Kyocera Document Solutions Inc.

Kyocera Mita Corporation

Yuko Iwashita

Kazunari Hamasaki

Kazutaka Sugimoto

Yukimasa Watanabe

Daisuke Kuboshima

Keiji Maruo

Junichiro Otsubo

Kazuaki Ezure

Takafumi Matsumoto

Shiho Kuboshima

Jun Azuma

Yuichi Yoshida

Yasuhiro Oishi

Kazuaki Edure

Kazuki Ezure

An electrophotographic photosensitive member includes a conductive substrate, an intermediate layer provided on the conductive substrate, and a photosensitive layer provided on the intermediate layer. The intermediate layer contains a specific polyamide resin and specific inorganic particles. The specific inorganic particles each include a metal oxide particle and a surface treatment layer covering at least a part of the surface of the metal oxide particle. The surface treatment layers contain a component derived from an organic siloxane compound and at least one of aluminum oxide and silica. The specific polyamide resin includes a first repeating unit derived from an aliphatic dicarboxylic acid with a carbon number of at least 8 and no greater than 20 and a second repeating unit derived from a diamine compound with a cycloalkane structure.

Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The hole transport material includes a compound represented by chemical formula (1-1) or (1-2). The photosensitive layer further contains an n-type pigment. The n-type pigment is preferably an azo pigment or a perylene pigment. 

An electrophotographic photosensitive member includes a photosensitive layer of a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. An optical response time is 0.05 milliseconds or longer and 0.85 milliseconds or shorter. The optical response time is a time from irradiation of a surface of the photosensitive layer charged to +800 V with pulse light having a wavelength of 780 nm to decay of a surface potential of the photosensitive layer from +800 V to +400 V. The pulse light has an intensity that allows the surface potential of the photosensitive layer to decay to +200 V from +800 V after 400 milliseconds elapse from the irradiation of the surface of the photosensitive layer charged to +800 V with the pulse light. The photosensitive layer has a Martens hardness at 50&#xb0; C. of at least 160 N/mm.

An electrophotographic photosensitive member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, an additive, and a binder resin. An optical response time is in a range from 0.05 milliseconds to 0.85 milliseconds. The optical response time is a time from irradiation of a surface of the photosensitive layer charged to +800 V with pulse light having a wavelength of 780 nm to surface potential decay of the photosensitive layer from +800 V to +400 V. An optical intensity of the pulse light is set so that the surface potential of the photosensitive layer becomes +200 V from +800 V after 400 milliseconds from pulse light irradiation of the surface of the photosensitive layer charged to the +800 V. The additive includes either of both an ultraviolet absorbing agent and an antioxidant.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer of a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. An optical response time is at least 0.05 milliseconds and no greater than 0.85 milliseconds. The binder resin includes a polycarbonate resin including a repeating unit represented by general formula (1) shown below and a repeating unit represented by general formula (2) shown below. 

An electrophotographic photosensitive member includes a single-layer type photosensitive layer including phthalocyanine or a derivative thereof and an electron transport material. The electron transport material includes at least one first compound represented by formula (1) or (2) shown below and at least one second compound represented by formula (3), (4), or (5) shown below. A total amount of the at least one first compound and the at least one second compound is no less than 60 parts by mass and no greater than 120 parts by mass relative to 100 parts by mass of the binder resin. An amount of the at least one first compound is no less than 35 parts by mass and no greater than 80 parts by mass. An amount of the at least one second compound is no less than 25 parts by mass and no greater than 40 parts by mass. 

Electrophotographic photosensitive member, image forming apparatus, and process cartridge

An electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer contains a charge generating material and a hole transport material represented by general formula (1) shown below in a single layer. Titanyl phthalocyanine contained as the charge generating material exhibits a main peak at a Bragg angle 2&#x3b8;&#xb1;0.2&#xb0;=27.2&#xb0; in a CuK&#x3b1; characteristic X-ray diffraction spectrum and satisfies either (B) or (C), shown below, in a differential scanning calorimetry spectrum. (B) A peak is not present in a range from 50&#xb0; C. to 400&#xb0; C., other than a peak resulting from vaporization of adsorbed water. (C) A peak is not present in a range from 50&#xb0; C. to 270&#xb0; C., other than a peak resulting from vaporization of adsorbed water, and a peak is present in a range from 270&#xb0; C. to 400&#xb0; C. 

