| 摘要 |
PROBLEM TO BE SOLVED: To assure the potential necessary for transfer and to enable uniform transfer without using a high-voltage powder source at all by providing a transfer roller with an electret layer having permanent charges by permanent polarization on its surface. SOLUTION: This transfer roller has a base body roller 2 having a shaft 1 and is formed with the electret layer 3 on its surface. A metallic roller or a conductive resin roller dispersed with conductive powder is generally used as the base body roller 2 and may be an insulative roller consisting of various kinds of insulative resins, etc. The electret layer 3 may be obtained by electreting a dielectric substance and may be easily formed by, for example, winding an electreted dielectric sheet around the surface of the base body roller 2. Sheets consisting of fluororesins, such as PFA resins, PTFE resins and FEP resins, are particularly adequate in terms of charge holdability and durability, as the dielectric sheet forming the electret layer 3.
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