Tsuneaki Kawanishi

Effect of Molecular Orbital Distributions on Charge Transport Properties of Polymers Doped with Triphenylamine Derivatives

The hole drift mobilities of polymers doped with triphenylamine derivatives including heterocyclic groups have been measured and the effect of molecular orbital distributions of triphenylamine derivatives on the charge transport properties has been studied. The temperature dependence of the mobilities of polymers doped with two kinds of triphenylamine derivatives has been analyzed using the disorder formalism presented by Bassler and co-workers[H. Bassler, Phys. Status Solidi B 175(1993) 15.] and it has been found that highest occupied molecular orbital (HOMO) distribution of the triphenylamine derivatives has little effect on the diagonal and off-diagonal disorder but has a large effect on the disorder-free mobility in this formalism.

Effect of Electronic States of Triphenylamine Derivatives on Their Charge Transport Properties

The hole drift mobilities of polymers doped with triphenylamine derivatives have been measured and the effect of the electronic states of triphenylamine derivatives on the charge transport properties has been studied. The HOMO (highest occupied molecular orbital) distribution strongly affects the charge transport properties and it was found that when the triphenylamine part had more HOMO distribution, the mobility increased. Moreover, 2-[p-di(p-tolyl)aminostyryl]-4-methylthiazole was found as a new charge transport material having rather high drift mobility.

Photocarrier Generation Process of Phthalocyanine Particles Dispersed in a Polymer: Effects of Pigment Particle Size, Polymer Matrix and Addition of Fine γ-Alumina Particles

In systems of phthalocyanine particles dispersed in polymer, the effects of pigment particle size, electric property of the polymer and addition of fine γ-alumina particles on photocarrier generation efficiency have been studied. With smaller pigment particle size and higher dielectric constant of the polymer, the photocurrent increased. Addition of γ-alumina particles also caused a considerable increase in the photocurrent. It seemed that photocarrier generation occurred at the surface of the pigment particles and adsorbed oxygen played an important role in the process.

Effect of Binder Matrices on Charge Transport in Polymers Doped with a Butadiene Derivative

The effects of polymer matrices on charge transport in polymers doped with a butadiene derivative have been studied. Transient photocurrent shapes in polysulfone and polyestercarbonate are very different from those in polystyrene and polycarbonate. It appears that the low-energy levels of the polymer matrices affect transient current shapes.

Electrophotographic Properties of an Organic Photoconductor and a Triboelectric Magnetic Toner for a New Diode Laser Printer

The electrophotographic properties of a newly developed organic photoconductor and triboelectric magnetic toner were investigated for a nonimpact printer with a diode laser. The photoconductor was composed of a metal-free phthalocyanine layer and an oxazole-derivative-doped polymer layer. The photoconductor had a charge acceptance of -1000 V and a light sensitivity of more than 0.1 m2/mJ at 780 nm. The magnetic toner had a resistivity as high as 1014 ¿ cm and could accept triboelectric charge of -3.5 ¿C/g. Chrome dye was employed for a negative charge control agent to affect the sign and magnitude of triboelectric charge on toner particles. Using the developed organic photoconductor and triboelectric magnetic toner, good quality prints on plain paper were obtained with the new diode laser printer. Toner mass density deposited on the photoconductor was improved by more than 20 percent as compared with that of conventionally used conductive or high-resistance magnetic toners. It was found that the triboelectric magnetic toner had a very high transfer efficiency of as large as 80 percent, even on plain paper.