Abstract: The object of the present invention is to achieve a dry toner that is of improved low-temperature fixability, pulverizability, offset resistance, durability and storability as well as improved transparency and light resistance and so provides a useful color toner, and provide a dry toner production process of improved continuous productivity. The dry toner of the invention is characterized by comprising as a binder resin a polymer that is obtained by bulk polymerization of a compound having at least two isocyanate groups and a compound having at least two functional groups, each containing active hydrogen, contains an urethane bond or urea bond in its main chain and has a number-average molecular weight (Mn) of 1,500 to 20,000 as measured on a polystyrene basis.

Abstract: A toner for developing an electrostatic image comprising a resin, a colorant and a releasing agent in which the toner particles are obtained by salting out/fusion-adhering a resin particle comprising a binding resin and a releasing agent together with a colorant particle is disclosed. The toner comprises the toner particles having a variation coefficient of not more than 16% and a number variation coefficient of the number particle size distribution of not more than 27%.

Abstract: A two-component developer consists of a toner, which contains at least a resin and a colorant and to which an external additive is added, and a carrier. This two-component developer has the toner that has a number average molecular weight (Mn) of 3,000 or less and contains particles having a molecular weight of 1,000 or less at 40 number % or more, and also has the carrier that satisfies general formula (1) as follows: 3,000,000≦&sgr;1000×Dc3≦20,000,000  (1) where &sgr;1000 represents a magnetization (emu/g) of a carrier at 1,000 oersted, and Dc represents volume average particle diameter (&mgr;m) of the carrier.

Abstract: An electrophotographic photosensitive member capable of forming images with less defects, such as ghost, while retaining a high photo-sensitivity, is provided. The photosensitive member includes a support and a photosensitive layer disposed on the support, wherein said photosensitive layer contains a phthalocyanine pigment and an azo calix[n]arene compound represented by the formula (1) below: wherein n denotes an integer of 4-8; a number (n) of R1 independently denote a hydrogen atom or an alkyl group capable of having a substituent and including at least one alkyl group capable of having a substituent; a number (2n) of R2 independently denote a hydrogen atom or an alkyl group capable of having a substituent; and a number (n) of Ar independently denote a monovalent group selected from an aromatic hydrocarbon ring group capable of having a substituent, a heterocyclic ring group capable of having a substituent, and a combination of these groups capable of having a substituent.

Abstract: A magnetic toner includes: magnetic toner particles each comprising at least a binder resin and magnetic toner, and inorganic fine powder. The magnetic toner has an average circularity of at least 0.970, and a magnetization of 10-50 Am2/kg at a magnetic field of 79.6 kA/m. The magnetic powder comprises at least magnetic iron oxide. The magnetic toner particles retain carbon in an amount of A and iron in an amount of B at surfaces thereof as measured by X-ray photoelectron spectroscopy, satisfying: B/A<0.001. The binder resin comprises a resin formed by polymerization of a monomer comprising at least styrene monomer. The magnetic toner has a residual styrene monomer content of less than 300 ppm, and contains at least 50% by number of toner particles satisfying a relationship of: D/C≦0.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor has a difference in ionization potential between the photosensitive layer and the hardenable resinous layer of not more than 0.4 eV, and a response time T10 defined in the specification is not more than 0.25 second. An image forming method and apparatus employing the photoreceptor are also disclosed.

Abstract: An imaging apparatus including a support member including a support surface for supporting a layer of marking material; a marking material supply apparatus for depositing marking material on the surface of the support member to form a layer of marking material thereon; a charging source for selectively delivering charge species to the layer of marking material in an imagewise manner to form an electrostatic latent image in the layer of marking material, wherein the electrostatic latent image includes image areas defined by a first charge voltage and nonimage areas defined by a second charge voltage distinguishable from the first charge voltage; and a separator member for selectively separating portions of the marking material layer in accordance with the latent image in the marking material layer to create a developed image and wherein said marking material is comprised of a liquid developer comprised of a nonpolar liquid, resin, colorant, and a charge acceptance component comprised of a cyclodextrin.

Abstract: Disclosed are marking particles comprising a first polymer a second polymer, a chelating agent, and a spiropyran material of the formula wherein n is an integer representing the number of repeat —CH2— units and R is —H or —CH═CH2. The marking particles comprise a core containing the first polymer in which is dispersed the chelating agent and the spiropyran and encapsulated within a shell of the second polymer formulated by an interfacial polymerization.

