Pulp and process for pulping

Abstract

The invention relates to a new pulp, which is derived from lignocellulosic material subjected to agitation in an aqueous tetra-alkylammonium salt solution under microwave irradiation. The invention relates also to a process for pulping lignocellulosic material and to a process for softening lignocellulosic material. The treated material is preferably wood, softwood or hardwood.

1 . A pulp prepared by a process comprising subjecting a lignocellulosic material to agitation in an aqueous tetra-alkylammonium salt solution under microwave irradiation. 
     
     
         2 . The pulp according to  claim 1 , wherein the lignocellulosic material is softwood or hardwood. 
     
     
         3 . The pulp according to  claim 1 , wherein the content of tetra-alkylammonium salt in the aqueous tetra-alkylammonium salt solution is 1-75 wt-%. 
     
     
         4 . The pulp according to  claim 1 , wherein the cation of the tetra-alkylammonium salt is 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3 , and R 4  are independently a C 1 -C 30  alkyl, C 3 -C 8  carbocyclic, or C 3 -C 8  heterocyclic group; and the anion of the tetra-alkylammonium salt is halogen, pseudohalogen, perchlorate, C 1 -C 6  carboxylate, or hydroxide. 
       
     
     
         5 . The pulp according to  claim 4 , wherein R 1 , R 2 , R 3 , and R 4  are independently C 4  alkyl; and the anion is hydroxide. 
     
     
         6 . The pulp according to  claim 1 - 4 , wherein the agitation is carried out at a temperature between 40° C. and 270° C. 
     
     
         7 . A process for pulping lignocellulosic material, comprising subjecting a lignocellulosic material to agitation in aqueous tetra-alkylammonium salt solution under microwave irradiation. 
     
     
         8 . The process according to  claim 7 , wherein the lignocellulosic material is softwood or hardwood. 
     
     
         9 . The process according to  claim 7 , wherein the content of tetra-alkylammonium salt in the aqueous tetra-alkylammonium salt solution is 1-75 wt-%. 
     
     
         10 . The process according to  claim 7 , wherein the cation of the tetra-alkylammonium salt is 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , R 3 , and R 4  are independently a C 1 -C 30  alkyl, C 3 -C 8  carbocyclic, or C 3 -C 8  heterocyclic group; and the anion of the tetra-alkylammonium salt is halogen, pseudohalogen, perchlorate, C 1 -C 6  carboxylate, or hydroxide. 
     
     
         11 . The process according to  claim 10 , wherein R 1 , R 2 , R 3 , and R 4  are independently C 4  alkyl; and the anion is hydroxide. 
     
     
         12 . The process according to  claim 7 , wherein the agitation is carried out at a temperature between 40° C. and 270° C. 
     
     
         13 - 18 . (canceled) 
     
     
         19 . The process according to  claim 7 , wherein the process is effective to establish partial or complete delignification.