Claims
- 1. A pneumatic tire having a tread comprised of, (A) a combination of elastomers consisting essentially of cis 1,4-polybutadiene, medium vinyl polybutadiene and high vinyl polybutadiene elastomers and, based on 100 parts by weight rubber, as (i) about 10 to about 50 phr of cis 1,4-polybutadiene rubber, (ii) about 30 to about 70 phr of medium vinyl polybutadiene rubber having a vinyl content in a range of about 30 to about 60 percent and (iii) up to about 90 phr of a high vinyl polybutadiene rubber having a vinyl content in a range of about 60 to about 95; wherein the total of said medium and high vinyl polybutadiene rubbers is in a range of about 50 to about 90 phr, (B) about 50 to about 110 phr particulate silica, (C) and at least one silica coupler having a silane moiety reactive with silicon dioxide and a sulfur moiety reactive with said elastomer, in a weight ratio of silica to coupler of about 7/1 to about 15/1.
- 2. The tire of claim 1 where said silica is characterized by having a BET surface area in a range of about 100 to about 250 and a DBP absorption value in a range of about 200 to about 400.
- 3. The tire of claim 1 where the weight ratio of silica to carbon black is at least 10/1.
- 4. The tire of claim 1 where the said coupler is a bis-3-(triethoxysilylpropyl)tetrasulfide.
- 5. The tire of claim 1 where said tread also contains about 5 to about 20 phr cis 1,4-polyisoprene natural rubber.
- 6. The tire of claim 1 wherein said tread composition contains up to 50 phr of carbon black, wherein the weight ratio of silica to carbon black is at least 2/1 and the total of silica and carbon black is in a range of about 60 to about 120 phr.
- 7. A pneumatic tire having a tread comprised of, (A) a combination of elastomers consisting essentially of cis 1,4-polybutadiene, medium vinyl polybutadiene and high vinyl polybutadiene elastomers present and, based on 100 parts by weight rubber, as (i) about 10 to about 50 phr of cis 1,4-polybutadiene rubber, (ii) up to about 90 phr of medium vinyl polybutadiene rubber having a vinyl content in a range of about 30 to about 60 percent and (iii) about 40 to about 70 phr of a high vinyl polybutadiene rubber having a vinyl content in a range of about 60 to about 95; wherein the total of said medium and high vinyl polybutadiene rubbers is in a range of about 50 to about 90 phr, (B) about 50 to about 110 phr particulate silica, and (C) at least one silica coupler having a silane moiety reactive with silicon dioxide and a sulfur moiety reactive with said elastomer, in a weight ratio of silica to coupler of about 7/1 to about 15/1.
- 8. The tire of claim 7 where the weight ratio of silica to carbon black is at least 10/1.
- 9. The tire of claim 7 where the said coupler is a bis-3-(triethoxysilylpropyl)tetrasulfide.
- 10. The tire of claim 7 where said tread also contains about 5 to about 20 phr cis 1,4-polyisoprene natural rubber.
- 11. The tire of claim 7 wherein said tread composition contains up to 50 phr of carbon black, wherein the weight ratio of silica to carbon black is at least 2/1 and the total of silica and carbon black is in a range of about 60 to about 120 phr.
Parent Case Info
This is a continuation of application Ser. No. 08/116,623, filed Sep. 7, 1993, abandoned.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
116623 |
Sep 1993 |
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