Fire performance for wood veneer laminated ceiling tile

Abstract

The present invention is directed to a building panel having a laminate structure comprising a cellulosic layer; and a topcoat layer that is substantially impervious to ambient moisture. The topcoat layer comprises a sealant sub-layer, an intumescent sub-layer comprising an intumescent composition, and the sealant sub-layer is positioned between the cellulosic layer and the intumescent sub-layer such that the intumescent sub-layer is separated from the first major surface of the cellulosic layer by the sealant sub-layer. The resulting building panel exhibits superior flame retardancy resulting in a Class A fire rating, according to ASTM E-84.

What is claimed is: 
     
         1 . A ceiling panel comprising a laminate structure, the laminate structure comprising:
 a cellulosic veneer layer comprising a first major surface opposite a second major surface;   a topcoat layer comprising:
 a first sub-layer atop the cellulosic veneer layer, the first sub-layer comprising a sealant composition comprising a first polymer; and 
 a second sub-layer atop the first sub-layer, the second sub-layer comprising the intumescent composition. 
   an adhesive layer formed from an adhesive composition comprising a thermoplastic polymer; and   a metallic substrate layer, the cellulosic veneer layer at least partially bonded to the metallic substrate by the adhesive layer.   
     
     
         2 . The ceiling panel according to  claim 1 , wherein the topcoat layer is substantially clear. 
     
     
         3 . The ceiling panel according to  claim 1 , wherein the first sub-layer directly contacts the first major surface of the cellulosic veneer layer and the adhesive layer directly contacts the second major surface of the cellulosic veneer layer. 
     
     
         4 . The ceiling panel according to  claim 1 , wherein the first major surface of the cellulosic veneer layer comprises pores, and wherein the first sub-layer directly contacts the first major surface of the cellulosic veneer layer thereby sealing at least a portion of the pores. 
     
     
         5 . The ceiling panel according to  claim 1 , wherein the adhesive layer directly contacts the second major surface of the veneer layer and the second sub-layer is separated from the first major surface of the veneer layer by a height of the first sub-layer. 
     
     
         6 . The ceiling panel according to  claim 1 , wherein the intumescent composition comprises:
 a carbon donor compound; and   an acid donor compound comprising ammonium phosphate, di-ammonium phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate, melamine phosphate, guanylurea phosphate, urea phosphate, p-toluenesulphonic acid, ammonium sulfate, ammonium borate, and combinations thereof.   
     
     
         7 . The ceiling panel according to  claim 1 , wherein the first polymer comprises one or more of vinyl or acrylic homopolymers or copolymers formed from ethylenically unsaturated monomers such as ethylene or butadiene and vinyl monomers such as styrene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrates, acrylic acid, methacrylic acid, or esters of acrylic acid and/or esters of methacrylic acid. 
     
     
         8 . The ceiling panel according to  claim 1 , wherein the topcoat layer further comprises a third sub-layer that is atop the second sub-layer, the third sub-layer being substantially impervious to ambient moisture. 
     
     
         9 . The ceiling panel according to  claim 8 , wherein the second sub-layer further comprises a second polymer having a second glass transition temperature and the third sub-layer further comprises a third polymer having a third glass transition temperature, the third glass transition temperature being equal to or less than the second glass transition temperature. 
     
     
         10 . The ceiling panel according to  claim 1 , wherein the second sub-layer comprises a second polymer that is a carbon donor compound of the intumescent composition. 
     
     
         11 . The ceiling panel according to  claim 1 , wherein the adhesive composition is a hot-melt composition. 
     
     
         12 . The ceiling panel according to  claim 1 , wherein the metallic substrate has a thickness ranging from about 35 mils to about 65 mils and the cellulosic veneer layer has a thickness ranging from about 25 mils to about 45 mils. 
     
     
         13 . A ceiling panel comprising a laminate structure, the laminate structure comprising:
 a topcoat layer comprising:
 a sealant composition; and 
 an intumescent composition; 
   a cellulosic veneer layer having a first major surface opposite a second major surface;   an adhesive layer formed from an adhesive composition comprising a thermoplastic polymer; and   a metallic substrate layer.   
     
     
         14 . The ceiling panel according to  claim 13 , wherein the topcoat includes a first sub-layer comprising the sealant composition and a second sub-layer comprising the intumescent composition. 
     
     
         15 . The ceiling panel according to  claim 14 , wherein the first major surface of the cellulosic veneer layer comprises pores that are at least partially sealed by the first sub-layer of the topcoat layer. 
     
     
         16 . The ceiling panel according to  claim 14 , wherein the second sub-layer is separated from the first major surface of the veneer layer by a height of the first sub-layer. 
     
     
         17 . A building panel comprising a laminate structure, the laminate structure comprising:
 a cellulosic layer; and   a topcoat layer that is substantially impervious to ambient moisture, the topcoat layer comprising:
 a sealant sub-layer; and 
 an intumescent sub-layer comprising an intumescent composition; 
 the sealant sub-layer positioned between the cellulosic layer and the intumescent sub-layer such that the intumescent sub-layer is separated from the first major surface of the cellulosic layer by the sealant sub-layer. 
   
     
     
         18 . The building panel according to  claim 17 , wherein the second sub-layer comprises a second polymer that is a carbon donor compound of the intumescent composition. 
     
     
         19 . The building panel according to  claim 18 , wherein the topcoat layer further comprises a third sub-layer that is atop the second sub-layer, the third sub-layer being substantially impervious to ambient moisture. 
     
     
         20 . The building panel according to  claim 19 , wherein the second polymer has a second glass transition temperature and the third sub-layer further comprises a third polymer having a third glass transition temperature, the third glass transition temperature being equal to or less than the second glass transition temperature.