Abstract: A process for the preparation of chemical toner by mixing a colorant, a latex, optionally a wax, and a first coagulant of, for example, a polyaluminum sulfosilicate and a second cationic coagulant of, for example, a benzylalkonium chloride.

Abstract: An electrophotographic image forming method employing a photoreceptor is disclosed. The decrease &Dgr;Hd (in &mgr;m), in layer thickness per rotation in wear test of the organic electrophotographic photoreceptor defined in the specification, is in the range of 0≦&Dgr;Hd<1×10−5, and a toner used in said development process is one which is obtained by suspension-polymerizing a polymerizable composition consisting of at least a polymerizable monomer and a colorant in a water based medium or one which is obtained by fusing resinous particles in a water based medium.

Abstract: The present invention is aimed at providing a toner binder for electrophotography that is excellent in the fixing property, offset resistance, blocking property, grindability, durable developing property and the like to correspond to the high-speed movement of a copier. The purpose of the present invention could be achieved by a toner binder having the following features for electrophotography. That is, when the viscoelasticity of the toner binder is measured in the temperature range of 50 to 200 ° C. and at a heating rate of 2° C./min., the viscoelasticity curve in the temperature range of 100 to 200° C. showing the relationship between the storage modulus and temperature, in which curve the axis of ordinate is the logarithm (Pa) of storage modulus G′ and the axis of abscissa is temperature (° C.), has a concave in the temperature range of 140 to 180° C.

Abstract: A toner comprising separate toner particles each of which comprises a fixable core, the core being provided with a conductive surface layer containing a doped electrically conductive polymer and an intermediate layer, particularly a polymer-containing intermediate layer disposed between the surface layer and the core.

Abstract: An electrophotographic photoconductor has an electroconductive support, and a charge generation layer and a charge transport layer successively formed on the electroconductive support, the charge transport layer allowing any monochromatic light with a wavelength in a wavelength region of 390 to 460 nm to pass through and exhibiting a fluorescence generation coefficiency of 0.8 or less when irradiated with the monochromatic light. An electrophotographic image forming apparatus and a process cartridge employ the above-mentioned photoconductor.

Abstract: A toner for use in electrophotography, which includes a coloring agent and a binder including a binder resin which contains therein a cyclized rubber, is proposed, and an image formation method using this toner is also proposed.

Abstract: An electrophotographic photosensitive member exhibiting a good durability and stable electrophotographic performances regardless of environmental change is provided by coating the photosensitive layer with a specific protective layer. The protective layer has a thickness of 1-7 &mgr;m and comprises a cured phenolic resin and metal particles or metal oxide particles dispersed therein.

Abstract: The invention relates to an electrophotosensitive material comprising an organic photosensitive layer and an inorganic surface protective layer, wherein at least an outermost part of the organic photosensitive layer contains a diphenylamine compound represented by a formula (1): wherein ‘A’ denotes a groups combined with two phenyl groups in the formula in a manner to jointly form a &pgr;-electron conjugated system. The electrophotosensitive material features more excellent durability because the compound functions as a binder for combining the organic photosensitive layer with the inorganic surface protective layer so that the surface protective layer is less prone to suffer cracks or delamination.

Abstract: A photoconductor comprises a substrate and a charge generation layer comprising cyclic carbonate polymer and a charge generation molecule. The photoconductor exhibits improved electrical characteristics.

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: A toner for developing an electrostatic latent image, a process for producing the same, and a developer for developing an electrostatic latent image using the same are provided, in which the toner flowability, the charging property, the developing property, the transferring property and the fixing property are simultaneously satisfied in a long period of time. The toner for developing an electrostatic latent image comprising a colored particles containing a binder resin, a coloring agent and a releasing agent, and an external additive, the external additive containing a monodisperse spherical inorganic oxide having a true specific gravity of from 1.3 to 1.9 and a volume average particle diameter of from 80 to 300 nm. It is preferred that the inorganic oxide is silica, the colored particles have a shape coefficient of 125 or less, and the external additive further contains a reaction product of metatitanic acid and a coupling agent, which has an electric resistance of 1010 &OHgr;.cm or more.

