Abstract: Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

Abstract: Provided is a photoreceptor for electrophotography, having high sensitivity and high-speed response performance, and which prevents accumulation of residual potential even when used repeatedly. Also, provided are a photoreceptor cartridge and an image forming apparatus, each employing the photoreceptor.

Abstract: Provided is a photoreceptor for electrophotography, having high sensitivity and high-speed response performance, and which prevents accumulation of residual potential even when used repeatedly. Also, provided are a photoreceptor cartridge and an image forming apparatus, each employing the photoreceptor.

Abstract: Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

Abstract: Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

Abstract: Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

Abstract: Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

Abstract: A method of forming an image including an electrophotographic photoreceptor and a toner, wherein a photosensitive layer in the electrophotographic photoreceptor includes an undercoat layer including metal oxide particles, a charge generation layer including hydroxygallium phthalocyanine, and a charge transport layer, and the toner contains toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 ?m to 7.0 ?m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 ?m to 3.56 ?m satisfies—0.0517EXP(22.4/Dv50)?Dns?0.233EXP(17.3/Dv50) where Dv50 is the volume median diameter (?m) of the toner, and Dns is the percentage in number of toner particles having a particle diameter of from 2.00 ?m to 3.56 ?m.

Abstract: An object of the invention is to provide a toner which is effective in improving image quality while inhibiting white-background fouling, residual-image phenomenon (ghost), blurring (suitability for solid printing), and the like that occur depending on the proportion of a fine powder having a particle diameter not larger than a specific value, and which has satisfactory removability in cleaning, mitigates problems concerning fouling, etc. in long-term use even on a high-speed printer, and attains excellent image stability. Another object is to provide an image-forming apparatus and a toner cartridge each employing the toner. The invention provides a toner for electrostatic-image development satisfying all of the following (1) to (4) or a toner for electrostatic-image development which is a toner containing a charge control agent and satisfying all of the following (5) to (7). The invention further provides an image-forming apparatus and a toner cartridge each employing the toner.

Abstract: Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

Abstract: A method of forming an image on a substrate with an electrophotographic photoreceptor and a toner, a photosensitive layer of the electrophotographic photoreceptor contains a resin having a structural unit represented by the following formula (A) the toner containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 ?m to 7.0 ?m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 ?m to 3.56 ?m satisfies following formula (1) Dns?0.233EXP(17.3/Dv50)??(1).

Abstract: It is to provide a sheet-shaped electrophotographic photoreceptor which has an uncoated area, is good in mechanical adhesiveness between the photosensitive layer and the sheet-shaped conductive substrate but excellent ease of peeling with a solvent, and is further good in electrical properties. The electrophotographic photoreceptor comprises a sheet-shaped conductive substrate and a photosensitive layer provided thereon, wherein the electrophotographic photoreceptor contains a photosensitive layer-uncoated area within the sheet surface, and the photosensitive layer contains a copolycarbonate resin having an extremely restricted specific structure.

Abstract: To provide an electrophotographic photoreceptor excellent in electric characteristics and various characteristics, capable of forming a uniform photosensitive layer and excellent in repetitive characteristics, an image forming apparatus using it and an electrophotgraphic cartridge. A lamination type electrophotographic photoreceptor comprising an electroconductive substrate and a photosensitive layer formed thereon, characterized in that the photosensitive layer contains a compound represented by the following formula (1), the ratio of the weight of the compound represented by the formula (1) to the weight content of all binder resins contained in the photosensitive layer is from 0.15 to 0.

Abstract: An image-forming apparatus including an electrophotographic photoreceptor of which photosensitive layer contains oxytitanium phthalocyanine showing main diffraction peaks at Bragg angles (2?) of 9.0° and 27.2° and at least one main diffraction peak in the range of 9.3° to 9.8° to CuK? rays, and the toner satisfies all the following requirements (1) to (3): (1) the volume median diameter (Dv50) is 4.0 ?m or more and 7.0 ?m or less, (2) the average sphericity is 0.93 or more, and (3) the relation between the volume median diameter (Dv50) and the content (% by number: Dns) of toner particles of 2.00 ?m or more and 3.56 ?m or less satisfies Dns?0.233EXP(17.3/Dv50).

Abstract: An electrophotographic photoreceptor having high sensitivity and hardly affected by the transfer in an electrophotographic process is provided. The electrophotographic photoreceptor includes an undercoat layer containing metal oxide particles and a binder resin and a photosensitive layer disposed on the undercoat layer, wherein the metal oxide particles have a volume average particle diameter of 0.1 ?m or less and a 90% cumulative particle diameter of 0.3 ?m 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 a binder resin having an ester bond.

Abstract: Provided is an excellent phthalocyanine crystal having high sensitivity and little fluctuation in sensitivity for a humidity change in a use environment and applicable to the martial for solar battery, electronic paper, electrophotographic photoreceptor, etc. Namely, phthalocyanine crystal obtained by bringing a phthalocyanine crystal precursor into contact with an aromatic aldehyde compound to convert the crystal form. Also, provided is an electrophotographic photoreceptor that not only exhibits high sensitivity but also has little fluctuation in sensitivity for a humidity change in a use environment. Further, provided is an electrophotographic photoreceptor cartridge and an image-forming device, both of which can produce a stable quality images for a humidity change in a use environment by using the electrophotographic photoreceptor.

Abstract: To realize an electrophotographic photoreceptor excellent in abrasion resistance, the photosensitive layer of the photoreceptor comprises a polyester resin containing a repeating structural unit represented by the formula (1) and a hydrazone compound. (In the formula (1), Ar1 to Ar4 each represents, independently of each other, an arylene group which may have a substituent. X1 represents a bivalent group (including a single bond) and X2 represents a bivalent group (including a single bond) with 3 or less atoms.

Abstract: An image forming apparatus comprising an electrophotographic photoreceptor having a photosensitive layer on an electroconductive substrate, and a toner for developing an electrostatic charge image, wherein the photosensitive layer of the electrophotographic photoreceptor contains a phthalocyanine obtained via an acid paste step; the toner for developing an electrostatic charge image is a toner for developing an electrostatic charge image containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 ?m to 7.0 ?m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 ?m to 3.56 ?m satisfies the following formula (1): Dns?0.233 EXP(17.3/Dv50)??(1).

Abstract: An image forming apparatus comprising an electrophotographic photoreceptor having a photosensitive layer on an electroconductive substrate, and a toner for developing an electrostatic charge image, wherein the photosensitive layer of the electrophotographic photoreceptor contains a phthalocyanine obtained via an acid paste step; the toner for developing an electrostatic charge image is a toner for developing an electrostatic charge image containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 ?m to 7.0 ?m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 ?m to 3.56 ?m satisfies the following formula (1): Dns?0.233 EXP(17.3/Dv50)??(1).

Abstract: An image forming apparatus containing an electrophotographic photoreceptor and a toner for developing an electrostatic charge image, where the electrophotographic photoreceptor has an undercoat layer containing metal oxide particles; the toner for developing an electrostatic charge image is a toner for developing an electrostatic charge image containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 ?m to 7.0 ?m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 ?m to 3.56 ?m satisfies the following formula (1): Dns?0.233EXP(17.3/Dv50)??(1) where Dv50 is the volume median diameter (?m) of the toner, and Dns is the percentage in number of toner particles having a particle diameter of from 2.00 ?m to 3.56 ?m.