Claims
- 1. A method for preparing asphalt and polymer compositions comprising:heating the asphalt in a stirred tank to a temperature sufficient to allow stirring of the asphalt in the tank, wherein said temperature is at least 330° F.; adding an elastomeric polymer to the tank in an amount not greater than twelve percent by weight of the total composition to form a mixture; adding a crosslinking composition to the composition; continue stirring and maintain the temperature in the tank for at least forty-five minutes, wherein the crosslinking composition comprises at least 0.08 percent by weight based on the asphalt of 2-mercaptobenzothiazole from 0.08 to 0.3 percent by weight based on the asphalt of elemental sulfur, at least 0.04 percent by weight based on the asphalt of zinc oxide, less than 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid.
- 2. The method of claim 1 wherein the elastomeric polymer is a styrene-butadiene polymer.
- 3. The method of claim 1 wherein the ratio of 2-mercaptobenzothiazole to zinc oxide to elemental sulfur is 2.0/1.0/2.0.
- 4. The method of claim 1 wherein the elastomeric polymer does not exceed 10 percent by weight of the total composition.
- 5. The method of claim 1 wherein the asphalt is heated to a temperature not greater than 380° F. prior to the addition of the crosslinking composition.
- 6. The method of claim 1 wherein the crosslinking composition comprises at least 0.08 percent by weight based on the asphalt of 2-mercaptobenzothiazole, from 0.08 to 0.3 percent by weight based on the asphalt of elemental sulfur, at least 0.04 percent by weight based on the asphalt of zinc oxide, less than 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid, and wherein 2-mercaptobenzothiazole is present in amounts from 2 percent to 5 percent by weight of elastomeric polymer.
- 7. The asphalt composition made in accordance with claim 1 wherein the asphalt:properties comply with Federal standards for grade AC-20.
- 8. A method far preparing asphalt and polymer compositions comprising:heating the asphalt in a stirred tank to a temperature sufficient to allow stirring of the asphalt in the tank, wherein said temperature is at least 330° F.; adding an elastomeric polymer to the tank in an amount not greater than twelve percent by weight of the total composition to form a mixture; adding a crosslinking composition to the composition; continue seining and maintain the temperature in the tank for at least forty-five minutes; wherein the crosslinking composition comprises at least 0.05 percent by weight based on the asphalt of zinc 2-mercaptobenzothiazole, at least 0.2 percent by weight based on the asphalt of dithiodimorpholine, less than 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid.
- 9. The method of claim 8 wherein the ratio of zinc 2-mercaptobenzothiazole to dithiodimorpholine is 1.0/4.0.
- 10. The asphalt composition made in accordance with claim 8 wherein the asphalt properties comply with Federal standards for grade AC-20.
- 11. A method for preparing asphalt and polymer compositions comprising:heating the asphalt in a stirred milk to a temperature sufficient to allow stirring of the asphalt in the tank, wherein said temperature is at least 330° F.; adding at elastomeric polymer to the tank in an amount not greater than twelve percent by weight of the total composition to form a mixture; adding a crosslinking composition to the composition; continue stirring and maintain the temperature in the tank for at least forty-five minutes, wherein the crosslinking composition comprises at least 0.02 percent by weight based on the asphalt of 2-mercaptobenzothiazole, at least 0.1 percent by weight based on the asphalt of mixed polythiomorpholine, at least 0.03 percent by weight based on the asphalt of zinc oxide, less than 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid.
- 12. The method of claim 11 wherein the crosslinking composition comprises at least 0.02 percent by weight based on the asphalt of 2-mercaptobenzothiazole, at least 0.2 percent by weight based on the asphalt of mixed polythiomorpholine, at least 0.03 percent by weight based on the asphalt of zinc oxide, less that 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid.
- 13. The method of claim 11 wherein the crosslinking composition comprises at least 0.06 percent by weight based on the asphalt of 2-mercaptobenzothiazole, at least 0.1 percent by weight based on the asphalt of mixed polythiomorpholine, at least 0.03 percent by weight based on the asphalt of zinc oxide, less than 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid.
- 14. The method of claim 11 wherein the crosslinking composition comprises at least 0.02 percent by weight based on to asphalt of 2-mercaptobenzothiazole, at least 0.1 percent by weight based on the asphalt of mixed polythiomorpholine, at least 0.06 percent by weight based on the asphalt of zinc oxide, less than 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid.
