Rubber blend, sulfur-crosslinkable rubber mixture, and vehicle tire
The invention relates to a rubber blend, to a sulfur-crosslinkable rubber mixture comprising the rubber blend and to a vehicle tire comprising such a rubber mixture. The rubber blend comprises at least one solution-polymerized diene polymer A of high molecular weight and at least one solution-polymerized polymer B of low molecular weight, wherein at least one of polymers A and B has been functionalized at the chain end and/or along the polymer chain and/or at a coupling site with at least one group selected from epoxy groups, hydroxyl groups, carboxyl groups, silane sulfide groups, amino groups, siloxane groups, organosilicon groups, phthalocyanine groups and amino group-containing alkoxysilyl groups and wherein the rubber blend includes 35 to 100 phr (based on the at least one solution-polymerized diene polymer A of high molecular weight), preferably 35 to 70 phr, of the at least one solution-polymerized polymer B of low molecular weight.
1. A rubber blend comprising:
a solution-polymerized diene polymer A of high molecular weight, formed from at least one conjugated diene and one or more optional vinylaromatic compound(s), wherein the one or more optional vinylaromatic compound(s) have a content of vinylaromatic compound of 0% to 50% by weight, a vinyl content of 8% to 80% by weight based on any diene content present, and wherein the one or more optional vinylaromatic compound(s), has a glass transition temperature Tg according to DSC of −100° C.<Tg<+20° C., a molecular weight Mw according to GPC of at least 438020 g/mol and a polydispersity PD of 1.1<PD<3; and
a solution-polymerized polymer B of low molecular weight, formed from at least one conjugated diene, at least one conjugated diene and one or more vinylaromatic compound(s), or at least one or more vinylaromatic compound(s), wherein the one or more vinylaromatic compound(s) has a content of vinylaromatic compound of 0% to 100% by weight, a vinyl content of 8% to 80% by weight based on any diene content present, and wherein the one or more vinylaromatic compound(s) has a glass transition temperature Tg according to DSC of −100° C.<Tg<+80° C., a molecular weight Mw according to GPC of 1300 g/mol <Mw<10 000 g/mol and a polydispersity PD of 1<PD<1.5;
wherein at least one of polymers A and B has been functionalized at the chain end and/or along the polymer chain and/or at a coupling site with at least one group selected from epoxy groups, hydroxyl groups, carboxyl groups, silane sulfide groups, amino groups, siloxane groups, organosilicon groups, phthalocyanine groups and amino group-containing alkoxysilyl groups;
wherein the rubber blend includes 35 to 100 phr of the at least one solution-polymerized polymer B of low molecular weight, based on the at least one solution-polymerized diene polymer A of high molecular weight; and,
wherein polymers comprised in the rubber blend consist of the solution-polymerized diene polymer A, the solution-polymerized diene polymer B, and a diene rubber selected from the group consisting of synthetic polyisoprene (IR), natural polyisoprene (NR), polybutadiene (BR), and mixtures thereof.
2. The rubber blend as claimed in claim 1 , wherein at least the solution-polymerized polymer B of low molecular weight has been functionalized.
3. The rubber blend as claimed in claim 2 , wherein the solution-polymerized diene polymer A of high molecular weight has been functionalized.
4. The rubber blend as claimed in claim 1 , wherein at least one of polymer A and polymer B has been functionalized at the chain end with an amino group-containing alkoxysilyl group and at least one further amino group and/or at least one further alkoxysilyl group and/or at least one further amino group-containing alkoxysilyl group.
5. The rubber blend as claimed in claim 1 , wherein at least one of the polymers A and B has been functionalized at the chain end and/or along the polymer chain and/or at a coupling site with a silane sulfide group.
6. The rubber blend as claimed in claim 1 , wherein at least one of the polymers A and B has been functionalized at the chain end and/or along the polymer chain and/or at a coupling site with a siloxane group.
7. The rubber blend as claimed in claim 1 , wherein at least one of the polymers A and B has coupling sites.
8. The rubber blend as claimed in claim 1 having a Mooney viscosity (ML1+4, 100° C. according to ASTM-D 1646) of 40 to 100 Mooney units.
9. A sulfur-crosslinkable rubber mixture comprising the rubber blend as claimed in claim 1 and 30 to 300 phr of silica.
10. The rubber blend as claimed in claim 9 , wherein the proportion of the diene polymer A of the rubber blend in the rubber mixture is at least 50 phr based on the total amount of solid rubbers present in the rubber mixture.
11. The rubber blend as claimed in claim 9 , comprising 0.1 to 20 phr of carbon black.
12. A vehicle tire in which at least one component includes the sulfur-crosslinkable rubber mixture as claimed in claim 9 .
13. The vehicle tire as claimed in claim 12 , wherein at least the part of a tread that comes into contact with a driving surface comprises the sulfur-crosslinked rubber mixture.