Composition for the production of improved pulp

Abstract

Compositions and method for improving properties of pulp produced or reducing the digester cycle time in alkaline chemical pulping processes in which an effective amount of at least one selected phosphonate or carboxylate compound or mixtures thereof is admixed with the alkaline aqueous mixture in the digester of the chemical pulping process. The compositions and method are especially well suited for use in the Kraft pulping process.

1. An aqueous composition for improving properties of pulp produced, reducing the digester cycle time, or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes said composition comprising the alkaline composition of the digester of said process and at least one compound selected from the group consisting of phosphonates having the formula:
   X 2 NCH 2 PO 3 M 2   (I)  
 
       in an amount, on an active acid basis, of from about 0.5% to about 1% based upon the dry weight of the wood chips in said digester,
 (II) phosphonates having the formula: 
                 
 
 in an amount, on an active acid basis, of from about 0.3% to about 1% based upon the dry weight of the wood chips in said digester, 
                 
 
 in an amount, on an active acid basis, of from about 0.5%   0 . 05 % to about 1% based upon the dry weight of the wood chips in said digester, and,  
 on an active acid basis, from about 0.03% to about 1% of amine oxides of the phosphonates of formula (I), based upon the dry weight of wood chips in said digester, or mixtures thereof; wherein M is independently selected from hydrogen, alkali metal, alkaline earth metal or ammonium, X is independently selected from H, R, —CH 2 PO 3 M 2  wherein R is an alkyl group or —NX 2  substituted alkyl group having 2 to 6 carbon atoms, R′ is an alkyl group having 1 to 17 carbon atoms and R′ is optionally branched, optionally unsaturated, and optionally substituted with SO 3 M, Y is selected from —PO 3 M 2 , H or R′, and Z is selected from —OH or —NR 1 R 2  wherein R 1  and R 2  are independently selected from hydrogen or alkyl having 1 to 2 carbon atoms.  
 
     
     
       2. The composition of  claim 1  wherein M is independently selected from hydrogen or an alkali metal. 
     
     
       3. The composition of  claim 2  wherein M is sodium or potassium when M is an alkali metal. 
     
     
       4. The composition of  claim 1  wherein X is independently selected from —CH 2 PO 3 M 2  or R. 
     
     
       5. The composition of  claim 4  wherein at least one of X is R and R is —(CH 2 ) n NX′ 2 , wherein n is an integer from 2 to 6 and X′ is independently selected from R or —CH 2 PO 3 M 2 . 
     
     
       6. The composition of  claim 4  wherein each X is R and R is —(CH 2 ) n NX′ 2 , wherein n is an integer from 2 to 6 and X′ is independently selected from R or —CH 2 PO 3 M 2 . 
     
     
       7. The composition of  claim 1  wherein Y is —PO 3 M 2 . 
     
     
       8. The composition of  claim 7  wherein Z is —OH. 
     
     
       9. The composition of  claim 7  wherein R′ is an alkyl group having 1 to 11 carbon atoms. 
     
     
       10. The composition of  claim 7  wherein R′ is substituted with —SO 3 M. 
     
     
       11. The composition of  claim 7  wherein Z is —NR 1 R 2 . 
     
     
       12. The composition of  claim 1  wherein R′ is an alkyl group having 1 to 11 carbon atoms. 
     
     
       13. The composition of  claim 12  wherein R′ is an alkyl group having 1 to 5 carbon atoms. 
     
     
       14. The composition of  claim 1  wherein said compound is at least one phosphonate of formula (I). 
     
     
       15. The composition of  claim 14  wherein said phosphonate is
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 ) 2  and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       16. The composition of  claim 14  wherein said phosphonate is
 (M 2 O 3 PCH 2 ) 2 N(CH 2 ) 6 N(CH 2 PO 3 M 2 ) 2  and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       17. The composition of  claim 14  wherein said phosphonate is
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 ) 2  and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       18. The composition of  claim 14  wherein said phosphonate is
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 )CH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 ) 2  and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       19. The composition of  claim 1  wherein said compound is at least one phosphonate of formula (II). 
     
     
       20. The composition of  claim 19  wherein said phosphonate is
 CH 3 C(OH)(PO 3 M 2 ) 2  and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       21. The composition of  claim 1  wherein said compound is at least one compound of formula (IV). 
     
     
       22. The composition of  claim 1  wherein said compound is a mixture of at least two phosphonates of formula (I). 
     
     
       23. The composition of  claim 22  wherein said phosphonate is a mixture of:
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 )CH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 ) 2 , and a second phosphonate selected from N(CH 2 PO 3 M 2 ) 3 ,  
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 ) 2 , (M 2 O 3 PCH 2 ) 2 N(CH 2 ) 6 N(CH 2 PO 3 M 2 ) 2 , or  
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 ) 2 .  
 
