| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electroconductive roller such as a developing roller, a toner-conveying roller, a charging roller or the like that is inexpensive and exhibits good performances by forming a resin coating film layer by application directly onto an elastic layer composed of a polyurethane foam with good control of the surface properties while omitting formation of a sealing layer. <P>SOLUTION: The electroconductive roller comprises an elastic layer composed of a polyurethane foam prepared by the mechanical blowing of a polyurethane raw material comprising a polyol component and an isocyanate component, characterized in that the polyurethane foam constituting the elastic layer has a density of 0.75-0.99 g/cm<SP>3</SP>from the surface to a depth of 0.05 mm and a density of 0.2-0.7 g/cm<SP>3</SP>within the range of 0.05 mm thickness from the central part in the thickness direction with the difference of the density between the surface part and the central part of at least 0.25 g/cm<SP>3</SP>. <P>COPYRIGHT: (C)2009,JPO&INPIT |
