Nec Corporation

Yoshikazu Mimura

Keiichi Takano, Deceased

Tomohisa Gotou

Tomohisa Gotoh

Naoyuki Matsui

Shigemasa Takano

Mitsuo Usuba

A new composition of titanyl phthalocyanine is provided. This composition has in its infrared absorption spectrum characteristically strong absorptions at absorption wavenumbers (in unit of cm.sup.-1) of 1490.+-.2, 1415.+-.2, 1332.+-.2, 1119.+-.2, 1072.+-.2, 1060.+-.2, 961.+-.2, 893.+-.2, 780.+-.2, 751.+-.2 and 730.+-.2, and has an extremely high solvent stability and dispersibility, and a large photoelectric conversion efficiency. The new form of composition can be obtained by adding to titanyl phthalocyanine, compounds of other phthalocyanines or naphthalocyanines as additives, and treating the amorphous composition of the mixture to crystallize the composition. By applying an appropriate binder, with the novel composition crystals as a charge generation agent, on a substrate, it is possible to obtain an electrophotographic photosensitive material that has a charge generation layer with an extremely high dispersibility and an extremely large photoelectric conversion efficiency.

Titanyl phthaloycyanine crystal, method of manufacture thereof and its

A new crystal form of a titanyl phthalocyanine compound is provided. This crystal form shows characteristic strong absorption peaks at 1,332.+-.2 cm.sup.-1, 1,074.+-.2 cm.sup.-1, 962.+-.2 cm.sup.-1 and 783.+-.2 cm.sup.-1 in an infrared absorption spectrum and/or characteristic strong peaks at 27.2.degree., 9.7.degree. and 24.1.degree. of Bragg's angle 2.theta. in an X-ray diffraction spectrum and has very good dispersibility and stability in a solvent and also very good photoelectric conversion efficiency and so is very useful particularly as a charge generation agent highly sensitive in a semiconductor laser wavelength region as required in a photosensitive material for a highspeed high-definition printer. Such crystal form can be obtained by treating non-crystalline titanyl phthalocyanine with tetrahydrofuran.

Phthalocyanine crystal, process for manufacture thereof and its use for

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Tokyo, Japan

Yoshikazu Mimura