Rubber composition for tires and tire
A rubber composition for tires according to an embodiment includes, per 100 parts by mass of a rubber component, 0.1 to 20 parts by mass of a terpene-based resin containing an α-pinene unit and a β-pinene unit, and 1 to 30 parts by mass of vegetable granules having an average particle size of 0.1 to 500 μm.
1 . A rubber composition for tires, comprising, per 100 parts by mass of a rubber component, 0.1 to 20 parts by mass of a terpene-based resin comprising an α-pinene unit and a β-pinene unit, and 1 to 30 parts by mass of vegetable granules having an average particle size of 0.1 to 500 μm, wherein
the α-pinene unit content in the terpene-based resin is 4 to 10 mass %, and the β-pinene unit content in the terpene-based resin is 90 to 96 mass %.
2 . The rubber composition for tires according to claim 1 , further comprising 0.1 to 20 parts by mass of a rosin-based resin and/or a petroleum resin.
3 . The rubber composition for tires according to claim 1 , wherein the content of the terpene-based resin is 1 to 5 parts by mass per 100 parts by mass of the rubber component,
the average particle size of the vegetable granules is 100 to 400 μm, and
the vegetable granules include surface-treated vegetable granules that have been subjected to a surface treatment with a resin liquid of a rubber adhesion improver and non-treated vegetable granules that have not been subjected to the surface treatment.
4 . The rubber composition for tires according to claim 2 , wherein the content of the terpene-based resin is 1 to 5 parts by mass per 100 parts by mass of the rubber component,
the average particle size of the vegetable granules is 100 to 400 μm, and
the vegetable granules include surface-treated vegetable granules that have been subjected to a surface treatment with a resin liquid of a rubber adhesion improver and non-treated vegetable granules that have not been subjected to the surface treatment.
5 . The rubber composition for tires according to claim 1 , wherein 100 parts by mass of the rubber component further includes 40 to 90 parts by mass of a natural rubber and 10 to 60 parts by mass of a butadiene rubber.
6 . The rubber composition for tires according to claim 1 , wherein the terpene-based resin has a softening point of 60 to 150° C.
7 . The rubber composition for tires according to claim 1 , wherein the terpene-based resin has a glass transition temperature of 38 to 81° C.
8 . A tire made from the rubber composition for tires according to claim 1 .
9 . A tire made from the rubber composition for tires according to claim 2 .
10 . A tire made from the rubber composition for tires according to claim 3 .
11 . A tire made from the rubber composition for tires according to claim 4 .
12 . A tire made from the rubber composition for tires according to claim 5 .
13 . A tire made from the rubber composition for tires according to claim 6 .
14 . A tire made from the rubber composition for tires according to claim 7 .
15 . The tire according to claim 8 , being a heavy-duty tire.
16 . The rubber composition for tires according to claim 3 , wherein the content of the vegetable granules is 3 to 10 parts by mass per 100 parts by mass of the rubber component.
17 . A tire made from the rubber composition for tires according to claim 16 .