Ricoh Company, Ltd.

Toshihiro Ishida

Tetsuro Suzuki

Eiji Kurimoto

Tomoharu Asano

Daisuke Nii

Naohiro Toda

Tetsuya Toshine

Takafumi Iwamoto

Hiroshi Ikuno

Kazuhiro Egawa

Yohta Sakon

Hidetoshi Kami

Akihiro Sugino

Masahiro Ohmori

Keisuke Shimoyama

Ryohta Takahashi

A photoconductor including a conductive support, an undercoat layer, a charge-generating layer, and a charge-transporting layer, at least the undercoat layer, the charge-generating layer, and the charge-transporting layer being disposed on the conductive support in an order mentioned, wherein the undercoat layer includes a binder resin and metal oxide particles, and the charge-generating layer includes a binder resin, a titanyl phthalocyanine pigment, and a salicylic acid derivative.

Photoconductor, image forming apparatus, and process cartridge

An electrophotographic photoconductor including a support, an undercoat layer, and a photoconductive layer, the undercoat layer and the photoconductive layer being disposed on the support in an order mentioned, wherein the undercoat layer includes zinc oxide particles, a urethane bond-containing resin, and methylethyl ketone oxime, and the undercoat layer satisfies a formula below:10&#x3c;&#x3c;400&#x2003;&#x2003;(Formula)where M is a ratio (ppm) of the methylethyl ketone oxime included in the undercoat layer, and L is an average thickness (&#x3bc;m) of the undercoat layer.

Electrophotographic photoconductor, image forming apparatus, and process cartridge

A photoconductor is provided. The photoconductor includes a support, an undercoat layer overlying the support, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a binder resin and a zinc oxide particle. The photosensitive layer includes a compound represented by the following formula (1): where each of Rand Rindependently represents an alkyl group or an aromatic hydrocarbon group.

A photoconductor includes an electroconductive substrate; an undercoat layer overlying the electroconductive substrate; and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a urethane resin, a metal oxide particle and a compound having the following formula (1): wherein R1 to R8 independently represent a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group, a saturated or an unsaturated aliphatic hydrocarbon group optionally having a substituent, an aromatic hydrocarbon group optionally having a substituent, an alkoxy group optionally having a substituent, an aryloxy group optionally having a substituent, a sulfo group optionally having a substituent, an amino group, a dialkylamino group optionally having a substituent or an diarylamino group optionally having a substituent; and R3 and R4, R4 and R5, R6 and R7, and R7 and R8 may be bonded with each other to form an aromatic ring.

A photoconductor including: a conductive support; an undercoat layer; and a photoconductive layer, the undercoat layer being disposed over the conductive support, the photoconductive layer being disposed over the undercoat layer, wherein the undercoat layer includes zinc oxide particles, wherein when a film thickness of the undercoat layer is 20 &#x3bc;m, the undercoat layer has transmittance of 50% or more to light having a wavelength in a range of 500 nm or more but 800 nm or less, wherein a lowest transmittance of light is 85% or less in the range, and wherein when an electric field of 5 V/&#x3bc;m is applied to the undercoat layer, volume resistivity of the undercoat layer is 1.0&#xd7;10&#x3a9;&#xb7;cm or more but 5.0&#xd7;10&#x3a9;&#xb7;cm or less at an environment of 23&#xb0; C. and 55% RH.

Provided is a photoconductor including a conductive support, an intermediate layer containing metal oxide particles, and a photoconductive layer. The intermediate layer and the photoconductive layer are provided over the conductive support in the order of reciting. An elastic power (We/Wt value) of the intermediate layer is greater than or equal to 20.0% but less than 35.0%. A Martens hardness (HM) of the intermediate layer is greater than or equal to 350 [N/mm] but less than 450 [N/mm].

Photoconductor, electrophotographic method, electrophotographic apparatus, and electrophotographic process cartridge

A electrophotographic photoconductor is provided. The electrophotographic photoconductor includes a conductive support, an undercoat layer overlying the conductive support, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a metal oxide particle, binder resin, and a compound having a urea group.

An electrophotographic photoconductor including a support, an undercoat layer overlying the support, and a photosensitive layer overlying the undercoat layer is provided. The undercoat layer includes zinc oxide particles and a binder resin. The undercoat layer has a voltage (V)-current (I) characteristics such that, when S1 is a value obtained by integrating current (I [A]) in terms of voltage (V [V]) from 0 to a distribution voltage V[V] distributed to the undercoat layer, and S2 is a value obtained by integrating a line connecting two points at a voltage (V [V]) of 0 and the distribution voltage V[V] in terms of voltage (V [V]) from 0 to the distribution voltage V[V], S1 is within a range of from 1.0&#xd7;10to 1.0&#xd7;10and a ratio (S1/S2) of S1 to S2 is 0.50 or less.

An electrophotographic photoreceptor includes a substrate, an undercoat layer overlying the substrate, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a binder resin, a metal oxide particle and a compound having a thiol group.

Electrophotographic photoreceptor, image forming apparatus, and process cartridge

An electrophotographic photoconductor, including: an electroconductive substrate; and at least a photoconductive layer and a surface layer in this order over the electroconductive substrate, wherein the surface layer includes a resin having no charge transport properties, and first inorganic fine particles, and wherein the first inorganic fine particles are inorganic fine particles having surfaces modified with at least one of a primary amino group and a secondary amino group, and a volume resistivity of the first inorganic fine particles is 1&#xd7;10&#x3a9;&#xb7;cm or less.

A photoconductor is provided. The photoconductor includes an electroconductive substrate; an intermediate layer located overlying the electroconductive substrate; and a photosensitive layer located overlying the intermediate layer. The intermediate layer includes at least a resin, and a particulate zinc oxide that includes sodium, sulfur and calcium in amounts of from 10 ppm to 200 ppm, from 50 ppm to 500 ppm, and from 10 ppm to 200 ppm, respectively.

Electrophotographic photoconductor, and image forming method, image forming apparatus, and process cartridge using the electrophotographic photoconductor

An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer overlying the electroconductive substrate; and a surface layer overlying the photosensitive layer, wherein the surface layer includes a resin having no charge transportability; and an inorganic particulate material, wherein the inorganic particulate material is a zinc oxide doped with a boron group, and wherein the electrophotographic photoreceptor has a surface specific resistivity (R1) not less than 10&#x3a9;/cmwhen the surface layer has an electric field intensity of 1&#xd7;10V/cm, and a ratio (R1/R15) of the surface specific resistivity (R1) to a surface specific resistivity (R15) when the surface layer has an electric field intensity of 1.5&#xd7;10V/cm of from 100 to 5,000.

Electrophotographic photoreceptor, image forming apparatus and process cartridge

An image forming apparatus including an image bearing member having a surface layer A having a surface hardness of 200 N/mmor greater, the surface layer A containing fillers made of a metal oxide and a cleaning blade having a reed-like elastic blade having a front edge portion to remove toner from the surface layer A in motion while the front edge portion is in contact with the surface layer A, the front edge portion having a laminate structure formed of a substrate of the elastic blade, a mixed layer of the substrate and an acrylic and/or methacrylic resin, the mixed layer having a thickness of 1.0 &#x3bc;m or greater, and a surface layer B having an acrylic and/or methacrylic resin, the surface layer B having a thickness of 0.1 &#x3bc;m or greater.

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Shizuoka, Japan

Toshihiro Ishida