Mitsubishi Chemical Corporation

Hiroe Fuchigami

Teruyuki Mitsumori

Mitsuo Wada

Kozo Ishio

Hiroaki Takamura

Akira Ando

Takahiro Choda

Wataru Miyashita

Yasunori Kawai

Shunichiro Kurihara

An object of the present invention is to provide an electrophotographic photoreceptor which can prevent an increase in potential even using a fluorine resin in a charge transport layer, and can achieve both electrical properties and abrasion resistance, and present invention relates to a lamination type electrophotographic photoreceptor, in which a charge transport layer of the lamination type electrophotographic photoreceptor contains a compound having an E_homo of &#x2212;4.550 eV or more based on structure optimization calculation by density functional calculation B3LYP/6-31G (d, p) and fluorine resin particles, and a content of the fluorine resin particles is 3% by weight to 20% by weight based on a total mass of the charge transport layer.

Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge and image forming apparatus

The present invention relates to an electrophotographic photoreceptor which is a positive charging type electrophotographic photoreceptor comprising a conductive support and a photosensitive layer on the conductive support, wherein the photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin in the same layer, and a residual potential VLat a point at which an exposure amount for forming a latent image is 0.3 &#x3bc;J/cmis equal to or lower than 130 V when an initial surface potential V0 is set to +700 V, exposure with monochromatic light of 780 nm is performed and measurement is performed by a dynamic method.

Electrophotographic photoreceptor, image forming apparatus, and coating liquid for forming photosensitive layer

The present invention relates to an electrophotographic photoreceptor comprising an electroconductive support and at least a photosensitive layer formed on the support, wherein the photosensitive layer contains a specific charge transport substance.

Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge, image-forming apparatus, and triarylamine compound

A coating fluid for photosensitive-layer formation having high productivity and stability and a process thereof are provided. Also provided are a high-performance electrophotographic photoreceptor and an image-forming apparatus which are capable of forming high-quality images even in various use environments and are less apt to cause image defects such as black spots or color spots. The objects are accomplished with a process for producing a coating fluid which is for forming a photosensitive layer of an electrophotographic photoreceptor and comprises a charge-generating material and a binder resin, wherein a dispersing medium having an average particle diameter in the range of from 1.0 &#x3bc;m to 350 &#x3bc;m is used as a dispersing medium for dispersing the charge-generating material in the coating fluid for photosensitive-layer formation. The coating fluid for photosensitive-layer formation produced by this process is preferable as a photosensitive layer of an electrophotographic photoreceptor. The charge-generating material preferably comprises a phthalocyanine pigment and the phthalocyanine pigment in the coating fluid preferably has a 50% cumulative particle diameter (D50) of 0.13 &#x3bc;m or smaller as determined by a dynamic light scattering method.

Coating fluid for photosensitive-layer formation, process for producing the same, photoreceptor produced with the coating fluid, image-forming apparatus employing the photoreceptor, and electrophotographic cartridge employing the photoreceptor

Provided is a coating liquid for forming an undercoat layer of an electrophotographic photoreceptor exhibiting high stability. In the coating liquid for forming an undercoat layer of an electrophotographic photoreceptor containing metal oxide particles and a binder resin, the metal oxide particles have a cumulative volume average diameter Dof 0.1 &#x3bc;m or less and a volume particle size distribution width index SD satisfying the following Expression (1) which are measured by a dynamic light-scattering method in the coating liquid for forming an undercoat layer,0.010&#x2266;SD&#x2266;0.040&#x2003;&#x2003;(1)where SD=(DD)/2, where Drepresents the particle diameter (&#x3bc;m) at a point of 84% in the cumulative volume particle size distribution curve, and Drepresents the particle diameter (&#x3bc;m) at a point of 16% in the cumulative volume particle size distribution curve.

