Paper making process and crosslinking compositions for use in same

Abstract

The present invention relates to methods for manufacturing paper or paperboard with improved strength, the methods comprising the addition of an aqueous aldehyde generating compound or a glyoxal releasing compound into or onto a fiber furnish prior to drying of the paper or paperboard sheet.

1 . A method for manufacturing paper or paperboard sheet with increased strength, the method comprising the steps of: 
 providing a fiber slurry and a gelatinized starch composition, each of which is suitable for use in making paper or paperboard;    providing at least one crosslinker composition comprising at least one aldehyde generating compound capable of forming at least two or more covalent bonds to functional groups present in the starch or fiber of the web;    mixing the gelatinized starch composition and the crosslinker composition;    adding the mixture of gelatinized starch composition and crosslinker composition to the fiber slurry contemporaneously to mixing the gelatinized starch composition and the crosslinker composition; and    forming the paper or paperboard sheet.    
     
     
         2 . The method of  claim 1 , wherein the gelatinized starch composition and the crosslinker composition are mixed together in a batch process prior to addition to the fiber slurry.  
     
     
         3 . The method of  claim 1 , wherein the gelatinized starch composition and the crosslinker composition are mixed together in a continuous flow process prior to addition to the fiber slurry.  
     
     
         4 . The method of  claim 1 , wherein the gelatinized starch composition and the crosslinker composition are mixed together less than about 1 hour prior to addition to the fiber slurry.  
     
     
         5 . The method of  claim 1 , wherein the gelatinized starch composition and the crosslinker composition are mixed together less than about 30 minutes prior to addition to the fiber slurry.  
     
     
         6 . The method of  claim 1 , wherein the gelatinized starch composition and the crosslinker composition are mixed together less than about 10 minutes prior to addition to the fiber slurry.  
     
     
         7 . The method of  claim 1 , wherein the gelatinized starch composition and the crosslinker composition are mixed together less than about 1 minute prior to addition to the fiber slurry.  
     
     
         8 . The method of  claim 1 , wherein a paper sheet is prepared by the method of manufacture.  
     
     
         9 . The method of  claim 1 , wherein a paperboard sheet is prepared by the method of manufacture.  
     
     
         10 . The method of  claim 1 , wherein the starch is self-retaining.  
     
     
         11 . The method of  claim 10 , wherein the starch is a cationic starch.  
     
     
         12 . The method of  claim 10 , wherein the starch is pregelatinized self-retaining starch selected from potato, corn or wheat starch.  
     
     
         13 . The method of  claim 1 , wherein the crosslinker composition comprises between about 0.001% to about 80% aldehyde generating compound by weight in an aqueous media.  
     
     
         14 . The method of  claim 13 , wherein the crosslinker composition does not comprise starch or gelatinized starch.  
     
     
         15 . The method of  claim 13 , wherein the crosslinker composition is stable in the absence of starch, gelatinized starch, or pulp fiber for at least one week and reacts at a temperature of greater than about 25° C. to form covalent bonds with starch, gelatinized starch or pulp fiber in less than an hour.  
     
     
         16 . The method of  claim 13 , wherein the crosslinker composition comprises at least one equivalent of a compound having at least two aldehyde residues and between about 0.25 and about 5 equivalents of one or more stabilizing compounds.  
     
     
         17 . The method of  claim 16 , wherein the compound having at least two aldehyde residues is glyoxal.  
     
     
         18 . The method of  claim 16 , wherein the stabilizing agent is a linear, branched or cyclic organic molecule having at least two functional groups capable of blocking an aldehyde residue.  
     
     
         19 . The method of any one of claims  1  through  18 , wherein the crosslinker composition further comprises at least one aldehyde blocking agent.  
     
     
         20 . The method of  claim 19 , wherein the crosslinker composition comprises at least 0.1 molar equivalent of aldehybe blocking agent relative to the aldehyde generating compound.  
     
