| Research Abstract |
Recently electrophotography is widely applied for various non-impact printing systems, for example photo-copying machines, laser beam printers, LED printers, etc. Although two-component developers are mainly used in the systems at the present time, mono-component developer is more desirable to improve their maintenance. Scince a mono-component developer usually contains magnetic materials, however, it is difficult to make color mono-component developers.
We have studied fundamental properties and conitions which non-magnetic monocomponent developers must have. First electrical properties of several kinds of polymer powders, such as polystylene, epoxy, polyethylene, etc. were studied, which may be the main constituent of the mono-component developers. It was found that polymers, such as polyvinyl alcohol, polyvinyl chloride, nylon, could not keep charge for a long time. While, polymer powders, such as polyethylene, epoxy, Teflon, etc. could keep charge for more than several days.
Next, electrical properties of the powders, consisting of a polymer and a pigment, were characterized. The amounts of tribo charge in those powders were in the range og 1 - 10 <micrn>C/g. Electrical properties of the pwders are similar to those of the main polmers, for example, the pwder, consisting of polyvinyl chloride and a pigment, cannot keep charge for a long time. It is concluded that polyethylene, epoxy, etc. may be the main polymer for mono-component developers.
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