US6433065B1 — Silica-reinforced rubber compounded with mercapto…

Claim 1

Independent Claim 112 words

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; an alkyl alkoxysilane present in an amount of about 0.1% to about 20% by weight based on the silica; a mercaptosilane silica coupling agent; wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1; and a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure, wherein the elastomer, the silica, the alkyl alkoxysilane and the mercaptosilane are mixed together, in the absence of the cure agent, at a temperature of about 155° C. to about 200° C.

Claim 2

Dependent Claim 112 words

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; an alkyl alkoxysilane present in an amount of about 0.1% to about 20% by weight based on the silica; a mercaptosilane silica coupling agent; wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1; and a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure, wherein the elastomer, the silica, the alkyl alkoxysilane and the mercaptosilane are mixed together, in the absence of the cure agent, at a temperature of about 155° C. to about 200° C.

Claim 3

Dependent Claim 23 words

The compound of claim 1 , wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is about 0.001:1 to about 0.10:1.

Claim 4

Dependent Claim 23 words

The compound of claim 2 , wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is about 0.01:1 to about 0.10:1.

Claim 5

Dependent Claim 29 words

The compound of claim 1 , wherein the mercaptosilane is present in an amount of about 0.0001% to about 3% by weight, based on the weight of the silica.

Claim 6

Dependent Claim 29 words

The compound of claim 4 , wherein the mercaptosilane is present in an amount of about 0.001% to about 1.5% by weight, based on the weight of the silica.

Claim 7

Dependent Claim 29 words

The compound of claim 5 , wherein the mercaptosilane is present in an amount of about 0.01% to about 1% by weight, based on the weight of the silica.

Claim 8

Dependent Claim 27 words

The compound of claim 1 , wherein the alkyl alkoxysilane is present in an amount of about 0.1% to about 20% by weight, based on the silica.

Claim 9

Dependent Claim 27 words

The compound of claim 7 , wherein the alkyl alkoxysilane is present in an amount of about 1% to about 15% by weight, based on the silica.

Claim 10

Dependent Claim 27 words

The compound of claim 8 , wherein the alkyl alkoxysilane is present in an amount of about 1% to about 10% by weight, based on the silica.

Claim 11

Dependent Claim 71 words

The compound of claim 1 , wherein the mercaptosilane has the formula wherein X is a halogen or an alkoxy; R is C 1 to C 4 alkylene; R′ is independently C 1 to about C 10 alkyl, about C 7 to about C 30 alkaryl, about C 5 to about C 30 cycloaliphatic, or C 6 to about C 20 aromatic; and “n” is an integer from 1 to 3.

Claim 12

Dependent Claim 83 words

The compound of claim 1 , wherein the alkyl alkoxysilane compound has the formula R 1 p Si(OR 2 ) 4−p wherein the alkoxy groups are the same or different from each other, each R 1 independently comprises C 1 to about C 20 aliphatic, about C 5 to about C 20 cycloaliphatic, or about C 6 to about C 20 aromatic, each R 2 independently comprises C 1 to about C 6 , and p is an integer from 1 to 3.

Claim 13

Dependent Claim 14 words

The compound of claim 11 , wherein the alkyl alkoxysilane is an alkyl trialkoxysilane.

Claim 14

Dependent Claim 36 words

The compound of claim 1 , wherein the elastomer is selected from the group consisting of homopolymers of conjugated diene monomers, and copolymers and terpolymers of the conjugated diene monomers with monovinyl aromatic monomers and trienes.

Claim 15

Dependent Claim 38 words

The compound of claim 1 , wherein the elastomer, the silica, the alkyl alkoxysilane, and the mercaptosilane are mixed together, in the absence of the cure agent, at a temperature of about 130° C. to about 200° C.

Claim 16

Dependent Claim 17 words

The compound of claim 14 , wherein the temperature is about 155° C. to about 200° C.

Claim 17

Dependent Claim 17 words

The compound of claim 15 , wherein the temperature is about 170° C. to about 185° C.

