Rubber composition and pneumatic tire using same
View Patent ↗A rubber composition includes a sulfur-crosslinkable diene rubber, from 1 to 100 parts by mass of carbon black and/or from 5 to 150 parts by mass of an inorganic filler, from 0.5 to 30 parts by mass of a sulfur-containing compounding agent, and from 0.01 to 20 parts by mass of a phosphine borane compound based on 100 parts by mass of the sulfur-crosslinkable diene rubber. The rubber composition may be applied in at least one type selected from the group consisting of a capped tread, a side wall, a belt, an inner liner, a carcass, and a bead of a pneumatic tire.
1. A rubber composition comprising:
a sulfur-crosslinkable diene rubber, wherein said sulfur-crosslinkable diene rubber is a styrene-butadiene copolymer rubber;
from 3 to 90 parts by mass of carbon black and from 40 to 100 parts by mass of silica per 100 parts by mass of the sulfur-crosslinkable diene rubber;
from 0.1 to 10 parts by mass of sulfur per 100 parts by mass of the sulfur-crosslinkable diene rubber;
from 0.1 to 10 parts by mass of at least one sulfur-containing vulcanization accelerator comprising sulfenamide compounds per 100 parts by mass of the sulfur-crosslinkable diene rubber;
from 0.5 to 20 parts by mass of at least one sulfur-containing silane coupling agent per 100 parts by mass of the sulfur-crosslinkable diene rubber; and
from 0.01 to 20 parts by mass of a phosphine borane compound represented by the formula (11) below per 100 parts by mass of the sulfur-crosslinkable diene rubber,
wherein a molar ratio of the phosphine borane compound with respect to the sulfur-containing silane coupling agent is from 0.01 to 2.5:
wherein R 11 and R 12 are each independently a hydrogen atom, an optionally substituted hydrocarbon group having from 1 to 18 carbon atoms or an optionally substituted aromatic group having from 6 to 18 carbon atoms; i and j are each independently an integer from 0 to 5.
2. The rubber composition according to claim 1 , wherein said sulfur-containing vulcanization accelerator is selected from sulfenamide compounds.
3. The rubber composition according to claim 2 , wherein said sulfenamide compounds comprise N-cyclohexyl-2-benzothiazole sulfenamide and N-t-butyl-2-benzothiazole sulfenamide.
4. The rubber composition according to claim 3 , wherein said sulfur-crosslinkable diene rubber is selected from the group consisting of aromatic vinyl-conjugated diene copolymer rubbers.
5. The rubber composition according to claim 4 , wherein said sulfur-crosslinkable diene rubber is a styrene-butadiene copolymer rubber.
6. The rubber composition according to claim 3 , wherein said phosphine borane compound is triphenylphosphine triphenylborane.
7. The rubber composition according to claim 6 , wherein said sulfur-crosslinkable diene rubber is selected from the group consisting of aromatic vinyl-conjugated diene copolymer rubbers.
8. The rubber composition according to claim 7 , wherein said sulfur-crosslinkable diene rubber is a styrene-butadiene copolymer rubber.
9. The rubber composition according to claim 2 , wherein said phosphine borane compound is triphenylphosphine triphenylborane.
10. The rubber composition according to claim 9 , wherein said sulfur-crosslinkable diene rubber is selected from the group consisting of aromatic vinyl-conjugated diene copolymer rubbers.
11. The rubber composition according to claim 10 , wherein said sulfur-crosslinkable diene rubber is a styrene-butadiene copolymer rubber.
12. The rubber composition according to claim 2 , wherein said sulfur-crosslinkable diene rubber is selected from the group consisting of aromatic vinyl-conjugated diene copolymer rubbers.
13. The rubber composition according to claim 12 , wherein said sulfur-crosslinkable diene rubber is a styrene-butadiene copolymer rubber.
14. The rubber composition according to claim 1 , wherein said phosphine borane compound is triphenylphosphine triphenylborane represented by the formula:
15. The rubber composition according to claim 14 , wherein said sulfur-crosslinkable diene rubber is selected from the group consisting of aromatic vinyl-conjugated diene copolymer rubbers.
16. The rubber composition according to claim 15 , wherein said sulfur-crosslinkable diene rubber is a styrene-butadiene copolymer rubber.
17. The rubber composition according to claim 1 , wherein said sulfur-crosslinkable diene rubber is selected from the group consisting of aromatic vinyl-conjugated diene copolymer rubbers.
18. The rubber composition according to claim 17 , wherein said sulfur-crosslinkable diene rubber is a styrene-butadiene copolymer rubber.
19. A pneumatic tire comprising at least one of a capped tread, a side wall, a belt, an inner liner, a carcass, or a bead formed from the rubber composition of claim 1 .