Abstract: An electrophotographic article having a complex of charge generating material and at least one transfer material selected from the group consisting of electron transfer material and hole transfer material is formed by admixing the charge generating material, at least one transfer material, and an organic binder in a solvent to form a coatable dispersion comprising a complex of charge generating material and said at least one transfer material; and coating said coatable dispersion onto a conductive substrate to form a charge transfer layer on the electrophotoconductive article. A novel S-form titanyl oxyphthalocyanine is also preferred, the novel form displaying major peaks of Bragg's 2theta angle to the CuK-alpha characteristic X-ray (wavelength 1.541 Angstrom) at least at 9.5±0.2 degrees, 9.7±0.2 degrees, 11.7±0.2 degrees, 13.5±0.2 degrees, (optionally at 21±0.2 degrees and/or 23.5±0.2 degrees,) 24.1±0.2 degrees, 26.4±0.2 degrees, and 27.3±0.

Abstract: An electrophotographic image forming apparatus comprising:

Abstract: The present invention relates to the electrophotographic apparatus wherein the photoconductor takes 200 msec or less to reach from the light irradiator to the developer, an exposure energy upon irradiation of a write light having a resolution of 600 dpi or greater from the light irradiator to the photoconductor is 5 erg/cm2 or less on the surface thereof, the photoconductor is obtained by stacking a charge generation layer and a charge transport layer in this order on a conductive support, and the charge generation layer contains titanyl phthalocyanine crystals having, as a diffraction peak (±0.2°) of Bragg angle 2&thgr; relative to CuK&agr; ray (wavelength: 1.542 angstrom), a maximum diffraction peak at least at 27.2°, main peaks at 9.4°, 9.6° and 24.0°, and a peak at 7.3° as a diffraction peak on the lowest angle side, and not having a peak within a range of 7.4 to 9.3°.

Abstract: A charge transport layer for an imaging member comprising a charge transport layer wherein the charge transport layer comprises the application of charge transport molecules and a poly(fluoroacrylate)-graft-poly(methyl methacrylate) surfactant. The charge transport layer exhibits excellent wear resistance, excellent electrical performance, excellent print quality and decreased crystallization of the charge transport component.

Abstract: An amorphous mixture consisting essentially of TiOFPc and TiOPc and containing more than 75 weight percent of substantially chlorine-free TiOPc is produced by forming a mixture of crude crystalline TiOFPc and crude crystalline, substantially chlorine-free TiOPc that contains less than 80 weight percent TiOPc, treating the mixture under conditions effective to form a substantially amorphous mixture of TiOFPc and TiOPc containing less than 75 weight percent TiOPc, which is then treated with water, and dried. A further amount of crude crystalline, substantially chlorine-free TiOPc sufficient to form a new mixture containing more than 75 weight percent of substantially chlorine-free TiOPc is added, and the new mixture is converted to a substantially amorphous mixture of TiOFPc and TiOPc. A nanoparticulate cocrystalline composition is obtained by forming a slurry in an organic solvent of the dried substantially amorphous mixture, and wet milling the slurry to form the cocrystalline composition.

Abstract: In a process for forming a nanoparticulate crystalline titanium phthalocyanine pigment composition, a titanium phthalocyanine pigment is contacted with substantially pure 1,1,2-trichloroethane (TCE) under conditions effective to convert the titanium phthalocyanine pigment to the nanoparticulate crystalline composition.

Abstract: A photoconductive imaging member containers of a supporting substrate, and thereover a single layer comprised of a mixture of a photogenerator component, a charge transport component, an electron transport component, and a polymer binder, and wherein the photogenerating component is a pigment.

Abstract: An electrophotographic photoreceptor containing a charge generation material composition comprising a sandwich-type metal bisphthalocyanine compound represented by the general formula (I), having a primary particle diameter of 1 micron or less, and a phthalocyanine-based charge generation material represented by the general formula (II):

Abstract: A photoreceptor including an electroconductive substrate; a charge generation layer located overlying the electroconductive substrate optionally with an intermediate layer therebetween; and a charge transport layer formed overlying the charge generation layer using a non-halogenated solvent and including a charge transport material and a resin, wherein the charge generation layer includes a polyvinyl acetal resin and a charge generation material having an average particle diameter less than a roughness of a surface of either the electroconductive substrate or the intermediate layer, on which the charge generation layer is located.

