Enzymatic opacifying composition for paper, pulp or paperboard, processes using same and pulp, paper or paperboard produced therefrom

Abstract

An organic agent for enhancing opacity in paper, paperboard or pulp comprises a hydrolase or an oxido-reductase; this enzymatic opacifying agent overcomes drawbacks associated with traditional organic and inorganic opacifying agents but also serves to provide increased strength and reduced porosity in paper and paperboard.

1 . In a method of enhancing opacity in a paper composition, in which an organic opacifying agent is incorporated in the paper composition, the improvement wherein the organic opacifying agent comprises an enzyme selected from the group consisting of hydrolases and oxidoreductases.  
   
   
       2 . A method according to  claim 1 , wherein the paper composition is a paper or paperboard and wherein the organic opacifying agent is incorporated in a papermaking pulp slurry and the pulp slurry is formed into the paper or paperboard.  
   
   
       3 . A method according to  claim 1 , wherein the paper composition is a papermaking pulp and wherein the organic opacifying agent is incorporated in a slurry of the papermaking pulp.  
   
   
       4 . A method according to  claim 1 , wherein said enzyme is a hydrolase.  
   
   
       5 . A method according to  claim 4 , wherein said hydrolase is a cellulase.  
   
   
       6 . A method according to  claim 1 , wherein said enzyme is an oxidoreductase.  
   
   
       7 . A method according to  claim 6 , wherein said oxidoreductase is a laccase.  
   
   
       8 . A method according to  claim 7 , wherein said organic opacifying agent further comprises a mediator.  
   
   
       9 . A method according to  claim 1 , wherein said enzyme is incorporated in said paper composition in an amount of 0.00002 to 2%, by weight, catalytic protein based on the oven dry weight of pulp fibers of said paper composition.  
   
   
       10 . A method according to  claim 9 , wherein said amount is 0.0002 to 0.2%, by weight, catalytic protein based on the oven dry weight of pulp fibers of said paper composition.  
   
   
       11 . An opacifying agent for use in enhancing opacity in a paper composition selected from paper, paperboard and papermaking pulp, comprising an enzyme selected from the group consisting of hydrolases and oxidoreductases.  
   
   
       12 . An agent according to  claim 11 , wherein said enzyme is associated with at least one surfactant or stabilizing agent.  
   
   
       13 . An agent according to  claim 11 , wherein said enzyme is a cellulase or a laccase.  
   
   
       14 . A papermaking stock comprising: 
 pulp slurry of papermaking fibers and an organic opacifying agent in an aqueous vehicle;    said organic opacifying agent comprising an enzyme selected from hydrolases and oxidoreductases.    
   
   
       15 . A papermaking stock according to  claim 14 , wherein said slurry further comprises at least one papermaking additive selected from the group consisting of fillers, brighteners and sizing agents.  
   
   
       16 . A papermaking stock according to  claim 14 , wherein said enzyme is selected from cellulases and laccases, and is present in said slurry in an amount of 0.00002 to 2%, by weight catalytic protein, based on the oven dry weight of papermaking fibers.  
   
   
       17 . An opacified paper composition comprising papermaking fibers and an organic opacifying agent, wherein said organic opacifying agent comprises an enzyme selected from the group consisting of hydrolases and oxidoreductases.  
   
   
       18 . An opacified paper composition according to  claim 17 , wherein said enzyme is a hydrolase or laccase, and said enzyme is present in an amount of 0.00002 to 2%, by weight catalytic protein, based on the oven dry weight of papermaking fibers.  
   
   
       19 . A process of producing paper or paperboard of enhanced opacity comprising: 
 i) providing a pulp slurry of papermaking fibers,    ii) adding an organic opacifying agent to said slurry, and    iii) forming paper or paperboard from said slurry, wherein said organic opacifying agent comprises an enzyme selected from hydrolases and oxidoreductases.    
   
   
       20 . A process according to  claim 19 , wherein said enzyme is a cellulase or a laccase, and said enzyme is in an amount of 0.00002 to 2%, by weight, catalytic protein based on the oven dry weight of papermaking fibers.