Claims
- 1. An asymmetrical tin-coupled rubbery polymer which is particularly valuable for use in manufacturing tire tread compounds, said asymmetrical tin-coupled rubbery polymer being comprised of a tin atom having at least three polydiene arms covalently bonded thereto, wherein-said polydiene arms have a weight average molecular weight which is within the range of about 80,000 to about 300,000, wherein the polydiene arms do not contain blocks of more than about 4 repeat units of vinyl aromatic monomers, and wherein the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical tin-coupled rubbery polymer is within the range of about 1.4 to about 2.0.
- 2. An asymmetrical tin-coupled rubbery polymer as specified in claim 1 wherein the polydiene arms are comprised of a member selected from the group consisting of random styrene-polyisoprene chains, random styrene-butadiene chains, random α-methylstyrene-butadiene chains, random α-methylstyrene-isoprene chains, random styrene-isoprene-butadiene chains, random α-methylstyrene-isoprene-butadiene chains and random α-methylstyrene-styrene-isoprene-butadiene chains.
- 3. An asymmetrical tin-coupled rubbery polymer as specified in claim 2 wherein 4 polydiene arms are covalently bonded to the tin atom.
- 4. An asymmetrical tin-coupled rubbery polymer as specified in claim 3 wherein the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical tin-coupled rubbery polymer is within the range of about 1.45 to about 1.8.
- 5. An asymmetrical tin-coupled rubbery polymer as specified in claim 4 wherein said polydiene arms have a weight average molecular weight which is within the range of about 120,000 to about 250,000.
- 6. An asymmetrical tin-coupled rubbery polymer as specified in claim 5 wherein the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical tin-coupled rubbery polymer is within the range of about 1.5 to about 1.7.
- 7. An asymmetrical tin-coupled rubbery polymer as specified in claim 6 wherein at least one of the polydiene arms covalently bonded to the tin atom has a weight average molecular weight of less than about 150,000.
- 8. An asymmetrical tin-coupled rubbery polymer as specified in claim 7 wherein at least one of the polydiene arms covalently bonded to the tin atom has a weight average molecular weight of greater than about 200,000.
- 9. An asymmetrical tin-coupled rubbery polymer as specified in claim 8 wherein said polydiene arms are random styrene-isoprene-butadiene chains.
- 10. An asymmetrical tin-coupled rubbery polymer as specified in claim 8 wherein said polydiene arms are random styrene-isoprene chains.
- 11. An asymmetrical tin-coupled rubbery polymer as specified in claim 8 wherein said polydiene arms are random styrene-butadiene chains.
Parent Case Info
This application claims priority from Provisional application Ser. No. 60/236,524, filed Sep. 29, 2000.
US Referenced Citations (15)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0314256 |
May 1989 |
EP |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/236524 |
Sep 2000 |
US |