Patent ID: 6713549
Filing Date: 2004-03-30
Classification: B60C,C08K

Abstract:
A tire which contains at least one component comprised of a rubber composition which comprises(A) 100 parts by weight of at least one diene-based elastomer, (B) about 25 to about 100 phr of particulate reinforcing filler comprised of (1) about 25 to about 100 phr of a preformed hydrophobated silica composite of synthetic amorphous silica aggregates and coupling agent and, correspondingly, (2) from zero to about 75 phr of carbon black; wherein said synthetic amorphous silica aggregates for said preformed silica composite are of a precipitated silica and contain hydroxyl groups on their surface; and(C) said coupling agent for said preformed silica composite is selected from at least one of the group consisting of: (1) carboxymaleimidophenyl ester, (2) disodium salt of 2,2â€²dithiosalicylic acid, (3) bis-succinimide polysulfide, (4) 2-benzothiazyl-3-(propane-1,2-diol), (5) o-salicylsalicylic acid, (6) pyrazine amide, (7) 3,3â€²-tetrathiodipropanol, (8) hydroxyethyl-phenoxyacetic acid, (9) 3,3â€²tetrathiodipropionamide, (10) poly-(2-propanol-1,3-polysulfide), (11) 3,3â€²-tetrathiodipropionitrile, (12) nicotinamide, (13) zinc and sodium salts of salicylic acid, (14) diaminodirosinate salts, and (15) bisaniline PD bismaleimide, wherein said preformed hydrophobated silica composite is prepared prior to being mixed with said elastomer, and wherein said pre-formed silica composite is prepared by pre-reacting said coupling agent with (1) said synthetic amorphous silica aggregates, or (2) an aqueous dispersion of colloidal silica particles from which the precipitated silica is recovered to form said pre-formed silica composite, wherein said preformed silica composite is hydrophobated by: A. reacting said preformed silica composite with an alkylsilane of general formula (I): Xnâ€”Siâ€”R4âˆ’nâ€ƒâ€ƒ(I) wherein X is a radical selected from the group consisting of alkoxy radicals having from 1 through 3 carbon atoms, chlorine radicals and bromine radicals; R is an alkyl radical having from 1 to 18 carbon atoms; and n is an integer of 1 through 3, or byB. reacting said precipitated silica with a combination of said coupling agent and said alkylsilane of said general formula (I).