High performance tyre
AssigneePirelli Tyre S.p.A.
InventorsLuca CASTELLANI, Thomas HANEL, Davide DALL'ABACO, Enrico ALBIZZATI, Antonio PROTO, Carmine CAPACCHIONE
Life of this patent
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Abstract
A tire for wheels of vehicles, in particular motor vehicles, is described. The tire has a tread with at least one iso-styrene/trans-butadiene elastomeric copolymer with a styrene content higher than 30% by weight with respect to the total weight of copolymer and a molecular weight higher than 500,000. The tread has improved dynamic-mechanical behaviour at high temperatures, with higher dynamic modulus and hysteresis values, and at the same time better properties at break, optimum elasticity at low temperature and higher abrasion resistance.
Claims16
A tyre for vehicle wheels comprising:
- a carcass structure;
- and
- a tread band applied in radially outer position with respect to said carcass structure;
- wherein said tread band comprises a crosslinked elastomeric material obtained by crosslinking a crosslinkable elastomeric composition, and
- wherein said elastomeric composition comprises at least an iso-styrene/trans-butadiene elastomeric copolymer having a styrene content higher than 30% by weight with respect to the total weight of copolymer and molecular weight higher than 500,000.
An iso-styrene/trans-butadiene elastomeric copolymer, wherein said copolymer consists in a random sequence of butadiene in trans conformation and styrene in isotactic configuration, having a styrene content higher than 30% by weight with respect to the total weight of said copolymer and molecular weight higher than 500,000.
A copolymerization process of styrene and butadiene comprising
- preparing a solution of said styrene and butadiene in a suitable solvent, and
- adding to said solution a homogeneous catalytic system,
- wherein said homogeneous catalytic system comprises a homogeneous catalyst having the following formula (I),
- wherein
- Tr is a transition metal,
- X and X′, which are equal or different, are a halogen atom,
- R1 and R2, which are the same or different, are a H atom or a linear or branched alkyl group having from 1 to 10 carbon atoms,
- from R3 to R6, which are the same or different, are a H atom or a linear or branched alkyl group having from 1 to 10 carbon atoms, or a linear or branched arylalkyl group having from 7 to 14 carbon atoms,
- Y and Y′, which are the same or different, are an oxygen, sulphur, selenium or tellurium atom, or a NR7 or PR7 group,
- D and D′, which are the same or different, are an oxygen, sulphur, selenium or tellurium atom, or a NR7 or PR7 group,
- R7 is a H atom or a linear or branched alkyl group having from 1 to 10 carbon atoms,
- n is an integer from 1 to 10,
- wherein R4 and R6 are linked to the benzene ring in ortho position with respect to the D and D′ substituent, and are represented by a linear or branched arylalkyl group having from 7 to 14 carbon atoms, and R3 and R5 are linked to the benzene ring in para position with respect to the D and D′ substituent, and are represented by a linear or branched alkyl group having from 1 to 10 carbon atoms, and
- wherein said copolymerization process provides the formation of a iso-styrene/trans-butadiene elastomeric copolymer having a styrene content higher than 30% by weight with respect to the total weight of said copolymer and molecular weight higher than 500,000.
Dependencies are inferred from the claim text.