Transfer roller

A transfer roller for use in contact with a photoconductive body, comprising:

• a metal shaft;
• a rubber roller formed around the shaft, said rubber roller being sponge-like and electrically semiconductive, and containing a low-molecular material;
• and
• a resin tube having a lower resin layer formed on said rubber roller and an upper resin layer formed on said lower resin layer;
• wherein one of the upper resin layer and the lower resin layer comprises carbon black which has a sealing effect so that the low-molecular material forming said rubber roller is prevented from passing through said resin tube to the photoconductive body, and the other of the upper resin layer and the lower resin layer includes an organic ion electrically conductive material which stabilizes an electrical resistance of said resin tube.

A transfer roller for use in contact with a photoconductive body, comprising:

• a metal shaft;
• a rubber roller formed around the shaft, said rubber roller being sponge-like and electrically semiconductive, and containing a low-molecular material;
• and
• a lower resin layer formed on said rubber roller and an upper resin layer formed on said lower resin layer;
• wherein a first one of the upper resin layer and the lower resin layer comprises carbon black that increases a sealing effect so that the first one of the upper resin layer and the lower resin layer has a higher sealing effect against the low-molecular material forming said rubber roller than a second one of the upper resin layer and the lower resin layer;
• and
• the second one of the upper resin layer and the lower resin layer comprises an organic ion electrically conductive material that increases a stability of an electrical resistance so that the second one of the upper resin layer and the lower resin layer has a more stable electrical resistance over duration and value of a voltage applied thereto than the first one of the upper resin layer and the lower resin layer.