamide is about 70% or greater.  
     
     
         45 . A bicomponent strengthening system as defined in  claim 42 , wherein the degree of hydrolyzation of the polyvinylformamide is about 90% or greater.  
     
     
         46 . A method for decreasing the amount of low molecular weight organic chlorinated compounds in the waste stream of a paper manufacturing process comprising: 
 providing a paper manufacturing process, wherein said paper manufacturing process comprises the formation of a slurry of pulp fibers and the addition of a chlorinated strengthening agent to a paper;    eliminating the addition of said chlorinated strengthening agent from the paper manufacturing process;    adding 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 to the slurry of pulp fibers;    adding a second component to the slurry of pulp fibers, the second component being selected from the group consisting of polymeric anionic compounds and polymeric aldehyde functional compounds wherein the second component is added to the slurry of pulp fibers separately from the first component;    depositing the slurry of pulp fibers containing the first and second components on a forming fabric; and    drying the slurry of pulp fibers to form a paper web, wherein the first and second components form a bicomponent strengthening system which replaces the chlorinated strengthening agent in the paper web.    
     
     
         47 . A method as defined in  claim 46 , wherein the chlorinated strengthening agent comprises a polyamide-epichlorohydrin strengthening agent.  
     
     
         48 . A method as defined in  claim 46 , wherein the first component comprises a polyvinylamine.  
     
     
         49 . A process as defined in  claim 48 , wherein the polyvinylamine has at least about 50 mole % vinylamine per gram of polyvinylamine.  
     
     
         50 . A process as defined in  claim 48 , wherein the polyvinylamine has at least about 70 mole % vinylamine per gram of polyvinylamine.  
     
     
         51 . A method as defined in  claim 46 , wherein the first component comprises a polysaccharide having primary amine functionality.  
     
     
         52 . A method as defined in  claim 46 , wherein the first component is added to the slurry of pulp fibers before the second component.  
     
     
         53 . A method as defined in  claim 46 , wherein the first component is added to the slurry of pulp fibers after the second component.  
     
     
         54 . A method as defined in  claim 46 , wherein the second component is a cationic polymeric aldehyde functional compound.  
     
     
         55 . A method as defined in  claim 54 , wherein the second component is a glyoxylated polyacrylamide.  
     
     
         56 . A method as defined in  claim 46 , further comprising adjusting the pH of the slurry of pulp fibers to a pH less than about 6.  
     
     
         57 . A method as defined in  claim 46 , further comprising adjusting the pH of the slurry of pulp fibers to a pH greater than about 6.  
     
     
         58 . A method as defined in  claim 46 , wherein the first component has greater than about 11 m-eq primary amine per gram of polymer  
     
     
         59 . A method as defined in  claim 46 , wherein the first component has greater than about 15 m-eq primary amine per gram of polymer.  
     
     
         60 . A method as defined in  claim 46 , wherein the first and second components are added to the slurry of pulp fibers in a ratio of between about 5:1 to about 1:5.  
     
     
         61 . A method as defined in  claim 46 , wherein the second component comprises a polymeric anionic compound having carboxy functionality.  
     
     
         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.