37results about How to "Low residual potential" patented technology

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 μm or less and a 90% cumulative particle diameter of 0.3 μm 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 (2θ±0.2°) of 27.0° to 29.0° in an X-ray diffraction spectrum.

An electrophotographic photoconductor having a layer of a crosslinked resin obtained by reacting an epoxy group-containing amine compound having a charge transferability-imparting group with at least one silicon compound selected from an epoxy ring-free alkoxysilane compound, an epoxy ring-free silanol compound, an epoxy ring-containing alkoxysilane compound and an epoxy ring-containing silanol compound.

A charge transporting material for use in an electrophotographic photoreceptor, which comprises a compound represented by the formula (1); and an electrophotographic photoreceptor using this charge transporting material. As the electrophotographic photoreceptor using the charge transporting material, there are illustrated, for example, a lamination type photoreceptor having a charge generating layer 2 and a charge transporting layer 3 and, as needed, an interlayer 7, and a single layer type photoreceptor. In the formula, R<1> to R<5> each independently represents a hydrogen atom, an alkyl group, a halogen atom, an alkoxy group, an aryl group or a substituted aryl group, and R<6> represents a hydrogen atom, an alkyl group, an aryl group or a substituted aryl group.

An electrophotographic photoreceptor is provided including an undercoat layer and a photosensitive layer that are sequentially formed on an electrically conductive substrate, wherein the undercoat layer includes a silane compound represented by Formula 1, a metal oxide, and a binder resin, and an electrophotographic imaging apparatus employing the electrophotographic photoreceptor, wherein R1 to R4 are each independently a C1-C9 alkyl group, a C1-C9 alkoxy group, a phenyl group, or a phenoxy group. The electrophotographic photoreceptor has excellent electrical properties such as low residual potential and high sensitivity and excellent image quality and stability.

An object of the present invention is to provide an electrophotographic photosensitive body which is not impaired in electrophotographic characteristics such as charged potential and residual potential, and which is also excellent in repeating stability. The present invention provides an electrophotographic photosensitive body including a conductive support having thereon a layer containing a specific p-terphenyl compound and at least one additive.

An object of the present invention is to provide a charge transport material and an electrophotographic photoreceptor using the charge transport material, the charge transport material sufficiently satisfying characteristics conventionally desired for a charge transport material for an electrophotographic photoreceptor, specifically, the charge transport material having a good solubility in a binder polymer, allowing formation of a stable and high-concentration organic thin film therefrom, and having a high carrier mobility. To achieve the object, the present invention provides a tris(4-styrylphenyl)amine derivative represented by the following general formula (1):wherein R1 represents a methyl group or methoxy group, and R2 represents a hydrogen atom, methyl group, or methoxy group, provided that a case where R1 and R2 are a methyl group and R2 is at the meta-position is excluded; wherein 50% or more of geometrical isomers have three double bonds which are all trans.

The present invention discloses an electrophotographic photosensitive body with excellent electrical characteristics, which enables to obtain a high-quality image wherein occurrence of ghost phenomenon is suppressed. Specifically disclosed is an electrophotographic photosensitive body comprising, on a conductive supporting body, a foundation layer containing metal oxide particles and a binder resin and a photosensitive layer formed on the foundation layer. In this electrophotographic photosensitive body, the metal oxide particles dispersed in a solvent obtained by mixing methanol and 1-propanol at a weight ratio of 7:3 have a volume average particle diameterof not more than 0.1 [mu]m and a cumulative 90% particle diameter of not more than 0.3 [mu]m, as measured by dynamic light scattering; and a compound represented by the formula (I) below is contained in the photosensitive layer. In the formula (I), Ar<1>-Ar<6> independently represent an optionally substituted aromatic residue; X represents an optionally substituted organic residue; and n1 and n2 independently represent an integer of 0-2.

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 VL1 at a point at which an exposure amount for forming a latent image is 0.3 μJ / cm2 is 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.

Disclosed is a triphenylamine derivative represented by general formula (1):wherein R1, R2, R3, and R5 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted phenyl group, R4 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted phenyl group, Ar represents a substituted or unsubstituted phenyl group, and m represents an integer of 1 to 3.

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 μm or less and a 90% cumulative particle diameter of 0.3 μm 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 (2θ±0.2°) of 27.0° to 29.0° in an X-ray diffraction spectrum.

An electrophotographic photoconductor having a layer of a crosslinked resin obtained by reacting an epoxy group-containing amine compound having a charge transferability-imparting group with at least one silicon compound selected from an epoxy ring-free alkoxysilane compound, an epoxy ring-free silanol compound, an epoxy ring-containing alkoxysilane compound and an epoxy ring-containing silanol compound.