Abstract: An electrophotographic apparatus includes an electrophotographic photosensitive member comprising a support and a photosensitive layer thereon, a charging means for charging the photosensitive member, a multi-beam exposure means for illuminating the photosensitive member with a plurality of laser beams to form an electrostatic latent image on the photosensitive member, a developing means for developing the electrostatic latent image to form a toner image on the photosensitive member, and a transfer means for transferring the toner image from the photosensitive member to a transfer-receiving material. The electrophotographic apparatus is not equipped with a charge-removal means for uniformly charge-removing the photosensitive member in advance of operation of the charging means. Further, the photosensitive member has a photosensitive layer containing oxytitanium phthalocyanine and exhibits a charge mobility of 7.0×10−5 to 2.0×10−5 cm2/volt.sec.

Abstract: The invention provides an electrophotographic photoreceptor, in which suppression of image defects and high sensitivity are compatible, and a method for production thereof. The invention also provides a coating fluid for forming a photosensitive layer and a method for production thereof, as well as an image-forming apparatus using said electrophoto-graphic photoreceptor. Briefly, the electrophoto-graphic photoreceptors may be constructed by forming an undercoating layer on a conductive support, and then forming a photosensitive layer on the undercoating layer. The undercoating layer contains titanium oxide particles in at least either needle shape or dendrite shape. The photosensitive layer contains an electric charge-generating material of which the primary particle size and cohesive particle size are in a range of 0.01 &mgr;m-10 &mgr;m. Accordingly, in the electrophotographic photoreceptors, it is possible to maintain high sensitivity and excellent durability and to form an image with no defect.

Abstract: A titanylphthalocyanine crystal having an X-ray diffraction spectrum having plural diffraction peaks and a primary particle diameter not greater than 0.2 &mgr;m, wherein a maximum diffraction peak is observed at a Bragg (2&thgr;) angle of 27.2±0.2°; main peaks are observed at 9.4°, 9.6° and 24.0°; and a minimum diffraction peak is observed at 7.3°; and preferably no diffraction peak is observed at an angle greater than 7.3° and less than 9.4° when a specific X-ray of CuK&agr; having a wavelength of 1.542 Å irradiates the titanylphthalocyanine crystal.

Abstract: An electrostatographic article including: a substrate; a charge generator layer overcoated on the substrate and which layer is sensitive to blue light; and a charge transport layer overcoated on the charge generator layer and which charge transport layer is transparent to blue light.

Abstract: Charge transport layers comprise a charge transport compound and binder including styrene-acrylic resin. Dual layer photoconductors comprise a substrate, a charge transport layer as described, and a charge generation layer.

Abstract: An electrophotographic photoconductor exhibits excellent electrophotographic performance, particularly high sensitivity. A method of manufacturing an electrophotographic photoconductor includes forming a photosensitive layer exhibiting high sensitivity using a coating liquid. The electrophotographic photoconductor includes a photosensitive layer that contains photoconductive substances, a principal component of which is a metallophthalocyanine compound and a subcomponent of which is a phthalocyanine compound having central elements of hydrogen. The content of the subcomponent is in a proportion of 1 &mgr;mol to 200 mmol with respect to 1 mol of the principal component. The manufacturing method uses a coating liquid containing photoconductive substances, including principal component of a metallophthalocyanine compound and a subcomponent of a phthalocyanine compound having central elements of hydrogen in a proportion of 1 &mgr;mol to 200 mmol with respect to 1 mol of the principal component.

Abstract: A di-substituted alkylene glycolate titanium phthalocyanine compound comprising a reaction mixture of a threo-alkanediol having one hydroxy group per each of the two adjacent carbon atoms, said carbon atoms each being a secondary carbon atom, and an oxytitanium phthalocyanine compound, and an organic photoconductor comprising the di-substituted alkylene glycolate titanium phthalocyanine compound are disclosed.

Abstract: The invention provides an electrophotographic photoreceptor, in which suppression of image defects and high sensitivity are compatible, and a method for production thereof. The invention also provides a coating fluid for forming a photosensitive layer and a method for production thereof, as well as an image-forming apparatus using said electrophoto-graphic photoreceptor. Briefly, the electrophoto-graphic photoreceptors may be constructed by forming an undercoating layer on a conductive support, and then forming a photosensitive layer on the undercoating layer. The undercoating layer contains titanium oxide particles in at least either needle shape or dendrite shape. The photosensitive layer contains an electric charge-generating material of which the primary particle size and cohesive particle size are in a range of 0.01 &mgr;m-10 &mgr;m. Accordingly, in the electrophotographic photoreceptors, it is possible to maintain high sensitivity and excellent durability and to form an image with no defect.

