Charging member, process unit cartridge, and image forming apparatus

1. A charging member comprising:

a conductive metal shaft; and

a conductive elastic layer on the shaft,

wherein the conductive elastic layer comprises:

a rubber material; and

a calcium oxide having an average particle size D50 of 18 μm or smaller, and

wherein the rubber material contains 50% to 100% by weight of epichlorohydrin rubber containing 56 mol % or more of an ethylene oxide.

2. The charging member according to claim 1 ,

wherein the rubber material contains 50% to 100% by weight of epichlorohydrin rubber containing 60 mol % or more of an ethylene oxide.

3. The charging member according to claim 1 ,

wherein the rubber material contains 50% to 100% by weight of epichlorohydrin rubber containing 70 mol % or more of an ethylene oxide.

4. The charging member according to claim 1 ,

wherein the calcium oxide is present in an amount of 1 to 15 parts by weight based on 100 parts by weight of the rubber material.

5. The charging member according to claim 1 ,

wherein the calcium oxide is present in an amount of 3 to 10 parts by weight based on 100 parts by weight of the rubber material.

6. The charging member according to claim 1 ,

wherein the calcium oxide having an average particle size D50 of 14 μm or smaller.

7. The charging member according to claim 1 ,

wherein the calcium oxide having an average particle size D50 of 6 μm or smaller.

8. A removable process unit cartridge comprising:

an image carrier; and

a charging unit being in contact with the image carrier and adapted to charge the surface of the image carrier,

wherein the charging unit comprises the charging member according to claim 1 .

9. An image fowling apparatus comprising:

an image carrier; and

a charging unit being in contact with the image carrier and adapted to charge the surface of the image carrier,

wherein the charging unit comprises the charging member according to claim 1 .