High density polyurethane and polyisocyanurate construction boards and composite boards

Abstract

A covered roof includes a roof deck, an insulation board, and a coverboard. The insulation board includes a polyurethane, a polyisocyanurate, or a mix of polyurethane and polyisocyanurate cellular structure, has a density that is less than 2.5 pounds per cubic foot, and has a first planar surface and a second planar surface, each having a facer positioned adjacent thereto. The coverboard includes a polyurethane, a polyisocyanurate, or a mix of polyurethane and polyisocyanurate cellular structure, has a density greater than about 2.5 pounds per cubic foot and less than 6 pounds per cubic foot, an iso index of at least 175, and a first planar surface and a second planar surface, each having a facer positioned adjacent thereto.

1 - 10 . (canceled) 
     
     
         11 . A composite board comprising:
 a) a layer of gypsum; and   b) a layer of polyisocyanate, said layer of polyisocyanate being 0.5 to 4.5 inches thick, and being characterized by a density of from about 3.5 to less than 6.0 pounds per cubic foot as determined by ASTM C303.   
     
     
         12 . The composite board of  claim 11 , said composite further comprising a layer of glass fabric disposed on said layer of polyisocyanurate opposite said layer of gypsum. 
     
     
         13 . The composite board of  claim 11 , where said gypsum layer is about 0. 2 to about 1.5 inches thick. 
     
     
         14 . A method of installing a roof system, the method comprising:
 a) applying a layer of insulation board to a roof deck, where the insulation board includes a polyisocyanurate core characterized by a density of from about 1.5 to about 2.0 pounds per cubic foot as determined by ASTM C303 and an iso index of at least 200, said insulation board further including first and second facers, where the facers include cellulosic fibers;   b) applying over said insulation boards, a coverboard, where the coverboard includes a polyisocyanurate core characterized by a density of from about 3.5 to less than 6.0 pounds per cubic foot as determined by ASTM C303, said coverboard further including first and second facers, where the facers include glass fibers, said coverboard having a thickness of from 0.5 to 4.5 inches; and   c) applying, over said coverboard, a membrane system.   
     
     
         15 . The method of  claim 14 , where said insulation board and said coverboard include an isopentane encapsulated within said respective polyisocyanurate cores. 
     
     
         16 . The method of  claim 14 , where the foam cores of both said insulation board and said coverboard are formed from a polyester polyol and an aromatic isocyanate. 
     
     
         17 . The method of  claim 14 , where the foam cores of both said insulation board and said coverboard are formed from a polyether polyol and an aromatic isocyanate. 
     
     
         18 . A method of manufacturing a composite board, the method comprising:
 a) forming a high-density layer of polyisocyanurate on a glass-containing fabric;   b) forming a low-density layer of polyisocyanurate on a cellulose-containing fabric; and   c) adhering the high-density layer to the low-density layer via a hot-melt adhesive.