Abstract: A composition for a charge generating layer of a positively-charged electrophotographic organophotoreceptor and the positively-charged electrophotographic organophotoreceptor having a charge generating layer formed using the composition are utilized in a photocopy apparatus/organophotoreceptor drum/organophotoreceptor cartridge and a method of manufacturing the positively-charged electrophotographic organophotoreceptor. The charge generating layer composition for the positively-charged electrophotographic organophotoreceptor, which has a charge transport layer and a charge generating layer sequentially coated on a conductive support, includes a charge generating material, a binder, and an organic solvent containing an alcoholic solvent and an acetate solvent in a ratio from 1:9 to 5:5 by weight.

Abstract: A phthalimide salt compound is contained in a photosensitive material having a charge generating function. Such a photosensitive material exhibits high retention rates of the surface charge. An electrophotographic photoconductor comprising such a photosensitive material is useful in, for example, printers, photocopiers, and facsmilie machines.

Abstract: A photoconductive member with a supporting substrate, and thereover a first layer comprised of a mixture of a photogenerator component, a hole transport component, and an electron transport component; and thereover a second layer comprised of a charge transport component.

Abstract: An electrophotographic photosensitive body has a photosensitive layer formed on a conductive substrate. The photosensitive layer contains a phthalocyanine compound as a photoconductive material, wherein the content of a phthalocyanine dimer compound in the layer that contains the phthalocyanine compound is present from about 100 nmol to about 300 mmol per 1 mol of the phthalocyanine compound. The resulting electrophotographic photosensitive body has excellent potential retention properties.

Abstract: A photoreceptor including an electroconductive substrate and a photosensitive layer which is formed on the electroconductive substrate and which includes a charge generation material, wherein the charge generation material comprises an organic pigment and wherein the photosensitive layer further includes at least one ion selected from the group consisting of K+, Na+, NO3−, HCOO−, NO2−, Cl−, Br−, and NH4+ or one or more water-soluble inorganic salts.

Abstract: An electrophotographic photoreceptor containing a charge generation material composition comprising a sandwich-type metal bisphthalocyanine compound represented by the general formula (I), having a primary particle diameter of 1 micron or less, and a phthalocyanine-based charge generation material represented by the general formula (II):

Abstract: To provide a novel reaction product useful as an organic photoconductive material for electrophotographic photoconductors. A product obtainable by reacting (i) a nitrile derivative, (ii) a phthalonitrile derivative or a 1,3-diiminoisoindoline derivative and, if necessary, (iii) a metal or a metal-containing compound.

Abstract: The present invention intends to provide a TPD derivative being excellent in electric properties as a compound due to its extremely less content of impurities (TPD analogues) as well as being excellent in film-forming property due to its low crystallinity.

Abstract: The present invention provides an electrophotographic photosensitive member wherein a maximum height (RmaxD) of a surface roughness of a support portion is 1.2 &mgr;m RmaxD≦5.0 &mgr;m, an average roughness (Rz) of 10 points is 1.2 &mgr;m≦Rz≦3.0 m, an arithmetic average roughness (Ra) is 0.15 &mgr;m≦Ra≦0.5 &mgr;m, and an irregularity average interval (Sm) is 30 &mgr;m≦Sm≦80 &mgr;m. The photosensitive member's charge generation layer contains a phthalocyanine compound, its charge transport layer has a thickness which is at least 9 &mgr;m but not larger than 18 &mgr;m, the electrophotographic photosensitive member in every 1 cm2 area has an electrostatic capacity (C) of 130 pF or more. This invention also provides a process cartridge and an electrophotographic apparatus containing the electrophotographic photosensitive member.

Abstract: An electrophotographic apparatus includes an electrophotographic photosensitive member comprising a support and a photosensitive layer thereon, a charging means for charging the photosensitive member, a multi-beam exposure means for illuminating the photosensitive member with a plurality of laser beams to form an electrostatic latent image on the photosensitive member, a developing means for developing the electrostatic latent image to form a toner image on the photosensitive member, and a transfer means for transferring the toner image from the photosensitive member to a transfer-receiving material. The electrophotographic apparatus is not equipped with a charge-removal means for uniformly charge-removing the photosensitive member in advance of operation of the charging means. Further, the photosensitive member has a photosensitive layer containing oxytitanium phthalocyanine and exhibits a charge mobility of 7.0×10−5 to 2.0×10−5 cm2/volt.sec.

