Hydrofluorocarbon compositions

Abstract

A composition which comprises 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and 1,1,1,3,3-pentafluoropropane (HFC-245fa) in a weight ratio HFC-365mfc/HFC-245fa of from 60:40 to 75:25.

1 . A composition which comprises 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and 1,1,1,3,3-pentafluoropropane (HFC-245fa) in a weight ratio HFC-365mfc/HFC-245fa of from 60:40 to 75:25.  
   
   
       2 . The composition according to  claim 1 , wherein the weight ratio HFC-365mfc/HFC-245fa is from 65:35 to 73:27.  
   
   
       3 . The composition according to  claim 1 , wherein the weight ratio HFC-365mfc/HFC-245fa is from 67:33 to 72:28.  
   
   
       4 . The composition according to  claim 1 , wherein the weight ratio HFC-365mfc/HFC-245fa is about 70:30.  
   
   
       5 . The composition according to  claim 1 , which consists essentially of HFC-365mfc and HFC-245fa.  
   
   
       6 . A premix intended for the preparation of polyurethane or modified polyurethane foams comprising 
 a) at least one polyol    b) a catalyst for the reaction of isocyanates with polyols    c) a composition according to  claim 1 .    
   
   
       7 . A process for the manufacture of polyurethane or modified polyurethane foams in which at least one isocyanate is reacted with at least one polyol in the presence of at least one catalyst and in the presence of the composition according to  claim 1 .  
   
   
       8 . A polyurethane or modified polyurethane foam which is obtainable according to the process of  claim 7 .  
   
   
       9 . The polyurethane or modified polyurethane foam according to  claim 8 , which is a rigid closed cell foam.  
   
   
       10 . A thermal insulation material, which comprises a polyurethane or modified polyurethane foam according to  claim 8 .  
   
   
       11 . A thermal insulation material, which comprises the polyurethane or modified polyurethane foam according to  claim 9.