A dispersant-attached polytetrafluoroethylene particle includes a polytetrafluoroethylene particle and a dispersant that attaches to a surface of the polytetrafluoroethylene particle and contains a fluorine atom. The particle size distribution index [D.sub.50-D.sub.10] is less than 50 nm and the electrical conductivity is 7 S/cm or less.

The present invention aims to provide an electrophotographic photoreceptor excellent in abrasion resistance and electrical properties, which uses polymers excellent in surface-active functions such as fluororesin dispersibility and electrical properties, and relates to an electrophotographic photoreceptor which contains a polymer containing a repeating unit represented by the following Formula (A1), provided that the definitions of X.sup.1, X.sup.2, R.sup.11 to R.sup.16 in Formula (A1), and R.sup.21 in Formula (A2) are shown in the specification

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An image forming apparatus includes an electrophotographic photoreceptor that includes a conductive substrate and a photosensitive layer disposed on the conductive substrate, the electrophotographic photoreceptor having an outermost surface layer that contains a binder resin, a charge-transporting material, and a fluorine-containing resin particle, the fluorine-containing resin particle containing 0 or more and 30 or less carboxy groups per 10.sup.6 carbon atoms, a charging device that charges the electrophotographic photoreceptor, an electrostatic latent image forming device that forms an electrostatic latent image on the electrophotographic photoreceptor that is charged, a developing device that houses a developer containing a toner and that develops, with the developer, the electrostatic latent image formed on the electrophotographic photoreceptor into a toner image, a transfer device that transfers the toner image onto a transfer-receiving medium, and an optical discharging device that, after the toner image is transferred onto the transfer-receiving medium and before the electrophotographic photoreceptor is charged, irradiates the electrophotographic photoreceptor with discharging light with a light quantity of 1.0 ?W or more and 50.0 ?W or less to perform discharging.

An image forming apparatus includes an electrophotographic photoreceptor that includes a conductive substrate and a photosensitive layer disposed on the conductive substrate, the electrophotographic photoreceptor having an outermost surface layer that contains a binder resin, a charge-transporting material, and a fluorine-containing resin particle, the fluorine-containing resin particle containing 0 or more and 30 or less carboxy groups per 10.sup.6 carbon atoms, a charging device that charges the electrophotographic photoreceptor, an electrostatic latent image forming device that forms an electrostatic latent image on the electrophotographic photoreceptor that is charged, a developing device that houses a developer containing a toner and that develops, with the developer, the electrostatic latent image formed on the electrophotographic photoreceptor into a toner image, a transfer device that transfers the toner image onto a transfer-receiving medium, and an optical discharging device that, after the toner image is transferred onto the transfer-receiving medium and before the electrophotographic photoreceptor is charged, irradiates the electrophotographic photoreceptor with discharging light with a light quantity of 1.0 ?W or more and 50.0 ?W or less to perform discharging.

An image forming apparatus includes an electrophotographic photoreceptor that has an outermost surface layer containing fluorine-containing resin particles, a charge transport material, and a binder resin, in which the number of carboxy groups contained in the fluorine-containing resin particles is 0 or greater and 30 or less per 10.sup.6 carbon atoms, and the outermost surface layer has a tan ? of 0.025 or greater and 0.030 or less, a charging device that comes into direct contact with the electrophotographic photoreceptor and applies only a DC voltage to charge the electrophotographic photoreceptor, an electrostatic latent image forming device that forms an electrostatic latent image on a surface of the charged electrophotographic photoreceptor, a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image, a transfer device that transfers the toner image by bringing the electrophotographic photoreceptor and a medium to be transferred into direct contact with each other, and a cleaning device that cleans the surface of the electrophotographic photoreceptor.

The present invention provides an aqueous dispersion of a low-molecular-weight polytetrafluoroethylene (PTFE), which contains an easily removable surfactant, and has a good dispersion stability. Specifically, the present invention provides an aqueous dispersion of a low-molecular-weight PTFE comprising tetrafluoroethylene (TFE) units, or TFE units and modifying monomer units which are copolymerizable with the TFE units, wherein the aqueous dispersion contains from 70 to 9,000 ppm, based on the aqueous dispersion, of a fluorine-containing compound of the formula (1) below:
X(CF.sub.2).sub.mY(1)
where X is H or F; m is an integer from 3 to 5; and Y is SO.sub.3M, SO.sub.4M, SO.sub.3R, SO.sub.4R, COOM, PO.sub.3M.sub.2 or PO.sub.4M.sub.2, M being H, NH.sub.4 or an alkali metal, and R being an alkyl group having 1 to 12 carbons, and the low-molecular-weight PTFE has an average primary particle size of from 100 to 350 nm.

An electrostatic charge image developing toner includes toner particles, silica particles having an average particle diameter of 80 nm to 200 nm, lubricant particles N which has negatively chargeable property, and lubricant particles P which has positively chargeable property, wherein a content (s) of the silica particles, a content (n) of the lubricant particles N, and a content (p) of the lubricant particles P satisfy relationships of Expression (1): 0.002p/s0.2; and Expression (2): 0.02n/s0.5.

An image forming apparatus includes an electrophotographic photoreceptor that has an outermost surface layer containing fluorine-containing resin particles, a charge transport material, and a binder resin, in which the number of carboxy groups contained in the fluorine-containing resin particles is 0 or greater and 30 or less per 10.sup.6 carbon atoms, and the outermost surface layer has a tan of 0.025 or greater and 0.030 or less, a charging device that comes into direct contact with the electrophotographic photoreceptor and applies only a DC voltage to charge the electrophotographic photoreceptor, an electrostatic latent image forming device that forms an electrostatic latent image on a surface of the charged electrophotographic photoreceptor, a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image, a transfer device that transfers the toner image by bringing the electrophotographic photoreceptor and a medium to be transferred into direct contact with each other, and a cleaning device that cleans the surface of the electrophotographic photoreceptor.

A toner includes toner particles. The toner particles each include a toner mother particle containing a binder resin and an external additive attached to a surface of the toner mother particle. The external additive includes fluorine-containing particles. The fluorine-containing particles include a fluorine atom at least in surface layers thereof. The amount of the fluorine-containing particles is at least 0.10 parts by mass and no greater than 0.50 parts by mass relative to 100 parts by mass of the toner mother particles. When ultrasonication is performed, a residual amount ratio of remaining fluorine-containing particles is at least 0% by mass and no greater than 20% by mass relative to the amount of the fluorine-containing particles attached to the toner mother particles before the ultrasonication.