Provided is a photoconductor for electrophotography having high sensitivity, low residual potential, and good wear resistance and contamination resistance, and that is less likely to cause light-induced fatigue and filming, and also exhibits good potential stability before and after repeated printing, even without a surface protective layer formed on a photosensitive layer. Provided also are a process of producing the photoconductor and an electrophotographic apparatus. The photoconductor for electrophotography includes a conductive substrate and a photosensitive layer formed on the conductive substrate and including a hole transport material having a structure represented by general formula (1) below; a binder resin having a repeating structure represented by general formula (2) below; and at least one electron transport material having a structure represented by general formulae (ET1) to (ET3) below:

The purpose of the present invention is to provide an electrophotographic photoreceptor that is not liable to cause filming, insufficient cleaning, abnormal noise, and the like, that has excellent abrasion resistance and excellent adhesiveness with a substrate or lower layer, that exhibits fast response in terms of electrical characteristics and sufficiently low electric potential in exposure parts, and that has excellent gas resistance and image memory characteristics. The present invention relates to an electrophotographic photoreceptor having at least a photosensitive layer on an electrocondutive support medium, wherein the electrophotographic photoreceptor contains: a charge transport substance having a specific structure in the photosensitive layer; and a specific polyester resin.

An electrophotographic photoreceptor including: an electrically conductive substrate; a charge generating layer disposed on the electrically conductive substrate and includes a charge generating material dispersed or dissolved in a binder resin and an asymmetric naphthalenetetracarboxylic acid diimide derivative having a nitro group dispersed or dissolved in the binder resin. The photoreceptor also has a charge transporting layer that is disposed on the charge generating layer and includes a charge transporting material that is dispersed or dissolved in the binder resin. An electrophotographic image forming apparatus including the electrophotographic photoreceptor. The two-layered type electrophotographic photoreceptor has good interlayer adhesive force and good electrical properties such as good photosensitivity and low residual potential after exposure.

An object of the present invention is to provide an image forming apparatus containing an electrophotographic photoconductor, a charging unit, an exposing unit, a developing unit, a transfer unit and a cleaning unit,wherein the electrophotographic photoconductor contains a support and at least a photosensitive layer disposed on the support, wherein the photosensitive layer contains a charge generating material and a compound expressed by the following Structural Formula (1), andwherein, in the Structural Formula (1), “R1” and “R2” may be identical to each other or different, and represent any one of hydrogen atom, alkyl group which may be substituted, cycloalkyl group which may be substituted and aralkyl group which may be substituted. “R3”, “R4”, “R5”, “R6”, “R7”, “R8”, “R9”, “R10”, “R11”, “R12”, “R13” and “R14” may be identical to each other or different, and represent any one of hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, alkyl group which may be substituted, cycloalkyl group which may be substituted and aralkyl group which may be substituted. “n” is a number of replication and represents an integer of 0 to 100.

An object of the present invention is to provide an electrophotographic photosensitive body which is not impaired in electrophotographic characteristics such as charged potential and residual potential, and which is also excellent in repeating stability. The present invention provides an electrophotographic photosensitive body including a conductive support having thereon a layer containing a specific p-terphenyl compound and at least one additive.

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 VL1 at a point at which an exposure amount for forming a latent image is 0.3 μJ / cm2 is 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.

A photoreceptor for electrophotography, a method for manufacturing the photoreceptor, and an electrophotographic device including the photoreceptor are disclosed. The photoreceptor for electrophotography includes a conductive substrate; and a photosensitive layer that is provided on the conductive substrate and that has an outermost surface layer containing at least a resin binder and an electron transport material. The resin binder is composed of a polyarylate resin having a structural unit represented by a Chemical Structural Formula 1, and the electron transport material is composed of a compound having a structure represented by a Structural Formula (ET2-3). The photoreceptor has high sensitivity, low residual electric potential, no light fatigue and sufficient stain resistance.

An improved electrophotographic photosensitive device is disclosed. The device comprises a photosensitive layer coupled to a conductive substrate. The photosensitive layer preferably includes a vinyl chloride resin and the vinyl chloride resin preferably comprises an acid esterified vinyl chloride polymer having polymer hydroxy groups, epoxy groups and strong acid radicals as substituent groups, so that the epoxy groups and the hydroxy groups are partially esterified.