Abstract: In an electrophotographic apparatus comprising an electrophotographic photosensitive member around which a charging means, an exposure means, a developing means and a transfer means are provided in this order and not having any charge elimination means between the transfer means and the charging means, the electrophotographic photosensitive member comprises a support and provided thereon a charge generation layer containing a phthalocyanine compound and a charge transport layer, and has a light-area dark attenuation rate A and a dark-area dark attenuation rate B which satisfy the following expression (1):

Abstract: A photoreceptor including an electroconductive substrate; a charge generation layer formed overlying the electroconductive substrate and including as a charge generation material a titanyl phthalocyanine crystal having an X-ray diffraction spectrum such that a maximum diffraction peak is observed at a Bragg (2&thgr;) angle of 27.2°±0.2° when a specific X-ray of Cu-K&agr; having wavelength of 1.542 Å irradiates the titanyl phthalocyanine crystal; and a charge transport layer formed on the charge generation layer and including a binder resin, a charge transport material, water and tetrahydrofuran, wherein a weight ratio of the water to the tetrahydrofuran in the charge transport layer is from 1/50 to 1/0.5.

Abstract: An electrophotographic photoconductor includes a photosensitive layer on a conductive substrate. The photosensitive layer contains a pigment that consists of crystallites composed of molecules having a titanylphthalocyanine structure, wherein a crystallite diameter of the pigment is not smaller than 20 nm and a primary particle diameter of the pigment is not larger than 500 nm.

Abstract: Disclosed are a phthalocyanine composition suitable for use in an electrophotographic photoreceptor that exhibits a high charge potential and a high sensitivity and which exhibits stable performances without causing a change in various properties in repeated use, a process for the production thereof, and an electrophotographic photoreceptor to which the above phthalocyanine composition is applied. The present invention provides a phthalocyanine composition comprising a oxytitanium phthalocyanine and a metal-free phthalocyanine and having a crystal form having peaks at Bragg angles (2&thgr;±0.2°) of 7.0°, 9.0°, 14.1°, 18.0°, 23.7° and 27.3°, and having no peak at a Bragg angle (2&thgr;±0.2°) of 9.5°, in CuK&agr; 1.

Abstract: An electrophotographic photoconductor includes a conductive substrate and a photosensitive layer formed on a substrate. The photosensitive layer includes a phthalocyanine compound as a charge generation substance. An embodiment of the photosensitive layer contains a first phthalocyanine compound as a main component and a second phthalocyanine compound as a secondary component and as a result, has greater ability to generate negative charges than the ability of the first phthalocyanine compound.

Abstract: Poly(vinyl butyral) compounds of Formula 1 where R1 is alkyl, dialkyl ether, alkyl carbonyl, cycloalkyl, cycloalkyl alkyl, aryl, aryl carbonyl, alkaryl carbonyl, aralkyl, or alkyl aralkyl; Z is —OH or —NHR2, where R2 is independently alkyl, dialkyl ether, alkyl carbonyl, cycloalkyl, cycloalkyl alkyl, aryl, aryl carbonyl, alkaryl carbonyl, aralkyl, alkyl, aralkyl or R2 is H. x is 60 to 95 mol %, y is 3 to 40 mol %, z is 0 to 20 mol %; and x+y+z is 100 mol %, a process for preparing compounds of Formula I, an intermediate in the synthesis of compounds of Formula I, and a photoconductor for electrophotography containing a compound of Formula I as a binder in the charge generation layer are described.

Abstract: An electrophotographic photoreceptor highly sensitive to laser light, which is capable of forming an image without forming an interference fringe and a coating liquid for a charge generating layer for forming the same are provided, and the photoreceptor is produced with excellent coating properties and high electric characteristics at a low cost. The electrophotographic photoreceptor comprises an electroconductive support and a photosensitive layer thereon having a charge generating layer containing TiOPc as a charge generating material and having a Y value by a color measuring apparatus of 37 or less, and particularly 35 or less, and a charge transporting layer, accumulated thereon, containing a charge transporting material. In an X-ray diffraction spectrum, the TiOPc has major diffraction peaks at Bragg angles (2&thgr;±0.2°) of 7.3°, 9.4°, 9.6°, 11.6°, 13.3°, 17.9°, 24.1° and 27.2°, and in particular, the diffraction peaks at the Bragg angles (2&thgr;±0.

