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US 11,535,687 B2Granted
Silica-filled rubber composition and method for making the same
AssigneeBridgestone Americas Tire Operations, LLC
InventorMaryangel G. Dunlavy
Life of this patent
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Abstract
Disclosed is a method of preparing a rubber composition comprising the steps of (a) blending in at least one preparatory mixing step at least one natural or synthetic rubbery polymer, a silica filler, a silica coupling agent, and at least one vulcanization accelerator; and (b) subsequently blending therewith in a final mixing step a sulfur curative, wherein the average glass transition temperature of the polymer(s) is −55° C. or less.
Claims14
A method of preparing a tire tread rubber composition comprising:
- a. blending in at least one preparatory mixing step
- (i) at least one natural or synthetic rubbery polymer selected from the group consisting of natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber (SBR), polybutadiene, and mixtures thereof and wherein the at least one natural or synthetic rubbery polymer contains no butadiene-isoprene rubber but includes at least styrene-butadiene rubber,
- (ii) a silica filler and a carbon black filler wherein the carbon black filler is present in an amount of 5 to 100 phr,
- (iii) one silica coupling agent wherein the only one silica coupling agent is selected from the group consisting of organosilane polysulfides selected from the group consisting of 3,3′-bis(trimethoxysilylpropyl)disulfide, 3,3′-bis(triethoxysilylpropyl)disulfide, 3,3′-bis(tributoxysilylpropyl)disulfide, 3,3′-bis(trihexoxysilylpropyl)disulfide, 3,3′-bis(tri-t-butoxysilylpropyl)disulfide, 3,3′-bis(dimethylmethoxysilylethyl)disulfide, 3,3′-bis(diphenylcyclohexoxysilylpropyl)disulfide, 3,3′-bis(ethyldi-secbutoxysilylpropyl)disulfide, 3,3′-bis(propyldiethoxysilylpropyl)disulfide, 12,12′-bis(triisopropyloxysilyldodecyl)disulfide, 3,3′-bis(dimethoxyphenylsilylpropyl)disulfide, organoalkoxymercaptosilanes, and capped organoalkoxymercaptosilanes,
- (iv) an oil, and
- (v) at least one vulcanization accelerator in an amount of about 1 to 3 phr, wherein the only vulcanization accelerator(s) is selected from the group consisting of guanidine-based vulcanization accelerators,
- wherein no preparatory mixing step adds elemental sulfur, a thiocarbamate-based compound, a benzothiazole-based compound, a thiuram sulfide-based compound, or 4,4-dithiodimorpholine (DTDM) and the at least one vulcanization accelerator is either added in a preparatory mixing step that includes oil or in a separate preparatory mixing step after (i), (ii), (iii) and (iv);
- and
- b. subsequently blending therewith in a final mixing step a sulfur curative selected from the group consisting of elemental sulfur and sulfur donating compounds and 2.5 phr of zinc oxide, wherein the average glass transition temperature of the at least one natural or synthetic rubbery polymer(s) is −55.2° C. to about −61° C., and
- wherein the only ingredient used to couple the silica filler to the at least one natural or synthetic rubbery polymer consists of (iii) and the only ingredient used to catalyze the reaction between the silica coupling agent and the at least one natural or synthetic rubbery polymer consists of (v).
7 more elements
A method of preparing a tire tread rubber composition comprising:
- a. blending in at least one preparatory mixing step
- (i) at least one natural or synthetic rubbery polymer selected from the group consisting of natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber (SBR), and mixtures thereof and wherein the at least one natural or synthetic rubbery polymer contains no butadiene-isoprene rubber but includes at least styrene-butadiene rubber,
- (ii) a silica filler and a carbon black filler wherein the carbon black filler is present in an amount of 5 to 100 phr,
- (iii) one silica coupling agent wherein the only one silica coupling agent is selected from the group consisting of organosilane polysulfides selected from the group consisting of 3,3′-bis(trimethoxysilylpropyl)disulfide, 3,3′-bis(triethoxysilylpropyl)disulfide, 3,3′-bis(tributoxysilylpropyl)disulfide, 3,3′-bis(trihexoxysilylpropyl)disulfide, 3,3′-bis(tri-t-butoxysilylpropyl)disulfide, 3,3′-bis(dimethylmethoxysilylethyl)disulfide, 3,3′-bis(diphenylcyclohexoxysilylpropyl)disulfide, 3,3′-bis(ethyldi-secbutoxysilylpropyl)disulfide, 3,3′-bis(propyldiethoxysilylpropyl)disulfide, 12,12′-bis(triisopropyloxysilyldodecyl)disulfide, and bis(dimethoxyphenylsilylpropyl)disulfide, organoalkoxymercaptosilanes, and capped organoalkoxymercaptosilanes,
- (iv) an oil, and
- (v) at least one vulcanization accelerator in an amount of about 1 to about 3 phr, wherein the only vulcanization accelerator(s) is selected from the group consisting of guanidine accelerators and includes 1,3-diphenyl guanidine, wherein no preparatory mixing step adds elemental sulfur, a thiocarbamate-based, a benzothiazole-based, a thiuram sulfide-based compound, or 4,4-dithiodimorpholine (DTDM) and the at least one vulcanization accelerator is either added in a preparatory mixing step that includes oil or in a separate preparatory mixing step after (i), (ii), (iii) and (iv);
- and
- b. subsequently blending therewith in a final mixing step a sulfur curative selected from the group consisting of elemental sulfur and sulfur donating compounds and 2.5 phr of zinc oxide, wherein the average glass transition temperature of the at least one natural or synthetic rubbery polymer(s) is −55.2° C. to about −61° C., and wherein the only ingredient used to couple the silica filler to the at least one natural or synthetic rubbery polymer consists of (iii) and the only ingredient used to catalyze the reaction between the silica coupling agent and the at least one natural or synthetic rubbery polymer consists of (v).
5 more elements
Dependencies are inferred from the claim text.