Back to results
US 5,962,541 AGranted
Isocyanate-terminated prepolymers and rigid-foams produced therefrom
AssigneeBayer Aktiengesellschaft
InventorsBrian H. Peterson, Frank C. Rossitto, William J. Nicola, Jr., Clarence D. Blue
Life of this patent
Estimating the term…
Abstract
NCO-terminated prepolymers are made by reacting a polymeric diphenylmethane diisocyanate (PMDI) and a polyol having a functionality of from about 1.8 to about 4.0 and a molecular weight of from about 400 to about 2,000. The PMDI and polyol are reacted in amounts such that the equivalent ratio of isocyanate groups to hydroxyl groups is from about 15:1 to about 160:1. These prepolymers are useful in the production of polyurethane foams, particularly laminated foams.
Claims6
A process for the production of a rigid polyurethane foam comprising mixing
- a) an NCO-terminated prepolymer which is the reaction product of
- 1) a polymeric diphenylmethane diisocyanate having a viscosity at 25.degree. C. of from about 50 to about 1,000 mPa.multidot.s and
- 2) a polyester polyol blend having a functionality of from about 1.8 to about 4.0 and a molecular weight of from about 400 to about 2,000
- formed by reacting 1) and 2) in amounts such that the equivalent ratio of isocyanate groups to hydroxyl groups is from about 15:1 to about 160:1,
- b) a compound containing isocyanate-reactive hydrogen atoms, and
- c) a blowing agent selected from the group consisting of 1,1-dichloro-1-fluoroethane, 1,1,1,3,3-pentafluoropropane, n-pentane, cyclopentane, isopentane, and tetrafluoroethane and allowing the reaction mixture to form a foam.
3 more elements
Dependencies are inferred from the claim text.