Ricoh Company, Ltd.

Hiromi Tada

Nozomu Tamoto

Yoshiki Yanagawa

Tomoyuki Shimada

Chiaki Tanaka

Yuuji Tanaka

Masafumi Ohta

Tetsuya Toshine

Michio Kimura

Takafumi Iwamoto

Norio Nagayama

Tatsuya Niimi

Naohiro Toda

Katsuichi Ohta

Yoshinori Inaba

An electrophotographic photoreceptor, including a charge generation layer and a charge transport layer on an electroconductive substrate, wherein the charge generation layer includes titanylphthalocyanine and a binder resin which is a crosslinked material of a resin comprising a polyvinylbutyrat site having the following formula (1) and an isocyanate compound having the following formula (2): wherein R1 and R2 independently represent an alkyl group having 1 to 3 carbon atoms; k, l, m and n represent composition ratios and k+1 is from 0.60 to 0.80, wherein k or 1 may be 0, m is from 0.02 to 0.03, and n is from 0.20 to 0.40; wherein A represents a substituted or unsubstituted organic group having 2 to 4 valences; and O represents an integer of from 2 to 4.

Electrophotographic photoreceptor, and image forming apparatus and process cartridge therefor using the photoreceptor

An electrophotographic photoreceptor, including an electroconductive substrate; and a photosensitive layer overlying the substrate, wherein the photosensitive layer comprises a complex azo pigment comprising an azo compound having the following formula (a):A(H)&#x2003;&#x2003;(a)wherein A represents a residue of an azo compound, bonded with n pieces of hydrogen atom through one or more heteroatom being N or O and forming a part of the residue A; H represents a hydrogen atom; and n represents an integer of from 1 to 9,and a pigment.

A method of preparing a complex-azo pigment having plural pigment components including at least an azo pigment represented by the following formula (a)A(H)&#x2003;&#x2003;(a)Pigments, both limited and unlimited by the process of making.

Method of preparing complex-AZO pigment and complex-AZO pigment thereof

An electrophotographic photoreceptor is provided that contains a conductive substrate, an undercoat layer, a charge generation layer, and a charge transport layer, wherein the under coat layer contains a binder resin and multiple inorganic pigments each having different average primary particle diameters in a total amount of from 75 to 86% by weight, the charge generation layer contains a binder resin and a titanyl phthalocyanine pigment having a specific X-ray diffraction spectrum in an amount of from 70 to 85% by weight, the charge transport layer comprises a specific distyryl compound, and the following formulae (2-1) to (2-3) are satisfied:0.2&#x2266;((2)/())&#x2266;0.5&#x2003;&#x2003;(2-1)0.2&#x2266;(1)&#x2003;&#x2003;(2-2)(2)&#x2266;(1)&#x2003;&#x2003;(2-3)wherein D(F1) (&#x3bc;m) and D(F2) (&#x3bc;m) represent average primary particle diameters of the largest and smallest inorganic pigments, respectively, and D(G) (&#x3bc;m) represents an average primary particle diameter of the titanyl phthalocyanine pigment.

Electrophotographic photoreceptor, image forming apparatus using the electrophotographic photoreceptor, and method of producing electrophotographic photoreceptor

There is provided an electrophotographic photoconductor containing a conductive substrate, and a photosensitive layer, disposed thereon, containing a charge transporting material having a triarylamine structure represented by General Formula 1, and wherein the photosensitive layer satisfies Mathematical Formula 1 when peak heights in raman scattering spectra of the triarylamine structure are measured at a wavenumber of 1,324&#xb1;2 cmby a confocal raman spectroscopy using z-polarized light: where Ar, Ar, and Arare substituted or unsubstituted aromatic hydrocarbon groups, and Arand Ar, Arand Ar, and Arand Arare optionally combined to form heterocyclic rings, respectively,&#x3b5;=&#x2267;1.1&#x2003;&#x2003;Mathematical Formula 1where Irepresents the peak height in of the raman scattering spectrum obtained at a depth of 5 &#x3bc;m or more from the photosensitive layer surface and Irepresents the peak height in the raman scattering spectrum obtained at a depth of less than 5 &#x3bc;m from the photosensitive layer surface.

Electrophotographic photoconductor and method for producing the same, image forming apparatus, and process cartridge

A method for preparing a photoreceptor including forming a photosensitive layer overlying an electroconductive substrate; coating a liquid including a radically polymerizable compound to form a protective layer; irradiating the protective layer with light to crosslink the protective layer; and then contacting the protective layer with a fluid, which is selected from the group consisting of supercritical fluids and subcritical fluids and which includes a charge transport material. A photoreceptor prepared by the method. An image forming method, an image forming apparatus and a process cartridge using the photoreceptor.

Method for preparing photoreceptor, photoreceptor prepared by the method, and image forming method and apparatus and process cartridge using the photoreceptor

The present invention provides an electrophotographic photoconductor capable of reducing latent electrostatic image stability defects caused by adhesion/adsorption of an electric discharge product formed by a charger in an image forming process, degradation of charge transportability and cleaning defects caused when removing a residual toner. The electrophotographic photoconductor has a conductive substrate, and a photosensitive layer which contains at least a binder, a charge generating material and a charge transporting material and is formed on the substrate, wherein the photosensitive layer contains an injection material composed of at least any one of one wax selected from paraffin waxes, Fisher-Tropsh waxes, polyolefin waxes and a polyorganosiloxane compound in an area from the surface of the photosensitive layer to 50% of the thickness thereof in the thickness direction of the electrophotographic photoconductor, and the content of the injection material is 3% by mass or more to the content of the binder.

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Numazu, Japan

Hiromi Tada