Tire tread and method of making the same

Patent metadata

Field	Value
Publication number	US-9827726-B2
Application number	US-201314402558-A
Country	US
Kind code	B2
Filing date	May 30, 2013
Priority date	May 30, 2012
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A method of making a tire tread includes mixing a tire tread compound including a virgin rubber component and a reclaimed rubber component, forming a green sheet from the tire tread compound, and curing the green sheet to form a cured tire tread. The reclaimed rubber component may have a Mooney viscosity (ML (1+4) @ 100° C.) of greater than 65. The reclaimed rubber component may also have a crosslink density that is between 20 and 50% of the crosslink density of the reclaimed rubber prior to reclaiming.

First claim

What is claimed is:

1. A method of manufacturing a tire tread comprising:
a. mixing a tire tread compound including a rubber component, wherein the rubber component includes a virgin rubber component and from 1-25 weight percent of a reclaimed rubber component based on the total weight of the rubber component, the reclaimed rubber component having a Mooney viscosity (ML (1+4) @ 100° C.) of greater than 65 and a crosslink density of greater than 25% of the crosslink density of the reclaimed rubber prior to devulcanization;
b. forming a green sheet from the tire tread compound;
c. placing the green sheet in a mold; and
d. curing the green sheet under pressure to form a cured tire tread.

2. The method of claim 1 , where said Mooney viscosity of the reclaimed rubber component is between approximately 65 and 120.

3. The method of claim 1 , where said step of mixing further includes mixing one or more additives with the rubber component, the one or more additives selected from a filler, a processing oil, an antidegredant, and a curative.

4. The method of claim 1 , where the step of forming a green sheet includes extruding the tire tread compound to form a green extrusion.

5. The method of claim 4 , where the green extrusion is in the form of a generally flat green sheet.

6. The method of claim 1 , further comprising the step of cutting the green sheet to a desired size prior to curing.

7. The method of claim 1 , where the virgin rubber component includes styrene-butadiene rubber.

8. The method of claim 1 , where the virgin rubber component includes high cis butadiene rubber.

9. A method of manufacturing a cured tire tread comprising:
a. mixing a tire tread compound including a rubber component, wherein the rubber component includes a virgin rubber component and from 1 to 25 weight percent of a reclaimed rubber component based on the total weight of the rubber component, the reclaimed rubber component having crosslink density of greater than 25% of the crosslink density of the reclaimed rubber prior to devulcanization;
b. extruding the tire tread compound to form a green extrusion that is in the form of a generally flat green sheet; and
c. curing the green sheet under pressure to form a cured tire tread including a reclaimed rubber component.

10. The method of claim 9 , where the reclaimed rubber component has a Mooney viscosity of between approximately 70and 90.

11. The method of claim 9 , where said step of mixing further includes mixing one or more additives with the rubber component, the one or more additives selected from a filler, a processing oil, an antidegredant, and a curative.

12. The method of claim 9 , further comprising the step of cutting the green sheet to a desired size prior to curing.

13. The method of claim 9 , where the virgin rubber component includes styrene-butadiene rubber.

14. The method of claim 9 , where the virgin rubber component includes high cis butadiene rubber.

Assignees

• Bridgestone Bandag Llc

Inventors

• Norton Craig B

Classifications

• B60C1/0016

  Compositions of the tread · CPC title

• B29D30/52 Primary

  Unvulcanised treads, e.g. on used tyres; Retreading (apparatus for forming {treads by extrusion B29C48/00; apparatus for} vulcanising treads B29C35/02; apparatus characterised by the means for holding wheels or parts thereof B60B30/00) · CPC title

• B60C11/02

  Replaceable treads · CPC title

• C08L2207/24

  recycling of old tyres and caoutchouc and addition of caoutchouc particles · CPC title

• B60C11/00

  Tyre tread bands; Tread patterns; Anti-skid inserts · CPC title