Preparation of industrial asphalt
View Patent ↗The present invention relates to a method for preparing an industrial asphalt comprising sparging an oxygen containing gas through an asphalt flux in the presence of 0.25 weight percent to about 12 weight percent of a highly saturated rubbery polymer at a temperature within the range of about 400° F. to about 550° F. for a period of time which is sufficient to increase the softening point of the asphalt flux to a value which is within the range of 185° F. to 250° F. and a penetration value of at least 15 dmm to produce the industrial asphalt. The highly saturated rubbery polymer can be a styrene-ethylene/butylene-styrene block copolymer rubber or a highly saturated styrene-ethylene/propylene-styrene block copolymer rubber.
1. A method for preparing an industrial asphalt comprising sparging an oxygen containing gas through an asphalt flux in the presence of 0.25 weight percent to 5 weight percent of a highly saturated rubbery polymer at a temperature within the range of about 400° F. to about 550° F. for a period of time which is sufficient to increase the softening point of the asphalt flux to a value which is within the range of 190° F. to 220° F. and a penetration value which is within the range of 15 dmm to 25 dmm to produce the industrial asphalt.
2. The method of claim 1 wherein the asphalt flux is a hard asphalt flux.
3. The method as specified in claim 1 wherein the highly saturated rubbery polymer contains repeat units of the formula: —(CH 2 —C(CH 3 ) 2 )—.
4. The method as specified in claim 1 wherein the highly saturated rubbery polymer is a styrene-ethylene/butylene-styrene rubber.
5. A method for preparing an industrial asphalt comprising sparging an oxygen containing gas through an asphalt flux in the presence of 0.25 weight percent to 5 weight percent of a highly saturated rubbery polymer at a temperature within the range of about 400° F. to about 550° F. for a period of time which is sufficient to increase the softening point of the asphalt flux to a value which is within the range of 185° F. to 250° F. and a penetration value of at least 15 dmm to 25 dmm to produce the industrial asphalt, wherein the highly saturated rubbery polymer is a styrene-ethylene/propylene-styrene rubber.
6. The method as specified in claim 1 wherein the oxygen containing gas is sparged through the asphalt flux for a period of time which is within the range of 2 hours to 8 hours.
7. The method as specified in claim 1 wherein asphalt flux is further comprised of an air blowing catalyst.
8. The industrial asphalt made by the process specified in claim 1 .
9. A method for preparing an industrial asphalt comprising (1) heating an asphalt flux to a temperature of at least 120° F. to produce a hot asphalt flux, (2) adding from about 0.1 weight percent to 5 weight percent of a highly saturated rubbery polymer to the hot asphalt flux, (3) mixing the highly saturated rubbery polymer throughout the hot asphalt flux for a period of time which is within the range of about 10 minutes to about 10 hours at a temperature which is within the range of about 200° F. to 400° F. to prepare a highly saturated rubbery polymer modified asphalt flux, (4) heating the highly saturated rubbery polymer modified asphalt flux to a temperature which is within the range of about 400° F. to about 550° F. to produce a hot highly saturated rubbery polymer modified asphalt flux, (5) sparging an oxygen containing gas through the hot highly saturated rubbery polymer modified asphalt flux for a period of time-which is within the range of 2 hours to 8 hours and at a temperature which is within the range of about 400° F. to 550° F. to increase the softening point of the highly saturated rubbery polymer modified asphalt flux to a value which is within the range of 190° F. to 220° F. and a penetration value which is within the range of 15 dmm to 25 dmm to produce the industrial asphalt.
10. The method as specified in claim 9 wherein the highly saturated rubbery polymer contains repeat units of the formula: —(CH 2 —C(CH 3 ) 2 )—.
11. The method as specified in claim 9 wherein the highly saturated rubbery polymer is a styrene-ethylene/propylene-styrene rubber.
12. The method of claim 5 wherein the asphalt flux is a hard asphalt flux.
13. The method as specified in claim 5 wherein the oxygen containing gas is sparged through the asphalt flux for a period of time which is within the range of 2 hours to 8 hours.
14. The method as specified in claim 5 wherein asphalt flux is further comprised of an air blowing catalyst.
15. The industrial asphalt made by the process specified in claim 5 .
16. The method of claim 9 wherein the asphalt flux is a hard asphalt flux.
17. The method as specified in claim 9 wherein the highly saturated rubbery polymer is a styrene-ethylene/butylene-styrene rubber.
18. The method as specified in claim 9 wherein asphalt flux is further comprised of an air blowing catalyst.