     
         21 . The method of  claim 19 , wherein the crosslinker composition comprises at least one aldehyde blocking agent selected from urea, thiourea, amines, alkanols, alkane diols, and alkylene glycols.  
     
     
         22 . The method of  claim 1 , wherein the aldehyde generating compound is a compound of Formula I:  
       
         
           
           
               
               
           
         
         wherein  
         Z is monovalent or divalent urea, monovalent or divalent α,ω-C 2-8 alkanediol, C 2-8 alkylene glycol, poly(ethylene glycol) having a molecular weight of less than about 20,000, ω-amino-α-C 2-8 alkanol or Z is a 5 to 7 member optionally substituted heterocyclic group having one ring nitrogen atom, at least one additional ring heteroatom selected from N, O, or S, and zero or one oxo substitutents;  
         n is 0, 1, or 2;  
         m is 0 or 1;  
         n′=n if m=1 or n′=0 if m=0, wherein at least one of m and n is not zero.  
       
     
     
         23 . The method of  claim 1 , wherein the aldehyde generating compound is a compound of Formula II:  
       
         
           
           
               
               
           
         
         wherein  
         A is an optionally substituted methylene group, an optionally substituted C 2-4 alkylene group, or a single bond;  
         B is carbonyl, thiocarbonyl, or an optionally substituted 1,2-ethylene residue;  
         X 1  and X 2  are independently selected from the group consisting of oxygen and NR 3 ;  
         R 1  and R 2  are independently selected from the group consisting of hydrogen, hydroxy, optionally substituted C 1-20 alkyl, optionally substituted C 1-20 alkoxy, optionally substituted urea, optionally substituted thiourea, or  
         R 1  and R 2 , taken in combination, form a N,N′-divalent urea;  
         R 3  is independently selected at each occurrence of R 3  from the group consisting of hydrogen, 1-hydroxy-ethan-2-al-1-yl group, or a blocked glyoxal residue.  
       
     
     
         24 . The method of  claim 1 , wherein the aldehyde generating compound is a compound of Formula III:  
       
         
           
           
               
               
           
         
         wherein  
         each of X 1 , X 2 , and X 3  are independently selected from the group consisting of CH or N; and  
         R 4  and R 5  are independently selected at each occurrence of R 4  and R 5  in Formula III from the group selected from hydrogen, a 1-hydroxy-ethan-2-al-1-yl group, or a blocked glyoxal residue; or  
         one or more occurrences of NR 4 R 5  in Formula III, taken in combination form an optionally substituted N-piperazinyl residue.  
       
     
     
         25 . The method of  claim 24 , wherein each of X 1 , X 2 , and X 3  is nitrogen.  
     
     
         26 . The method of  claim 24 , wherein one or more occurrences of NR 4 R 5  in Formula III, taken in combination form an optionally substituted N-2,3,5,6-tetrahydroxypiperazinyl residue.  
     
     
         27 . The method of  claim 24 , wherein the aldehyde generating compound is a compound of Formula IV:  
       
         
           
           
               
               
           
         
         wherein  
         each of X 1 , X 2 , and X 3  are independently selected from the group consisting of CH or N; and  
         R 6  is independently selected at each occurrence from the group selected from optionally substituted alkyl, optionally substituted carboxamide.  
       
     
     
         28 . The method of  claim 27 , wherein R 6  is independently selected at each occurrence from —C(O)NH 2  or —C(O)NHCH(OH)CHO.  
     
     
         29 . A method for manufacturing paper or paperboard sheet with increased strength, the method comprising the steps of: 
 providing a fiber slurry and a gelatinized starch composition, each of which is suitable for use in making paper or paperboard;    providing at least one crosslinker composition comprising at least one aldehyde generating compound capable of forming at least two or more covalent bonds to functional groups present in the starch or fiber of the web;    preparing a paper or paperboard web comprising pulp fiber and at least one starch prepared by mixing the gelatinized starch composition and the fiber slurry;    contacting the web with the crosslinker composition under conditions conducive to formation at least two or more covalent bonds to functional groups present in the starch or fiber of the web.    
     