Abstract: A process for producing a polymerization toner, which comprises preparing a polymerizable-monomer composition which contains at least a polymerizable monomer and a colorant and does not contain any polymerization initiator, i) introducing the polymerizable-monomer composition into an aqueous medium to effect granulation, adding a polymerization initiator to the aqueous medium in the course of the granulation or after the granulation has been completed, or ii) adding a polymerization initiator in an aqueous medium, introducing the polymerizable-monomer composition into the aqueous medium to effect granulation, and then polymerizing the polymerizable-monomer composition having been granulated, to produce toner particles. In the process, the polymerization initiator is added in a specific time and a specific manner.

Abstract: The present invention relates to a developer for electrostatic image development comprising: a toner for electrostatic image development which comprises a resin and a colorant; and a carrier formed by a carrier core material and a resin layer including a resistance control agent which is formed on the surface of the carrier core material, wherein the resin layer of the carrier has a concentration gradient of the resistance control agent toward the thickness direction of the resin layer, a concentration of the resistance control agent is the highest in the vicinity of the carrier core material, and is gradually lowered toward the surface of the resin layer, and the resistance control agent is present on the surface of the resin layer, as well as relates to an image forming method, wherein it comprises a step of developing an electrostatic image at a developing speed of 20 m/min or higher, by means of employing the developer for electrostatic image development.

Abstract: A process for the preparation of toner which comprises (1) aggregating and coalescing in the presence of a coagulant an encapsulated colorant, and (2) blending with at least one toner.

Abstract: Disclosed is a developing agent comprising toner particles including a binder resin mainly containing an ethylene-norbornene copolymer and a coloring agent mainly containing a cyanine dye and an organic boron ammonium salt. The developing agent can be decolored by irradiation with light having a predetermined wavelength region.

Abstract: A toner comprised of resin, colorant, and a potassium stearate charge enhancing additive.

Abstract: An electrophotographic photosensitive member exhibiting a high sensitivity and a potential stability on repetitive use and capable of suppressing image defects, such as black spots in a reversal development scheme, is provided. The photosensitive member includes a support, and a phthalocyanine layer formed on the support and a novel phthalocyanine crystal, which comprises a phthalocyanine compound and a substituted or unsubstituted condensed polycyclic hydrocarbon compound.

Abstract: A process for the preparation of a latex polymer by (i) preparing or providing a water aqueous phase containing an anionic surfactant in an optional amount of less than or equal to about 20 percent by weight of the total amount of anionic surfactant used in forming the latex polymer; (ii) preparing or providing a monomer emulsion in water which emulsion contains an anionic surfactant; (iii) adding about 50 percent or less of said monomer emulsion to said aqueous phase to thereby initiate seed polymerization and to form a seed polymer, said aqueous phase containing a free radical initiator; and (iv) adding the remaining percent of said monomer emulsion to the composition of (iii) and heating to complete an emulsion polymerization thus forming a latex polymer.

Abstract: The present invention provides a toner that contains release agent, does not cause contamination in an electrophotographic apparatus, and has environmental stability and charge stability. This release agent-containing toner includes a center portion that contains low-polarity release agent and pigment, and a surface layer formed by a resin phase that covers the center portion.

Abstract: The present invention provides a toner which does not cause problems on generation of an offensive odor and a stain on a surface of a cooling unit and which is excellent in an offset resistance, a low temperature fixability and an environmental dependency. In the toner for developing an electrostatic latent image comprising a polyester resin as a principal component which is formed by reacting dicarboxylic acids of a polybasic acid with diols of a polyhydric alcohol, dimethyl phthalate remaining in the polyester resin described above without reacting has a content of 0.1 % by weight or less.

Abstract: An image bearing material including a matrix resin and, within the matrix resin, a core/shell graft copolymer including a core including one or more polymers and a shell including a graft polymer which has a linear chain connected with the core and which is formed from one or more monomers. The image bearing material is preferably used for a surface layer of an electrophotographic photoreceptor, an intermediate transfer medium, and the like image bearing members to improve the abrasion resistance thereof.

Abstract: A process for producing an electrophotographic photosensitive member which has a charge-generating layer and a charge-transporting layer on a substrate, has steps of applying a solution containing a charge-transporting material, binder resin, dimethoxymethane, and an aromatic hydrocarbon-based solvent having a boiling point of 130° C. or higher, and drying the solution, to form the charge-transporting layer.

Abstract: The present invention relates to an electrophotosensitive material wherein a layer containing a binder resin and a pigment among a photosensitive layer is formed by applying and drying a coating solution prepared by dispersing the binder resin and the pigment in a dispersion medium containing alcohol represented by the formula (1): wherein R1, R2 and R3 are the same or different and represent a hydrogen atom or an alkyl group; the electrophotosensitive material is free from lowering of the sensitivity due to formation of agglomerates of the pigment and is superior in sensitivity characteristics.