Polyurethane foams having improved heat sag and a process for their production

Abstract

Rigid, closed-cell polyurethane foams are produced by a RIM process by reacting an organic polyisocyanate with an isocyanate-reactive mixture in which a significant amount of a bio-based polyol is present. The foams produced by this process are characterized by improved heat sag and heat distortion temperature.

What is claimed is:  
     
         1 . An isocyanate-reactive component useful for the production of a rigid closed cell polyurethane foam by a RIM process comprising: 
 a) from 0.5 to 30% by weight, based on total weight of isocyanate-reactive component, of a bio-based polyol,    b) from 5 to 80% by weight, based on total weight of isocyanate-reactive component, of an isocyanate-reactive material having a functionality of at least 1 and a number average molecular weight of from 400 to 10,000,    c) a chain extender or a crosslinking agent,    d) a blowing agent, and    e) a catalyst.    
     
     
         2 . The isocyanate-reactive component of  claim 1  in which up to 25% by weight of the total isocyanate reactive-component is the bio-based polyol.  
     
     
         3 . The isocyanate-reactive component of  claim 1  in which up to 20% by weight of the total isocyanate-reactive component is the bio-based polyol.  
     
     
         4 . The isocyanate-reactive component of  claim 1  in which at least 0.5% by weight of the total isocyanate-reactive component is the bio-based polyol.  
     
     
         5 . The isocyanate-reactive component of  claim 1  in which at least 5% by weight of the total isocyanate-reactive component is the bio-based polyol.  
     
     
         6 . The isocyanate-reactive component of  claim 1  in which the bio-based polyol is a blown soybean oil.  
     
     
         7 . An isocyanate-reactive component useful for the production of a rigid closed cell polyurethane foam by a RIM process comprising: 
 a) at least 10% by weight, based on total weight of isocyanate reactive component, of a soybean oil based polyol,    b) from 5 to 80% by weight, based on total weight of isocyanate-reactive component of a polyether polyol having a functionality of from 2 to 8 and a number average molecular weight of from 400 to 10,000,    c) from 1 to 75% by weight, based on total weight of isocyanate-reactive component of a chain extender,    d) water, and    e) a catalyst.    
     
     
         8 . A RIM process for the production of a rigid, closed-cell polyurethane foam comprising 
 a) intimately mixing the isocyanate-reactive component of  claim 1  with an organic polyisocyanate in an amount such that the ratio of NCO to OH groups is from 0.8:1 to 1.3:1 and    b) introducing the mixture from a) into a mold.    
     
     
         9 . A RIM process for the production of a rigid, closed-cell polyurethane foam comprising: 
 a) intimately mixing the isocyanate-reactive component of  claim 2  with an organic polyisocyanate in an amount such that the ratio of NCO to OH groups is from 0.8:1 to 1.3:1 and    b) introducing the mixture from a) into a mold.    
     
     
         10 . A RIM process for the production of a rigid, closed-cell polyurethane foam comprising: 
 a) intimately mixing the isocyanate-reactive component of  claim 3  with an organic polyisocyanate in an amount such that the ratio of NCO to OH groups is from 0.8:1 to 1.3:1 and    b) introducing the mixture from a) into a mold.    
     
     
         11 . A RIM process for the production of a rigid, closed-cell polyurethane foam comprising: 
 a) intimately mixing the isocyanate-reactive component of  claim 6  with an organic polyisocyanate in an amount such that the ratio of NCO to OH groups is from 0.8:1 to 1.3:1 and    b) introducing the mixture from a) into a mold.    
     
     
         12 . A RIM process for the production of a rigid, closed-cell polyurethane foam comprising: 
 a) intimately mixing the isocyanate-reactive component of  claim 7  with an organic polyisocyanate in an amount such that the ratio of NCO to OH groups is from 0.8:1 to 1.3:1 and    b) introducing the mixture from a) into a mold.    
     
     
         13 . A rigid, closed-cell polyurethane foam produced by the process of  claim 8 .  
     
     
         14 . A rigid, closed-cell polyurethane foam produced by the process of  claim 9 .  
     
     
         15 . A rigid, closed-cell polyurethane foam produced by the process of  claim 10 .  
     
     
         16 . A rigid, closed-cell polyurethane foam produced by the process of  claim 11 .  
     
     
         17 . A rigid, closed-cell polyurethane foam produced by the process of  claim 12.