Claims
- 1. In a pneumatic tire carcass or tread-grade rubber compound consisting essentially of a homogenous admixture of (a) an elastomer selected from the group consisting of a styrene-butadiene copolymer, polybutadiene, polyisoprene, an ethylene propylene terpolymer, natural rubber and mixtures thereof; (b) a reinforcing amount of carbon black; (c) an aromatic extender oil in the amount of about 21-42 parts by weight per 100 parts of said elastomer; (d) zinc oxide; (3) stearic acid; (f) sulfur in an amount of not in excess of about 3 parts by weight per 100 parts of said elastomer; and (g) effective amounts of a cure accelerator and an oxidation stabilizer; the improvement of including within the compound as a total or partial replacement of said extender oil component an unoxidized thermal petroleum pitch having a softening point between about 100.degree. and 240.degree. F.
- 2. The improvement in accordance with claim 1 wherein said pitch has a softening point between about 170.degree. and 240.degree. F.
- 3. The improvement in accordance with claim 2 wherein said pitch has a softening point of about 170.degree. F.
- 4. The improvement in accordance with claim 2 wherein said pitch has a softening point of about 240.degree. F.
- 5. The heat-cured product of the compound in accordance with the improvement of claim 1.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 828,301 filed Aug. 29, 1977 now abandoned, the latter being a continuation of application Ser. No. 509,172 filed Sept. 25, 1974, now abandoned, which in turn is a continuation of application Ser. No. 342,831 filed Mar. 19, 1973, now adandoned.
US Referenced Citations (5)
Non-Patent Literature Citations (2)
Entry |
Chem. Abst. 66:8640x, 1967. |
Chem. Abst. 82:141,328t, 1975. |
Continuation in Parts (3)
|
Number |
Date |
Country |
Parent |
828301 |
Aug 1977 |
|
Parent |
509172 |
Sep 1974 |
|
Parent |
342831 |
Mar 1973 |
|