Abstract: An electrophotographic photoreceptor, an electrophotographic photoreceptor cartridge, and an image forming apparatus, which are excellent in electrical characteristics such as a responsivity and at the same time, excellent in the crack resistance, are provided. Two kinds of charge transport substances each having a specific structure and a polyester resin having a specific structure are combined, whereby the crack resistance can be improved.

Abstract: An electrophotographic photoreceptor, an electrophotographic photoreceptor cartridge, and an image forming apparatus, which are excellent in electrical characteristics such as a responsivity and at the same time, excellent in the crack resistance, are provided. Two kinds of charge transport substances each having a specific structure and a polycarbonate resin having a specific structure are combined, whereby the electrical characteristics such as responsivity and the crack resistance can be improved at the same time.

Abstract: The present invention relates to an electrophotographic photoreceptor comprising a conductive support and at least a photosensitive layer provided thereon, wherein the electrophotographic photoreceptor comprises an outermost layer which contains a specific charge transport substance and a specific compound.

Abstract: The invention provides a laminate-type electrophotographic photoreceptor for use in a negative charge system, comprising a conductive support, and a photosensitive layer containing a charge generation layer and a charge transport layer, on the conductive support, wherein in addition to a fluorene compound and a diamine compound which are responsible for charge transport, a compound having a specific structure is used in combination.

Abstract: The invention can provide an electrophotographic photoreceptor comprising a photosensitive layer containing a specific charge transport material and a specific copolymerized polycarbonate resin, and an image-forming apparatus and an electrophotographic cartridge which use the electrophotographic photoreceptor.

Abstract: When an abutting pressure of the cleaning blade on a photoreceptor is increased, a chattering occurs due to the so-called a stick-slip phenomenon that the blade repeatedly undergoes sticking to the outermost surface of the photoreceptor and slipping thereon. As a result, a possibility of noise generation becomes higher and there is a possibility that toner particles might pass through during slipping to cause a cleaning failure, resulting in a streaky image defect. There is also a higher possibility that the so-called a filming phenomenon might occur, in which a component of the toner sticks to the photoreceptor surface by the action of the blade pressure and becomes difficult to remove, so as to lead to persistent image defects. Furthermore, since the photoreceptor is rotated with toners in the state of being strongly pressed thereagainst, the image defects are apt to be caused due to peripheral-direction scratches.

Abstract: The invention provides an image forming apparatus and an electrophotographic photoreceptor, comprising: a conductive support; and at least a charge generation layer and a charge transport layer on the conductive support, wherein said charge generation layer contains a hydroxygallium phthalocyanine synthesized using a halogen solvent, said charge transport layer contains a polyester resin having a specific structural unit, and said charge transport layer is formed using a non-halogen solvent.

Abstract: The invention provides a laminate-type electrophotographic photoreceptor for use in a negative charge system, comprising a conductive support, and a photosensitive layer containing a charge generation layer and a charge transport layer, on the conductive support, wherein in addition to a fluorene compound and a diamine compound which are responsible for charge transport, a compound having a specific structure is used in combination.

Abstract: The invention can provide an electrophotographic photoreceptor comprising a photosensitive layer containing a specific charge transport material and a specific copolymerized polycarbonate resin, and an image-forming apparatus and an electrophotographic cartridge which use the electrophotographic photoreceptor.

Abstract: When an abutting pressure of the cleaning blade on a photoreceptor is increased, a chattering occurs due to the so-called a stick-slip phenomenon that the blade repeatedly undergoes sticking to the outermost surface of the photoreceptor and slipping thereon. As a result, a possibility of noise generation becomes higher and there is a possibility that toner particles might pass through during slipping to cause a cleaning failure, resulting in a streaky image defect. There is also a higher possibility that the so-called a filming phenomenon might occur, in which a component of the toner sticks to the photoreceptor surface by the action of the blade pressure and becomes difficult to remove, so as to lead to persistent image defects. Furthermore, since the photoreceptor is rotated with toners in the state of being strongly pressed thereagainst, the image defects are apt to be caused due to peripheral-direction scratches.

Abstract: The invention is to provide an image forming apparatus and an electrophotographic cartridge, which are free from problems of cleaning failure, filming, soiling, residual images (ghosts), fogging, density reduction, noise and the like and which can provide high-definition images even when a toner having a small particle size and having a high degree of circularity is used and even when a photoreceptor having a small outer diameter is used.