Coating liquid for forming undercoat layer, method for preparing coating liquid for forming undercoat layer, electrophotographic photoreceptor, image-forming apparatus, and electrophotographic cartridge

An electrophotographic photoreceptor, comprising an electroconductive substrate, an undercoat layer comprising a binder resin and metal oxide particles having a refractive index of at least 2.0 formed on the electroconductive substrate, and a photosensitive layer formed on the undercoat layer, wherein a ratio of a specular reflection of the undercoat layer calculated as a thickness of 2 &#x3bc;m to a light having a wavelength of 480 nm, to the specular reflection of the electroconductive substrate to a light having a wavelength of 480 nm, is at least 50%.

Electrophotographic photoreceptor having undercoat layer

An electrophotographic photoreceptor having high sensitivity and hardly affected by the transfer in an electrophotographic process is provided. The electrophotographic photoreceptor includes an undercoat layer containing metal oxide particles and a binder resin and a photosensitive layer disposed on the undercoat layer, wherein the metal oxide particles have a volume average particle diameter of 0.1 &#x3bc;m or less and a 90% cumulative particle diameter of 0.3 &#x3bc;m or less which are measured by a dynamic light-scattering method in a liquid of the undercoat layer dispersed in a solvent mixture of methanol and 1-propanol at a weight ratio of 7:3, and the photosensitive layer contains a binder resin having an ester bond.

Electrophotographic photoreceptor, image-forming apparatus, and electrophotographic cartridge

To provide a coating fluid for forming an undercoat layer having high stability, a high quality and long-life electrophotographic photoreceptor capable of forming a high quality image in various environments, with which image defects such as black spots or color spots hardly occur, an image forming apparatus using such a photoreceptor, and an electrophotographic cartridge using such a photoreceptor. A coating fluid for forming un undercoat layer of an electrophotographic photoreceptor containing titanium oxide particles and a binder resin, characterized in that titanium oxide agglomerated secondary particles in the coating fluid have a volume average particle size of at most 0.1 &#x3bc;m and a cumulative 90% particle size of at most 0.3 &#x3bc;m.

Coating fluid for forming undercoat layer and electrophotographic photoreceptor having undercoat layer formed by Applying said coating fluid

Provided are a coating liquid for forming an undercoat layer exhibiting high stability, a process for forming the coating liquid, a high-performance electrophotographic photoreceptor that is capable of forming a high-quality image under various use environments and exhibiting reduced image defects such as black spots and color spots, and an image-forming apparatus and electrophotographic cartridge including the electrophotographic photoreceptor. In the coating liquid for forming an undercoat layer of an electrophotographic photoreceptor containing metal oxide particles and a binder resin, the metal oxide particles have a number average particle diameter of 0.10 &#x3bc;m or less and a 10% cumulative particle diameter of 0.060 &#x3bc;m or less which are measured by a dynamic light-scattering method in the coating liquid for forming an undercoat layer.

Coating liquid for forming undercoat layer, photoreceptor having undercoat layer formed of the coating liquid, image-forming apparatus including the photoreceptor, and electrophotographic cartridge including the photoreceptor

An electrophotographic photoreceptor having high sensitivity and low residual potential is provided. The electrophotographic photoreceptor includes an undercoat layer containing metal oxide particles and a binder resin on an electroconductive substrate, and a photosensitive layer disposed on the undercoat layer, wherein the metal oxide particles have a volume average particle diameter of 0.1 &#x3bc;m or less and a 90% cumulative particle diameter of 0.3 &#x3bc;m or less which are measured by a dynamic light-scattering method in a liquid of the undercoat layer dispersed in a solvent mixture of methanol and 1-propanol at a weight ratio of 7:3; and the photosensitive layer contains crystalline phthalocyanine showing at least one distinct main diffraction peak at a Bragg angle (2&#x3b8;&#xb1;0.2&#xb0;) of 27.0&#xb0; to 29.0&#xb0; in an X-ray diffraction spectrum.

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Odawara, Japan

Hiroe Fuchigami