Tire, tread for retread tire, method for manufacturing the tread for retread tire, retread tire having the tread for retread tire, and method for manufacturing the retread tire

Patent metadata

Field	Value
Publication number	US-10059070-B2
Application number	US-201213985932-A
Country	US
Kind code	B2
Filing date	Feb 24, 2012
Priority date	Feb 25, 2011
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

Provided are a tire having a small difference in a loss tangent (tan δ) at a tire tread outer surface position and that at a middle position, a tread for a retread tire having an even vulcanization degree in a whole tread rubber area, a tire having the tread for the retread tire, and a method for manufacturing the tire. The tire satisfies the following formula:

−0.05≤(tan δ a −tan δ b )/tan δ b ≤0.05,
where (tan δ a ) represents a loss tangent of strain at 2% at 25° C. in a portion (a) within 1 mm deep from a tire tread outer surface in a direction perpendicular to a tread surface, and (tan δ b ) represents a loss tangent of strain at 2% at 25° C. in a portion (b) within 2 mm from a median center between a tread portion outer surface and a bottom surface in the direction perpendicular to the tread surface.

First claim

The invention claimed is:

1. A method for manufacturing a tread for a retread tire comprising a tread portion having an outer surface and a bottom surface, wherein a vulcanization degree (A) at the position (a) within 1 mm deep from the tread portion outer surface in the direction perpendicular to the tread surface and a vulcanization degree (B) at the position (b) within 2 mm from the median center between the tread portion outer surface and the tread portion bottom surface in the direction perpendicular to the tread surface satisfy the following relationship:
1.1≤ A/B≤ 1.2

comprising vulcanization of an unvulcanized tread for manufacturing the tread portion, wherein, where T represents a time from start of vulcanization to a time when temperature reaches 99.5% of maximum vulcanization temperature,
after T/4 minutes, a vulcanization degree (A T/4 ) at a position (a) within 1 mm deep from the tread portion outer surface in the direction perpendicular to a tread surface and a vulcanization degree (B T/4 ) at a position (b) within 2 mm from a median center between the tread portion outer surface and the bottom surface in a direction perpendicular to the tread surface satisfy the following relationship:
0≤ A T/4 ≤0.13,0≤ B T/4 ≤0.05, and also,

after T/2 minutes, a vulcanization degree (A T/2 ) at the position (a) within 1 mm deep from the tread portion outer surface in the direction perpendicular to the tread surface and a vulcanization degree (B T/2 ) at the position (b) within 2 mm from the median center between the tread portion outer surface and the tread portion bottom surface in the direction perpendicular to the tread surface satisfy the following relationship:
0.1≤ A T/2 ≤0.29,0.05≤ B T/2 ≤0.2,

the vulcanization comprising vulcanization of an unvulcanized tread using a vulcanization press apparatus, and a non-vulcanizable sheet being placed between the vulcanization press apparatus and the unvulcanized tread, and
the non-vulcanizable sheet has a thickness of 0.05 to 3.5 mm and thermal conductivity at 0.02 to 30 W·m −1 ·K −1 , and the non-vulcanizable sheet is paper or nonwoven fabric.

2. The method according to claim 1 , wherein the non-vulcanizable sheet has a melting point at 130° C. or higher and is made of a material that does not cause a crosslinking reaction at least at an outermost surface of a non-vulcanizable surface.

3. A method for manufacturing a retread tire including a step of carrying out vulcanization bonding of the tread manufactured according to claim 1 and a base tire at 80° C. or higher.

Assignees

• Miura Takahiro
• Bridgestone Corp

Inventors

• Miura Takahiro

Classifications

• Y10T428/24942

  including components having same physical characteristic in differing degree · CPC title

• B60C2011/0025

  Modulus or tan delta · CPC title

• B60C11/02

  Replaceable treads · CPC title

• B60C11/005

  with cap and base layers · CPC title

• B29D2030/0677

  Controlling temperature differences · CPC title