Rigid foams with improved insulation and physical properties

• US 5,426,127 A
• Filed: 09/26/1994
• Issued: 06/20/1995
• Est. Priority Date: 09/26/1994
• Status: Expired due to Term

• Current Assignee: Bayer Corporation (Bayer AG)
• Original Assignee: Miles, Inc. (Bayer AG)
• Inventors: Doerge, Herman P.
• Primary Examiner(s): Foelak, Morton
• Application Number:
  US08/312,346
• Time in Patent Office: 267 Days
• Field of Search: 521/131, 521/164
• US Class Current: 521/131
• CPC Class Codes: C08G 18/5021 having nitrogen
• CPC Class Codes: C08G 2110/0025 rigid
• CPC Class Codes: C08J 2375/04 Polyurethanes
• CPC Class Codes: C08J 9/146 only fluorine as halogen atoms

Abstract

Rigid polyurethane foams are produced by reacting an organic polyisocyanate with an amine-based polyether polyol in the presence of a catalyst, a hydrogen-containing fluorocarbon and a minor amount of water. These foams are characterized by K-factors which are about 0.135 BTU-in./hr.ft.² °F. or less.

Claims

1. A process for the production of rigid polyurethane foams having a K-factor which is about 0.135 BTU-in./hr.ft.² °

F. or less comprising reacting

a) an amine-initiated polyol having a molecular weight of at least 149 and a functionality of at least three with

b) an organic polyisocyanate in the presence of

c) water in an amount greater than 0 but less than or equal to 1.0% by weight, based on total weight of the foam-forming reaction mixture and

d) a hydrogen-containing fluorocarbon.

2. The process of claim 1 in which the reaction mixture further includes one or more polyols having molecular weights of from about 92 to about 1500 which are not the same as amine-initiated polyol a).

3. The process of claim 1 in which the amine-initiated polyol has a molecular weight of from about 149 to about 1500.

4. The process of claim 1 in which the amine-initiated polyol a) is initiated with ethylene diamine, diethylenetriamine, hexamethylene diamine, an aromatic diamine, monoethanolamine, diethanolamine, triethanolamine or ammonia.

5. The process of claim 1 in which the HFC blowing agent is selected from the group consisting of hexafluorobutanes, hexafluoropropanes, pentafluoropropanes, pentafluorobutanes, difluoroethanes, tetrafluoroethanes and mixtures thereof.

6. The process of claim 1 in which the HFC d) is included in an amount of from about 5 to about 20%, based on the total weight of the foam-forming composition.

7. The process of claim 1 in which the equivalent ratio of isocyanate groups of b) to active-hydrogen groups of a) is from about 1.0 to about 1.8.

8. The process of claim 1 in which isocyanate b) is selected from the group consisting of polymeric MDI and isocyanate-terminated prepolymers prepared therefrom.

9. The process of claim 1 in which the amine-initiated polyol a) has a molecular weight of from about 300 to about 800 and isocyanate b) is polymeric MDI.