Sulfur-crosslinkable rubber mixture and vehicle tire
The invention relates to a sulfur-crosslinkable rubber mixture, in particular for rubber-coating reinforcements in elastomer products, especially in vehicle tires, or inner components of vehicle tires, as well as to a vehicle tire. The rubber mixture comprises a diene rubber, an adhesive system, 10 to 200 phr silica, and 2 to 20 phr of a silane of the formula [(R 1 ) 3 Si—X] m S n (R 2 ) 2-m , where residues R 1 are identical or different alkoxy groups, cyclic dialkoxy groups, cycloalkoxy groups, phenoxy groups, aryl groups, alkyl groups, alkenyl groups, aralkyl groups, or halides, and where X is a polar organic group containing urea, m represents the value 1 or 2, n is an integer between 1 and 8, and R 2 is a hydrogen atom or an acyl group comprising 1 to 20 carbon atoms.
1. A sulfur-crosslinkable rubber mixture comprising:
at least one diene rubber;
at least one bonding system;
10 to 200 phr of at least one silica; and
2 to 20 phr of at least one silane having the general empirical formula
[(R 1 ) 3 Si—X] m S n (R 2 ) 2-m I)
wherein the R 1 radicals within a molecule may be the same or different and are alkoxy groups having 1 to 10 carbon atoms or cyclic dialkoxy groups having 2 to 10 carbon atoms or cycloalkoxy groups having 4 to 10 carbon atoms or phenoxy groups or aryl groups having 6 to 20 carbon atoms or alkyl groups having 1 to 10 carbon atoms or alkenyl groups having 2 to 20 carbon atoms or aralkyl groups having 7 to 20 carbon atoms or halides,
wherein X is a polar organic urea-containing group and where m assumes the value of 1 or 2 and where n is an integer from 1 to 8 and where R 2 is a hydrogen atom or an acyl group having 1 to 20 carbon atoms,
wherein the polar organic urea-containing X group has at least one urea derivative as a polar functionality that bears an organic hydrocarbyl group on the two nitrogen atoms, and
wherein the group between the first nitrogen atom of the urea-containing group and the sulfur of the S n group is aliphatic, and the group between the second nitrogen atom of the urea-containing group and the silicon atom of the (R 1 ) 3 Si group is aliphatic or aromatic.
2. The sulfur-crosslinkable rubber mixture of claim 1 , wherein the polar organic urea-containing X group has at least one urea derivative as a polar functionality that bears an organic hydrocarbyl group on the two nitrogen atoms, where the group between the first nitrogen atom of the urea-containing group and the sulfur of the S n group is aliphatic and the group between the second nitrogen atom of the urea-containing group and the silicon atom of the (R 1 ) 3 Si group is aliphatic.
3. The sulfur-crosslinkable rubber mixture of claim 1 , wherein the polar organic urea-containing X group is a 1-ethyl-3-propylurea radical.
4. The sulfur-crosslinkable rubber mixture of claim 1 , wherein the silane is a mixture with n=1.8 to 2.3 and at least the silane of formula VI) is present in the silane mixture to an extent of more than 50% by weight:
5. The sulfur-crosslinkable rubber mixture of claim 1 , comprising 5 to 30 phr of at least one butadiene rubber and 70 to 95 phr of at least one natural and/or synthetic polyisoprene.
6. The sulfur-crosslinkable rubber mixture of claim 1 , comprising 40 to 80 phr of silica.
7. A vehicle tire, comprising the sulfur-crosslinkable rubber mixture of claim 1 in at least one component.
8. The vehicle tire of claim 7 , wherein the component is a strength member ply.
9. The vehicle tire of claim 8 , wherein the strength members are metallic strength members.
10. The vehicle tire of claim 9 , wherein the bonding system is a steel cord bonding system based on organic cobalt salts and reinforcer resins and more than 2.5 phr sulfur.
11. The vehicle tire of claim 7 , wherein the component is an inner component.