Mono-Component Electret Toner for Color Photocopy Machines and Laser Printers

在复印机和激光打印机的发展中，曾尝试将使用前充过电的碳粉应用。首先，通过摩擦充电、电晕充电和电子束辐照对碳粉进行充电，并对碳粉的电荷保持特性进行了研究。在三种充电方式中，摩擦充电的碳粉保持电量的时间最长。对碳粉进行了等离子体处理，提高了碳粉的电荷维持能力。结果发现，氟等离子体处理大大增加了带电碳粉的电荷衰减时间常数。此外，氟等离子体处理使碳粉的充电倾向向负方向偏移。另一方面，氩等离子体处理降低了碳粉的电荷维持能力，使碳粉的充电倾向向正极方向转变。但氟等离子体处理对固定效果有不良影响。采用热激电荷衰减（TSCD）测量方法研究了碳粉的电荷衰减机理。聚丙烯中正电晕充电、负电晕充电和摩擦充电的陷阱深度分别为0.99eV、1.2eV和0.19eV。这些值足够大，可以在碳粉中长期保持电荷。对含电荷控制剂（CCA）的聚合物进行了热刺激电流（TSC）测量。捕获点位于聚合物和CCA之间。最后，检查了与搅拌、运输等处理相关的碳粉电荷的变化，这些变化应该在实际应用中得到清除。

Application of toners, which had been charged before use, was tried to the development in photocopy machines and laser printers. First, toners were charged by tribocharging, corona-charging and electron beam irradiation, and charge keeping characteristics of toners were examined. The toner, when charged by tribocharging, kept its charge for the longest period among the three ways of charging. Plasma treatment was applied to the toners to improve its charge maintaining ability. As a result, fluorine plasma treatment was found to increase the time constant considerably for charge decay from charged toner. In addition, the fluorine plasma treatment shifted charging tendency of the toner in negative direction. On the other hand, argon plasma treatment of toners decreased their charge maintaining ability and shifted their charging tendency in positive direction. However, the fluorine plasma treatment gave wrong influence of fixing.Thermally stimulated charge decay (TSCD) measurements were carried out on charged polymer layers to study the charge decay mechanism from toners. The trap depths in polypropylene were 0.99eV, 1.2eV and 0.19eV for positive corona-charging, negative corona-charging and tribocharging, respectively. These values are large enough for long term charge maintaining in toners. Thermally stimulated current (TSC) measurements were made on polymers containing charge control agent (CCA). Trapping sites were found to be located between the polymer and CCA.Finally, change in toner charge associated with handling, such as agitation, transport, etc. was examined, which should be cleared for practical applications.