1990 Volume 29 Issue 4 Pages 373-383
Polymorphism on oxotitanium phthalocyanines (TiOPcs) and their xerographic application as charge generation materials for multi-layered photoreceptors has been investigated. It was found that TiOPc has five typical polymorphs, i.e., amorphous, α, β, γ, and m-forms. Their differences can be seen evidently in X-ray powder diffraction patterns, infrared and optical absorption spectra and electron spin resonance ones. Crystals of copper phthalocyanine (CuPc) and TiOPc grown from solvents in solvent were observed with a scanning electron microscope, and their crystals were found to be hexagonal and pyramida1, respectively.
The photoreceptors using these TiOPc as charge generation materials showed high electrophotographic properties at near-infrared region. The order of photosensitivity was γ ≥ amorphous > m > α > β. Especially, a photoreceptor of γ-TiOPc/butadiene derivative exhibited excellent performance; the dark decay = 54 V/sec, E1/2 = 1.8 erg/cm2, a surface voltage with irradiations of 5 erg/cm2 = -35 V, 10 erg/cm2= - 30 V and 30 erg/cm2 = - 25 V at 790 nm.