Abstract: Disclosed is a toner comprising particles of a vinyl resin, an optional colorant, and poly(3,4-ethylenedioxypyrrole), wherein said toner particles are prepared by an emulsion aggregation process. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a vinyl resin, an optional colorant, and poly(3,4-ethylenedioxypyrrole), wherein said toner particles are prepared by an emulsion aggregation process.

Abstract: Added to magnetic toner particles are 0.5 to 5% by weight based on the total weight of the toner particles of a magnetic powder and 0.01 to 0.5% by weight based on the total weight of the toner particles of stearate particles having an average particle diameter of 1 &mgr;m to 5 &mgr;m.

Abstract: A toner for developing an electrostatic latent image, a process for producing the same, and a developer for developing an electrostatic latent image using the same are provided, in which the toner flowability, the charging property, the developing property, the transferring property and the fixing property are simultaneously satisfied in a long period of time. The toner for developing an electrostatic latent image comprising a colored particles containing a binder resin, a coloring agent and a releasing agent, and an external additive, the external additive containing a monodisperse spherical inorganic oxide having a true specific gravity of from 1.3 to 1.9 and a volume average particle diameter of from 80 to 300 nm. It is preferred that the inorganic oxide is silica, the colored particles have a shape coefficient of 125 or less, and the external additive further contains a reaction product of metatitanic acid and a coupling agent, which has an electric resistance of 1010 &OHgr;·cm or more.

Abstract: A magnetic toner with a negative polarity for developing latent electrostatic images is made of toner particles, each toner particle containing a binder resin, a magnetic powder, and a charge control agent, the surface of the magnetic toner satisfying the relationship of 2×10−7≦C/Sw≦10×10−7, provided C≦8×10−3, wherein C is an amount (g/g) of the charge control agent dissolved in a solvent comprising water and methanol, and Sw is a specific surface area (cm2/cm3) of the toner particles determined from a weight-average particle diameter of the toner particles. An image forming apparatus has an electrostatic image bearing member, and a unit for developing the electrostatic image with the above magnetic toner, the unit having a developer holding member provided with a magnet, and a developer container.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor has a resin layer comprising a siloxane resin formed by hardening a compound represented by Formula 1, 2 or 3, or a hydrolyzed product which has a structural unit having a charge transportation ability, and a ratio M1/M2 of the sum of the amount in moles M1 of the compound represented by Formula 1 and that represented by Formula 2 to the amount in moles of the compound represented by Formula 3 is within the range of from 0.01 to 1.

Abstract: A toner for developing electrostatic latent image is disclosed. The toner comprises a crystalline compound, and exhibits at least one recrystallization peak during the second heating process in the DSC curve of said toner. An image forming method employing the toner is also disclosed.

Abstract: In a fixing method for fixing a toner image to a transfer medium, heat-and-pressure fixing is carried out using a specific pressure member and a specific toner. The pressure member has a heat-resistant elastic layer having a thermal conductivity of 0.20 W/m·K or below. The toner has, in its DSC endothermic curve, at least a maximum value in the region of temperature of from 105° C. to 150° C., and, in GPC of THF-soluble component of the toner, a main peak in the region of molecular weight of from 2,000 to 25,000, a sub-peak or shoulder in the region of molecular weight of 70,000 or higher, and an Mw/Mn ratio of 8 or higher, containing 20% to 70% of a component belonging to the region of molecular weight of from 1,000 to 10,000.

Abstract: A toner for developing electrostatic latent image is disclosed. The toner comprise of particles having a volume average particle diameter of from 3 to 8 &mgr;m, and said resin is obtained by either emulsion polymerization, mini-emulsion polymerization employing or suspension polymerization employing thioglycerin or at least one compound selected from compounds represented by the Formula (1) as the chain transfer agent. HS—R1—COOR2  (1) In the formula, R1 is an aliphatic group having carbon atoms from 1 to 10, which may have a substituent, and R2 is an aliphatic group having carbon atoms from 1 to 15, which may have a substituent.

Abstract: An organic electrophotographic receptor comprising at least an undercoating layer, an electric charge generating layer, and an electric charge transferring layer which are laminated in said order, wherein a coating fluid 5 for forming said electric charge generating layer comprising an electric charge generating material, a binding resin, a silicon oil having a surface tension of 22 mN/m or less, and an organic solvent is stored inside a tank 4, and a photosensitive base 1 supported by a chucking device 8 is dipped into said coating tank 4 so as to form said electric charge generating layer.