Circular body, circular body unit, and image forming apparatus
View Patent ↗This invention provides a circular body, which is used for an image forming apparatus employing an electrophotographic system, the circular body containing: at least an inner layer containing resin and an outer layer that is laminated on an outer circumferential surface side of the inner layer and contains resin; and, as a conductive agent, polyaniline in the outer layer and carbon black in the inner layer; and satisfying the following relational expressions (1) and (2): 13.0≦C1≦15.0 (1) 21.5≦C2≦25.0 (2), wherein C 1 represents the content (parts by weight) of the polyaniline with respect to 100 parts by weight of the resin forming the outer layer, and C 2 represents the content (parts by weight) of the carbon black with respect to 100 parts by weight of the resin forming the inner layer, as well as a circular body unit using the circular body and an image forming apparatus using the circular body.
1. A circular body, which is used for an image forming apparatus employing an electrophotographic system, the circular body comprising:
at least an inner layer containing resin and an outer layer that is laminated on an outer circumferential surface side of the inner layer and contains resin; and
as a conductive agent, polyaniline in the outer layer and carbon black in the inner layer, and
satisfying the following relational expressions (1) and (2):
13.0≦C1≦15.0 (1)
21.5≦C2≦25.0 (2),
wherein C 1 represents the content (parts by weight) of the polyaniline based on 100 parts by weight of the resin forming the outer layer, and C 2 represents the content (parts by weight) of the carbon black based on 100 parts by weight of the resin forming the inner layer.
2. The circular body of claim 1 , wherein C 1 satisfies the following relational expression:
13.3≦C1≦14.7.
3. The circular body of claim 1 , wherein C 1 satisfies the following relational expression:
13.6≦C1≦14.4.
4. The circular body of claim 1 , wherein C 2 satisfies the following relational expression:
22.0≦C2≦24.5.
5. The circular body of claim 1 , wherein C 2 satisfies the following relational expression:
22.5≦C2≦24.0.
6. The circular body of claim 1 , satisfying the following relational expression (3):
50 ≦du/ ( du+dl )×100≦80 (3),
wherein du represents a film thickness (μm) of the outer layer, and dl represents a film thickness (μm) of the inner layer.
7. The circular body of claim 6 , wherein du and dl satisfy the following relational expression:
55 ≦du/ ( du+dl )×100≦76.
8. The circular body of claim 6 , wherein du and dl satisfy the following relational expression:
61 ≦du/ ( du+dl )×100≦74.
9. The circular body of claim 1 , wherein a sum of a thickness of the inner layer and a thickness of the outer layer is from 50 μm to 130 μm.
10. The circular body of claim 1 , wherein the resin is
a thermoplastic resin selected from the group consisting of polycarbonate resin, polyvinylidene fluoride resin, polyalkylene phthalate resin, a blended material of polycarbonate/polyalkylene phthalate, and an ethylenetetrafluoroethylene copolymer, or
a thermosetting resin selected from the group consisting of polyimide, polyamidoimide, and a copolymer of polyimide and polyamide.
11. A circular body tensioning device comprising:
the circular body of claim 1 ; and
two or more rotating members for rotatably passing therearound the circular body from an inner surface side in a state in which tension is applied.
12. An image forming apparatus comprising:
an image support;
a charging device for charging the image support;
an exposure device for forming an electrostatic latent image on the image support charged by the charging device,
a developing device for developing the electrostatic latent image on the image support to form a toner image;
a primary transfer unit for transferring the toner image to an intermediate transfer belt;
a secondary transfer unit for transferring the toner image transferred to the intermediate transfer belt to a transfer-receiving medium; and
a fixing device for fixing the toner image on the transfer-receiving medium,
the intermediate transfer belt being the circular body of claim 1 .
13. The image forming apparatus according to claim 12 , wherein the toner image is a full color multiple toner image.
14. The image forming apparatus according to claim 12 , wherein, in the primary transfer unit, the surface of a primary transfer member touching an inner surface of the intermediate transfer belt is formed of metal.
15. The image forming apparatus according to claim 12 , wherein, in the secondary transfer unit, the surface of a secondary transfer member touching the inner surface of the intermediate transfer belt is formed of metal.
16. The image forming apparatus according to claim 14 , wherein the metal is metal having a surface plated with nickel, copper, or chromium.
17. The image forming apparatus according to claim 15 , wherein the metal is metal having a surface plated with nickel, copper, or chromium.