[Problems] To provide a novel compound having a high carrier mobility and is useful as a charge transporting agent which not only makes it possible to stably form a photosensitive layer without precipitating crystals or without developing pinholes when the photosensitive layer is being formed but also makes it possible to form an organic photosensitive material for electrophotography of a high sensitivity and a low residual potential.[Means for Solution] An indole derivative represented by the following general formula (1),wherein R1 and R2 are alkyl groups, k is an integer of 0 to 3, j is an integer of 0 to 4, a ring Z is a 5- to 6-membered ring and is, specifically, a cyclopentane ring, and X1 and X2 are hydrocarbon groups having at least one ethylenically unsaturated bond.

The object of the present invention is to provide a positive charging electrophotographic photoreceptor having high sensitivity, low residual potential, and excellent chargeability, and relates to a positive charging electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a protective layer in this order, the photosensitive layer containing a charge generation substance, a positive hole transport substance, and an electron transport substance in the same layer, in which the positive hole transport substance includes at least one of the compounds represented by any one of the following formulas (1) to (5), and a binder resin of the protective layer is an alcohol-soluble thermoplastic resin, providing that the symbols in the formula are defined in the specification.

The invention relates to a method for preparing a polymorphism photosensitivity TiOPc nano particle and application thereof in an organic photoconductor. The method comprises steps of dissolving crude oxotitanium phthalocyanine in -5 DEG C-5 DEG C concentrated sulfuric acid, dripping into a constantly stirring transformation solvent at certain speed at the feeding temperature; then regulating the heat preservation temperature, continuously stirring for 1-72 hours so as to obtain a blue emulsion, adding lower alcohol into the blue emulsion, repeatedly extracting through deionized water till the blue emulsion is neutral, separating an organic phase out; adding a precipitator to allow TiOPc nano particles to settle; washing filter cakes through methyl alcohol, pulping through deionized water, freeze drying so as to obtain different crystal forms of oxotitanium phthalocyanine nano particles corresponding to the feeding temperature. The polymorphism photosensitivity TiOPc nano particle has small grain size, has good compatibility with PVB (polyvinyl butyral) resin, and is applicable to the material of the organic photoconductor producing electric charge, and the prepared photoconductor has high sensitivity, low dark failure, low residual potential, and good photoconduction performance.

The object of the present invention is to provide a positive charging electrophotographic photoreceptor having high sensitivity, low residual potential, and excellent chargeability, and relates to a positive charging electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a protective layer in this order, the photosensitive layer containing a charge generation substance, a positive hole transport substance, and an electron transport substance in the same layer, in which the positive hole transport substance includes at least one of the compounds represented by any one of the following formulas (1) to (5), and a binder resin of the protective layer is an alcohol-soluble thermoplastic resin, providing that the symbols in the formula are defined in the specification.

[Problems] To provide a novel compound which has a high carrier mobility and is useful as a charge-transporting agent that is not only capable of stably forming a photosensitive layer without precipitating crystals or forming pinholes at the time of forming the photosensitive layer but is also capable of forming an organic photosensitive material for electrophotography that has a high sensitivity and a low residual potential.[Means for Solution] A diphenylnaphthylamine derivative represented by the following general formula (1),wherein R1 to R3 are alkyl groups, k is an integer of 0 to 3, j is an integer of 0 to 4, l is an integer of 0 to 6, and X1 and X2 are hydrocarbon groups having at least one ethylenically unsaturated bond.

A photoreceptor for electrophotography, a method for manufacturing the photoreceptor, and an electrophotographic device including the photoreceptor are disclosed. The photoreceptor for electrophotography includes a conductive substrate; and a photosensitive layer that is provided on the conductive substrate and that has an outermost surface layer containing at least a resin binder and an electron transport material. The resin binder is composed of a polyarylate resin having a structural unit represented by a Chemical Structural Formula 1, and the electron transport material is composed of a compound having a structure represented by a Structural Formula (ET2-3). The photoreceptor has high sensitivity, low residual electric potential, no light fatigue and sufficient stain resistance.

To provide an electrophotographic photoreceptor having a high sensitivity, a good balance of various electric properties such as chargeability and residual potential, a good stability of the coating solution, and an excellent light resistance.An electrophotographic photoreceptor comprising an electroconductive support having thereon a photosensitive layer, wherein the photosensitive layer contains a compound represented by the following formula (1):(wherein R1 represents a group having a chiral center, R2 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent, R3 and R4 each independently represents an alkylene group which may have a substituent, or an arylene group which may have a substituent, and R5, R6, R7 and R8 each independently represents an alkyl group which may have a substituent, or an aryl group which may have a substituent, and at least one member of R5 to R8 is an aryl group having a substituent).