Rigid polyurethane foams with improved properties
In the process of the present invention, an organic polyisocyanate is reacted with a sorbitol-based polyether polyol having a number average molecular weight of from about 400 to about 1500, in the presence of a pentafluoropropane blowing agent, and a catalyst.
1 . A process for preparing a rigid polyurethane foam comprising reacting:
a) an organic polyisocyanate with
b) a sorbitol-based polyether polyol having a number average molecular weight of from about 400 to about 1500, in the presence of
c) a pentafluoropropane blowing agent, and
d) a catalyst.
2 . The process of claim 1 , wherein said blowing agent is selected from the group consisting of 1,1,2,2,3-pentafluoropropane, 1,1,2,3,3-pentafluoropropane, 1,1,1,2,3 pentafluoropropane and 1,1,1,3,3-pentafluoropropane.
3 . The process of claim 2 , wherein said sorbitol-based polyether polyol is an ethylene oxide, propylene oxide polyether polyol.
4 . The process of claim 2 , wherein polyols which are not based on sorbitol are also included in the reaction mixture.
5 . The process of claim 2 , wherein water is also included in the reaction mixture.
6 . and 7 . (Cancelled).
8 . A process for preparing a rigid polyurethane foam comprising reacting:
a) an organic polyisocyanate with
b) a sorbitol-based polyether polyol having a number average molecular weight of from about 400 to about 1500, in the presence of
c) a pentafluoropropane blowing agent chosen from 1,1,2,2,3-pentafluoropropane, 1,1,2,3,3-pentafluoropropane, 1,1,1,2,3-pentafluoropropane and 1,1,1,3,3-pentafluoropropane, and
d) a catalyst.
9 . The process of claim 8 , wherein said sorbitol-based polyether polyol is an ethylene oxide, propylene oxide polyether polyol.
10 . The process of claim 8 , wherein polyols which are not based on sorbitol are also included in the reaction mixture.
11 . The process of claim 8 , wherein water is also included in the reaction mixture.