     
         30 . The method of  claim 29 , wherein the method of manufacture further comprises the step of drying the paper or paperboard web.  
     
     
         31 . The method of  claim 30 , wherein the crosslinker composition is contacted with the web prior to the drying process.  
     
     
         32 . The method of  claim 30 , wherein the crosslinker composition is contacted with the paper or paperboard web after the drying step has removed at least a portion of moisture from the paper or paperboard web.  
     
     
         33 . The method of  claim 29 , wherein the crosslinker composition increases at least one of the wet strength or the dry strength of the paper or paperboard prepared by the method of manufacture.  
     
     
         34 . The method of  claim 1 , wherein the crosslinker composition comprises between about 0.001% to about 80% aldehyde generating compound by weight in an aqueous media.  
     
     
         35 . The method of  claim 34 , wherein the crosslinker composition does not comprise starch or gelatinized starch.  
     
     
         36 . The method of  claim 34 , wherein the crosslinker composition is stable in the absence of starch, gelatinized starch, or pulp fiber for at least one week and reacts at a temperature of greater than about 25° C. to form covalent bonds with starch, gelatinized starch or pulp fiber in less than an hour.  
     
     
         37 . The method of  claim 34 , wherein the crosslinker composition comprises at least one equivalent of a compound having at least two aldehyde residues and between about 0.25 and about 5 equivalents of one or more stabilizing compounds.  
     
     
         38 . The method of  claim 37 , wherein the compound having at least two aldehyde residues is glyoxal.  
     
     
         39 . The method of  claim 37 , wherein the stabilizing agent is a linear, branched or cyclic organic molecule having at least two functional groups capable of blocking an aldehyde residue.  
     
     
         40 . The method of any one of claims  29  through  39 , wherein the crosslinker composition further comprises at least one aldehyde blocking agent.  
     
     
         41 . The method of  claim 40 , wherein the crosslinker composition comprises at least 0.1 molar equivalent of aldehybe blocking agent relative to the aldehyde generating compound.  
     
     
         42 . The method of  claim 40 , wherein the crosslinker composition comprises at least one aldehyde blocking agent selected from urea, thiourea, amines, alkanols, alkane diols, and alkylene glycols.  
     
     
         43 . The method of  claim 29 , wherein the aldehyde generating compound is a compound of Formula I:  
       
         
           
           
               
               
           
         
         wherein  
         Z is monovalent or divalent urea, monovalent or divalent α,ω-C 2-8 alkanediol, C 2-8 alkylene glycol, poly(ethylene glycol) having a molecular weight of less than about 20,000, ω-amino-α-C 2-8 alkanol or Z is a 5 to 7 member optionally substituted heterocyclic group having one ring nitrogen atom, at least one additional ring heteroatom selected from N, O, or S, and zero or one oxo substitutents;  
         n is 0, 1, or 2;  
         m is 0 or 1;  
         n′=n if m=1 or n′=0 if m=0, wherein at least one of m and p is not zero.  
       
     
     
         44 . The method of  claim 29 , wherein the aldehyde generating compound is a compound of Formula II:  
       
         
           
           
               
               
           
         
         wherein  
         A is an optionally substituted methylene group, an optionally substituted C 2-4 alkylene group, or a single bond;  
         B is carbonyl, thiocarbonyl, or an optionally substituted 1,2-ethylene residue;  
         X 1  and X 2  are independently selected from the group consisting of oxygen and NR 3 ;  
         R 1  and R 2  are independently selected from the group consisting of hydrogen, hydroxy, optionally substituted C 1-20 alkyl, optionally substituted C 1-20 alkoxy, optionally substituted urea, optionally substituted thiourea, or  
         R 1  and R 2 , taken in combination, form a N,N′-divalent urea;  
         R 3  is independently selected at each occurrence of R 3  from the group consisting of hydrogen, 1-hydroxy-ethan-2-al-1-yl group, or a blocked glyoxal residue.  
       
