Canon Kabushiki Kaisha

Yosuke Morikawa

Kimihiro Yoshimura

Kouichi Nakata

Daisuke Tanaka

Kunihiko Sekido

Michiyo Sekiya

Hideaki Nagasaka

Nobumichi Miki

Tatsuya Ikezue

Takashige Kasuya

Katsuhisa Yamazaki

Hiroyuki Tanaka

Hiroshi Saito

Tsuyoshi Takiguchi

Kaori Hiratsuka

Shuji Ishii

An electrophotographic photosensitive member has a support, a charge generation layer containing a charge-generating material and a binder resin, provided on the support, and a hole transport layer containing a hole-transporting material, provided on the charge generation layer. The charge generation layer contains a phenanthrene compound having a structure represented by the following formula (2): wherein Zand Zeach independently represent an oxygen atom, a &#x2550;C(CN)group or a &#x2550;N-Ph group; Rrepresents a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkoxy group; and Rrepresents a halogen-atom-substituted alkyl group.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

An electrophotographic photosensitive member includes a conductive layer, an intermediate layer and a photosensitive layer in this order on a substrate, in which the conductive layer contains a binder resin and conductive particles. The conductive particles are TiOparticles coated with oxygen-deficient SnO, the conductive particles have an average particle size of 0.2 to 0.6 &#x3bc;m and the conductive layer has a volume resistivity of 5&#xd7;10to 8&#xd7;10&#x3a9;&#xb7;cm. Also this invention provides a process cartridge and an electrophotographic apparatus equipped with such electrophotographic photosensitive member.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

An electrophotographic photosensitive member includes a support, a charge generation layer containing a charge generating material, and a binder resin, on the support, and a hole transport layer containing a hole transporting material, on the charge generation layer. The charge generation layer contains an acenaphthene compound represented by the following formula: Zand Zeach independently represent an oxygen atom, a &#x2550;C(CN)group or a &#x2550;N Ph group; and Rand Reach independently represented a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkoxy group. The acenaphthene compound has the structure represented by the above formula (4) is contained in the charge generation layer in an amount of from 51% by weight to 80% by weight based on the weight of the binder resin in the charge generation layer.

An electrophotographic photosensitive member includes a conductive layer, an intermediate layer and a photosensitive layer in this order on a substrate, in which the conductive layer contains a binder resin and conductive particles. The conductive particles are TiOparticles coated with oxygen-deficient SnO, the conductive particles have an average particle size of 0.2 to 0.6 &#x3bc;m and the conductive layer has a volume resistivity of 5&#xd7;10to 8&#xd7;10&#x3a9;cm. Also this invention provides a process cartridge and an electrophotographic apparatus equipped with such electrophotographic photosensitive member.

An electrophotographic photosensitive member having a support and a charge generation layer containing a charge-generating material and a binder resin, provided on the support, and a hole transport layer containing a hole-transporting material, provided on the charge generation layer. The charge generation lays contains a phenanthroline compound according to formula (3) discussed in the specification or an acenaphthene compound according to formula (4) discussed in the specification. Also disclosed are a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.

A toner exhibits excellent image characteristics, and also has an excellent charging property even if the toner is used in a cleaning-simultaneous-with-developing system having a direct injection charging mechanism. The toner includes toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 &#x3bc;m to 12.0 &#x3bc;m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm/cm) of 5&#xd7;10to 100&#xd7;10; a medium diameter (D) of 0.4 &#x3bc;m to 4.0 &#x3bc;m with respect to a volume-based particle diameter distribution, the medium diameter (D) being smaller than the weight average particle diameter of the toner; and a 90% particle diameter Dof 6.0 &#x3bc;m or less with respect to a volume-based particle diameter.

