Tire comprising a composition essentially free of guanidine derivative and comprising a hydroxyalkylpiperazine
View Patent ↗A tire comprises a rubber composition based on at least one diene elastomer, a reinforcing filler predominantly comprising silica, a crosslinking system, and a hydroxyalkylpiperazine of formula (I): in which R 1 represents a linear or branched alkyl group comprising from 1 to 18 carbon atoms, R 2 represents a linear or branched alkylene group comprising from 1 to 18 carbon atoms, it being understood that R 1 and R 2 can bear one or more additional hydroxyl groups. The rubber composition is essentially devoid of guanidine derivative.
1. A tire comprising a rubber composition comprising:
at least one diene elastomer,
a reinforcing filler predominantly composed of silica,
a crosslinking system, and
a hydroxyalkylpiperazine of formula (I):
in which R 1 represents a linear or branched alkyl group comprising from 1 to 18 carbon atoms,
R 2 represents a linear or branched alkylene group comprising from 1 to 18 carbon atoms,
wherein R 1 and R 2 may bear one or more additional hydroxyl groups, and
wherein the rubber composition includes less than 0.5 phr of guanidine derivative.
2. The tire according to claim 1 , wherein the rubber composition includes less than 0.45 phr of guanidine derivative.
3. The tire according to claim 2 , wherein the rubber composition includes less than 0.4 phr of guanidine derivative.
4. The tire according to claim 3 , wherein the rubber composition is devoid of guanidine derivative.
5. The tire according to claim 1 , wherein the hydroxyalkylpiperazine is present in the rubber composition at a content of from 0.1 to 8 phr.
6. The tire according to claim 5 , wherein the content of hydroxyalkylpiperazine is from more than 0.15 phr to 7 phr.
7. The tire according to claim 6 , wherein the content of hydroxyalkylpiperazine is from 0.2 to 5 phr.
8. The tire according to claim 7 , wherein the content of hydroxyalkylpiperazine is from more than 0.25 phr to 4 phr.
9. The tire according to claim 1 , wherein R 1 and R 2 comprise from 2 to 12 carbon atoms.
10. The tire according to claim 9 , wherein R 1 and R 2 comprise from 2 to 6 carbon atoms.
11. The tire according to claim 10 , wherein R 1 and R 2 comprise from 2 to 4 carbon atoms.
12. The tire according to claim 1 , wherein R 1 and R 2 are linear carbon-based chains.
13. The tire according to claim 1 , wherein the hydroxyalkylpiperazine of formula (I) bears an additional hydroxyl group on R 1 or R 2 .
14. The tire according to claim 13 , wherein the hydroxyalkylpiperazine of formula (I) bears the additional hydroxyl group on R 1 .
15. The tire according to claim 1 , wherein the silica is present in the rubber composition at a content of from 30 to 150 phr.
16. The tire according to claim 1 , wherein the reinforcing filler comprises a minor amount of carbon black.
17. The tire according to claim 16 , wherein the carbon black is present in the rubber composition at a content of from 0.5 to 50 phr.
18. The tire according to claim 1 , wherein the diene elastomer is selected from the group consisting of: polybutadienes, synthetic polyisoprenes, natural rubber, butadiene copolymers, isoprene copolymers, and mixtures thereof.
19. The tire according to claim 1 , wherein the diene elastomer is predominantly composed of non-isoprene diene elastomer.
20. The tire according to claim 19 , wherein the diene elastomer is composed of 100 phr of non-isoprene diene elastomer.
21. The tire according to claim 19 , wherein the non-isoprene diene elastomer is selected from the group consisting of: polybutadienes, butadiene copolymers, isoprene copolymers, and mixtures thereof.
22. The tire according to claim 1 , wherein the rubber composition is additionally based on a plasticizer.
23. The tire according to claim 22 , wherein the plasticizer is selected from the group consisting of: plasticizing resins, extending oils, and mixtures thereof.
24. The tire according to claim 22 , wherein the plasticizer is present in the rubber composition at a content of from 5 to 100 phr.
25. The tire according to claim 1 , wherein the rubber composition comprises less than 0.5 phr zinc.
26. The tire according to claim 25 , wherein the rubber composition comprises less than 0.3 phr zinc.
27. The tire according to claim 26 , wherein the rubber composition is devoid of zinc.
28. The tire according to claim 27 , wherein the rubber composition is additionally based on a coupling agent.
29. The tire according to claim 28 , wherein the coupling agent is a hydroxysilane polysulphide corresponding to the general formula (III):
(HO) a R (3-a) Si—R′—S x R′—SiR (3-b) (OH) b (III),
wherein the R radicals, which are identical or different, are hydrocarbon groups;
wherein the R′ radicals, which are identical or different, are divalent connecting groups;
wherein a and b, which are identical or different, are equal to 1 or 2; and
wherein x is a number greater than or equal to 2.
30. The tire according to claim 29 , wherein the R radicals are hydrocarbon groups comprising from 1 to 15 carbon atoms.
31. The tire according to claim 29 , wherein the R′ radicals are divalent connecting groups comprising from 1 to 18 carbon atoms.
32. The tire according to claim 29 , wherein the coupling agent is a monohydroxysilane in which a and b are equal to 1.
33. The tire according to claim 29 ,
wherein the R radicals are selected from the group consisting of: C 1 -C 6 alkyls, C 5 -C 8 cycloalkyls, and a phenyl radical, and
wherein the R′ radicals are selected from the group consisting of: C 1 -C 18 alkylenes and C 6 -C 12 arylenes.
34. The tire according claim 29 , wherein the R radicals are selected from the group consisting of: C 1 -C 6 alkyls and the R′ radicals are selected from the group consisting of: C 1 -C 10 alkylenes.
35. The tire according to claim 29 , wherein the hydroxysilane is a monohydroxysilane polysulphide of formula (IV):
wherein the R radicals are C 1 -C 3 alkyls;
wherein the R′ radicals are C 1 -C 4 alkylenes; and
x is greater than or equal to 2.
36. The tire according to claim 35 , wherein the R radicals are each methyl.
37. The tire according to claim 35 , wherein the R′ radicals are selected from the group consisting of: methylene, ethylene, and propylene.
38. The tire according to claim 29 , wherein the hydroxysilane is a bis(propyldimethylsilanol) polysulphide of specific formula (IVa):
39. The tire according to claim 1 , wherein the rubber composition is a composition of a tire layer selected from the group consisting of: all or part of a tread, all or part of a tire belt, and combinations thereof.
40. The tire according to claim 39 , wherein the rubber composition comprises all or part of the tread.