     
     
         45 . The method of  claim 29 , wherein the aldehyde generating compound is a compound of Formula III:  
       
         
           
           
               
               
           
         
         wherein  
         each of X 1 , X 2 , and X 3  are independently selected from the group consisting of CH or N; and  
         R 4  and R 5  are independently selected at each occurrence of R 4  and R 5  in Formula III from the group selected from hydrogen, a 1-hydroxy-ethan-2-al-1-yl group, or a blocked glyoxal residue; or  
         one or more occurrences of NR 4 R 5  in Formula III, taken in combination form an optionally substituted N-piperazinyl residue.  
       
     
     
         46 . The method of  claim 45 , wherein each of X 1 , X 2 , and X 3  is nitrogen.  
     
     
         47 . The method of  claim 45 , wherein one or more occurrences of NR 4 R 5  in Formula III, taken in combination form an optionally substituted N-2,3,5,6-tetrahydroxypiperazinyl residue.  
     
     
         48 . The method of  claim 45 , wherein the aldehyde generating compound is a compound of Formula IV:  
       
         
           
           
               
               
           
         
         wherein  
         each of X 1 , X 2 , and X 3  are independently selected from the group consisting of CH or N; and  
         R 6  is independently selected at each occurrence from the group selected from optionally substituted alkyl, optionally substituted carboxamide.  
       
     
     
         49 . The method of  claim 48 , wherein R 6  is independently selected at each occurrence from —C(O)NH 2  or —C(O)NHCH(OH)CHO.  
     
     
         50 . The method of  claim 29 , wherein the glyoxal generating compound is a compound according to Formula II-a:  
       
         
           
           
               
               
           
         
         wherein  
         A is an optionally substituted methylene group, an optionally substituted C 2-4 alkylene group, or a single bond;  
         B is carbonyl, thiocarbonyl, or an optionally substituted 1,2-ethylene residue;  
         X 1  and X 2  are independently selected from the group consisting of oxygen and NR 3 ;  
         R 1  and R 2  are independently selected from the group consisting of hydrogen, hydroxy, optionally substituted C 1-20 alkyl, optionally substituted C 1-20 alkoxy, optionally substituted urea, optionally substituted thiourea, or  
         R 1  and R 2 , taken in combination, form a N,N′-divalent urea;  
         R 3  is independently selected at each occurrence of R 3  from the group consisting of hydrogen, optionally substituted C 1-20 alkyl, and unblocked and blocked glyoxal residues, where unblocked glyoxal residue is a 1-hydroxy-2-ethanal-1-yl group and the blocked glyoxal residue is a 1-hydroxy-2-(protected aldehyde residue)-ethan-1-yl group; or  
         R 3  is a 1,2-dihydroxyethylene residue coupled to two rings according to Formula I; and  
         wherein the aldehyde generating compound according to Formula I degrades to generate at least one equivalent of glyoxal when the crosslinking composition is contacted with starch or pulp fiber.  
       
     
     
         51 . The method of  claim 50 , wherein 
 R 1  and R 2  are independently selected from the group consisting of hydrogen, hydroxy, methanol, ethanol, urea, or    R 1  and R 2 , taken in combination, form a N,N′-divalent urea;    R 3  is independently selected at each occurrence of R 3  from the group consisting of hydrogen, methyl, and ethyl, or    R 3  is an unblocked glyoxal residue or a blocked glyoxal residue selected from the group consisting of 1,2-dihydroxy-2-(C 1-4 -alkoxy)-ethan-1-yl, 1,2-dihydroxy-2-(3-hydroxypropoxy)-ethan-1-yl, and 1,2-dihydroxy-2-(2-hydroxypropoxy)-ethan-1-yl.    
     
