Rubber mixture and vehicle tires
Disclosed are sulfur-crosslinkable rubber mixtures that can be incorporated into treads of vehicle tires, and vehicle tires comprising the disclosed sulfur-crosslinkable rubber mixtures. The rubber mixtures comprise: at least one diene rubber, at least one silica, at least one hydrocarbon resin, and 1 to 40 phr of at least one liquid polybutadiene having terminal organosilicon modification and having a weight-average molecular weight Mw by GPC of 500 to 12 000 g/mol.
1. A sulfur-crosslinkable rubber mixture comprising:
at least one diene rubber,
at least one silica,
at least one hydrocarbon resin, and
1 to 40 phr of at least one liquid polybutadiene having terminal organosilicon modification and having a weight-average molecular weight Mw by GPC of 500 to 12 000 g/mol.
2. The rubber mixture according to claim 1 , wherein the at least one liquid polybutadiene is modified with at least one radical of formula I):
(R 1 R 2 R 3 )Si— I)
wherein:
R 1 , R 2 , R 3 are the same or different and are selected from: linear or branched alkoxy, cycloalkoxy, alkyl, cycloalkyl, or aryl groups having 1 to 20 carbon atoms, the radical of formula I) is attached to the polymer chain of the at least one liquid polybutadiene directly or via a bridge, and
the bridge consists of a saturated or unsaturated carbon chain that optionally comprises cyclic aliphatic or aromatic elements and heteroatoms in or on the carbon chain.
3. The rubber mixture according to claim 2 , wherein the radical of formula I) is attached not directly but via a bridge of formula II):
(R 1 R 2 R 3 )Si—Y—X— II)
wherein:
Y is an alkyl chain (—CH 2 ) n — with n=1 to 8, and
X is a functional group selected from the group consisting of: ester, ether, urethane, urea, amine, amide, thioether, and thioester.
4. The rubber mixture according to claim 3 , wherein the organosilicon-modified at least one liquid polybutadiene has a structure of formula III):
5. The rubber mixture according to claim 1 , wherein the at least one liquid polybutadiene with terminal organosilicon modification has a glass transition temperature T g by DSC of −85 to −30° C.
6. The rubber mixture according to claim 1 , wherein the at least one liquid polybutadiene having terminal organosilicon modification is present in the mixture in an amount of 2 to 17 phr.
7. The rubber mixture according to claim 1 , wherein the hydrocarbon resin has a softening point to ASTM E 28 of 60 to 99° C.
8. The rubber mixture according to claim 1 , wherein the hydrocarbon resin has a molecular weight Mw of 500 to 4000 g/mol and a Z-average molecular weight Mz of 2500 to 10 000 g/mol.
9. The rubber mixture according to claim 1 , wherein the hydrocarbon resin is an aliphatic C 5 resin and/or a hydrocarbon resin formed from alpha-methylstyrene and styrene.
10. A vehicle tire comprising at least one component comprising the sulfur-vulcanized rubber mixture according to claim 1 .
11. The vehicle tire according to claim 10 , where the at least one component is a tire tread.