Rubber composition for tires, and pneumatic tire manufactured using same

1. A rubber composition for a tire comprising: a diene rubber; and a composite silica comprising a block copolymer and silica, the block copolymer comprising a first block obtained by polymerizing a first monomer containing at least a (meth)acrylate having a hydroxyl group and a second block obtained by polymerizing at least one of a second monomer selected from the group consisting of styrene, derivatives thereof, and isoprene; the composite silica being produced in an organic solvent in the presence of the silica; and an amount of the composite silica being from 10 to 200 parts by mass per 100 parts by mass of the diene rubber, wherein an amount of the block copolymer is from 2 to 50 mass % in the composite silica.

2. The rubber composition for a tire according to claim 1 , wherein the first block covers a surface of the silica.

3. The rubber composition for a tire according to claim 1 , wherein the second block is dispersed in the diene rubber.

4. The rubber composition for a tire according to claim 1 , wherein the first block of the composite silica is adsorbed to a surface of the silica.

5. The rubber composition for a tire according to claim 1 , wherein the silica has a silanol group.

6. The rubber composition for a tire according to claim 1 , wherein a number average molecular weight of the block copolymer is from 1,000 to 1,000,000.

7. The rubber composition for a tire according to claim 1 , wherein a molecular weight distribution of the block copolymer is from 1.1 to 3.0.

8. The rubber composition for a tire according to claim 1 , wherein the composite silica is produced by polymerizing the block copolymer in the organic solvent in the presence of the silica or is produced by mixing the silica and the block copolymer in the organic solvent.

9. The rubber composition for a tire according to claim 1 , wherein the block copolymer is produced by living radical polymerization.

10. The rubber composition for a tire according to claim 1 , wherein the first monomer is polymerized in the organic solvent in the presence of the silica.

11. The rubber composition for a tire according to claim 1 , wherein the composite silica is produced by a production method comprising: a polymerization step of producing the block copolymer; and a mixing step of mixing the block copolymer produced by the polymerization step and the silica in the organic solvent.

12. A pneumatic tire comprising the rubber composition for a tire described in claim 1 .

13. The rubber composition for a tire according to claim 2 , wherein the first block of the composite silica is adsorbed to a surface of the silica.

14. The rubber composition for a tire according to claim 2 , wherein the silica has a silanol group.

15. The rubber composition for a tire according to claim 2 , wherein a number average molecular weight of the block copolymer is from 1,000 to 1,000,000.

16. The rubber composition for a tire according to claim 2 , wherein a molecular weight distribution of the block copolymer is from 1.1 to 3.0.

17. The rubber composition for a tire according to claim 2 , wherein the composite silica is produced by polymerizing the block copolymer in the organic solvent in the presence of the silica or is produced by mixing the silica and the block copolymer in the organic solvent.

18. The rubber composition for a tire according to claim 2 , wherein the block copolymer is produced by living radical polymerization.