Method for pressure treating boards

Abstract

A method for treating wood products is provided wherein wood products are treated in an aqueous solution of a silicate, a rheology modifier, a wetting agent and, optionally, borax and/or a bacteriocide or fungicide; the aqueous solution having a pH of at least 9.0, preferably, a pH of 10-14, and most preferably, 13.0. A suitable dye can be added to the aqueous solution to color the wood product. The present invention is also directed to an aqueous solution for pressure treating wood and a wood product prepared according to the method of the present invention.

1 . A method for rendering wood products fire, rot and insect resistant comprising the step of pressure treating said wood products with an aqueous solution consisting essentially of a silicate, a wetting agent and a rheology modifier, wherein the pH of the aqueous solution is at least 9.0.  
     
     
         2 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 1   , wherein said aqueous solution further includes borax.  
     
     
         3 . The method as claimed in    claim 1   , wherein the aqueous solution further includes an environmentally safe bacteriocide or fungicide.  
     
     
         4 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 1    wherein said pressure treating step includes the steps of: 
 a. placing said wood products in a pressure vessel;  
 b. contacting said wood products with said aqueous solution;  
 c. increasing said pressure in said pressure vessel;  
 d. draining said aqueous solution from said pressure vessel;  
 e. reducing said pressure in said pressure vessel; and  
 f. drying said wood products.  
 
     
     
         5 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 1   , wherein the wood product is green lumber.  
     
     
         6 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 3   , further including a step of applying a vacuum to the wood products immediately prior to the contacting step.  
     
     
         7 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 3   , wherein in the step of increasing the pressure, the pressure is increased to 40-160 pounds for 20-90 minutes.  
     
     
         8 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 6   , wherein the wood products are one of particle board, medium-density fiberboard and oriented strand board and the pressure is increased to about 40 pounds.  
     
     
         9 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 6   , wherein the wood products are one of a natural wood product and green lumber and the pressure is increased to about 140 pounds.  
     
     
         10 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 1   , wherein the pH of the solution is about 11.2-1.4.  
     
     
         11 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 1   , wherein the aqueous solution includes a suitable dye.  
     
     
         12 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 1   , wherein said aqueous solution includes 18 to 60% sodium silicate, 0.01 to 2% wetting agent and 0.01 to 2% rheology modifier and water.  
     
     
         13 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 1   , wherein the aqueous solution consists essentially of about 38% sodium silicate, about 0.1% wetting agent and about 0.1% rheology modifier, the solution having about 21% solids.  
     
     
         14 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 13   , wherein the solution consists of an aqueous solution of 38% sodium silicate, 0.1% wetting agent and 0.1% rheology modifier, the solution having 21% solids.  
     
     
         15 . The method for rendering wood products fire, rot and insect resistant as claimed in    claim 13   , wherein the solution further includes 1-10% borax.  
     
     
         16 . A solution for rendering wood products fire, rot and insect resistant consisting essentially of a silicate and one of a wetting agent and a rheology modifier, wherein the pH of said solution is at least 9.0.  
     
     
         17 . The solution as claimed in    claim 16   , further including an environmentally safe bacteriocide or fungicide.  
     
     
         18 . The solution as claimed in    claim 16   , wherein the pH of the solution is about 11.2-1.4.  
     
     
         19 . The solution for rendering wood products fire, rot and insect resistant as claimed in    claim 16   , wherein said solution further comprises borax.  
     
     
         20 . The solution for rendering wood products fire, rot and insect resistant as claimed in    claim 16   , wherein the solution includes 18 to 60% sodium silicate, 0.01 to 2% wetting agent and 0.01 to 2% rheology modifier.  
     
     
         21 . The solution for rendering wood products fire, rot and insect resistant as claimed in    claim 20   , wherein said aqueous solution further comprises 1-10% borax.  
     
     
         22 . A pressure treated wood product prepared by pressure treating said wood product according to the method of    claim 1   .  
     
     
         23 . The pressure treated wood product as claimed in    claim 22   , wherein the aqueous solution includes 18-60% sodium silicate and one of 0.1-2% wetting agent, 0.1-2% rheology modifier and 1-10% borax.  
     
     
         24 . The pressure treated wood product as claimed in    claim 22   , wherein the aqueous solution further includes one of an environmentally safe bacteriocide or fungicide and borax.