Toner, method for forming image using the toner, and process cartridge

An electrophotographic photosensitive member superior in dot reproducibility and a process cartridge and an process cartridge having the electrophotographic photosensitive member are provided. Where in a light attenuation curve drawn in a way in which the surface of the electrophotographic photosensitive member is so charged that intensity of an electric field is 15 (V/&#x3bc;m) to establish the surface potential of the electrophotographic photosensitive member into a given value E(V) and then exposed to light under conditions that the electrophotographic photosensitive member has a surface potential of 0.8 E(V) at a time point T(ms) passes after exposure starts, the inclination of the light attenuation curve at a time point T(ms) passes after exposure starts is represented by m, and in a dark-time surface potential attenuation curve drawn in a way in which the surface of the electrophotographic photosensitive member is charged under conditions that the electrophotographic photosensitive member has a surface potential of 0.8 E(V) at a time point T(ms) passes after charging is finished and thereafter no exposure is performed, the inclination of the dark-time surface potential attenuation curve at a time point T(ms) passes after charging is finished is represented by m', the m and m&#x2032; satisfy |m&#x2212;m&#x2032;|&#x2266;0.020, provided that T=[{d/(&#x3bc;&#xd7;E)}&#xd7;100]&#xd7;10, where d is the layer thickness (&#x3bc;m) of the charge transport layer and &#x3bc; is the drift mobility [cm/(V&#xb7;s)] of the charge transport layer.

An electrophotographic photosensitive member which has V, V, and d satisfying an expression (|&#x2212;600&#x2212;V|&#x2212;|&#x2212;600&#x2212;V|)/d=0.13 and Vsatisfying an expression &#x2212;5=&#x2212;(&#x2212;450&#x2212;V)=2 provides an excellent suppressing effect on ghost images and hardly causes a ghost phenomenon even when it is mounted on a color electrophotographic apparatus or an electrophotographic apparatus having no electrostatic removal device. The invention also relates to a process cartridge and an electrophotographic apparatus each having such an electrophotographic photosensitive member.

According to the present invention, there is provided: an electrophotographic photosensitive member having a photosensitive layer on a support in which a surface layer of the electrophotographic photosensitive member comprises an acrylic polymer having a polyfluoroolefin unit and an alkylene oxide unit, and having a number-average molecular weight in a range of 2,000 to 20,000; a process cartridge and an electrophotographic apparatus both comprising the electrophotographic photosensitive member.

Electrophotographic photosensitive member, electrophotographic apparatus, and process cartridge

The present invention relates to an electrophotographic photosensitive member comprising a surface layer excellent in adhesiveness and abrasion resistance, having a hardness and a toughness, and not degrading the charge transport property. One aspect of the present invention provides an electrophotographic photosensitive member comprising a photosensitive layer on a conductive support, wherein a surface layer of the photosensitive member contains a crosslinked epoxy-modified resol type phenolic resin, and at least one of a charge transport material and a conductive fine particle.

A phenolic compound having a plurality of substituted hydroxyphenyl groups and charge-transportable structure, the substituted hydroxyphenyl groups of which have a hydroxymethyl group; and a resol resin obtained by allowing a phenolic compound having hydroxyphenyl groups and charge-transportable structure, to react with formaldehyde in the presence of a basic catalyst, and having charge-transportable structure. Also disclosed are a cured product and an electrophotographic photosensitive member which make use of the above, and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.

PHENOLIC COMPOUND, NOVEL RESOL RESIN, CURED PRODUCTS THEREOF, ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER CONTAINING THEM, AND PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS WHICH HAVE THE ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

An electrophotographic photosensitive member is disclosed in which a photosensitive layer and a protective layer are formed on a conductive substrate in that order. In this photosensitive member, when its surface is charged to &minus;700 V under a 23&deg; C./5% RH environment and irradiated with white light in a light quantity of 10 lux&middot;sec, if the surface potential at the time 0.2 seconds have passed from the irradiation and the surface potential at the time 0.5 seconds have passed from the irradiation are defined as Vsl(0.2) and Vsl(0.5), respectively, the absolute value of Vsl(0.2) and the absolute value of Vsl(0.2)&minus;Vsl(0.5) satisfy specific conditions.

An electrophotographic apparatus and a process cartridge have a charge unit for charging the surface of a photosensitive member by direct injection of electrical charge from a contact charging member to the photosensitive member. The charging unit also functions as a unit for supporting residual toner on the surface of the photosensitive member after transfer, for normalizing the electrical charge of the residual toner, and for returning the normalized residual toner to the surface of the photosensitive member. A developing unit also functions as a unit for recovering the normalized residual toner returned to the surface of the photosensitive member. The absolute value of the difference in charged potential between a first rotation and a second rotation of the photosensitive member is higher than 5 V and lower than 70 V. The photosensitive member has a charge injection layer having a specific composition and the charging member supports charged particles having specific characteristics.

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Yokohama, Japan

Yosuke Morikawa