DEVELOPING ROLLER, AND DEVELOPING DEVICE, PROCESS CARTRIDGE AND IMAGE FORMING METHOD AND APPARATUS USING THE DEVELOPING ROLLER

摘要

A developing roller to bear toner thereon is provided. The developing roller includes a cylindrical electroconductive substrate; an electroconductive elastic layer located on a peripheral surface of the cylindrical electroconductive substrate; and a toner bearing layer located on a peripheral surface of the electroconductive elastic layer. The toner bearing layer includes a polyurethane resin, which is a reaction product of at least an isocyanate compound having an isocyanurate structure and a polyol at a NCO/OH molar ratio of from 90 to 110. The toner bearing layer has a water contact angle of from 135° to 155°, and a static friction coefficient of from 0.10 to 0.15.

主权项

1. A developing roller comprising:
A cylindrical electroconductive substrate; an electroconductive elastic layer located on a peripheral surface of the cylindrical electroconductive substrate; and a toner bearing layer located on a peripheral surface of the electroconductive elastic layer, wherein the toner bearing layer includes a polyurethane resin which is a reaction product of at least an isocyanate compound having an isocyanurate structure and a polyol at a NCO/OH molar ratio of from 90 to 110, and the toner bearing layer has a water contact angle of from 135° to 155°, and a static friction coefficient of from 0.10 to 0.15.