| 摘要 |
The present invention provides a rubber composition for a tire tread having excellent wet performance and low rolling resistance when formed into a tire as well as excellent processability. The present invention is a rubber composition for a tire tread containing a diene rubber component containing at least 20 mass% of a modified conjugated diene rubber, a silica, and a silane coupling agent; the modified conjugated diene rubber having at least one modified part and at least one conjugated diene rubber part; the conjugated diene rubber part having a conjugated diene copolymer block and an isoprene block containing from 70 mass% to 100 mass% of isoprene units in each conjugated diene rubber part; the modified part bonding to an end of the conjugated diene rubber part; the modified part having a functional group which interacts with the silica; the silane coupling agent being a polysiloxane represented by the following formula (1); a content of the silica being from 60 to 200 parts by mass per 100 parts by mass of the diene rubber component; and a content of the silcane coupling agent being from 1.0 to 20 mass% of the content of the silica; and a pneumatic tire having tire treads formed using the rubber composition.
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ(A) a (B) b (C) c (D) d (R 1 ) e SiO (4-2a-b-c-d-e)/2 €ƒ€ƒ€ƒ€ƒ€ƒ(1)
[Formula (1) is an average composition formula, and in formula (1), A is a divalent organic group containing a sulfide group; B is a monovalent hydrocarbon group having from 5 to 10 carbon atoms; C is a hydrolyzable group; D is an organic group containing a mercapto group; R 1 is a monovalent hydrocarbon group having from 1 to 4 carbon atoms; and a to e satisfy the relational expressions 0‰¤a<1, 0‰¤b<1, 0<c<3, 0<d <1, 0‰¤ e<2, and 0<2a+b+c+d+e<4. However, either a or b is not 0.] |
