Claims
- 1. A styrene-isoprene-butadiene rubber which is particularly valuable for use in making tire treads, said rubber being comprised of repeat units which are derived from about 5 weight percent to about 40 weight percent styrene, from about 1 weight percent to about 10 weight percent isoprene, and from about 50 weight percent to about 94 weight percent 1,3-butadiene, wherein the repeat units derived from styrene, isoprene, and 1,3-butadiene are in essentially random order, wherein the rubber has a glass transition temperature which is within the range of about -18.degree. C. to about -48.degree. C., and wherein over 90% of the repeat units in the SIBR which are derived from styrene are in blocks of containing less than three repeat units, wherein the rubber is coupled with a member selected from the group consisting of tin tetrachloride and silicon tetrachloride, wherein the rubber has a Mooney viscosity which is within the range of about 70 to about 120, and wherein the rubber has a number average molecular weight which is within the range of about 250,000 to about 300,000.
- 2. A styrene-isoprene-butadiene rubber as specified in claim 1 which is particularly valuable for use in making tire treads, wherein the rubber has a weight average molecular weight of about 400,000 to about 800,000, and wherein the rubber has an inhomogeneity which is within the range of about 0.5 to about 1.5.
- 3. A styrene-isoprene-butadiene rubber as specified in claim 2 wherein the repeat units in the rubber are derived from about 20 weight percent to about 35 weight percent styrene, from about 2 weight percent to about 6 weight percent isoprene, and from about 59 weight percent to about 78 weight percent 1,3-butadiene.
- 4. A styrene-isoprene-butadiene rubber as specified in claim 3 wherein at least 90% of the repeat units in the rubber which are derived from styrene are in blocks of two or less repeat units.
- 5. A styrene-isoprene-butadiene rubber as specified in claim 4 wherein said rubber has an inhomogeneity which is within the range of about 0.8 to about 1.2.
- 6. A styrene-isoprene-butadiene rubber as specified in claim 5 wherein the repeat units in said rubber are derived from about 25 weight percent to about 30 weight percent styrene, from about 3 weight percent to about 5 weight percent isoprene and from about 65 weight percent to about 72 weight percent 1,3-butadiene.
- 7. A styrene-isoprene-butadiene rubber as specified in claim 6 wherein said rubber has a glass transition temperature which is within the range of about -25.degree. C. to about -40.degree. C.
- 8. A styrene-isoprene-butadiene rubber as specified in claim 1 wherein said rubber has a Mooney viscosity which is within the range of about 80 to about 115.
- 9. A styrene-isoprene-butadiene rubber as specified in claim 1 wherein said rubber has a Mooney viscosity which is within the range of 90 to 110.
- 10. A styrene-isoprene-butadiene rubber as specified in claim 1 wherein said rubber has a glass transition temperature which is within the range of about -30.degree. C. to about -35.degree. C.
- 11. A styrene-isoprene-butadiene rubber as specified in claim 1 wherein over 95 percent of the repeat units which are derived from styrene are in blocks containing less than 4 repeat units.
- 12. A styrene-isoprene-butadiene rubber as specified in claim 7 wherein over 97 percent of the repeat units which are derived from styrene are in blocks containing less than 5 repeat units.
Parent Case Info
This is a Divisional of application Ser. No. 08/288,858, filed on Aug. 11, 1994, now U.S. Pat. No. 5,422,403.
US Referenced Citations (7)
Divisions (1)
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Number |
Date |
Country |
Parent |
288858 |
Aug 1994 |
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