Soy protein adhesive and uses thereof

Abstract

The present invention provides a soy protein-based adhesive composition and a process for making the composition that may be used in particleboards and similar wood composite systems and that is formed from an aqueous mixture of calcium oxide, pine oil, protein, lignin, and acid. The preferred protein is an enzymatically-modified soy protein and the preferred enzyme is urease.

1 . An adhesive composition comprising a mixture of:
 water;   calcium oxide;   pine oil;   enzyme-modified soy protein;   lignin; and   an acid.   
   
   
       2 . An adhesive composition comprising an aqueous mixture of:
 a hydrolyzation agent;   a defoamer;   a source of enzyme-modified soy protein;   a source of lignin; and   an antimicrobial agent.   
   
   
       3 . The adhesive composition of  claim 1 , wherein the soy protein modifying enzyme is urease. 
   
   
       4 . The adhesive composition of  claim 3 , wherein the acid is an organic acid. 
   
   
       5 . The adhesive composition of  claim 3 , wherein the acid is an inorganic acid. 
   
   
       6 . The adhesive composition of  claim 5 , wherein the inorganic acid is nitric acid. 
   
   
       7 . The adhesive composition of  claim 6 , comprising about 50% water; about 3% calcium oxide; about 2% pine oil; about 38% enzyme-modified soy protein; about 3% lignin; and about 4% nitric acid. 
   
   
       8 . A particleboard comprising:
 a binder comprising a mixture of water, calcium oxide, pine oil, enzyme-modified soy protein, lignin, and an acid; and   a source of lignocellulose.   
   
   
       9 . The particleboard of  claim 8 , wherein the soy protein modifying enzyme is urease. 
   
   
       10 . The particleboard of  claim 9 , wherein the acid is an organic acid. 
   
   
       11 . The particleboard of  claim 9 , wherein the acid is an inorganic acid. 
   
   
       12 . The particleboard of  claim 11 , wherein the inorganic acid is nitric acid. 
   
   
       13 . The particleboard of  claim 8 , wherein the source of lignocellulose is wood furnish. 
   
   
       14 . The particleboard of  claim 12 , wherein the binder is comprised of about 50% water; about 3% calcium oxide; about 2% pine oil; about 38% enzyme-modified soy protein; about 3% lignin; and about 4% nitric acid. 
   
   
       15 . A process for preparing an enzyme-modified soy protein adhesive composition, the process comprising the steps of:
 loading an effective amount of water in a reaction kettle;   adjusting the pH and temperature of the water for optimal enzymatic activity;   adding at least one enzyme to the water to form a mixture and allowing the mixture to stabilize;   adding at least one soy protein sequentially to the mixture under constant agitation;   continuing agitation for an additional 2-6 hours;   neutralizing the enzyme activity by adjusting reaction conditions;   adding effective amounts of calcium oxide, pine oil, lignin, and acid to the mixture; and   adjusting the pH of the mixture to about 7 before unloading the mixture.   
   
   
       16 . The process of  claim 15 , wherein the at least one enzyme is urease. 
   
   
       17 . The process of  claim 16 , wherein the acid is an organic acid. 
   
   
       18 . The process of  claim 16 , wherein the acid is an inorganic acid. 
   
   
       19 . The process of  claim 18 , wherein the inorganic acid is nitric acid. 
   
   
       20 . A soy protein adhesive composition made by the process of  claim 15 .