Pneumatic tire

Patent metadata

Field	Value
Publication number	US-12049111-B2
Application number	US-202117543784-A
Country	US
Kind code	B2
Filing date	Dec 7, 2021
Priority date	Dec 24, 2020
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

A pneumatic tire can include a tread portion, a pair of sidewall portions, a pair of bead portions, and a carcass. At least one of the sidewall portions can include a first sidewall rubber. The first sidewall rubber can include a base rubber layer, a different color rubber layer, and a barrier rubber layer. The base rubber layer can be in contact with the carcass. At least a part of the different color rubber layer can be exposed in the outer surface of the at least one of the sidewall portions. The barrier rubber layer can be arranged between the different color rubber layer and the base rubber layer. The barrier rubber layer can have a rubber compounding to suppress migration of rubber compounding agents on the base rubber layer side to the different color rubber layer. The barrier rubber layer can have a thickness of 1.0 mm or less.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a tread portion;
a pair of sidewall portions;
a pair of bead portions;
a carcass extending from one of the bead portions to another one of the bead portions;
a first outer surface including an outer surface of the tread portion and outer surfaces of outer parts in a tire radial direction of the sidewall portions and corresponding to an outer surface of a portion of the tire vulcanized in a tread mold;
second outer surfaces extending radially inward from the first outer surface and each forming the outer surface of a respective one of the sidewall portions other than the first outer surface and each corresponding to an outer surface of a portion of the tire vulcanized in a sidewall mold; and
a boundary defined between the first outer surface and one of the second outer surfaces,
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 base rubber layer, a different color rubber layer, and a barrier rubber layer,
the base rubber layer is in contact with the carcass,
the different color rubber layer has a color different from a basic color of a sidewall 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 sidewall outer surface of the at least one of the sidewall portions,
the barrier rubber layer is between the different color rubber layer and the base rubber layer,
the barrier rubber layer has a rubber compounding to suppress migration of rubber compounding agents on the base rubber layer side to the different color rubber layer,
the barrier rubber layer has a thickness of 1.0 mm or less,
the barrier rubber layer has an innermost end and an outmost end in the tire radial direction each exposed in an outer surface of the pneumatic tire without protruding from the outer surface of the at least one of the sidewall portions,
the at least one of the sidewall portions has the boundary,
the boundary includes a burr,
in the at least one of the sidewall portions, the different color rubber layer is entirely arranged radially inside the boundary,
in a tire meridian section, a distance from the boundary to an outmost end in the tire radial direction of the different color rubber layer is 10 mm or more and 30 mm or less,
the different color rubber layer includes an exposed portion exposed in the outer surface of the at least one of the sidewall portions,
the different color rubber layer has a thickness of 1.0 mm or more and 2.0 mm or less at a position away from the exposed portion by 10 mm outward in the tire radial direction,
each of the bead portions includes a clinch rubber forming a bead portion outer surface of a respective one of the bead portions,
the barrier rubber layer has a part exposed in the sidewall outer surface of the at least one of the sidewall portions, and
a distance along the sidewall outer surface of the at least one of the sidewall portions from an inner end in the tire radial direction of the barrier rubber layer to the clinch rubber is 10 mm or more and 30 mm or less.

2. The pneumatic tire according to claim 1 , wherein
the first sidewall rubber includes a cover rubber layer covering a different color rubber layer outer surface in the tire axial direction of the different color rubber layer except for a part of the different color rubber layer outer surface of the different color rubber layer left uncovered and exposed, and
the cover rubber layer is formed of a rubber compounding same as the barrier rubber layer.

3. The pneumatic tire according to claim 1 , wherein a distance in the tire radial direction from a bead baseline to an outer end in the tire radial direction of the barrier rubber layer is 65% or more of a tire section height.

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
the outer surface of the at least one of the sidewall portions is provided with a raised portion,
the raised portion has a top surface located on an outer side in the tire axial direction, and
the different color rubber layer is exposed in the top surface of the raised portion.

7. The pneumatic tire according to claim 1 , wherein
the base rubber layer includes a portion in contact with the clinch rubber, and
the barrier rubber layer and the different color rubber layer are spaced apart from the clinch rubber over an entirety thereof.

8. The pneumatic tire according to claim 7 further comprising a tread rubber forming the tread portion, wherein
the base rubber layer includes a portion in contact with the tread rubber, and
the barrier rubber layer and the different color rubber layer are spaced apart from the tread rubber over an entirety thereof.

9. The pneumatic tire according to claim 8 , wherein an outer end in the tire axial direction of the tread rubber is covered by the base rubber layer.

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

11. 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.

12. The pneumatic tire according to claim 1 , wherein a maximum thickness of the barrier rubber layer is 0.5 mm or more and 1.0 mm or less.

13. The pneumatic tire according to claim 1 , wherein a distance along the sidewall outer surface of the at least one of the sidewall portions from one of tread edges on the at least one of the sidewall portions side to an outer end in the tire radial direction of the barrier rubber layer is 20 mm or more.

14. The pneumatic tire according to claim 3 , wherein the distance from the bead baseline to the outer end of the barrier rubber layer is 75% or less of the tire section height.

15. The pneumatic tire according to claim 2 , wherein 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.

16. The pneumatic tire according to claim 2 , wherein the cover rubber layer has a thickness of 0.5 mm or more and 1.0 mm or less.

17. The pneumatic tire according to claim 2 , wherein
the outer surface of the at least one of the sidewall portions has a raised portion,
the raised portion has a top surface on an outer side in the tire axial direction,
the different color rubber layer is exposed in the top surface of the raised portion, and
the cover rubber layer is exposed on opposite sides of the raised portion in the tire radial direction at opposite portions where the cover rubber layer does not protrude from the sidewall outer surface of the at least one of the sidewall portions.

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

Assignees

• Sumitomo Rubber Ind

Inventors

• Mizokawa Hiroki

Classifications

• B60C2013/045

  comprising different sidewall rubber layers · CPC title

• B60C13/02

  Arrangement of grooves or ribs · CPC title

• B60C1/0025

  Compositions of the sidewalls · CPC title

• B60C2013/005

  Physical properties of the sidewall rubber · CPC title

• B60C13/001 Primary

  Decorating, marking or the like · CPC title