Abstract: A phthalocyanine composite with high sensitivity and low environmental dependence is provided. It comprises both at least one phthalocyanine compound expressed by general formula (1) and at least one phthalocyanine compound expressed by general formula (2): where, in the general formulae (1) and (2), M1 represents at least one arbitrary atom or atomic group that is capable of binding to a phthalocyanine, M2 represents an atom, or an atomic group containing an atom, selected from the second and subsequent periods of the periodic table and capable of binding to a phthalocyanine, M1 and M2 being different in kind from each other, X1-X4 represent, independently of each other, a halogen atom, and a, b, c, and d represent, independently of each other, an integer between 0 and 4 and satisfy a+b+c+d?1.

Abstract: A phthalocyanine composite with high sensitivity and low environmental dependence is provided. It comprises both a at least one phthalocyanine compound expressed by general formula (1) and a at least one phthalocyanine compound expressed by general formula (2): where, in the general formulae (1) and (2), M1 represents at least one arbitrary atom or atomic group that is capable of binding to a phthalocyanine, M2 represents an atom, or an atomic group containing an atom, selected from the second and subsequent periods of the periodic table and capable of binding to a phthalocyanine, M1 and M2 being different in kind from each other, X1-X4 represent, independently of each other, a halogen atom, and a, b, c, and d represent, independently of each other, an integer between 0 and 4 and satisfy a+b+c+d>1.

Abstract: A subject for the invention is to provide an electrophotographic photoreceptor which has high durability in exposure to ozone, NOx, etc., is excellent in mechanical properties including printing durability, wearing resistance, scratch resistance, and slip properties in repetitions of use, and further has excellent electrophotographic properties. The invention relates to an electrophotographic photoreceptor comprising an electro conductive substrate and at least a photosensitive layer formed thereover, characterized in that the photosensitive layer contains at least a polyarylate resin and an amine compound represented by a specific structure.

Abstract: Electrophotographic photoreceptors having improved mechanical properties, electrical properties with excellent response characteristics are prepared by forming a photosensitive layer on an electroconductive substrate. The photosensitive layer contains a binder resin, which may be a polyarylate or a copolymer of polyarylate. The binder resin may be mixed with other resins up to 50 wt % with other resins to impove surface slip properties or fire retardant properties.

Abstract: A high-sensitivity and long-life electrophotographic photoreceptor comprising an electroconductive substrate and at least a photosensitive layer on the electroconductive substrate is provided, wherein the photosensitive layer contains a polyarylate resin not having a nitrogen atom in its repeating unit, and the Hall mobility at an electric field strength of 3×105 (V/cm) and at a temperature of 21° C. of the photosensitive layer is 3×10−6 (cm2/Vs) or more.

Abstract: A high-sensitivity and long-life electrophotographic photoreceptor comprising an electroconductive substrate and at least a photosensitive layer on the electroconductive substrate is provided, wherein the photosensitive layer contains a polyarylate resin not having a nitrogen atom in its repeating unit, and the Hall mobility at an electric field strength of 3×105 (V/cm) and at a temperature of 21° C. of the photosensitive layer is 3×10−6 (cm2/Vs) or more.

Abstract: A high-sensitivity and long-life electrophotographic photoreceptor comprising an electroconductive substrate and at least a photosensitive layer on the electroconductive substrate is provided, wherein the photosensitive layer contains a polyarylate resin not having a nitrogen atom in its repeating unit, and the Hall mobility at an electric field strength of 3×105 (V/cm) and at a temperature of 21° C. of the photosensitive layer is 3×10−6 (cm2/Vs) or more.

Abstract: Electrophotographic photoreceptors having improved mechanical properties, electrical properties with excellent response characteristics are prepared by forming a photosensitive layer on an electroconductive substrate. The photosensitive layer contains a binder resin, which may be a polyarylate or a copolymer of polyarylate. The binder resin may be mixed with other resins up to 50 wt % with other resins to impove surface slip properties or fire retardant properties.

Abstract: A high-sensitivity and long-life electrophotographic photoreceptor comprising an electroconductive substrate and at least a photosensitive layer on the electroconductive substrate is provided, wherein the photosensitive layer contains a polyarylate resin not having a nitrogen atom in its repeating unit, and the Hall mobility at an electric field strength of 3×105 (V/cm) and at a temperature of 21° C. of the photosensitive layer is 3×10−6 (cm2/Vs) or more.