Canon Kabushiki Kaisha

Kan Tanabe

Kumiko Takizawa

Tsuyoshi Shimada

Haruhiko Mitsuda

Masato Tanaka

Tatsuya Ikezue

Wataru Kitamura

Ikuyo Kuroiwa

Hidetoshi Hirano

Takanori Ueno

Atsushi Fujii

Ryoichi Tokimitsu

Mai Murakami

Kazue Asakura

Koji Takahashi

Hideki Ogawa

Yuka Ishiduka

Shoji Amamiya

Naoaki Ichihashi

Takahiro Mitsui

Yoshihisa Saito

Mayumi Oshiro

Hideki Anayama

Hideyuki Takai

Kouichi Nakata

Eileen Takeuchi

An electrophotographic photosensitive member includes a support, an undercoat layer, a photosensitive layer, and a surface layer, the undercoat layer containing a binder resin and strontium titanate particles, the surface layer being a cured film of a composition containing at least one compound selected from a guanamine compound and a melamine compound, and a charge transport material having at least one substituent selected from &#x2014;OH, &#x2014;OCH, &#x2014;NH, &#x2014;SH, and &#x2014;COOH.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

Provided is an electrophotographic photosensitive member that can achieve both of abrasion resistance and the suppression of a ghost. The electrophotographic photosensitive member includes: a support; an undercoat layer; a charge-generating layer; and a charge-transporting layer, the undercoat layer, the charge-generating layer, and the charge-transporting layer being arranged in the stated order on the support, wherein the charge-transporting layer includes a charge-transporting substance, and a polymer containing a structure represented by the following general formula (1) and a structure represented by the following general formula (2), wherein the charge-generating layer includes a phthalocyanine crystal and a binder resin, and wherein the undercoat layer includes strontium titanate particles and a binder resin. 

An electrophotographic photoconductor includes, in sequence, a support member; an undercoating layer containing a binder resin and an inorganic particle; and a photosensitive layer, wherein the binder resin of the undercoating layer is an alkyd-melamine resin, and the inorganic particle of the undercoating layer contains a strontium titanate particle.

Electrophotographic photoconductor, process cartridge, and electrophotographic apparatus

The electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order, in which the undercoat layer contains metal oxide particles and a specific binder resin, the surface layer contains a charge transporting substance, fluororesin particles, and a specific binder resin, an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 &#x3bc;m or less, a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy a specific relationship, and a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy a specific relationship.

An electrophotographic apparatus includes an electrophotographic photosensitive member, a charging roller disposed so as to come into contact with the electrophotographic photosensitive member, and a charging device operable to apply only a DC voltage to charge the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a support member, an undercoat layer over the support member, and a photosensitive layer over the undercoat layer and having a plurality of discrete recesses in the surface thereof. The undercoat layer contains zinc oxide particles and a binder resin. The undercoat layer has cavities therein, and the cavities account for 5.00% or less of the volume of the undercoat layer.

Electrophotographic apparatus

There is provided an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus that are excellent in charging properties and can suppress residual potential in the case where a strontium titanate particle is used as a metal oxide particle in an undercoat layer of the electrophotographic photosensitive member. An electrophotographic photosensitive member in which an undercoat layer contains a strontium titanate particle having a maximum peak at a position of 2&#x3b8;=32.20&#xb1;0.20 (&#x3b8; represents a Bragg angle) in a CuK&#x3b1; characteristic X-ray diffraction pattern, the maximum peak having a half-value width of 0.10 deg or more and 0.50 deg or less, and a process cartridge and an electrophotographic apparatus each provided with the electrophotographic photosensitive member.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

The present invention provides an electrophotographic apparatus in which the deterioration of electrical properties in repetitive use is suppressed even in the case where an electrophotographic photosensitive member absorbs moisture under a high-temperature and high-humidity environment. An undercoat layer of the electrophotographic photosensitive member provided in the electrophotographic apparatus contains (&#x3b1;) a metal oxide particle, (&#x3b2;) a particular benzophenone compound and (&#x3b3;) a compound represented by the following formula (2). wherein Rto Reach independently represent a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group, an alkoxy group or an amino group and Arepresents an alkenyl group having 2 or more and 4 or less carbon atoms.