- 15. The method of claim 11 wherein the elastomeric polymer is a styrene-butadiene polymer.
- 16. The method of claim 11 wherein the ratio of 2-mercaptobenzothiazole to zinc oxide to mixed polythiomorpholine is 0.3/0.3/1.0.
- 17. The method of claim 11 wherein the elastomeric polymer does not exceed 10 percent by weight of the total composition.
- 18. The method of claim 11 wherein to asphalt is heated to a temperature not greater than 380° F. prior to the addition of the crosslinking composition.
- 19. The method of claim 11 wherein the crosslinking composition comprises at least 0.2 percent by weight based on the asphalt of 2-mercaptobenzothiazole, at least 0.1 percent by weight based on the asphalt of mixed polythiomorpholine, at least 0.03 percent by weight based on the asphalt of zinc oxide, less than 0.01 percent by weight based on the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of atomic acid and with the proviso that 2-mercaptobenzothiazole is present in amounts from 2 percent to 5 percent by weight of elastomeric polymer.
- 20. The asphalt composition made in accordance with claim 11 wherein the asphalt properties comply with Federal standards for grade AC-20.
- 21. A method for preparing asphalt and polymer compositions comprising:besting the asphalt in a stirred tank to a temperature sufficient to allow stirring of the asphalt in the tank, wherein said temperature is at least 330° F.; adding an elastomeric polymer to the tank in an amount not greater than ten percent by weight of the total composition to form a mixture; adding a crosslinking composition tote composition; continue stirring and maintain the temperature in the tank for at least forty-five minutes; wherein the asphalt is heated to a temperature not greater than 380° F. prior to the addition of the crosslinking composition; wherein the elastomeric polymer is a styrene-butadiene polymer; wherein the crosslinking composition comprises at least 0.08 percent by weight based on the asphalt of 2-mercaptobenzothiazole, from 0.08 to 0.3 percent by weight based on the asphalt of elemental sulfur, at least 0.04 percent by weight based onto asphalt of zinc oxide, less than 0.01 percent by weight based an the asphalt of tetramethylthiuram disulfide, and less than 0.02 percent by weight based on the asphalt of stearic acid; wherein the ratio of 2-mercaptobenzothiazole to zinc oxide to elemental sulfur is 2.0/1.0/2.0 and; with the proviso that 2-mercaptobenzothiazole is present in amounts from 2 percent to 5 percent by weight of elastomeric polymer.
- 22. A method for preparing asphalt and polymer compositions comprising:heating the asphalt in a stirred tank to a temperature sufficient to allow stirring of the asphalt in the tank, wherein said temperature is at least 330° F.; adding an elastomeric polymer to the tank in an amount not greater an twelve percent by weight of the total composition to form a mixture; adding a crosslinking composition to the composition; continue stirring and maintain the temperature in the tank for at least forty-live minutes; wherein the crosslinking composition cousins essentially of at least 0.05 percent by weight based on the asphalt of zinc 2-mercaptobenzothiazole, and at least 0.2 percent by weight based on the asphalt of dithiodimorpholine.
- 23. The method of claim 22 wherein the ratio of zinc 2-mercaptobenzothiazole to dithiodimorpholine is 1.0/4.0.
- 24. The asphalt composition made in accordance with claim 22 wherein the asphalt properties comply with Federal standards for grade AC-20.
CROSS REFERENCE TO OTHER PATENT APPLICATIONS
This application is a continuation-in-part of a prior U.S. application, Ser. No. 09/712,670 filed Nov. 14, 2000, now abandoned, that is turn a continuation-in-part of Ser. No. 09/389,785 U.S. Pat. No. 6,180,697 filed Sep. 4, 1999.
This application claims priority under 35 U.S.C. 120 of parent application Ser. No. 09/712,670 and U.S. Pat. No. 6,180,697, the contents of which are incorporated herein as if set forth in full.
US Referenced Citations (32)
Non-Patent Literature Citations (1)
Entry |
Superpave Performance Graded Asphalt Binder Specification and Testing, 1997 Printing, pp. 43-65. |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
09/712670 |
Nov 2000 |
US |
Child |
10/140317 |
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US |
Parent |
09/389785 |
Sep 1999 |
US |
Child |
09/712670 |
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US |