Canon Kabushiki Kaisha

Kazushi Iuchi

Hajime Miyazaki

Hideyuki Takai

Shintetsu Go

Itaru Yamazaki

Tetsuro Kanemaru

Toshie Miyaji

Akihiro Senoo

Masakazu Matsumoto

Toshiyuki Yoshihara

Hideki Anayama

Hideyuki Ainoya

Harumi Sakoh

Junichi Kishi

Nobuyuki Hanami

A new crystalline form of oxytitanium phthalocyanine is characterized by main peaks specified by Bragg angles (2.theta..+-.0.2 degrees) of 7.4 degrees, 10.2 degrees, 12.5 degrees, 15.0 degrees. 16.3 degrees, 18.3 degrees, 22.4 degrees, 24.2 degrees, 25.2 degrees and 28.5 degrees in X-ray diffraction pattern based on CuK.alpha. characteristic X-rays. The oxytitanium phthalocyanine is formed by treating amorphous oxytitanium phthalocyanine with a solvent selected from the group consisting of monohydric alcohols having at least two carbon atoms, cellosolves, diethylene glycol monoethers and diacetone alcohol. The oxytitanium phthalocyanine is useful as a charge generating material for providing an electrophotographic photosensitive member, which shows a stably high sensitivity to long wavelength light.

Oxytitanium phthalocyanine, process for producing same and

An to an electrophotographic photosensitive member includes a photosensitive layer containing a specified oxytitanium phthalocyanine and a polyvinyl acetal resin having a structural unit represented by Formula: ##STR1## wherein X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a nitro group, or a cyano group; and Y is a fluorine atom, a chlorine atom, a bromine atom, a nitro group, or a cyano group. The photosensitive member maintains a low residual potential without deterioration of the sensitivity during repeated use.

Electrophotographic photosensitive member, and electrophotographic

The present invention relates to a process for producing a crystalline I-type oxytitanium phthalocyanine having strong peaks in CuK.alpha. characteristic X-ray diffraction at Bragg angles (2.theta..+-.0.2.degree.) of 9.0.degree., 14.2.degree., 23.9.degree., and 27.1.degree., comprising milling-treatment of oxytitanium phthalocyanine or an aqueous paste thereof with a solvent containing a saturated hydrocarbon solvent.

Process for producing crystalline I-type oxytitanium phthalocyanine

An electrophotographic photosensitive member has a conductive support, and a charge generating layer and a charge transporting layer. The charge generating layer contains an acetal resin obtained from a reaction of polyvinyl alcohol, alkyl aldehyde having a structure shown in Formula (1) below, and aryl aldehyde having a structure shown in Formula (2) below:

Electrophotographic photosensitive member and electrophotographic

A process for producing crystalline oxytitanium phthalocyanine showing strong peaks in CuK.alpha. characteristic X-ray diffraction at Bragg angles 2.theta..+-.0.2.degree. of 9.0.degree., 14.2.degree., 23.9.degree., and 27.1.degree., which comprises a dispersion treatment of the aqueous paste of oxytitanium phthalocyanine in an ether type compound.

Process for producing crystalline oxytitanium phthalocyanine

An electrophotographic photosensitive member has a photosensitive layer on an electroconductive support. The photosensitive layer comprises a compound having a structure represented by the general formula (1) or (2) as a charge-generating material: ##STR1## wherein A.sub.1 and A.sub.3 are respectively an alkyl radical, an aralkyl radical, an aromatic radical or a heterocyclic radical which may have a substituent; A.sub.2 is hydrogen atom, or an alkyl radical, an aralkyl radical, an aromatic radical, or a heterocyclic radical which may have a substituent; A.sub.1 and A.sub.2 may be the same with or different from each other; A.sub.1 and A.sub.2 may be linked together to form a ring; and n is an integer of 1, 2, or 3.

