Claims
- 1. A method of making a rigid polyurethane foam, comprising mixing a polyisocyanate component with a polyol component in the presence of at least one catalyst for the reaction of a polyol or water with a polyisocyanate and subjecting the mixture to conditions sufficient to cure to form a polyurethane foam having a bulk density of 45 pounds per cubic foot (720 kg/m3) or less, wherein(a) the polyisocyanate component contains an isocyanate-terminated prepolymer made by reacting an excess of an organic polyisocyanate with (i) at least one polyol and (ii) at least one hydroxy-functional acrylate or methacrylate, (b) the polyol component contains an effective amount of a blowing agent and isocyanate-reactive materials have an average functionality of at least about 2.3 and include at least one polyol and, (c) the volume ratio of the polyisocyanate component to polyol component is no greater than 10:1, and (d) the ratio of isocyanate groups in the polyisocyanate component to the number of isocyanate-reactive groups in the polyol component is from about 0.8:1 to about 1.5:1.
- 2. The method of claim 1 wherein the volume ratio of polyisocyanate component to polyol component is 1:1.5 to 6:1.
- 3. The method of claim 1 wherein the polyol component and the prepolymer component are at a temperature of no greater than 70° C. when mixed.
- 4. The method of claim 1 wherein the hydroxy-functional acrylate or methacrylate is a methacrylate.
- 5. The method of claim 1 wherein at least one polyol in the polyol component contains a tertiary amine group.
- 6. The method of claim 1 wherein the catalyst includes a reactive amine catalyst.
- 7. The method of claim 1 wherein the blowing agent is water or a chemical blowing agent. that releases CO2.
- 8. An isocyanate-terminated prepolymer which is the reaction product of an excess of an organic polyisocyanate with (i) at least one polyol and (ii) at least one hydroxy-functional acrylate or methacrylate.
- 9. The prepolymer of claim 8 which has an isocyanate-equivalent weight of 150 to 500.
- 10. The prepolymer of claim 8 wherein the organic polyisocyanate is MDI or a polymeric MDI.
- 11. The prepolymer of claim 10 wherein the hydroxy-functional acrylate or methacrylate is hydroxyethyl methacrylate.
- 12. A reactive system comprising(a) a polyisocyanate component that contains an isocyanate-terminated prepolymer made by reacting an excess of an organic polyisocyanate with (i) at least one polyol and (ii) at least one hydroxy-functional acrylate or methacrylate, (b) a polyol component containing an effective amount of a blowing agent and isocyanate-reactive materials that have an average functionality of at least about 2.3 and include at least one polyol and, wherein the system is further characterized by(i) a volume ratio of polyisocyanate component to polyol component of no greater than 10:1, (ii) a ratio of isocyanate groups in the polyisocyanate component to isocyanate-reactive groups in the polyol component from about 0.8:1 to about 1.5:1 and (iii) at least one of the polyisocyanate component or the polyol component containing a catalyst for the reaction of an isocyanate with a polyol or water.
- 13. The reactive system of claim 12 wherein the volume ratio of polyisocyanate component to polyol component is 1:1.5 to 6:1.
- 14. The reactive system of claim 13 wherein the hydroxy-functional acrylate or methacrylate is a methacrylate.
- 15. The reactive system of claim 14 wherein the hydroxy-functional acrylate or methacrylate is hydroxyethyl methacrylate.
- 16. The reactive system of claim 12 wherein at least one polyol in the polyol component contains a tertiary amine group.
- 17. The reactive system of claim 12 wherein the catalyst includes a reactive amine catalyst.
- 18. The reactive system of claim 12 wherein the blowing agent is water or a chemical blowing agent that releases CO2.
- 19. The method of claim 1 wherein the hydroxy-functional acrylate or methacrylate is 2-hydroxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxy-n-butyl acrylate, 4-hydroxy-n-butyl methacrylate, 2-hydroxy-n-butyl acrylate, 2-hydroxy-n-butyl methacrylate or a poly(oxyethylene)- and/or poly(oxypropylene) ester of acrylic or methacrylic acid wherein the number of oxyethylene and/or oxypropylene groups is preferably from about 2 to about 10.
- 20. The method of claim 19 wherein the mixed isocyanate and polyol components are dispensed onto a part or assemblage and cured in place to form localized reinforcement, corrosion protection, sound insulation or vibration dampening on the part or assemblage.
- 21. The prepolymer of claim 8 wherein the hydroxy-functional acrylate or methacrylate is 2-hydroxyethyl methacrylate 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxy-n-butyl acrylate, 4-hydroxy-n-butyl methacrylate, 2-hydroxy-n-butyl acrylate, 2-hydroxy-n-butyl methacrylate or a poly(oxyethylene)- and/or poly(oxypropylene) ester of acrylic or methacrylic acid wherein the number of oxyethylene and/or oxypropylene groups is preferably from about 2 to about 10.
- 22. The reactive system of claim 12 wherein the hydroxy-functional acrylate or methacrylate is 2-hydroxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxy-n-butyl acrylate, 4-hydroxy-n-butyl methacrylate, 2-hydroxy-n-butyl acrylate, 2-hydroxy-n-butyl methacrylate or a poly(oxyethylene)- and/or poly(oxypropylene) ester of acrylic or methacrylic acid wherein the number of oxyethylene and/or oxypropylene groups is preferably from about 2 to about 10.
Parent Case Info
This application claims benefit of 60/280,728 filed Apr. 2, 2001.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
B-3832393 |
Jan 1994 |
AU |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/280728 |
Apr 2001 |
US |