Silica-reinforced rubber compounded with an alkoxysilane and a catalytic alkyl tin compound
AssigneeBridgestone Corporation
InventorsChenchy Jeffrey Lin, William L. Hergenrother
Life of this patent
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Abstract
Improvements in the tensile mechanical properties and dynamic viscoelastic properties of silica-reinforced sulfur-vulcanized rubbers can be achieved by compounding elastomers with silica, in the presence of a silane and a catalytic amount of an alkyl tin compound at a high compounding temperature.
Claims31
A sulfin-vulcanizable elastomeric compound, comprising:
- an elastomer optionally having an ailcoxysilatie terminal group;
- a reinforcing filler comprising silica or a mixture thereof with carbon black;
- an alkyl alkoxysilane;
- a mercaptosilane silica coupling agent, wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1;
- a catalytic amount of an alkyl tin compound;
- and
- a cure agent comprising an effective amount of suiffir to achieve a satisfactory cure.
A pneumatic tire comprising a component produced from a sulfur-vulcanized elastomeric compound that comprises an elastomer optionally having an alkoxysilane terminal group, a reinforcing filler comprising silica or a mixture thereof with carbon black, an alkyl alkoxysilane, a mercaptosilane silica coupling agent, wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1, a catalytic amount of an alkyl tin compound, and a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure.
A method for preparing a sulfur-vulcanized elastomeric compound, comprising the steps of:
- (a) mixing together at a temperature of about 130° C. to about 200° C. in the absence of added sulfur and cure agents, an elastomer optionally having an alkoxysilane terminal group, a reinforcing filler comprising silica or a mixture thereof with carbon black, an alkyl alkoxysilane and a mercaptosilane, wherein the ratio of the mercaptosilane to the alkyl ethoxysilane is a maximum of 0.14:1, and a catalytic amount of an alkyl tin compound;
- (b) allowing the mixture to cool below the mixing temperature;
- (c) mixing the mixture obtained in step (b), at a temperature lower than a vulcanization temperature, with a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure;
- and
- (d) curing the mixture obtained in step (c).
A sulfur-vulcanizable elastomeric compound, comprising:
- an elastomer optionally having an alkoxysilane terminal group;
- a reinforcing filler comprising silica or a mixture thereof with carbon black;
- a silica coupling agent selected from the group consisting of about 0.01% to about 1% by weight of a bis(trialkoxysilylorgano) tetrasulfide silica coupling agent based on the weight of the silica, about 0.1% to about 20% by weight of a bis(trialkoxysilylorgano) disulfide silica coupling agent, based on the weight of the silica, and mixtures thereof;
- a silica dispersing aid selected from the group consisting of a fatty acid ester of a hydrogenated or non-hydrogenated C5 or C6 sugar, and polyoxyethylene derivative of a fatty acid ester of a hydrogenated or non-hydrogenated C5 or C6 sugar, and mixtures thereof;
- a catalytic amount of an alkyl tin compound;
- and
- a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure.
A pneumatic tire comprising a component produced from a sulfur-vulcanized elastomeric compound, wherein the compound comprises an elastomer optionally having an alkoxysilane terminal group;
- a reinforcing filler comprising silica or a mixture thereof with carbon black;
- a silica coupling agent selected from the group consisting of about 0.01% to about 1% by weight of a bis(trialkoxysilylorgano) tetrasulfide silica coupling agent, based on the weight of the silica, about 0.1% to about 20% by weight of a bis(trialkoxysilylorgano) disulfide silica coupling agent, based on the weight of the silica, and mixtures thereof;
- a silica dispersing aid selected from the group consisting of a fatty acid ester of a hydrogenated or non-hydrogenated C5 or C6 sugar, a polyoxyethylene derivative of a fatty acid ester of a hydrogenated non-hydrogenated C5 or C6 sugar and mixtures thereof;
- a catalytic amount of an alkyl tin compound;
- and a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure.
A method for preparing a sulfur-vulcanized elastomeric compound, comprising the steps of:
- (a) mixing together at a temperature of 165° C. to about 200° C. in the absence of added sulfur and cure agents, an elastomer optionally having an alkoxysilane terminal group;
- a reinforcing filler comprising silica or a mixture thereof with carbon black;
- a silica coupling agent selected from the group consisting of about 0.01% to about 1% by weight of a bis(trialkoxysilylorgano) tetrasulfide silica coupling agent, based on the weight of the silica, about 0.1% to about 20% by weight of a bis(trialkoxysilylorgano) disulfide silica coupling agent, based on the weight of the silica, and mixtures thereof;
- a silica dispersing aid;
- and a catalytic amount of an alkyl tin compound;
- (b) allowing the mixture to cool below the mixing temperature;
- (c) mixing the mixture obtained in step (b), at a temperature lower than a vulcanization temperature, wit a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure;
- and
- (d) curing the mixture obtained in step (c).
Dependencies are inferred from the claim text.