| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain stable triboelectric property and excellent durability. SOLUTION: This carrier is composed of a powder of spherical composite particles having 1 to 1000μm average particle diameter. The spherical composite particle is composed of a core particle comprising a powder of iron oxide particles and a hardened phenol resin, and a coating layer comprising a hardened phenol resin and silica ((SiO2 )n .H2 O) formed on the surface of the core particle. The amt. of the iron oxide particle powder is specified to 80 to 99wt.%. This carrier is produced in the following processes. The iron oxide particle powder, phenols and aldehydes are allowed to react in a water-based medium in the presence of a basic catalyst to produce core particles comprising a hardened phenol resin and iron oxide particle powder. Then silicate is added to the water-based medium containing the core particles and the unreacted phenols remaining in the medium to allow the reaction of the silicate and the remaining phenols. Thus, a coating film of a phenol resin and silica ((SiO2 )n .H2 O) is formed on the surface of the core particle.</p> |
