Tire with rubber tread of circumferential zones with graduated physical properties

A tire having a rubber tread of a cap/base construction comprised of an outer rubber tread cap layer containing an outer running surface and an underlying rubber tread base layer, wherein said tread cap layer is comprised of a plurality of circumferential, longitudinal rubber tread cap zones of graduated physical properties, wherein said tread cap zones individually extend from said tread cap running surface radially inward to said tread base layer:

• wherein said tread cap zones are comprised of two primary tread cap zones, one central tread cap zone and two lateral tread cap;
• wherein said central tread cap zone is positioned between said primary tread cap zones and spans at least 5 percent of the total running surface of the tread cap layer, wherein said primary tread cap zones are of substantially equal widths and collectively span at least 50 percent of the total running surface of the tread cap layer, wherein said lateral tread cap zones are of substantially equal widths, span at least 5 percent of the total running surface of the tread cap layer and are individually positioned axially outward from said primary tread cap zone,
• wherein, said individual rubber tread cap zones are characterized by:
• (A) viscoelastic properties comprised of:
• (1) a dynamic storage modulus (G′) at 60° C., 3 percent strain and 10 Hertz of said lateral tread cap lateral zones at least 0.5 MPa greater than such storage modulus (G′) at 60° C. of said primary tread cap zones and such storage modulus (G′) at 60° C. of said central tread cap zone is at least 0.5 Mpa greater than such storage modulus (G′) at 60° C. of said primary tread cap zones;
• and
• (2) a dynamic storage modulus (G′) at −25° C., 3 percent strain and 10 Hertz of said central tread cap zone at least 5 MPa less than such storage modulus (G′) at −25° C. of said primary tread cap zones;
• and
• (3) the dynamic loss modulus (G″) at 0° C., 3 percent strain and 10 Hertz of said lateral tread cap zones at least 1 MPa greater than such loss modulus (G″) at 0° C. of said primary tread cap zones;
• or
• (B) viscoelastic properties comprised of:
• (1) a dynamic storage modulus (G′) at 60° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 0.5 to about 5 MPa, such storage modulus (G′), (at 60° C.), for said central tread cap zone in a range of from about 1 to about 6 MPa and such storage modulus (G′), (at 60° C.), for said lateral tread cap zones in a range of from about 1 to about 6 MPa;
• provided however that such storage modulus (G′) (at 60° C.) of said lateral tread cap zones and said central tread cap zone is greater than such storage modulus (G′) (at 60° C.) of said primary tread cap zones;
• and
• (2) a dynamic storage modulus (G′) at −25° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 10 to about 300 MPa, such storage modulus (G′), (at −25° C.), for said central tread cap zone in a range of from about 2 to about 295 MPa and such storage modulus (G′), (at −25° C.), of said lateral tread cap zones in a range of from about 10 to about 350 MPa;
• provided however that such storage modulus (G′), (at −25° C.) of said central tread cap zone is less than such storage modulus (G′), (at −25° C.) of said primary tread cap zones and
• (3) a dynamic loss modulus (G″) at 0° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 0.5 to about 20 MPa, such loss modulus (G″), (at 0° C.), for said central tread cap zone in a range of from about 0.5 to about 20 MPa such loss modulus(G″), (at 0° C.), for said lateral tread cap zones in a range of from about 1.5 to about 30 MPa;
• provided however that such loss modulus (G″), (at 0° C.), of the rubber composition of said lateral tread cap zones is greater than such loss modulus (G″), (at 0° C.), of said primary tread cap zones or
• (C) viscoelastic properties comprised of:
• (1) dynamic storage modulus (G′) at 60° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 0.5 to about 2 MPa, such storage modulus (G′),(at 60° C.), for said central tread cap zone in a range of from about 1 to about 3 MPa and such storage modulus (G′) (at 60° C.) for said lateral tread cap zones in a range of from about 1 to about 3 MPa;
• provided however that the storage modulus (G′), (at 60° C.), of said lateral tread cap zones is at least 0.5 MPa greater than such storage modulus (G′), (at 60° C.), of the primary and central tread cap zones and the storage modulus (G′), (at 60° C.), of said central tread cap zone is at least 0.5 MPa greater than such storage modulus (G′), (at 60° C.), of the primary tread cap zones;
• (2) a dynamic storage modulus (G′) at −25° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 10 to about 300 MPa, such storage modulus (G′), (at −25° C.), for said central tread cap zone in a range of from about 2 to about 295 MPa and such storage modulus (G′), (at −25° C.), for said lateral tread cap zones in a range of from about 10 to about 50 MPa;