     
     
       24. The composition of  claim 23  wherein said second phosphonate is
 N(CH 2 PO 3 M 2 ) 3 , and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       25. The composition of  claim 23  wherein said second phosphonate is selected from (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N (CH 2 PO 3 M 2 ) 2 , (M 2 O 3 PCH 2 ) 2 N(CH 2 ) 6 N(CH 2 PO 3 M 2 ) 2 , or (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 ) 2 , and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester. 
     
     
       26. The composition of  claim 22  wherein said phosphonate is a mixture of
 (M 2 O 3 PCH 2 ) 2 N(CH 2 ) 6 N(CH 2 PO 3 M 2 ) 2  and a second phosphonate selected from (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N (CH 2 PO 3 M 2 )CH 2 CH 2 N(CH 2 PO 3 M 2 ) 2  or N(CH 2 PO 3 M 2 ) 3 , and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       27. The composition of  claim 22  wherein said phosphonate is a mixture of
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 ) 2  and N(CH 2 PO 3 M 2 ) 3 , and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       28. The composition of  claim 22  wherein said phosphonate is a mixture of
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 ) 2  and a second phosphonate selected from  
 (M 2 O 3 PCH 2 ) 2 N(CH 2 ) 6 N(CH 2 PO 3 M 2 ) 2 ,  
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 ) 2 , or N(CH 2 PO 3 M 2 ) 3 , and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       29. The composition of  claim 1  wherein said compound is a mixture of at least one phosphonate of formula (I) and at least one phosphonate of formula (II). 
     
     
       30. The composition of  claim 29  wherein said phosphonate is a mixture of
 a first phosphonate selected from N(CH 2 PO 3 M 2 ) 3 ,  
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 ) 2 ,  
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 )CH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 ) 2 , (M 2 O 3 PCH 2 ) 2 N(CH 2 ) 6 N(CH 2 PO 3 M 2 ) 2 , or  
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 ) 2 , and a second phosphonate selected from CH 3 C(OH)(PO 3 M 2 ) 2 .  
 
     
     
       31. The composition of  claim 30  wherein where said first phosphonate is selected from (M 2 O 3 PCH 2 ) 2 N(CH 2 ) 6 N (CH 2 PO 3 M 2 ) 2 ,
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 )CH 2 CH 2 CH 2 N(CH 2 PO 3 M 2 ) 2 , (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 )CH 2 CH 2 N (CH 2 PO 3 M 2 ) 2 , or  
 (M 2 O 3 PCH 2 ) 2 NCH 2 CH 2 N(CH 2 PO 3 M 2 ) 2 , and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       32. The composition of  claim 30  wherein said first phosphonate is
 N(CH 2 PO 3 M 2 ) 3  and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.  
 
     
     
       33. The composition of  claim 1  wherein said compound is a mixture of at least two phosphonates of formula (II). 
     
     
       34. The composition of  claim 1  wherein said compound is a mixture of at least one compound of formula (IV) with at least one compound selected from the phosphonates of formula (I) or formula (II). 
     
     
       35. The composition of  claim 1  wherein said compound is an amine oxide of the phosphonates of formula (I). 
     
     
       36. The composition of  claim 35  wherein said amine oxide is  − O← + N—(CH 2 PO 3 M 2 ) 3 . 
     
     
       37. The composition of  claim 1  wherein the pH of said alkaline aqueous mixture is at least 9. 
     
     
       38. The composition of  claim 37  wherein the pH of said alkaline aqueous mixture is about 12 to 14. 
     
     
       39. The composition of  claim 1  further comprising anthroquinone. 
     
     
       40. An aqueous composition for improving properties of pulp produced in alkaline chemical pulping processes, said composition comprising the alkaline composition of the digester of said process and at least one compound selected from the group consisting of phosphonates having the formula:
   X 2 NCH 2 PO 3 M 2   (I)  
 in an amount, on an active acid basis, of from about 0.1% to about 0.5% based upon the dry weight of the wood chips in said digester, 
                 
 
 in an amount, on an active acid basis, of from about 0.05% to about 0.5% based upon the dry weight of the wood chips in said digester, 
                 
 
 in an amount, on an active acid basis, of from about 0.01%   0 . 05 % to about 0.5% based upon the dry weight of the wood chips in said digester, and, on an active acid basis, from about 0.03% to about 1% of amine oxides of the phosphonates of formula (I), based upon the dry weight of wood chips in said digester, or mixtures thereof;  
 wherein M is independently selected from hydrogen, alkali metal, alkaline earth metal or ammonium, X is independently selected from H, R, —CH 2 PO 3 M 2  wherein R is an alkyl group or —NX 2  substituted alkyl group having 2 to 6 carbon atoms, R′ is an alkyl group having 1 to 17 carbon atoms and R′ is optionally branched, optionally unsaturated, and optionally substituted with SO 3 M, Y is selected from —PO 3 M 2 , H or R′, and Z is selected from —OH or —NR 1 R 2  wherein R 1  and R 2  are independently selected from hydrogen or alkyl having 1 to 2 carbon atoms.