Patent 7356293 was granted and assigned to Sumitomo Rubber Industries on April, 2008 by the United States Patent and Trademark Office.
A toner transport roller (10) including a sealing member (3), for preventing leak of toner, which contacts a peripheral surface of a rubber roller (1) thereof slidably. The toner transport roller (10) contains 3 to 50 parts by mass of alumina for 100 parts by mass of an ionic-conductive rubber and a loss tangent-adjusting filler. The annular sealing member (3) is slidably fitted on both ends of the rubber roller (1) in an axial direction thereof. It is preferable that the specific gravity of the ionic-conductive rubber is set to not less than 1.2.