• provided however that such storage modulus (G′), (at −25° C.), of the rubber composition of said central tread cap zone is at least 5 MPa less than such storage modulus (G′), ( at −25° C.), of the primary tread cap zones and
• (3) a dynamic loss modulus (G″) at 0° C., 3 percent strain and 10 Hertz of said primary tread cap zones in a range of from about 0.5 to about 3 MPa, such loss modulus (G″), (at 0° C.), for said central tread cap zone in a range of from about 0.5 to about 3 MPa and such loss modulus (G″), (at 0° C.), for said lateral tread cap zones in a range of from about 1.5 to about 4 MPa;
• provided however that such loss modulus (G″), (at 0° C.), of said lateral tread cap zones is at least 1 MPa greater than such loss modulus (G″), (at 0° C.), of said primary tread cap zones, or
• (D) viscoelastic properties comprised of:
• (1) a dynamic storage modulus (G′) at 60° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 1.5 to about 4 MPa, such storage modulus (G′), (at 60° C.), for said central tread cap zone in a range of from about 2 to about 5 MPa and such storage modulus (G′), (at 60° C.), for said lateral tread cap zones in a range of from about 2 to about 5 MPa;
• provided however that the storage modulus (G′), (at 60° C.), of said lateral tread cap zones is at least 0.5 MPa greater than such storage modulus (G′), (at 60° C.), of said primary tread cap zones and such storage modulus (G′), (at 60° C.), of said central tread cap zone is at least 0.5 MPa greater than such storage modulus (G′), (at 60° C.), of said primary tread cap zones;
• (2) a dynamic storage modulus (G′) at −25° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 20 to about 50 MPa, such storage modulus (G′), (at −25° C.), for said central tread cap zone in a range of from about 5 to about 45 MPa and such storage modulus (G′), (at −25° C.), for said lateral tread cap zones in a range of from about 20 to about 100 MPa;
• provided however that such storage modulus (G′), (at −25° C.), of said central tread cap zone is at least 5 MPa less than such storage modulus (G′), (at −25° C.), of said primary tread cap zones and
• (3) a dynamic loss modulus (G″) at 0° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 1 to about 4 MPa, such loss modulus (G″), (at 0° C.), for said central tread cap zone in a range of from about 1 to about 4 MPa and such loss modulus (G″), (at 0° C.), for said lateral tread cap zones in a range of from about 2 to about 15 MPa;
• provided however that such loss modulus (G″), (at 0° C.), of said lateral tread cap zones is at least 1 MPa greater than such loss modulus (G″), (at 0° C.), of said primary tread cap zones, or
• (E) viscoelastic properties comprised of:
• (1) a dynamic storage modulus (G′) at 60° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 2 to about 5 MPa, such storage modulus (G′), (at 60° C.), for said central tread cap zone in a range of from about 2.5 to about 6 MPa and such storage modulus (G′), (at 60° C.), for said lateral tread cap zones in a range of from about 2.5 to about 6 MPa;
• provided however that the storage modulus (G′), (at 60° C.), of said lateral tread cap zones is at least 0.5 MPa greater than such storage modulus (G′), (at 60° C.), of said primary tread cap zones and such storage modulus (G′), (at 60° C.), of the rubber composition of said central tread cap zone is at least 0.5 Mpa greater than such storage modulus (G′), (at 60° C.), of said primary tread cap zones;
• (2) a dynamic storage modulus (G′) at −25° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 35 to about 300 MPa, such storage modulus (G′), (at −25° C.), for said central tread cap zone in a range of from about 30 to about 295 MPa and such storage modulus (G′), (at −25° C.), for said lateral tread cap zones in a range of from about 35 to about 350 MPa;
• provided however that such storage modulus (G′), (at −25° C.), of said central tread cap zone is at least 5 MPa less than such storage modulus (G′), ( at −25° C.), of said primary tread cap zones;
• and
• (3) a dynamic loss modulus (G″) at 0° C., 3 percent strain and 10 Hertz for said primary tread cap zones in a range of from about 2 to about 20 MPa, such loss modulus (G″), at 0° C., for said central tread cap zone in a range of from about 2 to about 20 MPa and such loss modulus (G″), (at 0° C.), for said lateral tread cap zones in a range of from about 3 to about 30 MPa;
• provided however that such loss modulus (G″), (at 0° C.), of said lateral tread cap zones is at least 1 MPa greater than such loss modulus (G″), (at 0° C.), of said primary tread cap zones, and
• wherein the running surface of said lateral tread cap zones is positioned axially outward of the free rolling footprint of the tire when inflated and running under 75 percent of its rated load and are thereby intended to be ground-contacting only under cornering conditions.