Pneumatic tire

Patent metadata

Field	Value
Publication number	US-12023964-B2
Application number	US-202117543766-A
Country	US
Kind code	B2
Filing date	Dec 7, 2021
Priority date	Dec 24, 2020
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

A pneumatic tire can include a tread portion, a pair of sidewall portions, bead portions, and a carcass. At least one sidewall portion can include a first sidewall rubber arranged outside the carcass in a tire axial direction. The first sidewall rubber can include a different color rubber layer and a barrier rubber layer. The different color rubber layer can have a color different from a basic color of an outer surface of the at least one sidewall portion. At least a part of the different color rubber layer can be exposed in the outer surface of the at least one sidewall portion. The barrier rubber layer can be arranged between the different color rubber layer and the carcass. The barrier rubber layer can include a first portion having a rubber compounding to suppress migration of rubber compounding agents on the carcass side to the different color rubber layer.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a tread portion;
a pair of sidewall portions;
a pair of bead portions; and
a carcass extending from a first of the bead portions to a second of the bead portions,
wherein, at least one of the sidewall portions includes a first sidewall rubber arranged outside the carcass in a tire axial direction,
the first sidewall rubber includes a different color rubber layer and a barrier rubber layer,
the different color rubber layer has a color different from a basic color of an outer surface of the at least one of the sidewall portions,
at least a part of the different color rubber layer is exposed in the outer surface of the at least one of the sidewall portions,
the barrier rubber layer extends from the different color rubber layer to the carcass,
the barrier rubber layer includes a first portion having a rubber compounding to suppress migration of rubber compounding agents on the carcass side to the different color rubber layer,
the barrier rubber layer is between the different color rubber layer and a tread rubber forming the tread portion,
the barrier rubber layer includes a third portion having the rubber compounding to suppress migration of the rubber compounding agents on the tread rubber side to the different color rubber layer, and
the third portion extends from the tread rubber to the different color rubber layer,
each of the bead portions includes a clinch rubber forming an outer surface of a respective one of the bead portions,
the first sidewall rubber includes an inner rubber portion in contact with the clinch rubber,
the barrier rubber layer is between the inner rubber portion and the different color rubber layer, and
the barrier rubber layer includes a second portion having the rubber compounding to suppress migration of the rubber compounding agents in the inner rubber portion to the different color rubber layer.

2. The pneumatic tire according to claim 1 , wherein
in a tire meridian section, a distance along an outer surface of the tread portion and the outer surface of the at least one of the sidewall portions from an outer end in a tire radial direction of the first sidewall rubber to one of tread ground contacting edges adjacent to the first sidewall rubber is 20 mm or more and 40 mm or less,
the first sidewall rubber consists of the different color rubber layer, the barrier rubber layer, and the inner rubber portion, and
a radially outer end of the third portion of the barrier layer is located radially outside a radially outer end of the carcass and axially inside an axially outer end of the carcass.

3. The pneumatic tire according to claim 1 , wherein the tread rubber has an outer end in the tire axial direction covered by the first sidewall rubber.

4. The pneumatic tire according to claim 1 , wherein a tire section height is 120 mm or less.

5. The pneumatic tire according to claim 1 , wherein the barrier rubber layer includes 60% or less of butyl-based rubber.

6. The pneumatic tire according to claim 1 , wherein a length of the inner rubber portion along the outer surface of the at least one of the sidewall portions or one of the bead portions adjacent to the at least one of the sidewall portions is 5 mm or more and 30 mm or less in a tire meridian section.

7. The pneumatic tire according to claim 6 , wherein the length of the inner rubber portion is 10 mm or more and 30 mm or less.

8. The pneumatic tire according to claim 1 further comprising:
a first outer surface vulcanized in a tread mold and including an outer surface of the tread portion and outer surfaces of outer parts in a tire radial direction of the sidewall portions;
a pair of second outer surfaces vulcanized in sidewall molds; and
a pair of boundaries each defined between the first outer surface and a respective one of the second outer surfaces and including a burr, wherein
the entire different color rubber layer is located radially inside one of the boundaries of the at least one of the sidewall portions, and
in a tire meridian section, a distance along the outer surface of the at least one of the sidewall portions from the one of the boundaries of the at least one of the sidewall portions to an outer end in the tire radial direction of the different color rubber layer is 10 mm or more and 30 mm or less.

9. The pneumatic tire according to claim 8 , wherein
the outer surface of the at least one of the sidewall portions has a raised portion,
the raised portion has a top surface located on an outer side in the tire axial direction,
the different color rubber layer is exposed in the top surface,
the different color rubber layer has an extension extending radially outward under the outer surface of the at least one of the sidewall portions from a portion of the different color rubber layer included in the raised portion, and
in a tire meridian section, the extension has a length along the outer surface of the at least one of the sidewall portions larger than a distance along the outer surface of the at least one of the sidewall portions from one of the boundaries of the at least one of the sidewall portions to the outer end in a tire radial direction of the different color rubber layer.

10. The pneumatic tire according to claim 1 , wherein
the different color rubber layer has an axially outer surface covered by a cover rubber layer except for the at least a part exposed in the outer surface of the at least one of the sidewall portions, and
the different color rubber layer is in contact only with the barrier rubber layer and not with any other rubber material, except for the cover rubber layer.

11. The pneumatic tire according to claim 10 , wherein the cover rubber layer has a thickness of 0.5 mm or more and 1.0 mm or less.

12. The pneumatic tire according to claim 10 , wherein the cover rubber layer is formed of the same rubber compounding as the barrier rubber layer.

13. The pneumatic tire according to claim 5 , wherein the barrier rubber layer includes 40% or more of the butyl-based rubber.

14. The pneumatic tire according to claim 5 , wherein the barrier rubber layer is formed entirely of a uniform rubber compounding.

15. The pneumatic tire according to claim 5 , wherein the barrier rubber layer contains an inorganic clay mineral including at least one of kaolin clay, clay, mica, feldspar, and a hydrous complex of silica and alumina.

16. The pneumatic tire according to claim 1 , wherein the rubber compounding agents include an anti-aging agent.

17. The pneumatic tire according to claim 1 . wherein
the carcass is formed by a pair of carcass plies,
the carcass includes a main body portion and a pair of turned up portions,
the main body portion extends between bead cores of the bead portions, one bead core in each of the bead portions,
each of the turned up portions is connected with the main body portion and turned up around a respective one of the bead cores to extend outward in a tire radial direction, and
in each of the turned up portions, outer ends of the carcass plies are displaced in the tire radial direction from each other.

18. A pneumatic tire comprising:
a tread portion;
a pair of sidewall portions;
a pair of bead portions;
a carcass extending from a first of the bead portions to a second of the bead portions;
a first outer surface vulcanized in a tread mold and including an outer surface of the tread portion and outer surfaces of outer parts in a tire radial direction of the sidewall portions;
a pair of second outer surfaces vulcanized in sidewall mold

Assignees

• Sumitomo Rubber Ind

Inventors

• Utsumi Daisuke

Classifications

• B60C13/02

  Arrangement of grooves or ribs · CPC title

• B60C1/0025

  Compositions of the sidewalls · CPC title

• Y02T10/86

  Optimisation of rolling resistance, e.g. weight reduction · CPC title

• B60C2013/045

  comprising different sidewall rubber layers · CPC title

• B60C2013/005

  Physical properties of the sidewall rubber · CPC title