Tire with sidewall carcass reinforcement

Abstract

A tire having at least one crescent-shaped rubber composition as an insert in its sidewall region which is comprised of at least one diene-based elastomer, carbon black and, optionally, silica and at least one of dithiodipropionic acid, benzoic acid and salicylic acid.

What is claimed is:  
     
         1 . A tire comprised of a toroidally-shaped carcass and an outer, circumferential tread designed to be ground contacting, wherein said carcass is comprised of two spaced apart inextensible bead portions, two spaced apart sidewalls each individually extending radially inward from and connecting said tread to said bead portions, and at least one cord reinforced ply extending from bead to bead and through the sidewalls; an improvement in which a substantially crescent shaped rubber insert is juxtapositioned to and axially inward of at least one of said carcass plies in each of said sidewalls or the tire; wherein the rubber composition of said insert has a Shore A hardness at 100° C. in a range of about 65 to about 85, a 100 percent Modulus in a range of about 3.5 to about 10, a Hot Rebound at 100° C. in a range of about 60 to about 80, an E′ value in a range of about 2 to about 20 MPa at 60 C. and a Tan.Delta value at 60 C. in a range of about 0.03 to about 0.15; and wherein said rubber composition of said insert is comprised of, based on 100 parts by weight rubber, (A) at least one diene-based elastomer, (B) about 30 to about 100 phr of particulate reinforcement as carbon black and, optionally, silica, and (C) about 0.5 to about 10 phr of a material selected from at least one of dithiodipropionic acid, benzoic acid and salicylic acid.  
     
     
         2 . The tire of  claim 1  wherein said carbon black and/or silica filler is pre-treated with at least one of said acids to form a composite thereof and said composite is first blended with ingredients for said rubber composition in the absence of free sulfur and of vulcanization accelerators and free sulfur and vulcanization accelerators subsequently mixed with the rubber composition; wherein said acid(s) is adsorbed, absorbed, coated or melt-sprayed onto the surface of said filler.  
     
     
         3 . The tire of  claim 1  wherein said acid is blended in-situ with ingredients for said rubber composition in the absence of free sulfur and vulcanization accelerators and free sulfur and vulcanization accelerators subsequently mixed with the rubber composition.  
     
     
         4 . The tire of  claim 1  wherein said acid is 3,3′-dithiodipropionic acid.  
     
     
         5 . The tire of  claim 2  wherein said acid is 3,3′-dithiodipropionic acid.  
     
     
         6 . The tire of  claim 3  wherein said acid is 3,3′-dithiodipropionic acid.  
     
     
         7 . The tire of  claim 1  wherein said insert is substantially in an entrunkated crescent shape, where the entrunkated portion thereof is juxtapositioned to the said tire bead portion.  
     
     
         8 . The tire of  claim 2  wherein said insert is substantially in an entrunkated crescent shape, where the entrunkated portion thereof is juxtapositioned to the said tire bead portion.  
     
     
         9 . The tire of  claim 3  wherein said insert is substantially in an entrunkated crescent shape, where the entrunkated portion thereof is juxtapositioned to the said tire bead portion.  
     
     
         10 . The tire of  claim 4  wherein said insert is substantially in an entrunkated crescent shape, where the entrunkated portion thereof is juxtapositioned to the said tire bead portion.  
     
     
         11 . The tire of  claim 1  wherein said tire carcass has from two to three plies comprised of a first axially inner ply and one or two additional plies as a second ply and third ply, respectively, each additional ply positioned sequentially axially outward from said first ply.  
     
     
         12 . The tire of  claim 1  wherein said tire carcass contains one ply wherein said insert is juxtapositioned to and axially inward of said ply in the sidewall region of the tire and where said ply is wrapped around the bead portion with a turn-up portion of the ply extending into the sidewall region and axially outward of the first ply.  
     
     
         13 . The tire of  claim 1  wherein said tire carcass contains an axially inner first ply and an axially outer second ply; wherein said insert is juxtapositioned to and axially inward of said first ply, in the sidewall region of the tire.  
     
     
         14 . The tire of  claim 13  wherein said second ply extends substantially from bead to bead through the sidewalls without connecting with the bead portion.  
     
     
         15 . The tire of  claim 1  wherein said carcass contains an axially inner first ply and an axially outer second ply; wherein said insert is juxtapositioned to and interposed between said first and second ply, in the sidewall region of the tire.  
     
