On the Eleetrophotographie Behaviour of Pink Zinc Oxide

The electrophotographic properties of pink zinc oxide powder embedded in silicone resin have been investigated in a standard measuring unit with a sample holder on a turntable, a translucent measuring probe, and a corona discharge in a vacuum box. The charging and subsequent discharging in the dark and under illumination have been recorded. From these curves, the half-life of the light-decay of pink zinc oxide layers was evaluated. Depending on a suitable preparation, the layers exhibited a negative charging up to 850 V and a positive charging up to 500 V. As could be demonstrated, both the dark-decay and the speed of the light discharge of some layers were comparable with electrofax paper available on the market for reprographic purposes. The remaining residual charge, however, is at present larger than that of electrofax paper. This larger residual voltage of the layers, however, can be possibly caused by the rather large portion of resin in the layers. The spectral dependence of the photocurrent of the pink zinc oxide resin layers exhibits two maxima, one at 490 and the other at 585 nm caused by the remission maximum and the fluorescence, respectively.