Honeycomb structure

1. A honeycomb structure comprising: a tubular honeycomb structure section including porous partition walls which partition and form a plurality of cells extending from one end surface to the other end surface to become through channels of a fluid, and an outer peripheral wall positioned in an outermost periphery; and a pair of electrode sections arranged on a side surface of the honeycomb structure section,

wherein an electrical resistivity of the honeycomb structure section is from 1 to 200 Ωcm,

each of the pair of electrode sections is formed into a band-like shape extending in a cell extending direction of the honeycomb structure section,

the one electrode section in the pair of electrode sections is disposed on an opposite side of the other electrode section in the pair of electrode sections via the center of the honeycomb structure section in a cross section which is perpendicular to the cell extending direction,

an angle which is 0.5 times as large as a central angle of each of the electrode sections is from 15 to 65° in the cross section which is perpendicular to the cell extending direction, and

each of the electrode sections is formed so as to become thinner from a center portion in a peripheral direction toward both ends in the peripheral direction in the cross section which is perpendicular to the cell extending direction.

2. The honeycomb structure according to claim 1 ,

wherein each of the electrode sections is constituted of the center portion in the peripheral direction, and expanded portions positioned on both sides of the center portion in the peripheral direction in the cross section which is perpendicular to the cell extending direction, and

the electrical resistivity of the center portion of the electrode section is smaller than that of each of the expanded portions of the electrode section.

3. The honeycomb structure according to claim 2 ,

wherein the electrical resistivity of the center portion of the electrode section is from 0.1 to 10 Ωcm.

4. The honeycomb structure according to claim 3 ,

wherein the electrical resistivity of the expanded portion of the electrode section is from 0.1 to 100 Ωcm.

5. The honeycomb structure according to claim 4 ,

wherein a thickness of the center portion of the electrode section is from 0.2 to 5.0 mm.

6. The honeycomb structure according to claim 5 ,

wherein in the cross section which is perpendicular to the cell extending direction, the angle which is 0.5 times as large as the central angle of the center portion of the electrode section is from 5 to 25°.

7. The honeycomb structure according to claim 2 ,

wherein the electrical resistivity of the expanded portion of the electrode section is from 0.1 to 100 Ωcm.

8. The honeycomb structure according to claim 2 ,

wherein a thickness of the center portion of the electrode section is from 0.2 to 5.0 mm.

9. The honeycomb structure according to claim 2 ,

wherein in the cross section which is perpendicular to the cell extending direction, the angle which is 0.5 times as large as the central angle of the center portion of the electrode section is from 5 to 25°.

10. The honeycomb structure according to claim 1 ,

wherein each of the electrode sections does not have any boundary portion and is continuously formed in the cross section which is perpendicular to the cell extending direction.

11. The honeycomb structure according to claim 10 ,

wherein the electrical resistivity of the electrode section is from 0.1 to 100 Ωcm.

12. The honeycomb structure according to claim 11 ,

wherein at a center position of the center portion of each of the electrode sections in the cell extending direction, there is disposed an electrode terminal protruding portion to which an electric wiring is fastened.

13. The honeycomb structure according to claim 1 ,

wherein at a center position of the center portion of each of the electrode sections in the cell extending direction, there is disposed an electrode terminal protruding portion to which an electric wiring is fastened.