     
         52 . The method of  claim 50 , wherein 
 X 1  and X 2  are NR 3 ;    A is a single bond;    B is a carbonyl or thiocarbonyl group; and    R 1  and R 2  are independently selected from hydroxy, C 1-6 alkoxy, or blocked glyoxal residues.    
     
     
         53 . The method of  claim 50 , wherein 
 X 1  and X 2  are NR 3 ;    A is a 1,1-C 1-6 alkylene group;    B is a carbonyl or thiocarbonyl group;    R 1  and R 2  are independently selected from hydrogen, hydroxy, C 1-6 alkoxy, and    R 3  is an unblocked glyoxal residue or a blocked glyoxal residue selected from the group consisting of 1,2-dihydroxy-2-(C 1-4 -alkoxy)-ethan-1-yl, 1,2-dihydroxy-2-(3-hydroxypropoxy)-ethan-1-yl, and 1,2-dihydroxy-2-(2-hydroxypropoxy)-ethan-1-yl.    
     
     
         54 . The method of  claim 50 , wherein the glyoxal generating compound is a compound according to Formula V:  
       
         
           
           
               
               
           
         
         wherein  
         m is an integer from 0 to about 1000;  
         A is an optionally substituted methylene group, an optionally substituted C 2-4 alkylene group, or a single bond;  
         B is carbonyl, thiocarbonyl, or an optionally substituted 1,2-ethylene residue;  
         R 1  and R 2  are independently selected from the group consisting of hydrogen, hydroxyl, optionally substituted C 1-20 alkyl, optionally substituted C 1-20 alkoxy, optionally substituted urea, optionally substituted thiourea, or  
         R 1  and R 2 , taken in combination, form a N,N′-divalent urea;  
         R 3  is independently selected at each occurrence of R 3  from the group consisting of hydrogen, optionally substituted C 1-20 alkyl, and unblocked and blocked glyoxal residues, where unblocked glyoxal residue is a 1-hydroxy-2-ethanal-1-yl group and the blocked glyoxal residue is a 1-hydroxy-2-(protected aldehyde residue)-ethan-1-yl group; or  
         R 4  is a 1,2-dihydroxyethylene residue; or  
         R 4  is a telechelic oligiomer comprising 2n+1 glyoxal residues alternating with n groups selected from the group consisting of α,ω-alkane diols, alkylene glycols, and poly(ethylene glycol); and  
         n is an integer of from 0 to about 100;  
         wherein the aldehyde generating compound according to Formula V degrades to generate at least one equivalent of glyoxal when the crosslinking composition is contacted with starch or pulp fiber.  
       
     
     
         55 . The method of  claim 50 , wherein the glyoxal generating compound is a compound according to Formula VI:  
       
         
           
           
               
               
           
         
         wherein  
         p is an integer from 1 to about 1000;  
         Z is independently selected at each occurrence from the group consisting of optionally substituted urea, optionally substituted thiourea, optionally substituted guanidine, optionally substituted alkylene glycol, optionally substituted α,ω-akanediol, optionally substituted poly(ethylene glycol), optionally substituted imidazolidin-2-one, and optionally substituted tetrahydro-pyrimidin-2-one;  
         wherein the aldehyde generating compound according to Formula VI degrades to generate at least one equivalent of glyoxal when the crosslinking composition is contacted with starch or pulp fiber.  
         R 5  is hydrogen, alkoxy, hydroxyalkoxy, amino, hydroxy, mono and dialkyl amino, optionally substituted alkane diol, optionally substituted urea, or optionally substituted alkylene glycol; and  
         R 6  is hydrogen, optionally substituted alkyl, optionally substituted alkanoyl, optionally substituted unblocked glyoxal residue, or blocked glyoxal residues.  
       
     
     
         56 . The method of  claim 55 , wherein 
 Z is urea, thiourea, C 2-10 α,ω-alkanediol, C 2-10 alkylene glycol, or poly(ethyleneglycol) having between 2 and about 100 glycol repeat units;