Claims
- 1. A method for preparing a polyurea polymer comprising admixing a polyurea formulation including a polyisocyanate, a polyepoxide, and a polyamine and heating at a temperature of greater than about 150.degree. C., the method having a first step of admixing the:
- (A) polyisocyanate;
- (B) polyepoxide; and
- (C) polyamine;
- at a temperature of less than about 130.degree. C. under reaction conditions sufficient to prepare a polyurea polymer, and a second step of postcuring the polyurea polymer at a temperature of greater than about 150.degree. C., wherein the polyisocyanate is selected from the group consisting of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymeric MDI (PMDI), polyisocyanates containing carbodiimide groups, uretonimine groups, prepolymers and mixtures thereof; the ratio of isocyanate groups to active hydrogen groups is from about 0.80 to about 1.20; the ratio of epoxide groups to amine groups is from about 0.05 to about 1.50; the admixing is done in a substantial absence of oxazolidinone catalyst and crosslinking materials known as uretidine diones and isocyanurates, and wherein the polymer, after humid aging, upon reheating for an hour at a temperature of 205.degree. C., does not blister.
- 2. The method of claim 1 wherein the polyamine is an alkylene polyamine, an amine derived from polyoxypropylene diols and/or triols, and mixtures thereof.
- 3. The method of claim 1 wherein the first step admixing is done by means of a reaction injection molding machine.
- 4. The method of claim 1 wherein the polyisocyanate and the polyepoxide are combined in one reservoir of the reaction injection molding machine.
- 5. The method of claim 1 wherein the polyurea polymer is cured during step 2 at from about 150.degree. C. to about 250.degree. C.
- 6. The method of claim 1 wherein the polyurea polymer is cured during step 2 at from about 165.degree. C. to about 220.degree. C.
- 7. The method of claim 1 wherein the polyurea polymer is cured during step 2 at from about 190.degree. C. to about 220.degree. C.
- 8. A polyurea polymer comprising a polymer prepared by the method of claim 1.
- 9. The polymer of claim 8 wherein the polyisocyanate is a prepolymer containing carbodiimide groups and or urethane groups from diphenylmethane diisocyanate.
- 10. The polymer of claim 8 wherein the polyamine is an alkylene polyamine, an aromatic polyamine, an amine derived from polyoxypropylene diols and/or triols, and mixtures thereof.
- 11. The polymer of claim 8 wherein the polyamine is an alkylene polyamine, an amine derived from polyoxypropylene diols and/or triols, and mixtures thereof.
- 12. The polymer of claim 10 wherein the aromatic polyamine is diethyltoluenediamine or di-tert-butyltoluenediamine.
- 13. The polymer of claim 8 wherein the polyepoxide is a diglycidyl ether of a cycloaliphatic single ring compound, a diglycidyl ether of a cycloalilphatic two ring compound, a diglycidyl ether of a dihydric single ring compound, a diglycidyl ether of a dihydric bisphenol, a polyglycidyl ether of a hydrocarbon phenolic resin, a polyglycidyl ether of a polyoxyalkylene glycol, a diglycidyl ether of an aliphatic diol, a polyglycidyl ether of a novolac resin or mixtures thereof.
- 14. The polymer of claim 13 wherein the polyepoxide is a diglycidyl ether of a dihydric bisphenol.
- 15. The polymer of claim 8 wherein the polymer is a filled polymer.
- 16. The polymer of claim 15 wherein the polymer is a reinforced polymer.
- 17. The polymer of claim 8 wherein the polyurea polymer also has polyurethane groups.
- 18. The method of claim 1 wherein the polyurea composition additionally includes a base polyol, a lower molecular weight active hydrogen containing material or mixtures thereof.
- 19. The method of claim 18 wherein the polyurea formulation additionally includes blowing agents, fillers, reinforcing substrates, mold release agents, surfactants, chain extenders, ultraviolet light stabilizers, fire retardants or mixtures thereof.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a Continuation In Part of U.S. Ser. No. 07/979,560, filed Nov. 20, 1992, entitled POLYUREA POLYMERS HAVING IMPROVED HIGH TEMPERATURE STABILITY AND METHOD OF MAKING SAME, which is now abandoned.
US Referenced Citations (26)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0294013A2 |
Jul 1988 |
EPX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
979560 |
Nov 1992 |
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