Mold resistant construction boards and methods for their manufacture

Abstract

A construction board comprising i) a foam layer, and ii) a first facer, where the first facer includes at least one mold-inhibiting agent.

1 . A method of manufacturing an insulation board, the method comprising: 
 preparing a felt facer that includes a mold-inhibiting agent, where said mold-inhibiting agent is incorporated into said felt facer during manufacture of the felt facer and prior to drying the felt facer; and    depositing a foam-forming material onto the felt facer.    
     
     
         2 . The method of  claim 1 , where the mold-inhibiting agent includes sodium borate, calcium metaborate, calcium borate, zinc borate, boric acid, borax, disodium orthoborate, copper sulfate, sodium tetrachlorophenate, ammonium fluorosilicate, and trimethyl ammonium chloride, and mixtures thereof.  
     
     
         3 . The method of  claim 1 , where the mold-inhibiting agent is selected from the group consisting of sodium borate, calcium metaborate, calcium borate, zinc borate, boric acid, borax, and disodium orthoborate.  
     
     
         4 . The method of  claim 1 , where the mold-inhibiting agent includes calcium metaborate and calcium borate.  
     
     
         5 . The method of  claim 1 , where the mold-inhibiting agent includes sodium borate.  
     
     
         6 . A method of manufacturing an insulation board, the method comprising: 
 (I) preparing a facer by: 
 (a) depositing an aqueous slurry of cellulose onto a felting mill to form a prefelt;  
 (b) after said step of depositing an aqueous slurry onto a felting mill, depositing a mold inhibiting agent onto the prefelt; and  
 (c) after said step of depositing a mold inhibiting agent onto the prefelt, treating the prefelt by drying the prefelt to form a felt facer; and  
   (II) depositing a foam forming material onto the felt facer.    
     
     
         7 . The method of  claim 6 , where the felt facer comprises cellulose fibers characterized by a diameter of from about 5 to about 1,000 microns and an aspect ratio of from about 0.25 to about 25,000.  
     
     
         8 . The method of  claim 6 , where the facer material includes from about 70 to about 90% by weight of the cellulose fibers, from about 6 to about 30% by weight of the glass fibers, from about 0.5 to about 10% by weight of a binder, from about 0.25 to about 6% by weight of a sizing agent, and from about 3 to about 25% by weight of a mold-inhibiting agent, based on the entire weight of the felt facer.  
     
     
         9 . The method of  claim 6 , where the mold-inhibiting agent includes sodium borate, calcium metaborate, calcium borate, zinc borate, boric acid, borax, disodium orthoborate, copper sulfate, sodium tetrachlorophenate, ammonium fluorosilicate, and trimethyl ammonium chloride, and mixtures thereof.  
     
     
         10 . The method  claim 6 , where the foam layer comprises a closed cell, rigid cellular structure.  
     
     
         11 . The method of  claim 10 , where the cellular structure comprises polyurethane or polyisocyanurate cellular material.  
     
     
         12 . The method of  claim 6 , where the first facer comprises a felt facer, and where the felt facer comprises cellulose fibers and glass fibers.  
     
     
         13 . The method of  claim 6 , where the at least one facer has a thickness of from 0.005 to about 0.05 inches.  
     
     
         14 . The method of  claim 6 , where the at least one facer has a thickness of from 0.010 to about 0.030 inches.  
     
     
         15 . The method of  claim 1 , where additional mold-inhibiting agent is added after said step of drying.  
     
     
         16 . The method of  claim 6 , where said step of depositing a mold inhibiting agent onto the prefelt includes a sequential addition of mold inhibiting agent.  
     
     
         17 . The method of  claim 16 , where said sequential addition includes first depositing sodium borate, followed by depositing calcium metaborate, followed by depositing calcium borate.  
     
     
         18 . A method of forming a felt facer, the method comprising 
 preparing a facer by: 
 (a) depositing an aqueous slurry of cellulose onto a felting mill to form a prefelt;  
 (b) after said step of depositing an aqueous slurry onto a felting mill, depositing a mold inhibiting agent onto the prefelt; and  
 (c) after said step of depositing a mold inhibiting agent onto the prefelt, subsequently treating the prefelt by drying the prefelt to form a felt facer.