Bituminous polyurethane interpenetrating elastomeric network compositions as coatings and sealants for roofing and other applications

Abstract

Elastomeric polyurethane interpenetrating network compositions are disclosed which are preferably developed by in situ reaction of polyols with different isocyanates and polyisocyanates in a bituminous material, such as, asphalt, coal tar, polymer modified asphalt, oxidized, and unoxidized asphalt. The composition is preferably formed at a temperature between 200° F. and 350° F. The reaction kinetics can be accelerated by including catalysts and curing agents. Bituminous polyurethane interpenetrating network elastomers are suitable for a wide variety of applications including but not limited to roofing, new construction, and wall and foundation waterproofing applications.

What is claimed is:  
     
         1 . A bituminous polyurethane interpenetrating elastomeric composition comprising: 
 a bituminous material;    a polyol;    a curing agent; and    an isocyanate.    
     
     
         2 . The composition of  claim 1  wherein said bituminous material including a rubber modified oxidized asphalt.  
     
     
         3 . The composition of  claim 1  wherein said bituminous material is a coal tar.  
     
     
         4 . The composition of  claim 1  wherein said bituminous material is a performance graded asphalt.  
     
     
         5 . The composition of  claim 1 , wherein said bituminous material is a rubberized asphalt.  
     
     
         6 . The composition of  claim 5  wherein said rubberized asphalt containing a polymer chosen from the group consisting of polyethylene, polypropylene, polystyrene, virgin rubber, and crumb rubber.  
     
     
         7 . The composition of  claim 6 , wherein said polymer comprises between five and seventy percent by weight of said rubberized asphalt.  
     
     
         8 . The composition of  claim 1  wherein said polyol is between forty and seventy-two percent by weight of said composition.  
     
     
         9 . The composition of  claim 1  wherein said isocyanate is between five and twenty percent by weight of said composition.  
     
     
         10 . The composition of  claim 1  wherein said isocyanate is chosen from the group consisting of diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.  
     
     
         11 . The composition of  claim 1  wherein said curing agent is between two and eight percent by weight of said composition.  
     
     
         12 . The composition of  claim 1 , further comprising a catalyst.  
     
     
         13 . The composition of  claim 12  wherein the amount of said catalyst is a less than one percent amount by weight.  
     
     
         14 . The composition of  claim 13  wherein the amount of catalyst is between one and five percent by weight of said polyol.  
     
     
         15 . The composition of  claim 13  wherein said catalyst is chosen from the group consisting of dibutyltin dilaurate, dioctyltin dilaurate, tertiary amine, and organometallic compounds of tin, organometallic compounds of lead, organometallic compounds of cobalt, and organometallic compounds of zinc.