Abstract: A photoconductor having a charge transport layer in illustrative embodiments of a polycarbonate binder, 30 to 60 percent by weight DEH hydrazone, 0.5 percent to 5 percent acetosol yellow, and 0.5 percent to 5 percent by weight of the butylated reaction product of p-cresol and dicyclopentadiene. The charge generation layer by type IV oxotitanium phthalocyanine in polyvinylbutyral, poly (methyl-phenyl) siloxane and polyhydroxystyrene. Light fatigue is largely eliminated while the physical and cost advantages of DEH are realized.

Abstract: A photosensitive layer of an electrophotographic photoconductor has at least one phthalocyanine compound, wherein the photosensitive layer contains a metal phthalocyanine compound bonded by an o-phthalonitrile compound as a ligand. The o-phthalonitrile ligand is present in an amount from about 100 nmol to about 200 nmol with respect to 1 mol of the phthalocyanine. The resulting electrophotographic photoconductor exhibits a high potential retention rate. A method for making such an electrophotographic photoconductor is also disclosed wherein a photosensitive layer is formed by coating, with a coating layer, to obtain a photosensitive layer having a high potential retention rate.

Abstract: A photoreceptor including an electroconductive substrate; a charge generation layer formed overlying the electroconductive substrate and including as a charge generation material a titanyl phthalocyanine crystal having an X-ray diffraction spectrum such that a maximum diffraction peak is observed at a Bragg (2&thgr;) angle of 27.2°±0.2° when a specific X-ray of Cu-K&agr; having wavelength of 1.514 Å irradiates the titanyl phthalocyanine crystal; and a charge transport layer formed on the charge generation layer and including a binder resin, a charge transport material, water and tetrahydrofuran, wherein a weight ratio of the water to the tetrahydrofuran in the charge transport layer is from 1/50 to 1/0.5.

Abstract: The present invention provides an electrophotographic photosensitive member wherein a maximum height (RmaxD) of a surface roughness of a support portion is 1.2 &mgr;m≦RmaxD≦5.0 &mgr;m, an average roughness (Rz) of 10 points is 1.2 &mgr;m≦Rz≦3.0 m, an arithmetic average roughness (Ra) is 0.15 &mgr;m≦Ra≦0.5 &mgr;m, and an irregularity average interval (Sm) is 30 &mgr;m<Sm≦80 &mgr;m. The photosensitive member's charge generation layer contains a phthalocyanine compound, its charge transport layer has a thickness which is at least 9 &mgr;m but not larger than 18 &mgr;m, the electrophotographic photosensitive member in every 1 cm2 area has an electrostatic capacity (C) of 130 pF or more. This invention also provides a process cartridge and an electrophotographic apparatus containing the electrophotographic photosensitive member.

Abstract: Disclosed are a phthalocyanine composition suitable for use in an electrophotographic photoreceptor that exhibits a high charge potential and a high sensitivity and which exhibits stable performances without causing a change in various properties in repeated use, a process for the production thereof, and an electrophotographic photoreceptor to which the above phthalocyanine composition is applied.

Abstract: A cylindrical electrophotographic photoreceptor is disclosed. The layer thickness decreasing amount &Dgr;Hd (in &mgr;m) is 0≦&Dgr;Hd<5×10−6 per rotatio,n and residual potential variation amount per cm2 is 0≦&Dgr;Vr<100 (in V) for 1 A of an electric current generated by charging and exposure.

Abstract: Controlled sensitivity of a photoconductor is obtained employing both type I and type IV titanyl phthalocyanine in a charge generation layer. The type I titanyl phthalocyanine is preferably premilled before milling the mixture.

Abstract: An electrophotographic photoconductor includes a conductive substrate and a photosensitive layer formed on a substrate. The photosensitive layer includes a phthalocyanine compound as a charge generation substance. An embodiment of the photosensitive layer contains a first phthalocyanine compound as a main component and a second phthalocyanine compound as a secondary component and as a result, has greater ability to generate negative charges than the ability of the first phthalocyanine compound.

Abstract: An object of the invention is to implement a photoreceptor having high sensitivity and faithfully realizing high-density recording. An electrophotographic photoreceptor used for an image forming apparatus for forming a latent image at a resolution of 1200 dpi or more by exposing an object to light and visualizing the latent image with a reversal development system using a toner having an average particle size of 6 &mgr;m or less, which comprises an electrically conductive support, and a photosensitive layer composed of a charge generating layer formed on the electrically conductive support, and a charge transport layer formed on the charge generating layer, having a thickness of 20 &mgr;m or less.

