Pneumatic tire

Patent metadata

Field	Value
Publication number	US-2020180368-A1
Application number	US-201716305653-A
Country	US
Kind code	A1
Filing date	May 19, 2017
Priority date	May 31, 2016
Publication date	Jun 11, 2020
Grant date	—

Abstract

Provided is a pneumatic tire which prevents accumulation of static electricity during travelling, which inhibits the tire from rising in an electric resistance with the passage of time, and which is reduced in a rolling resistance of the tire and excellent in durability thereof. In the pneumatic tire described above, a conductive rubber is arranged for a ply coating rubber of one surface, and a non-conductive rubber is arranged for the ply coating rubber of the other surface; assuming that the respective thicknesses thereof are T1 and T2, a carcass ply has a ply in which T1/T2 satisfies 0.2≤T1/T2≤0.9; and the conductive ply coating rubber is arranged at a tread side, and the non-conductive ply coating rubber is arranged at an inner liner side.

First claim

1 . A pneumatic tire comprises:
a carcass composed of at least one carcass ply as a skeleton extending in a toroidal form across a pair of beads; at least one belt layer arranged at an outside of a crown part of the carcass in a tire radial direction; a tread part forming a grounding surface part which is provided at an outside of the belt layer in a tire radial direction; and an inner liner layer arranged at an inside of the carcass ply in a tire radial direction, wherein a conductive rubber is arranged for a ply coating rubber of one surface, and a non-conductive rubber is arranged for the ply coating rubber of the other surface; assuming that the respective thicknesses thereof are T 1 and T 2 , the carcass ply has a ply in which T 1 /T 2 is 0.2≤T 1 /T 2 ≤0.9; and the conductive ply coating rubber is arranged at a tread side, and the non-conductive ply coating rubber is arranged at an inner liner side.

2 . The pneumatic tire as described in claim 1 , wherein the conductive ply coating rubber contains a conductive material.

3 . The pneumatic tire as described in claim 1 , wherein the non-conductive ply coating rubber contains carbon black having a nitrogen adsorption specific surface area (N 2 SA) of 30 to 40 m 2 /g.

4 . The pneumatic tire as described in claim 1 , wherein assuming that the loss tangents of the ply coating rubbers at 60° C. are tan D 1 and tan D 2 respectively, the loss tangents satisfy tan D 1 ≥tan D 2 .

5 . The pneumatic tire as described in claim 1 , wherein (T 1 ×tan D 1 )/(T 2 ×tan D 2 ) in the respective thicknesses T 1 and T 2 and the loss tangents tan D 1 and tan D 2 of the ply coating rubbers satisfy 0.2≤(T 1 ×tan D 1 )/(T 2 ×tan D 2 )≤1.2.

6 . The pneumatic tire as described in claim 1 , wherein assuming that the storage elastic moduli of the ply coating rubbers at 60° C. are E 1 and E 2 respectively, E 1 /E 2 satisfies 1.0≤E 1 /E 2 ≤1.5.

7 . The pneumatic tire as described in claim 1 , wherein the sum T 1 +T 2 of the respective thicknesses T 1 and T 2 of the ply coating rubbers satisfies 0.9 mm≤T 1 +T 2 ≤1.4 mm.

8 . The pneumatic tire as described in claim 1 , wherein the kinds of a cross-linking agent and a vulcanization accelerator contained in the conductive rubber and the non-conductive rubber are the same.

9 . The pneumatic tire as described in claim 1 , wherein assuming that the 10% vulcanization times (T 0 . 1 ) of the conductive rubber and the non-conductive rubber are s 1 and s 2 respectively, s 1 /s 2 satisfies 0.9≤s 1 /s 2 ≤1.1.

10 . A production method for a ply comprising a step of arranging a conductive rubber containing a conductive material on the ply coating rubber of one surface and a non-conductive rubber containing carbon black having a nitrogen adsorption specific surface area (N 2 SA) of 30 to 40 m 2 /g on the ply coating rubber of the other surface to coat the upper and lower surfaces at the same time.

11 . The production method for the ply as described in claim 10 , wherein the kinds of a cross-linking agent and a vulcanization accelerator contained in the conductive rubber and the non-conductive rubber are the same.

12 . A production method for a pneumatic tire comprising a step of using the ply produced by the method as described in claim 10 to arrange the conductive ply coating rubber at a tread side, and the non-conductive ply coating rubber at an inner liner side.

13 . The pneumatic tire as described in claim 2 , wherein the non-conductive ply coating rubber contains carbon black having a nitrogen adsorption specific surface area, N 2 SA of 30 to 40 m 2 /g.

14 . The pneumatic tire as described in claim 2 , wherein assuming that the loss tangents of the ply coating rubbers at 60° C. are tan D 1 and tan D 2 respectively, the loss tangents satisfy tan D 1 ≥tan D 2 .

15 . The pneumatic tire as described in claim 2 , wherein (T 1 ×tan D 1 )/(T 2 ×tan D 2 ) in the respective thicknesses T 1 and T 2 and the loss tangents tan D 1 and tan D 2 of the ply coating rubbers satisfy 0.2≤(T 1 ×tan D 1 )/(T 2 ×tan D 2 )≤1.2.

16 . The pneumatic tire as described in claim 2 , wherein assuming that the storage elastic moduli of the ply coating rubbers at 60° C. are E 1 and E 2 respectively, E 1 /E 2 satisfies 1.0≤E 1 /E 2 ≤1.5.

17 . The pneumatic tire as described in claim 2 , wherein the sum T 1 +T 2 of the respective thicknesses T 1 and T 2 of the ply coating rubbers satisfies 0.9 mm≤T 1 +T 2 ≤1.4 mm.

18 . The pneumatic tire as described in claim 2 , wherein the kinds of a cross-linking agent and a vulcanization accelerator contained in the conductive rubber and the non-conductive rubber are the same.

19 . The pneumatic tire as described in claim 2 , wherein assuming that the 10% vulcanization times, T 0 . 1 of the conductive rubber and the non-conductive rubber are s 1 and s 2 respectively, s 1 /s 2 satisfies 0.9≤s 1 /s 2 ≤1.1.

20 . The production method for a pneumatic tire comprising a step of using the ply produced by the method as described in claim 11 to arrange the conductive ply coating rubber at a tread side, and the non-conductive ply coating rubber at an inner liner side.

Assignees

• Bridgestone Corp

Inventors

• Yanagioka Masaki
• Yonemoto Makiko

Classifications

• Y02T10/86

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

• B60C2009/0276

  Modulus; Hardness; Loss modulus or "tangens delta" · CPC title

• B60C2009/0269

  Physical properties or dimensions of the carcass coating rubber · CPC title

• B60C1/0041

  Compositions of the carcass layers · CPC title

• B60C2009/0284

  Thickness · CPC title