Reinforcement Sheet to Reinforce a Cementitious Board

Abstract

A cementitious board and a reinforcement sheet for the board includes, a water vapor porous layer of glass fibers bonded together by a cured binder, and a hydrophilic coating material being mobile in slurry water to wet the binder coated glass fibers and spread a slurry of a cementitious compound, and the hydrophilic coating material being volatile to dissipate by evaporation at an elevated temperature at which the cementitious compound dries to form a dried cementitious board having both the cementitious compound and the binder coated glass fibers essentially free of the hydrophilic coating material.

1 . A reinforcement sheet for a cementitious board includes, a thin, water vapor porous layer of glass fibers bonded together by a cured binder to provide binder coated glass fibers, and a hydrophilic coating material on the binder coated glass fibers, the hydrophilic coating material being soluble and transferable to slurry water of a cementitious compound, and then being volatile in the slurry water to dissipate by evaporation at an elevated temperature and time duration at which the cementitious compound is dried to form a cementitious board. 
     
     
         2 . The reinforcement sheet of  claim 1 , comprising:
 a mesh of glass fibers to imbed in the slurry, wherein the mesh is attached to the thin, water vapor porous layer of the glass fibers.   
     
     
         3 . The reinforcement sheet of  claim 1 , wherein the binder is hydrophobic. 
     
     
         4 . The reinforcement sheet of  claim 1 , wherein the binder is hydrophilic. 
     
     
         5 . The reinforcement sheet of  claim 1  wherein, the hydrophilic coating material is semi-volatile at atmospheric temperatures and pressures. 
     
     
         6 . The reinforcement sheet of  claim 1  wherein, the hydrophilic coating material is non-volatile at atmospheric temperatures and pressures. 
     
     
         7 . The reinforcement sheet of  claim 1  wherein, the thin, water vapor porous layer is porous to a volatile form of the hydrophilic coating material. 
     
     
         8 . The reinforcement sheet of  claim 1  wherein, the thin, water vapor porous layer has pores for passage of the slurry. 
     
     
         9 . The reinforcement sheet of  claim 1  wherein the thin, water vapor porous layer has pores preventing passage of the slurry. 
     
     
         10 . The reinforcement sheet of  claim 1  wherein the glass fibers of the thin, water vapor porous layer are wet-laid and binder coated. 
     
     
         11 . The reinforcement sheet of  claim 1  wherein the glass fibers of the thin, water vapor porous layer are non-interlaced. 
     
     
         12 . The reinforcement sheet of  claim 1  wherein the glass fibers are accumulated in random or selected orientations. 
     
     
         13 . The reinforcement sheet of  claim 1  wherein the binder bonds the glass fibers together by curing prior to the hydrophilic coating material being applied on the binder coated glass fibers. 
     
     
         14 . The reinforcement sheet of  claim 1  wherein the hydrophilic coating material is volatile to dissipate by evaporation for the binder coated glass fibers to be essentially free of the hydrophilic coating material as a source of water and moisture absorption. 
     
     
         15 . The reinforcement sheet of  claim 1  wherein the thin, water vapor porous layer is provided with a hydrophobic surface. 
     
     
         16 . The reinforcement sheet of  claim 1  wherein the hydrophilic coating material is mobile in slurry water to dilute and disperse upon contact by surface molecules of the slurry water. 
     
     
         17 . The reinforcement sheet of  claim 16 , wherein the hydrophilic coating material is mobile in slurry water to wet and spread a slurry of the cementitious compound on the binder coated glass fibers.