An electrophotographic photosensitive member includes a support, an undercoat layer which contains a metal oxide particle and is formed on the support, a charge generating layer formed on the undercoat layer, and a charge transporting layer formed on the charge generating layer. Either or both of the undercoat layer and the charge generating layer contain a compound represented by formula (1).

Electrophotographic photosensitive member, method for producing electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

The present invention provides an electrophotographic photosensitive member which includes an undercoat layer, and the undercoat layer contains metal oxide particles and a compound represented by the formula (1). 

Electrophotographic photosensitive member, method for manufacturing the same, process cartridge, and electrophotographic apparatus

The subject invention relates to a charge transport layer forming coating liquid containing a charge transport material, at least one selected from the group consisting of polycarbonate resins and polyester resins, at least one of xylene and toluene, and cyclopentanone. The proportion of cyclopentanone in the charge transport layer forming coating liquid is in the range of 50% by mass to 85% by mass relative to the total mass of at least one of xylene and toluene and cyclopentanone.

Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, charge transport layer forming coating liquid, and method for manufacturing electrophotographic photosensitive member

An electrophotographic photosensitive member includes a charge transport layer containing (&#x3b1;) a charge transporting compound, (&#x3b2;) a binding resin in a proportion in the range of 50% by mass to 200% by mass relative to the mass of the charge transporting compound, (&#x3b3;) a compound being at least one of xylene and toluene with a content in the range of 0.01% by mass to 2.00% by mass relative to the total mass of the charge transport layer, and (&#x3b4;) a cycloalkanone with a content in the range of 0.01% by mass to 1.20% by mass relative to the total mass of the charge transport layer.

An electrophotographic apparatus and a process cartridge include an electrophotographic photosensitive member; a developing unit; and a cleaning unit, wherein depressed portions separated from each other and satisfying conditions below are formed in the surface of the electrophotographic photosensitive member at a density of 10 or more per unit area of 1 cm: a depth of the depressed portions is defined as Rdv[&#x3bc;m], a minor-axis diameter of the depressed portions is defined as Lpc[&#x3bc;m], a major-axis diameter of the depressed portions is defined as Rpc[&#x3bc;m], and an angle formed between a direction of a major-axis of each of the depressed portions and a direction of movement of the surface of the electrophotographic photosensitive member is defined as &#x3b8;[&#xb0;].5[&#xb0;]&#x2266;&#x3b8;[&#xb0;]&#x2266;85[&#xb0;]0.3&#xd7;[&#x3bc;m]&#x2266;[&#x3bc;m]&#x2266;0.5&#xd7;[&#x3bc;m]1.1&#xd7;[&#x3bc;m]&#x2266;[&#x3bc;m]&#x2266;1.5&#xd7;[&#x3bc;m]50/Sin &#x3b8;[&#x3bc;m]&#x2266;[&#x3bc;m]&#x2266;1500[&#x3bc;m]

Electrophotographic apparatus and process cartridge

An electrophotographic photosensitive member is provide which inhibits recovered toner from leaking out of the edge portion at the time of long-term use, and has good durability. Each of at least both edge portions of the surface layer of the electrophotographic photosensitive member has a region in which independent depressed portions are formed at a density of ten or more portions per 100 &#x3bc;m square. An average depth Rdv-A, an average short axis diameter Lpc-A, and an average long axis diameter Rpc-A, of the depressed portions are respectively in specific ranges. When an angle formed between the circumferential direction of the electrophotographic photosensitive member and the long axis of each of the depressed portions is represented by &#x3b8;, the depressed portions are formed so that the angle &#x3b8; satisfies the relationship of 90&#xb0;&#x3c;&#x3b8;&#x3c;180&#xb0; toward the center of the electrophotographic photosensitive member.

An electrophotographic photosensitive member exhibiting a high sensitivity and a potential stability on repetitive use and capable of suppressing image defects, such as black spots in a reversal development scheme, is provided. The photosensitive member includes a support, and a phthalocyanine layer formed on the support and a novel phthalocyanine crystal, which comprises a phthalocyanine compound and a substituted or unsubstituted condensed polycyclic hydrocarbon compound.

Growing community of inventors

Matsudo, Japan

Kan Tanabe