     
         16 . The tire of  claim 15  wherein said second ply extends substantially from bead to bead through the sidewalls without connecting with the bead portion.  
     
     
         17 . The tire of  claim 15  wherein another of said inserts is juxtapositioned to and axially inward of said first ply, in the sidewall region of the tire.  
     
     
         18 . The tire of  claim 17  wherein said second ply extends substantially from bead to bead through the sidewalls without connecting with the bead portion.  
     
     
         19 . The tire of  claim 16  wherein the carcass contains an axially inner first ply, a second ply axially outward from said first ply and a third ply axially outward from said second ply; wherein said insert is juxtapositioned to and axially inward of said first ply, in the sidewall region of the tire.  
     
     
         20 . The tire of  claim 1  wherein the carcass contains an axially inner first ply, a second ply axially outward from said first ply and a third ply axially outward from said second ply; wherein said insert is juxtapositioned to and interposed between said first and second plies, in the sidewall region of the tire.  
     
     
         21 . The tire of  claim 1  wherein the carcass contains an axially inner first ply, a second ply axially outward from said first ply and a third ply axially outward from said second ply; wherein said insert is juxtapositioned to and interposed between said second and third plies, in the sidewall region of the tire.  
     
     
         22 . The tire of  claim 20  wherein at least one of said second and third plies extends substantially from bead to bead through the sidewalls without connecting with the bead portion.  
     
     
         23 . The tire of  claim 21  wherein at least one of said second and third plies extends substantially from bead to bead through the sidewalls without connecting with the bead portion.  
     
     
         24 . The tire of  claim 20  wherein an additional insert is juxtapositioned to and axially inward of said first ply in the sidewall region of the tire.  
     
     
         25 . The tire of  claim 21  wherein an additional insert is juxtapositioned to and axially inward of said first ply in the sidewall region of the tire.  
     
     
         26 . The tire of  claim 22  wherein an additional insert is juxtapositioned to and axially inward of said first ply in the sidewall region of the tire.  
     
     
         27 . The tire of  claim 23  wherein an additional insert is juxtapositioned to and axially inward of said first ply in the sidewall region of the tire.  
     
     
         28 . The tire of  claim 1  wherein said innermost insert has a Shore A hardness in a range of about 65 to about 75, a 100 percent modulus in a range of about 3.5 to about 8 MPa, and E′ in a range of about 2 to about 15 MPa at 60° C. and a Tan.Delta at 60° C. in a range of about 0.03 to about 0.1 and said outward insert(s) has Shore A hardness in a range of about 70 to about 85, a 100 percent modulus in a range of about 5 to about 10 MPa, and E′ in a range of about 5 to about 20 MPa at 60° C. and a Tan.Delta at 60° C. in a range of about 0.05 to about 0.15.  
     
     
         29 . The tire of  claim 1  where the cords of said innermost ply are of steel, carbon fiber or fiberglass and the cords of said outer ply(ies) are of nylon or rayon.  
     
     
         30 . The tire of  claim 2  where the cords of said innermost ply are brass and/or zinc coated steel and the cords of said outer ply(ies) are of nylon or rayon.  
     
     
         31 . The tire of  claim 1 , wherein said material (C) is 3,3′-dithiodipropionic acid; wherein said carcass contains at least two plies with an insert juxtapositioned to and interposed between each of the plies and an additional insert juxtapositioned to and axially inward of the innermost ply; wherein the cords for the innermost ply are of brass and/or zinc plated steel and the cords for the outermost ply (plies) are of nylon or rayon; and wherein said insert(s) have a maximum thickness about midway between the bead portions and tread in the sidewall region of the tire.  
     
     
         32 . The tire of  claim 1  wherein said innermost insert has a Shore A hardness in a range of about 65 to about 75, a 100 percent modulus in a range of about 3.5 to about 8 MPa, and E′ in a range of about 2 to about 15 MPa at 60° C. and a Tan.Delta at 60° C. in a range of about 0.03 to about 0.1 and said outward insert(s) has Shore A hardness in a range of about 70 to about 85, a 100 percent modulus in a range of about 5 to about 10 MPa, and E′ in a range of about 5 to about 20 MPa at 60° C. and a Tan.Delta at 60° C. in a range of about 0.05 to about 0.15.  
     
     
         33 . The tire of  claim 31  wherein said insert is substantially in an entrunkated crescent shape, where the entrunkated portion thereof is juxtapositioned to the said tire bead portion.