| 摘要 |
PROBLEM TO BE SOLVED: To obtain a conductive roller which is low in hardness and small in permanent strains and is free from the contamination of a photoreceptor by providing the roller with a conductive elastic layer consisting of specific polyurethane elastomer. SOLUTION: The conductive roller, such as electrostatic charge roller or developing roller 2, is used around the photoreceptor 1 of an electrophotographic device. The developing roller 2 is provided with the conductive elastic layer concentrically with the outer periphery of the revolving shaft 5. The conductive elastic layer consists of the polyurethane elastomer obtd. by bringing the polyisocyanate consisting of the trimer of hexamethylene diisocyanate, buret substance or the mixture composed thereof and polyol consisting essentially of high mol.wt. polypropylene polyol into reaction at an isocyanate index of 80 to 120. The high mol.wt. polypropylene polyol having a mol.wt. of 2000 to 8000 and a functional group number of 2 to 3 is more preferably used. |
