Patent ID: 6515063
Filing Date: 2003-02-04
Classification: B60C,C08K,C08L,Y10T

Abstract:
A tire having a tread comprised of at least one non-black colored, exclusive of carbon black, rubber composition, wherein said tread is of a co-extruded cap/base construction; wherein said tread cap is configured with lugs and grooves; wherein said tread cap is comprised of said non-black colored rubber composition comprised of, based upon parts by weight per 100 parts by weight elastomer(s), (phr):(A) 100 phr of elastomer comprised of (1) about 5 to about 80 phr of a halogenated copolymer of isobutylene and p-methyl styrene, wherein said halogen is bromine, (2) about 20 to about 95 phr of at least one diene-based elastomer and (B) about 25 to about 100 phr of particulate reinforcing filler comprised of synthetic amorphous silica aggregates, wherein said silica aggregates contain hydroxyl groups (e.g. silanol groups) on their surface; and (C) about 0.5 to about 25 phr of at least one organo phosphite selected from monophosphites selected from formula (I) and diphosphites selected from formula (II) and diisodecyl pentearythritol diphosphite, distearyl pentaerythritol diphosphite and pentearythritol diphosphite: ((OR4)2â€”Pâ€”Oâ€”R5)2â€”R6â€ƒâ€ƒ(II) wherein each R4 radical is independently selected from alkyl radicals and phenyl radicals and alkyl substituted phenyl radicals; wherein said R4 alkyl radicals have from 1 to 18 carbon atoms, wherein R5 is a phenyl radical; and wherein R6 is selected from alkyl radicals having from 2 to 8 carbon atoms; wherein said organo phosphite is provided by one or more of the following: (a) by mixing said organo phosphite with said elastomer(s) and said synthetic silica, (b) by pre-reacting said halogenated copolymer of isobutylene and p-methyl styrene with said organo phosphite prior to blending said reinforcing filler therewith, (c) by pre-reacting said organo phosphite with an aqueous dispersion of colloidal silica particles from which a precipitated silica is recovered to form an organo phosphite/silica composite thereof, (d) mixing said organo phosphite with said elastomer(s) and said synthetic silica according to any of said steps (a), (b) or (c), wherein said synthetic silica includes at pre-hydrophobated silica aggregates which have been pre-hydrophobated prior to mixing with said elastomers with an alkylsilane of formula (III), (e) mixing said organo phosphite with said elastomer(s) and an alkylsilane of the said Formula (III) with said elastomer(s) and said synthetic silica, preferably in an internal rubber mixer, and (f) by pre-reacting said organo phosphite and said alkylsilane of Formula (III), and optionally with an organomercaptosilane of Formula (IV), with (i) said aggregates of synthetic precipitated silica or (ii) an aqueous dispersion of colloidal silica particles from which a precipitated silica is recovered to form a silica composite thereof, wherein said alkylsilane of the general Formula (III) is represented by Xnâ€”Siâ€”R4âˆ’nâ€ƒâ€ƒ(III) wherein R is an alkyl radical having from one to 18 carbon atoms, n is a value of from 1 to 3 and X is a radical selected from chlorine or bromine or alkoxy radical as (OR1)â€”, wherein R1 is an alkyl radical selected from methyl and ethyl radicals, and where said organomercaptosilane is of the general formula (IV): (X)n(R2O)3âˆ’nâ€”Siâ€”R3â€”SHâ€ƒâ€ƒ(IV) wherein X is a radical selected from chlorine, bromine, and alkyl radicals having from one to 16 carbon atoms: wherein R2 is an alkyl radical having from one to 16 carbon atoms and R3 is an alkylene radical having from one to 16 carbon atoms; and n is a value from zero to 3.