Tire incorporating a rubber composition including a specific hydrocarbon resin
Described herein are tires comprising a rubber composition based on at least an elastomer matrix comprising from 50 to 100 phr of one or more copolymers of butadiene and of vinylaromatic monomer, having a content of vinylaromatic units of between 0 and 5% by weight and a Tg within a range extending from −110° C. to −70° C.; and a hydrocarbon resin, wherein the hydrocarbon resin is based on a cyclic monomer selected from the group consisting of a distillation cut from a petroleum refinery stream, and/or C 4 , C 5 or C 6 cyclic olefins and mixtures thereof, and wherein the hydrocarbon resin has a content of aromatic protons (H Ar, expressed in mol %), a glass transition temperature (Tg, expressed in ° C.), and a number average molecular weight (Mn, expressed in g/mol) that are represented by (1) H Ar>6 mol %, (2) Tg≥95−2.2*(H Ar), and (3) Tg≥−53+(0.265*Mn).
1 . A tire comprising a rubber composition based on at least:
an elastomer matrix comprising from 50 to 100 phr of one or more copolymers of butadiene and of vinylaromatic monomer, having a content of vinylaromatic units of between 0 and 5% by weight and a Tg within a range extending from −110° C. to −70° C.; and
a hydrocarbon resin,
wherein the hydrocarbon resin is based on a cyclic monomer selected from the group consisting of a distillation cut from a petroleum refinery stream, C 4 , C 5 or C 6 cyclic olefins and mixtures thereof,
wherein the hydrocarbon resin has a content of aromatic protons (H Ar, expressed in mol %), a glass transition temperature (Tg, expressed in ° C.), and a number average molecular weight (Mn, expressed in g/mol) that are represented by:
HAr>6 mol %, (1)
Tg≥95−2.2*(HAr), (2)
and
Tg≥−53+(0.265*Mn), (3)
wherein a content of the hydrocarbon resin is within a range extending from 65 to 110 phr.
2 . The tire according to claim 1 , wherein the hydrocarbon resin comprises methylcyclopentadiene in an amount between 0.1 wt. % and 15 wt. %.
3 . The tire according to claim 1 , wherein the hydrocarbon resin has at least one of the following additional features:
a MMAP cloud point of between 10° C. and 60° C.;
a number average molecular weight (Mn) of between 150 and 800 g/mol;
a glass transition temperature (Tg) represented by Tg≥100−2.2*(H Ar);
a glass transition temperature (Tg) represented by Tg≥−32+(0.265*Mn); and
an aromatic proton content (H Ar) of greater than 6 mol % and less than 25 mol %.
4 . The tire according to claim 1 , wherein a content of the hydrocarbon resin is within a range extending from 15 to 150 phr.
5 . The tire according to claim 1 , wherein each copolymer of butadiene and of vinylaromatic monomer has a Tg within a range extending from −110° C. to −80° C.
6 . The tire according to claim 1 , wherein each copolymer of butadiene and of vinylaromatic monomer has a content of vinylaromatic units of 1 to 4% by weight relative to the total weight of the copolymer, and also a content of vinylaromatic units, relative to the diene portion, ranging from 8 to 15% by weight.
7 . The tire according to claim 1 , wherein the rubber composition further comprises a reinforcing filler.
8 . The tire according to claim 1 , wherein the hydrocarbon resin comprises the cyclic monomer in an amount between 10 wt. % and 90 wt. %.
9 . The tire according to claim 8 , wherein the cyclic monomer is selected from the group consisting of cyclopentene, cyclopentadiene, dicyclopentadiene, cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, methylcyclopentadiene, di(methylcyclopentadiene) and mixtures thereof.
10 . The tire according to claim 1 , wherein at least 70% by weight of the one or more copolymers of butadiene and of vinylaromatic monomer is functionalized.
11 . The tire according to claim 10 , wherein each copolymer of butadiene and of vinylaromatic monomer comprises more than 0 and up to 30% by weight, relative to a total weight of the copolymer of butadiene and of vinylaromatic monomer, of a star-branched copolymer of butadiene and of vinylaromatic monomer.
12 . The tire according to claim 1 , wherein the hydrocarbon resin is further based on an aromatic monomer.
13 . The tire according to claim 12 , wherein the aromatic monomer is selected from the group consisting of olefin-aromatic compounds, aromatic distillation cuts and mixtures thereof.
14 . The tire according to claim 13 , wherein the aromatic monomer is an aromatic distillation cut or an olefin-aromatic compound selected from the group consisting of indene derivatives, vinylaromatic compounds and mixtures thereof.
15 . The tire according to claim 14 , wherein the aromatic monomer comprises an indene derivative of Formula (I)
wherein R 1 and R 2 represent, independently of one another, a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group or an arylalkyl group,
or a vinylaromatic compound of Formula (II)
wherein R 3 and R 4 represent, independently of one another, a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group or an arylalkyl group.