Tire comprising a tread
View Patent ↗A tire comprises a tread which comprises a plurality of tread pattern elements (1) delimited by cut-outs (3, 4), the tread pattern elements respectively comprising at least one lateral face (13, 14, 15, 16), and a first rubber composition (FC) at least partially covered on at least one of the lateral face (13, 14, 15, 16) with a layer of a second rubber composition (SC) based on an elastomer matrix comprising more than 55 phr and up to 100 phr of a first diene elastomer having a glass transition temperature of less than −25° C. and 0 to less than 45 phr of a second diene elastomer, a reinforcing filler comprising more than 100 phr of a reinforcing inorganic filler, and more than 45 phr of a plasticizing agent predominately comprising at least one hydrocarbon resin having a glass transition temperature of more than 20° C.
1. A tire comprising a tread which comprises a plurality of tread pattern elements delimited by cut-outs, the tread pattern elements respectively comprising at least one lateral face and a contact surface intended to come into contact with the ground during rolling, and the tread pattern elements respectively comprising a first rubber composition at least partially covered on at least one of the lateral face with a layer of a second rubber composition which is different from the first rubber composition,
wherein the second rubber composition consists of:
an elastomer matrix comprising 55 phr to 100 phr of a first diene elastomer being a styrene-butadiene copolymer and having a glass transition temperature of less than −60° C., and 0 to less than 45 phr of a second diene elastomer;
a reinforcing filler comprising more than 100 phr of a reinforcing inorganic filler;
a coupling agent;
more than 45 phr of a plasticizing agent consisting of at least one liquid plasticizer and at least one hydrocarbon resin having a glass transition temperature of more than 20° C;
a crosslinking system; and
at least one additive selected from the group consisting of a pigment, a protection agent, a chemical antiozonant, an antioxidant, an antifatigue agents, and a reinforcing resin.
2. The tire according to claim 1 , wherein the reinforcing inorganic filler predominantly comprises silica.
3. The tire according to claim 1 , wherein the reinforcing filler comprises 0 to less than 40 phr of carbon black.
4. The tire according to claim 1 , wherein the at least one hydrocarbon resin is selected from the group consisting of cyclopentadiene homopolymer or copolymer resins, dicyclopentadiene homopolymer or copolymer resins, terpene homopolymer or copolymer resins, C5 fraction homopolymer or copolymer resins, C9 fraction homopolymer or copolymer resins, alpha-methyl styrene homopolymer or copolymer resins, and mixtures thereof.
5. The tire according to claim 1 , wherein the at least one liquid plasticizer is selected from the group consisting of liquid diene polymers, polyolefinic oils, naphthenic oils, paraffinic oils, Distillate Aromatic Extracts (DAE) oils, Medium Extracted Solvates (MES) oils, Treated Distillate Aromatic Extracts (TDAE) oils, Residual Aromatic Extracts (RAE) oils, Treated Residual Aromatic Extracts (TRAE) oils, Safety Residual Aromatic Extracts (SRAE) oils, mineral oils, vegetable oils, ether plasticizers, ester plasticizers, phosphate plasticizers, sulphonate plasticizers and mixtures thereof.
6. The tire according to claim 1 , wherein the layer of the second rubber composition has a thickness which is more than 0.1 mm.
7. The tire according to claim 1 , wherein the layer of the second rubber composition covers on the lateral face which has an orientation which is perpendicular to the circumferential direction of the tire.
8. The tire according to claim 1 , wherein the second rubber composition extends, in a new condition of the tire, as far as an edge corner formed by a boundary between the contact surface and the lateral face of the tread pattern elements.
9. The tire according to claim 1 , wherein the styrene-butadiene copolymer exhibits a styrene unit of less than 28% by weight per 100% by weight of the styrene-butadiene copolymer.
10. The tire according to claim 1 , wherein the elastomer matrix comprises 80 to 100 phr of the first diene elastomer, and 0 to 20 phr of the second diene elastomer.
11. The tire according to claim 10 , wherein the elastomer matrix comprises 90 to 100 phr of the first diene elastomer, and 0 to 10 phr of the second diene elastomer.
12. The tire according to claim 11 , wherein the elastomer matrix comprises 100 phr of the first diene elastomer.
13. The tire according to claim 1 , wherein the reinforcing filler comprises at least 110 phr of the reinforcing inorganic filler.
14. The tire according to claim 1 , wherein the second rubber composition is based on more than 50 phr of the plasticizing agent.
15. The tire according to claim 1 , wherein the plasticizing agent comprises more than 55% by weight of the at least one hydrocarbon resin per 100% by weight of the plasticizing agent.
16. The tire according to claim 1 , wherein the plasticizing agent comprises more than 25 phr of the at least one hydrocarbon resin.