High-rigidity rubber composition
A rubber composition comprises at least one phenol/aldehyde resin based on at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aldehyde of formula (A): in which X comprises N, S or O, and R represents —H or —CHO.
1. A method for manufacturing a solid rubber composition comprising the steps of:
incorporating, in a diene elastomer, during a first step, a reinforcing filler, to make a mixture and kneading the mixture thermomechanically until a maximum temperature of between 110° C. and 190° C. is reached;
cooling the mixture to a temperature of less than 100° C.;
then incorporating, during a second step, a crosslinking system, at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aldehyde of formula (A)
in which X comprises N, S or O, and R represents CHO; and
kneading the mixture up to a maximum temperature of less than 110° C.,
wherein the rubber composition comprises from 30 to 90 phr total reinforcing filler.
2. The method according to claim 1 , wherein the at least one aromatic ring bears three hydroxyl functions in the meta position relative to one another.
3. The method according to claim 1 , wherein the two positions ortho to each hydroxyl function are unsubstituted.
4. The method according to claim 1 , wherein the remainder of the at least one aromatic ring is unsubstituted.
5. The method according to claim 1 , wherein the at least one aromatic polyphenol comprises several aromatic rings, at least two of these each bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions of at least one aromatic ring being unsubstituted.
6. The method according to claim 1 , wherein at least one of the aromatic rings of the at least one aromatic polyphenol bears three hydroxyl functions in the meta position relative to one another.
7. The method according to claim 1 , wherein the two positions ortho to each hydroxyl function of at least one aromatic ring are unsubstituted.
8. The method according to claim 1 , wherein the two positions ortho to each hydroxyl function of each aromatic ring are unsubstituted.
9. The method according to claim 1 , wherein the at least one, or each, aromatic ring of the at least one aromatic polyphenol is a benzene ring.
10. The method according to claim 1 , wherein the at least one aromatic polyphenol is selected from the group consisting of resorcinol, phloroglucinol, 2,2′,4,4′-tetrahydroxydiphenyl sulphide, 2,2′,4,4′-tetrahydroxybenzophenone, resins pre-condensed from at least one of these phenols, and mixtures thereof.
11. The method according to claim 1 , wherein the at least one aldehyde is of general formula (A′)
12. The method according to claim 1 , wherein X represents NH, S or O.
13. The method according to claim 1 , wherein the at least one aldehyde is 2,5-furandicarboxaldehyde.
14. The method 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.