Fungus resistant gypsum-based substrate

Abstract

The present invention relates to a fungus resistant gypsum board, made of first and second polymeric fibrous sheets with a gypsum core sandwiched there between. The gypsum core containing less than 0.03% of formulation additives that serve as fungus nutrients and less than 0.5% of the dry gypsum core contains of fungus nutrients. The fibrous sheets are preferably nonwovens and the gypsum core preferably contains a fungicide. The invention is also directed to a process for making a fungus resistant gypsum board.

What is claimed is:  
     
         1 . A fungus resistant gypsum board, comprising: 
 first and second nonwoven polymeric fibrous sheets; and    a gypsum core sandwiched between said first and second nonwoven polymeric fibrous sheets, said gypsum core containing less than 0.03% by weight, based on the weight of the dry gypsum core, of formulation additives that serve as fungus nutrients.    
     
     
         2 . The board of  claim 1  further comprising a synthetic adhesive in said gypsum core.  
     
     
         3 . A fungus resistant gypsum-based substrate, comprising: 
 first and second polymeric fibrous nonwoven sheets; and    a wet and hydrated gypsum core sandwiched between said first and second polymeric fibrous nonwoven sheets, said gypsum core containing less than 0.02% by weight, based oh the weight of the wet gypsum core, of formulation additives that serve as fungus nutrients, and less than 0.33% by weight, based on the weight of the wet gypsum core, of naturally occuring contaminants which may serve as fungus nutrients;    wherein said first and second polymeric fibrous nonwoven sheets adhere to said wet gypsum core with an adhesive strength of at least 7.5 lb.