A positively chargeable electrophotographic photosensitive member has a photosensitive layer. The photosensitive layer at least includes the following layers layered in the stated order: (I) a charge transport layer at least containing a hole transport material and a binder resin; and (II) a charge generating-and-transporting layer at least containing a charge generating material, an electron transport material, a hole transport material, and a binder resin all within this layer. The binder resin contained in the charge transport layer is different from the binder resin contained in the charge generating-and-transporting layer, and either of the binder resins contains a polyvinyl acetal resin.

Positively chargeable electrophotographic photosensitive member and image forming apparatus

A single-layer-type electrophotographic photosensitive member includes a layer disposed on an electrically conductive substrate, the layer including at least a charge-generating material, an electron transport material, a hole transport material, and a binder resin within the same layer. The charge-generating material contains a phthalocyanine pigment and N-type pigments including at least a perylene-based pigment and an azo-based pigment, and the total amount of the N-type pigments is 0.03 to 10 parts by mass relative to 1 part by mass of the phthalocyanine pigment.

Electrophotographic photosensitive member and image forming apparatus including electrophotographic photosensitive member

Provided is a monolayer type photoconductor superior in sensitivity characteristics that allows reliable production by easy confirmation of the sensitivity characteristics, and an image forming device using such a monolayer type photoconductor. A monolayer type photoconductor including a base body and a single photo sensitive layer formed on the base body, the single photo sensitive layer containing a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin, wherein a maximum absorption wavelength (&#x3bb;) of the photo sensitive layer is set to a value of below 850 nm and an absorbance (A) of light at a wavelength of 850 nm per unit thickness of the photo sensitive layer is set to a value of 0.05 &#x3bc;mor less.

Monolayer type photoconductor and image forming device

Provided are an electrophotographic photoconductor which shows a small variation in sensitivity and exhibits a high sensitivity even at a small amount of light exposure and a tandem-system color image forming device provided with the electrophotographic photoconductor. A positive charging type electrophotographic photoconductor for use in a tandem-system color image forming device including a drum type electrophotographic photoconductor, a rotation speed of which is (70) rpm or more, and a color image forming device provided with the electrophotographic photoconductor, wherein, when Vb (V) denotes a sensitivity in the case where an amount of light exposure per unit area is 0.6 &#x3bc;J/cmand Va (V) denotes a sensitivity in the case where an amount of light exposure per unit area is 1.5 &#x3bc;J/cm, a sensitivity ratio represented by Vb/Va is adjusted to a value of below (2).

Electro photographic photoconductor and color image forming apparatus

There is provided a tandem color image forming apparatus and the like, which is capable of suppressing the generation of black spots during a continuous image forming process, even though a non-magnetic single-component developer is used and a cleaner-less type is adopted. The color image forming apparatus is a tandem type that includes a plurality of image carriers and a cleaner-less type that does not include a blade cleaner, wherein the resistance per square centimeter of a base body of an image carrier using for at least a black developer among the plurality of image carriers, or the resistance per square centimeter of the base body through an intermediate layer is set in a range of 1&#xd7;10to 1&#xd7;10&#x3a9; or more.

Color image forming apparatus and color image forming method

The present invention provides a monolayer type electrophotographic photoconductor which can effectively suppress the generation of an exposure memory and exhibits high sensitivity and an image forming apparatus using the monolayer type electrophotographic photoconductor. In an electrophotographic photoconductor which has a monolayer type photoconductive layer including at least a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin on a substrate, the charge generating agent contains oxo-titanyl phthalocyanine crystal, the electron transfer agent has a reduction potential thereof set to a value which falls within a range from &#x2212;0.97 to &#x2212;0.83 V, and the reflection absorbance (A/&#x2212;) of the photoconductive layer with respect to light having a wavelength of 700 nm, a film thickness (d/m) of the photoconductive layer, and the concentration (C/weight %) of the oxo-titanyl phthalocyanine crystal of the photoconductive layer (100 weight %) satisfy a following formula (1).&#x3e;1.75&#xd7;10&#x2003;&#x2003;(1)

Electrophotographic photoconductor having titanyl phthalocyanine and image forming apparatus

The present invention provides an electrophotographic photoconductive member comprising a substrate, and a photoconductive layer containing a hole transferring material, a charge generating material and a binder resin, wherein a value (IV/OV value) in which the inorganic value is divided by the organic value of the binder resin is 0.36 or more and the hole transferring material contains an amine compound represented by the following general formula (1): 

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Osaka, Japan

Yuko Iwashita