Fixing belt, fixing device, and method for manufacturing fixing belt

1. An endless fixing belt comprising:

a most inner layer; and

an outer layer disposed outside the most inner layer,

wherein the most inner layer contains filler particles, 75% or more of the filler particles having an aspect ratio of 5 or more and being oriented at an angle within ±30° from a longitudinal direction of the fixing belt.

2. The fixing belt according to claim 1 , wherein the most inner layer satisfies 2 μm≦Rz≦6 μm, where Rz is the surface roughness of the most inner layer.

3. The fixing belt according to claim 1 , wherein the filler particles contained in the most inner layer are at least one of carbon fibers, carbon nanotubes, aluminum borate, zinc oxide, titanium oxide, silicon nitride, silicon carbide, and potassium titanate.

4. The fixing belt according to claim 3 , wherein the most inner layer comprises a polyimide resin.

5. The fixing belt according to claim 1 , wherein the outer layer comprises a fluorine resin.

6. The fixing belt according to claim 5 , further comprising an elastic layer between the most inner layer and the outer layer.

7. A fixing device comprising:

a first rotating member and a second rotating member configured to fix a toner image formed on a sheet in a nip therebetween, the first rotating member being an endless belt including a most inner layer and an outer layer disposed outside the most inner layer; and

a pressing member disposed inside the belt and configured to press the belt against the second rotating member,

wherein the most inner layer contains filler particles, 75% or more of the filler particles having an aspect ratio of 5 or more and being oriented at an angle within ±30° from a longitudinal direction of the belt.

8. The fixing device according to claim 7 , wherein the most inner layer satisfies 2 μm≦Rz≦6 μm, where Rz is the surface roughness of the inner layer.

9. The fixing device according to claim 7 , wherein the filler particles contained in the most inner layer are at least one of carbon fibers, carbon nanotubes, aluminum borate, zinc oxide, titanium oxide, silicon nitride, silicon carbide, and potassium titanate.

10. The fixing device according to claim 9 , wherein the most inner layer comprises a polyimide resin.

11. The fixing device according to claim 7 , wherein the most inner layer is coated with a lubricant.

12. The fixing device according to claim 7 , wherein the outer layer comprises a fluorine resin.

13. The fixing device according to claim 12 , wherein the belt further includes an elastic layer between the most inner layer and the outer layer.

14. The fixing device according to claim 7 , wherein

the belt further includes a base layer, and

the fixing device further comprises a coil configured to cause the base layer to generate heat by electromagnetic induction.

15. The fixing device according to claim 7 , further comprising a resistor disposed on the pressing member and configured to generate heat when supplied with current.

16. A method for manufacturing an endless fixing belt, comprising the steps of:

adding filler particles having an aspect ratio of 5 or more to a resin;

providing a base layer for forming the fixing belt; and

applying the resin containing the filler particles inside the base layer while relatively moving the resin containing the filler particles relative to the base layer in a longitudinal direction of the base layer.

17. The method for manufacturing an endless fixing belt according to claim 16 , wherein a holding mechanism that holds the base layer is moved relative to a coating mechanism that applies the resin containing the filler particles in the applying step.

18. The method for manufacturing an endless fixing belt according to claim 16 , further comprising the steps of:

forming an elastic layer outside the base layer; and

forming a toner release layer outside the elastic layer.

19. The method for manufacturing an endless fixing belt according to claim 16 , wherein the filler particles added in the adding step are at least one of carbon fibers, carbon nanotubes, aluminum borate, zinc oxide, titanium oxide, silicon nitride, silicon carbide, and potassium titanate.

20. The method for manufacturing an endless fixing belt according to claim 16 , wherein

the resin is a polyimide resin, and

the filler particles added to the resin in the adding step are at least one of carbon fibers, carbon nanotubes, aluminum borate, zinc oxide, titanium oxide, silicon nitride, silicon carbide, and potassium titanate.