Abstract: An electrophotographic photosensitive body has a photosensitive layer formed on a conductive substrate. The photosensitive layer contains a phthalocyanine compound as a photoconductive material, wherein the content of a phthalocyanine dimer compound in the layer that contains the phthalocyanine compound is present from about 100 mmol to about 300 mmol per 1 mol of the phthalocyanine compound. The resulting electrophotographic photosensitive body has excellent potential retention properties.

Abstract: A photoconductor having a charge generation layer of pigment and a binder resin of a thorough mixture of polyvinylbutyral, a polysiloxane, and, preferably, a phenolic resin. An optimum formulation was Type IV oxotitanium phthalocyanine in a binder of, by weight 50 parts polyvinylbutyral, 45 parts poly(methyl-phenyl)siloxane, and 5 parts polyhydroxystyrene. This photoconductor provides excellent electrical properties and consistent, economical coating results.

Abstract: An object of the invention is to obtain an electrophotographic photoreceptor having high sensitivity, high image quality, high stability and high resolution. A charge generating layer of the electrophotographic photoreceptor contains, as a charge generating substance, a crystalline titanyl phthalocyanine composition exhibiting, in an X-ray diffraction spectrum of a CuK&agr; characteristic X-ray (wavelength: 1.5418 Å), at least four diffraction peaks at Bragg angles (2&thgr;±0.2°) of 10.0° or lower, and a diffraction peak at a Bragg angle of 27.2° having an intensity smaller than the maximum diffraction intensity of the four diffraction peaks, or a lowly crystalline titanyl phthalocyanine composition exhibiting a diffraction peak having the maximum diffraction intensity at a Bragg angle (2&thgr;±0.2°) of 27.3°. A charge transporting layer of the electrophotographic photoreceptor contains, as a charge transporting substance, a bisamine compound.

Abstract: A peroxide-modified titanyl phthalocyanine for use in preparing charge generating layer of a photoreceptor is disclosed. The peroxide-modified titanyl phthalocyanine is obtained by subjecting titanyl phthalocyanine to a peroxide-induced complexation-mediated crystal transformation at a low temperature. The peroxide-modified titanyl phthalocyanine is characterized by having Bragg diffraction angles of 7.3, 9.4, 14.0, 24.1, 25.7, 27.2 and 28.5 degrees, and vibrational absorption resonances at 1486 cm (superscript: −1), 1420 cm (superscript: −1), 1134 cm (superscript: −1), 1078 cm (superscript: −1), 966 cm (superscript: −1), 900 cm (superscript: −1), 762 cm (superscript: −1) and 736 cm (superscript: −1). The photoreceptor exhibits excellent photosensitivity at wavelengths in the near-infrared range and has a unique crystal form, especially the peroxide-modified titanyl phthalocyanine shows a higher distinct absorption peak at the wavelength of 780 nm.

Abstract: An electrophotographic photosensitive member comprising a support and a photosensitive layer. The photosensitive layer contains an oxytitanium phthalocyanine having the strongest peak at 27.2°±0.2° of the diffraction angle (2&thgr;) in CuK&agr; characteristic X-ray diffraction and a hydroxygallium phthalocyanine having strong peaks at 7.4°±0.2° and 28.2°±0.2° of the diffraction angle (2&thgr;) in CuK&agr; characteristic X-ray diffraction. A process cartridge and an electrophotographic apparatus, employing the electrophotographic photosensitive member, are also disclosed.

Abstract: A novel titanyl phthalocyanine crystal, a photoconductive material comprising the same, and an electrophotographic photoreceptor using the same are disclosed. The titanyl phthalocyanine crystal has a primary particle diameter ranging from 0.03 to 0.15 &mgr;m, shows a maximum X-ray diffraction peak at a Bragg angle (2&thgr;±0.2°) of 27.3°, has a ellipsoidal tabular form, and has a BET specific surface area of not less than 35 m2/g. The crystal has improved crystal form stability against solvents and holds its crystal form for an extended period of time in a dispersed and coated state. An electrophotographic photoreceptor using the crystal as a photoconductive material is excellent in sensitivity, stability, and durability.

Abstract: A cylindrical electrophotoreceptor is disclosed. The layer thickness decreasing amount &Dgr;Hd (in &mgr;m) is 0≦&Dgr;Hd<5×10−6 per rotation and residual potential variation amount per cm2 is 0≦&Dgr;Vr<100 (in V) for 1 A of an electric current generated by charging and exposure.