Rubber composition and pneumatic tire using same
A rubber composition contains a diene rubber component and a reinforcing filler, the diene rubber component containing a styrene-butadiene copolymer component including at least one type of styrene-butadiene copolymer and satisfying: the bonded styrene content is from 5 to 50 wt. %; of components obtained by ozone decomposition, a content of a decomposed component V1 containing one 1,2-bonded butadiene-derived unit out of a total of 100 mol % of decomposed components containing styrene-derived unit(s) and/or the 1,2-bonded butadiene-derived unit(s) is not less than 25 mol %; of the components obtained by ozone decomposition, a content of a decomposed component S2V1 containing two of the styrene-derived units and one of the 1,2-bonded butadiene-derived unit out of a total of 100 mol % of the decomposed components containing the styrene-derived unit(s) and/or the 1,2-bonded butadiene-derived unit(s) is not less than 5 mol %; and a vinyl content of a butadiene moiety is not less than 50%.
1. A rubber composition, comprising:
a diene rubber component containing a styrene-butadiene copolymer component including at least one styrene-butadiene copolymer;
and a reinforcing filler,
wherein the styrene-butadiene copolymer component including the at least one styrene-butadiene copolymer has characteristics (1) to (4):
(1) the bonded styrene content is from 5 to 50 wt. %;
(2) of components obtained by ozone decomposition, a content of a decomposed component V1 containing one 1,2-bonded butadiene-derived unit out of a total of 100 mol % of decomposed components containing styrene-derived unit(s) and/or the 1,2-bonded butadiene-derived unit(s) is not less than 25 mol %;
(3) of the components obtained by ozone decomposition, a content of a decomposed component S2V1 containing two of the styrene-derived units and one of the 1,2-bonded butadiene-derived unit out of a total of 100 mol % of the decomposed components containing the styrene-derived unit(s) and/or the 1,2-bonded butadiene-derived unit(s) is not less than 5 mol %; and
(4) a vinyl content of a butadiene moiety is not less than 50%;
the decomposed component V1 being a composition represented by Formula (I), and the decomposed component S2V1 being a composition represented by Formula (II):
2. The rubber composition according to claim 1 , wherein the diene rubber component further includes another diene rubber component other than the styrene-butadiene copolymer component.
3. The rubber composition according to claim 1 , wherein the reinforcing filler is at least one selected from silica and carbon black.
4. A pneumatic tire using the rubber composition according to claim 1 .
5. The pneumatic tire according to claim 4 , wherein the rubber composition is used in a cap tread.
6. The rubber composition according to claim 2 , wherein the reinforcing filler is at least one selected from silica and carbon black.
7. A pneumatic tire using the rubber composition according to claim 6 .
8. The pneumatic tire according to claim 7 , wherein the rubber composition is used in a cap tread.