Star-shaped polymers for improved tire treads
AssigneeGenCorp Inc.
InventorsFrancis J. Vitus, Ivan G. Hargis, Russell A. Livigni, Sundar L. Aggarwal
Life of this patent
Estimating the term…
Abstract
A tire having a tread exhibiting substantial low rolling resistance, traction and wear comprises a cured compounded carbon black reinforced blend of (A) a star-shaped substantially random vinyl containing rubbery solution polymerized polymer selected from the group consisting of polybutadienes, polyisoprenes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isoprene-styrene copolymers, butadiene-isoprene-styrene copolymers and mixtures of the same and (B) at least one other rubbery diene polymer.
Claims6
A tire having a tread of a compounded carbon black reinforced and vulcanized composition of a blend of (A) from about 40 to 60% by weight of a solution polymerized rubbery substantially random star-shaped polymer and (B) from 60 to 40% by weight of at least one rubbery polymer selected from the group consisting of natural rubber, synthetic cis-1,4-polyisoprene rubber, cis-1,4-polybutadiene rubber, high trans-1,4-polybutadiene rubber and high trans-1,4-butadiene-styrene rubbery copolymer,
- (A) being at least one polymer selected from the group consisting of polybutadienes, polyisoprenes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isoprene-styrene copolymers, butadiene-isoprene-styrene copolymers and mixtures of the same, said styrene containing copolymers containing up to about 30 weight % of styrene, preferably from about 10 to 25 weight % of styrene,
- having a vinyl content for the diene segments of from about 12 to 60 weight %,
- having an average of from about 4 to 9 arms,
- having a Mn of from about 100,000 to 500,000,
- and having a nucleus from an initiator (1) having a VPO Mn of from about 750 to 4,000, (2) having an average of from about 4 to 9 C-Li sites and (3) being the adduct of an aromatic compound selected from the group consisting of divinyl benzene and diisopropenyl benzene and mixtures thereof and RLi where R is selected from the group consisting of normal, secondary and tertiary alkyl and cycloalkyl radicals of from 2 to 20, or from 2 to 10, carbon atoms, the mold ratio of RLi to said aromatic compound being about 1:0.83.
A vulcanizable composition comprising a blend of (A) from about 40 to 60% by weight of a solution polymerized rubbery substantially random star-shaped polymer and (B) from 60 to 40% by weight of at least one rubbery polymer selected from the group consisting of natural rubber, synthetic cis-1,4-polyisoprene rubber, cis-1,4-polybutadiene rubber, high trans-1,4-polybutadiene rubber and high trans-1,4-butadiene-styrene rubbery copolymer,
- (A) being at least one polymer selected from the group consisting of polybutadienes, polyisoprenes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isoprene-styrene copolymers, butadiene-isoprene-styrene copolymers and mixtures of the same, said styrene containing copolymers containing up to about 30 weight % of styrene, preferably from about 10 to 25 weight % of styrene,
- having a vinyl content for the diene segments of from about 12 to 60 weight %,
- having an average of from about 4 to 9 arms,
- having a Mn of from about 100,000 to 500,000,
- and having a nucleus from an initiator (1) having a VPO Mn of from about 750 to 4,000, (2) having an average of from about 4 to 9 C-Li sites and (3) being the adduct of an aromatic compound selected from the group consisting of divinyl benzene and diisopropenyl benzene and mixtures thereof and RLi where R is selected from the group consisting of normal, secondary and tertiary alkyl and cycloalkyl radicals of from 2 to 20, or from 2 to 10, carbon atoms, the mold ratio of RLi to said aromatic compound being about 1:0.83.
A vulcanized compounded carbon black reinforced blend of (A) from about 40 to 60% by weight of a solution polymerized rubbery substantially random star-shaped polymer and (B) from 60 to 40% by weight of at least one rubbery polymer selected from the group consisting of natural rubber, synthetic cis-1,4-polyisoprene rubber, cis-1,4-polybutadiene rubber, high trans-1,4-polybutadiene rubber and high trans-1,4-butadiene-styrene rubbery copolymer,
- (A) being at least one polymer selected from the group consisting of polybutadienes, polyisoprenes, butadiene-styrene copolymers, butadiene-isoprene copolymers, isoprene-styrene copolymers, butadiene-isoprene-styrene copolymers and mixtures of the same, said styrene containing copolymers containing up to about 30 weight % of styrene, preferably from about 10 to 25 weight % of styrene,
- having a vinyl content for the diene segments of from about 12 to 60 weight %,
- having an average of from about 4 to 9 arms,
- having a Mn of from about 100,000 to 500,000,
- and having a nucleus from an initiator (1) having a VPO Mn of from about 750 to 4,000, (2) having an average of from about 4 to 9 C-Li sites and (3) being the adduct of an aromatic compound selected from the group consisting of divinyl benzene and diisopropenyl benzene and mixtures thereof and RLi where R is selected from the group consisting of normal, secondary and tertiary alkyl and cycloalkyl radicals of from 2 to 20, or from 2 to 10, carbon atoms, the mold ratio of RLi to said aromatic compound being about 1:0.83.
Dependencies are inferred from the claim text.