Patent ID: 6959743
Filing Date: 2005-11-01
Classification: B60C,C08K,C08L

Abstract:
1. A tire having a rubber tread composite comprised of an outer tread cap layer and an integral underlying transition zone composite comprised of a combination of a tread base layer and an intermediate layer positioned between said tread cap layer and tread base layer, wherein: (A) said outer tread cap layer has an outer running surface configured with lugs and grooves and is of a silica-rich rubber composition having a low shear (10 percent strain) G′ modulus property (at 30° C. measured at 10 Hz) in a range of about 5 to about 50 MPa, comprised of, based upon parts by weight per 100 parts by weight rubber (phr) (B) said intermediate layer of said transition zone composite extends to and includes a visible bottom portion of at least two of said grooves in said cap layer, wherein said grooves extend completely through the said cap layer, to thereby support an associated tread lug therebetween, wherein said intermediate layer is a carbon black-rich rubber composition having a low shear (10 percent strain) G′ modulus property (at 30° C. measured at 10 Hertz) in a range of about 3 to about 25 MPa, and wherein said low shear modulus property of said intermediate layer is at least ten percent lower that said low shear modulus property of said outer tread cap layer, comprised of, based upon parts by weight per 100 parts by weight rubber (phr) (C) said base layer of said transition zone composite is a carbon black-rich rubber composition having a low shear (10 percent strain) G′ modulus (at 30° C. measured at 10 Hertz) in a range of about 0.5 to about 10 MPa, and wherein said low shear modulus property of said base layer is at least ten percent lower that said low shear modulus property of said intermediate layer, comprised of, based upon parts by weight per 100 parts by weight rubber (phr);