Compositions and methods for inhibiting tannin release

Abstract

The invention relates to compositions and methods whereby tannin staining of a natural or synthetic lumber product can be inhibited or prevented. The compositions and methods described herein can be used in conjunction with compositions and methods for inhibiting microbial growth on or in lumber products.

What is claimed is:  
     
         1 . A method of treating a substrate that comprises cellulose and a tannin, the method comprising contacting a surface of the substrate with an aqueous composition comprising an agent that binds covalently with the tannin, wherein the pH of the composition is not greater than 9.0.  
     
     
         2 . The method of  claim 1 , wherein the pH of the composition is not less than 3.0.  
     
     
         3 . The method of  claim 1 , wherein the pH of the composition is in the range 4.0 to 8.5.  
     
     
         4 . The method of  claim 1 , wherein the pH of the composition is in the range 5.0 to 8.0.  
     
     
         5 . The method of  claim 1 , wherein the pH of the composition is in the range 6.0 to 7.5.  
     
     
         6 . The method of  claim 1 , wherein the pH of the composition is in the range 6.5 to 7.2.  
     
     
         7 . The method of  claim 1 , wherein the pH of the composition is substantially 7.  
     
     
         8 . The method of  claim 1 , wherein the antimicrobial agent is a compound that has the chemical formula 
       X—L—Tbm, 
       wherein 
 X is a chemical moiety that exhibits antimicrobial activity,  
 L is an optional linking moiety, and  
 Tbm is a tannin-binding moiety.  
 
     
     
         9 . The method of  claim 8 , wherein X is a quaternary ammonium moiety.  
     
     
         10 . The method of  claim 9 , wherein Tbm is selected from the group consisting of a silane moiety, and an alkoxysilyl moiety.  
     
     
         11 . The method of  claim 10 , wherein X has the chemical formula 
       ((R 1 ) 3 —N + )— 
       wherein each R 1  is independently selected from the group consisting of —H and branched and straight-chain C 1  to C 24  alkyl radicals.  
     
     
         12 . The method of  claim 11 , wherein L is a branched or straight-chain C 1  to C 24  alkyl diradical, optionally having one or more —O— or —N— diradicals in its backbone.  
     
     
         13 . The method of  claim 11 , wherein Tbm is selected from the group consisting of a silane moiety, and an alkoxysilyl moiety.  
     
     
         14 . The method of  claim 1 , wherein the antimicrobial agent is selected from the group consisting of an octadecylaminodimethyltrihydroxysilylpropyl ammonium salt and an octadecylaminodimethyltrimethoxysilylpropyl ammonium salt.  
     
     
         15 . The method of  claim 1 , wherein the antimicrobial agent is octadecylaminodimethyltrihydroxysilylpropyl ammonium chloride.  
     
     
         16 . The method of  claim 1 , wherein the composition comprises the conjugate base of an organic acid.  
     
     
         17 . The method of  claim 16 , wherein the organic acid is a dicarboxylic acid.  
     
     
         18 . The method of  claim 17 , wherein the organic acid is selected from the group consisting of oxalic acid, malonic acid, succinic acid, fumaric acid, and oxaloacetic acid.  
     
     
         19 . The method of  claim 17 , wherein the organic acid is oxalic acid.  
     
     
         20 . The method of  claim 1 , wherein the substrate is a polymer—cellulose composite.  
     
     
         21 . The method of  claim 20 , wherein the polymer is polyvinylchloride.  
     
     
         22 . The method of  claim 1 , wherein the substrate is wood.  
     
     
         23 . The method of  claim 1 , wherein the substrate is an exterior building material.  
     
     
         24 . The method of  claim 23 , wherein the substrate is a decking material.  
     
     
         25 . The method of  claim 24 , wherein the decking material is a plank.