Claim 18

Dependent Claim 108 words

The compound of claim 14 , wherein the compound exhibits an improved physical property compared to a similar compound containing the alkyl alkoxysilane mixed at the temperature in the absence of the mercaptosilane, the property selected from the group consisting of about a 10% to about a 30% decrease in filler flocculation after compounding as measured by ΔG′, about a 4% to about a 40% increase in the tensile modulus at 300% strain, reduced hysteresis as measured by about a 1% to about a 30% decrease in tangent δ at 65° C., about a 10% to about a 30% increase in the bound rubber content, and combinations thereof.

Claim 19

Dependent Claim 55 words

The compound of claim 1 , further comprising an additional processing aid selected from the group consisting of a fatty acid ester of a hydrogenated or non-hydrogenated C 5 or C 6 sugar, a polyoxyethylene derivative of a hydrogenated or non-hydrogenated C 5 or C 6 sugar, an ester of a polyol, and mixtures thereof.

Claim 20

Dependent Claim 35 words

The compound of claim 18 , wherein the fatty acid ester is selected from the group consisting of sorbitan monooleate, sorbitan dioleate, sorbitan trioleate, sorbitan sesquioleate, sorbitan laurate, sorbitan palmitate, sorbitan stearate, and mixtures thereof.

Claim 21

Dependent Claim 121 words

A pneumatic tire comprising a component produced from a sulfur-vulcanized elastomeric compound, the compound comprising an elastomer optionally having an alkoxysilanc terminal group, a reinforcing filler comprising silica or a mixture thereof with carbon black, an alkyl alkoxysilane present in an amount of about 0.1% to about 20% by weight based on the silica, a mercaptosilane silica coupling agent, wherein the ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1, and a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure, wherein the elastomer, the silica, the alkyl alkoxysilane and the mercaptosilane are mixed together, in the absence of the cure agent, at a temperature of about 155° C. to about 200° C.

Claim 22

Dependent Claim 121 words

A pneumatic tire comprising a component produced from a sulfur-vulcanized elastomeric compound, the compound comprising an elastomer optionally having an alkoxysilanc terminal group, a reinforcing filler comprising silica or a mixture thereof with carbon black, an alkyl alkoxysilane present in an amount of about 0.1% to about 20% by weight based on the silica, a mercaptosilane silica coupling agent, wherein the ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1, and a cure agent comprising an effective amount of sulfur to achieve a satisfactory cure, wherein the elastomer, the silica, the alkyl alkoxysilane and the mercaptosilane are mixed together, in the absence of the cure agent, at a temperature of about 155° C. to about 200° C.

Claim 23

Independent Claim 142 words

A method for preparing a sulfur-vulcanized elastomeric compound, comprising the steps of: (a) mixing together at a temperature of about 155° 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 present in an amount of about 0.1% to about 20% by weight based on the silica, and a mercaptosilane, wherein the ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1; (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).

Claim 24

Independent Claim 142 words

A method for preparing a sulfur-vulcanized elastomeric compound, comprising the steps of: (a) mixing together at a temperature of about 155° 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 present in an amount of about 0.1% to about 20% by weight based on the silica, and a mercaptosilane, wherein the ratio of the mercaptosilane to the alkyl alkoxysilane is a maximum of 0.14:1; (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).

Claim 25

Dependent Claim 21 words

The method of claim 21 , wherein the mixing temperature in step (a) is about 155° C. to about 200° C.

Claim 26

Dependent Claim 21 words

The method of claim 22 , wherein the mixing temperature in step (a) is about 170° C. to about 185° C.

Claim 27

Dependent Claim 23 words

The method of claim 21 , wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is about 0.001:1 to about 0.10:1.

Claim 28

Dependent Claim 23 words

The method of claim 24 , wherein the weight ratio of the mercaptosilane to the alkyl alkoxysilane is about 0.01:1 to about 0.10:1.

Claim 29

Dependent Claim 29 words

The method of claim 21 , wherein the mercaptosilane is present in an amount of about 0.0001% to about 3% by weight, based on the weight of the silica.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2005-08-12	2006-02-11	2006-08-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2009-08-12	2010-02-11	2010-08-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2013-08-12	2014-02-11	2014-08-13	$7700.00	Window Closed / Lapsed

Silica-reinforced rubber compounded with mercaptosilanes and alkyl alkoxysilanes

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