Electrophotographic photosensitive member

There are disclosed low crystalline oxytitanium phthalocyanines which have characteristic strong peaks at specific angles of Bragg angle 2.theta..+-.0.2.degree.. Using the low crystalline oxytitanium phthalocyanines, it is easy to obtain oxytitanium phthalocyanines having novel crystal forms. Electrophotographic photosensitive member containing the oxytitanium phthalocyanines having novel crystal forms have a very high photosensitivity to beams of long wavelength, a ver high potential stability as well as excellent durability in repetitive use.

Low crystalline oxytitanium phthalocyanine, process for producing

Oxytitanium phthalocyanine having a crystal form characterized by main peaks specified by Bragg angles (2.sigma..+-.0.2 degree) of 9.0 degrees, 14.2 degrees, 23.9 degrees and 27.1 degrees in X-ray diffraction pattern based on CuK.alpha. characteristic X-rays. The oxytitanium phthalocyanine crystal provides an electrophotosensitive member showing a high and stable photosensitivity for long-wavelength light as well as a stable chargeability even after photoirradiation.

An electrophotographic photosensitive member comprises a conductive support and a photosensitive layer provided thereon, wherein said photosensitive layer contains at least one of the compounds of the following Formula (I) and (II). ##STR1## wherein Y represents an oxygen atom or a sulfur atom; R.sub.1 represents a substituted or unsubstituted aromatic hydrocarbon group or aromatic heterocyclic group which may be bonded through a bonding group; R.sub.2 and R.sub.3 each represent a hydrogen atom, a substituted or unsubstituted alkyl group or aryl group; m is an integer of 1, 2 or 3; n.sub.2 is an integer of 1, 2 or 3; R.sub.4 represents a hydrogen atom, an alkyl group or a substituted or unsubstituted phenyl group; and n.sub.2 is an integer of 1, 2 or 3.

Electrophotographic photosensitive member containing a barbituric acid

An electrophotographic photosensitive member comprises an electroconductive support and a photosensitive layer laid on the electroconductive support, the photosensitive layer containing a compound represented by the following general formula (1): ##STR1## wherein R in a substituted or unsubstituted aromatic group or heterocyclic group; X is substituted or unsubstituted benzenediyl, 2,3-pyridinediyl, 3,4-pyridinediyl or 2,3-pyrazinediyl; Y is an oxygen atom, a sulfur atom or a dicyanomethylene group, Z is an oxygen atom, a sulfur atom, a dicyanomethylene group or ##STR2## m is an integer of 1 2 or 3; and n is an integer of 0 or 1.

An electrophotographic photosensitive member having a photosensitive layer on an electroconductive support, comprises an azo pigment represented by the general formula (1) as a charge-generating substance in the photosensitive layer ##STR1## wherein A.sub.1 and A.sub.2 are respectively an aromatic radical or an heterocyclic radical which may be linked through a linking radical; B is a radical necessary for forming together with the carbon atoms a five-membered, six-membered, or seven-membered ring which may be condensed with an aromatic ring; X is a radical condensing with the aromatic ring to form a polycyclic aromatic or heterocyclic ring; Y is oxygen, sulfur, dicyanomethylene, or cyanomethylene.

An electrophotographic photosensitive member has a photosensitive layer on an electroconductive support. The photosensitive layer comprises a compound represented by the general formula (1) or (2) having in the molecule thereof an electron-donating portion and an electron-accepting portion: ##STR1## where D is an electron-donating aromatic group or an electron-donating heterocyclic group; A is an electron-accepting aromatic group or an electron-accepting heterocyclic group; B is a hydrogen atom, or an aromatic or heterocyclic group which may form a ring together with A or D; m is an integer of 1, 2 or 3; and n is an integer of 0 or 1.

Electrophotographic photosensitive member with compound having electron

A laminated layer type electrophotographic photosensitive member has a charge generation layer and a charge transport layer on an electroconductive support, characterized in that the charge generation layer has at least one of disazo pigments represented by the formulae (1) and (2).

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Yokohama, Japan

Kazushi Iuchi