Rubber composition for use in tires
View Patent ↗A rubber composition for use in tires is described which provides increased fuel efficiency and improved wet grip performance. The rubber composition includes from 5 to 70 parts by mass of silica having a BET specific surface area from 50 to 200 m 2 /g per 100 parts by mass of a diene rubber. The rubber composition includes from 1 to 25 parts by mass of an aromatic modified terpene resin and at least one terpene per 100 parts by mass of a diene rubber. The rubber composition further includes from 1 to 70 parts by mass of a naphthenic oil per 100 parts by mass of a diene rubber, where a CN % proportion of a CA %·CP %·CN % ratio calculated according to ASTM D2140/ASTM D3238 is the greatest and the CA % proportion is less than 15%, and a dynamic viscosity at 40° C. is from 17 to 30 mm 2 /sec.
1. A rubber composition for use in tires, comprising a diene rubber and:
from 5 to 70 parts by mass of silica having a BET specific surface area from 50 to 200 m 2 /g;
from 1 to 25 parts by mass of an aromatic modified terpene resin obtained by polymerizing an aromatic compound and at least one terpene selected from the group consisting of α-pinene, β-pinene, dipentene, and limonene; and
from 1.5 to 70 parts by mass of a naphthenic oil where a CN % proportion of a CA %·CP %·CN % ratio calculated according to ASTM D2140/ASTM D3238 is the greatest and the CA % proportion is less than 15%; and a dynamic viscosity at 40° C. is from 17 to 30 mm 2 /sec;
per 100 parts by mass of the diene rubber.
2. The rubber composition according to claim 1 , wherein the aromatic compound used in the modification of the aromatic modified terpene resin is indene.
3. The rubber composition according to claim 1 , wherein the aromatic modified terpene resin comprises from 2 to 25 parts by mass per 100 parts by mass of the diene rubber.
4. The rubber composition according to claim 1 , wherein the aromatic compound comprises from 10 to 50 mass % per 100 parts by mass of the diene rubber.
5. The rubber composition according to claim 1 , wherein the silica comprises from 10 to 70 parts by mass per 100 parts by mass of the diene rubber.
6. The rubber composition according to claim 1 , wherein the BET specific surface area comprises from 60 to 190 m 2 /g.
7. The rubber composition according to claim 1 , further comprising a silane coupling agent used in a proportion of from 2 to 15 weight % with respect to a weight % of the silica.
8. The rubber composition according to claim 7 , wherein the silane coupling agent comprises from 3 to 10 weight % with respect to a weight % of the silica.
9. The rubber composition according to claim 1 , wherein the diene rubber comprises multiple different rubbers where at least 50 mass % of the diene rubber is styrene-butadiene copolymer rubber.
10. The rubber composition according to claim 1 , further comprising a carbon black filler.
11. The rubber composition according to claim 10 , wherein the carbon black filler comprises 90 parts by mass or less per 100 parts by mass of the diene rubber.
12. The rubber composition according to claim 10 , wherein the carbon black filler comprises a nitrogen specific surface area of from 50 to 140 m 2 /g, measured according to Japanese Industrial Standard K6217-2.
13. A rubber composition for use in tires, comprising:
from 10 to 70 parts by mass of silica having a BET specific surface area from 60 to 190 m 2 /g;
from 2 to 25 parts by mass of an aromatic modified terpene resin obtained by polymerizing an aromatic compound and at least one terpene selected from the group consisting of α-pinene, β-pinene, dipentene, and limonene; and
from 1.5 to 70 parts by mass of a naphthenic oil where a CN % proportion of a CA %·CP %·CN % ratio calculated according to ASTM D2140/ASTM D3238 is the greatest and the CA % proportion is less than 15%; and a dynamic viscosity at 40° C. is from 17 to 30 mm 2 /sec;
per 100 parts by mass of a diene rubber.
14. A pneumatic tire comprising the rubber composition according to claim 1 in a tread portion of the pneumatic tire.