Pneumatic tire

Abstract

The objective of the present invention is to provide a pneumatic tire that can desirably prevent generation of static electricity between the road face and the tire, while maintaining a low rolling resistance, so that the safety in use is further improved. In pneumatic tire of the present invention, each of tread rubber, breaker rubber and sidewall rubber that are respectively formed on a tread section, a breaker section and a sidewall section has a volume resistivity of 1×108 Ω·cm or more, with a conductive layer having a volume resistivity smaller than 1×108 Ω·cm and a thickness in a range from 0.2 to 2.0 mm being formed between a carcass ply forming the carcass and the sidewall rubber, and at least either conductive layer or a rubber cement layer that is formed so as to be made in contact with conductive layer and has a volume resistivity lower than that of the tread rubber is exposed to the surface of the tire.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing that shows right half of a cross-sectional view of a pneumatic tire in accordance with the present invention; and

FIG. 2 is a drawing that shows a tread section 2 of a pneumatic tire I in accordance with the present invention in an enlarged manner.

Claims

1. A pneumatic tire comprising at least: a tread section;a sidewall section;a bead section; anda carcass that reaches said bead section from said tread section through said sidewall section, with a breaker section being placed on the outside of said carcass in a tire radial direction,wherein: each of tread rubber, breaker rubber and sidewall rubber that are respectively formed on said tread section, said breaker section and said sidewall section has a volume resistivity of 1×108 Ω·cm or more, with a conductive layer having a volume resistivity of smaller than 1×108 Ω·cm and a thickness in a range from 0.2 to 2.0 mm being formed between a carcass ply forming said carcass and said sidewall rubber, and at least either said conductive layer or a rubber cement layer that is formed so as to be made in contact with said conductive layer and has a volume resistivity lower than that of said tread rubber is exposed to the surface of the tire.

2. The pneumatic tire according to claim 1, wherein said sidewall section is formed so that a height from the outside end of said sidewall section to the outside end of said tread section in the tire radial direction is set in a range of 0 to 15% of the height from the rim contacting portion to the outer end of said tread section in a tire radial direction in a state where the tire is mounted on a standard rim with a specified inner pressure applied thereto.

3. The pneumatic tire according to claim 1, wherein: said conductive layer contains at least a rubber component and carbon black that is blended in a range from 30 to 100 parts by mass per 100 parts by mass of said rubber component; said carbon black has a nitrogen adsorption specific surface area in a range from 100 m2/g or more to 1500 m2/g or less; and each of said tread rubber, said breaker rubber and said sidewall rubber contains a filler in such a manner that the rate at which silica occupies said filler is set to 50% by mass or more of said filler.

4. The pneumatic tire according to claim 3, wherein said sidewall section is formed so that a height from the outside end of said sidewall section to the outside end of said tread section in the tire radial direction is set in a range of 0 to 15% of the height from the rim contacting portion to the outer end of said tread section in a tire radial direction in a state where the tire is mounted on a standard rim with a specified inner pressure applied thereto.

5. The pneumatic tire according to claim 1, wherein: said conductive layer is formed so as not to be exposed to the surface of said tire; and said rubber cement layer is formed on an area containing one portion of a ground contacting face.

6. The pneumatic tire according to claim 5, wherein said sidewall section is formed so that a height from the outside end of said sidewall section to the outside end of said tread section in the tire radial direction is set in a range of 0 to 15% of the height from the rim contacting portion to the outer end of said tread section in a tire radial direction in a state where the tire is mounted on a standard rim with a specified inner pressure applied thereto.

7. The pneumatic tire according to claim 5, wherein: said conductive layer contains at least a rubber component and carbon black that is blended in a range from 30 to 100 parts by mass per 100 parts by mass of said rubber component; said carbon black has a nitrogen adsorption specific surface area in a range from 100 m/g or more to 1500 m2/g or less; and each of said tread rubber, said breaker rubber and said sidewall rubber contains a filler in such a manner that the rate at which silica occupies said filler is set to 50% or more by mass of said filler.

8. The pneumatic tire according to claim 7, wherein said sidewall section is formed so that a height from the outside end of said sidewall section to the outside end of said tread section in the tire radial direction is set in a range of 0 to 15% of the height from the rim contacting portion to the outer end of said tread section in a tire radial direction in a state where the tire is mounted on a standard rim with a specified inner pressure applied thereto.

9. The pneumatic tire according to claim 5, wherein: said rubber cement layer contains at least a rubber component and carbon black that is blended in a range from 30 to 100 parts by mass per 100 parts by mass of said rubber component; and said carbon black has a nitrogen adsorption specific surface area in a range from 100 m2/g or more to 1500 m2/g or less.

10. The pneumatic tire according to claim 9, wherein said sidewall section is formed so that a height from the outside end of said sidewall section to the outside end of said tread section in the tire radial direction is set in a range of 0 to 15% of the height from the rim contacting portion to the outer end of said tread section in a tire radial direction in a state where the tire is mounted on a standard rim with a specified inner pressure applied thereto.

11. The pneumatic tire according to claim 9, wherein: said conductive layer contains at least a rubber component and carbon black that is blended in a range from 30 to 100 parts by mass per 100 parts by mass of said rubber component; said carbon black has a nitrogen adsorption specific surface area in a range from 100 m2/g or more to 1500 m2/g or less; and each of said tread rubber, said breaker rubber and said sidewall rubber contains a filler in such a manner that the rate at which silica occupies said filler is set to 50% by mass or more of said filler.

12. The pneumatic tire according to claim 11, wherein said sidewall section is formed so that a height from the outside end of said sidewall section to the outside end of said tread section in the tire radial direction is set in a range of 0 to 15% of the height from the rim contacting portion to the outer end of said tread section in a tire radial direction in a state where the tire is mounted on a standard rim with a specified inner pressure applied thereto.