Abstract: A magnetic toner is formed of magnetic toner particles each comprising at least a binder resin and a magnetic iron oxide. The magnetic toner is provided with improved developing performances by realizing an appropriate surface-exposure state of the magnetic iron oxide, which is represented by a wettability characteristic in methanol/water mixture liquids of the magnetic toner such that it shows a transmittance of 80% for light at a wavelength of 780 nm at a methanol concentration in a range of 65-75% and a transmittance of 20% at a methanol concentration in a range of 66-76%.

Abstract: A toner showing a high transferability and suitable for use in cleanerless image forming system is formed of toner particles comprising at least a binder resin and magnetic iron oxide. The toner is characterized by a specific circularity distribution relative to its weight-average particle size and a controlled degree of surface-exposed magnetic iron oxide providing an extract solution with hydrochloric acid showing an absorbance of 1.0-2.5 at a wavelength of 340 nm. The toner is suitably produced by a production system including a rotary mechanical pulverizer and a one-pass surface treatment apparatus for continuously applying a mechanical impact force to pulverized toner particles therein.

Abstract: A toner for developing a latent electrostatic image to a toner image, including a binder resin, and a magnetic material which is blackened by coating the surface of a magnetic powder with a coloring agent, the magnetic material being in an amount of 10 wt. % to 40 wt. % of the entire weight of the toner, a method of forming an image, using a two-component developer containing the toner, an image formation apparatus using the two-component developer, and a toner container containing therein the toner, and an image formation apparatus equipped with the toner container are proposed.

Abstract: A magnetic toner is provided which can satisfactorily form an image by using a non-magnetic one-component developing system. The magnetic toner comprising a magnetic powder, a binder resin and a wax is subjected to a surface treatment with using a composite external additive composed of two kinds of external additives different in primary particle diameter.

Abstract: Black magnetic toner comprising:

Abstract: Magnetic toner particles are disclosed. The magnetic toner particles contain at least one polymeric binder and at least one magnetic additive, wherein the surface of the toner particle contains particles of positively chargeable inorganic fine powder particles. The inorganic fine powder particles have a mean volume average particle size of from about 0.5 to about 7 &mgr;m, and a cleaning ratio of from about 0.1 to about 5.0 and a cleaning ratio being the volume fraction of particles between 0 and 1.0 &mgr;m, divided by the volume fraction of particles greater than 1.0 &mgr;m; and the toner particles having on the surface thereof a flowability improving agent having a BET surface area of at least about 30 m2/g. Methods of forming electrostatic images are further disclosed. Also, images formed from the magnetic toner particles are further disclosed and have excellent character void frequency, total void area, and suitable magnetic signal strengths.

Abstract: Magnetic composite particles having an average particle diameter of 0.06 to 1.0 &mgr;m and a coercive force value of less than 39.790 kA/m, comprising: magnetic core particles, a coating formed on surface of said magnetic core particles, comprising at least one organosilicon compound selected from the group consisting of: (1) organosilane compounds obtainable from alkoxysilane compounds, and (2) polysiloxanes or modified polysiloxanes, and an organic blue-based pigment coat formed on said coating layer comprising said organosilicon compound, in an amount of from 1 to 50 parts by weight based on 100 parts by weight of said magnetic core particles. The magnetic composite particles are suitable for black magnetic toner not only exhibiting a deep black color but also having excellent light resistance and fluidity.

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: The present invention relates to a device and method for dusting smooth or sheet-like products, comprising at least one duster for spraying an air/powder mixture on said products. In order to ensure efficient dusting with no dirt accumulation in the printer or the surrounding area, it is suggested that part of the powder particles be magnetized and means be provided for creating a magnetic field in the powder deposit area so that said powder particles are subjected to a force drawing them towards the product.

Abstract: The invention relates to a toner containing low-silicone magnetite particles.

Abstract: Development systems and methods for developing using magnetic toner are disclosed. The present invention further discloses developers used in development systems as well as the toner used in developer for magnetic ink character recognition printing. With respect to the development system, a development system is disclosed which includes a supply of dry developer mixture which contains magnetic toner particles and hard magnetic carrier particles. The development system further includes a non-magnetic, cylindrical shell for transporting the developer between the supply and the development zone, wherein the shell can be rotatable or stationary. A rotating magnetic core of a pre-selected magnetic field strength and means for rotating at least the magnetic core to provide for the transport of the toner particles from the shell to an electrostatic image also provided as part of the development system.

Abstract: This invention relates to magnetite particles with a mean particle size of 0.1 to 0.3 &mgr;m, a specific surface area of 6 to 9 m2/g, a coercive force of 80 to 110 Oe, a residual magnetization of 13 to 20 nTm3/g, a pH of 7 to 10 and a bulk density of 0.6 to 0.9 g/cm3, by heating an aqueous solution of an alkaline component under inert gas, to a precipitation temperature of 65-85° C., adding iron (II) and iron (III) components and oxidizing the suspension with an oxidizing agent at a speed of 7-25 mol % Fe (II)/h.

Abstract: In an image forming system, an image-bearing member having a photoconductor layer comprising an Si-based non-single crystal material is charged at a relatively low potential of 250 to 600 volts by a contact charging member in the presence of electroconductive fine powder. An electrostatic latent image formed on the image-bearing member is developed with a magnetic toner which includes magnetic toner particles comprising at least a binder resin and a magnetic iron oxide, and inorganic fine powder and electroconductive fine powder present at the surface of the magnetic toner particles. The magnetic toner has a weight-average particle size of 3-10 &mgr;m and an average circularity of 0.950 to 0.995, and contains 0.05 to 3.00 % of isolated iron-containing particles.

Abstract: In an image-forming apparatus having at least i) an electrophotographic photosensitive member having at least a photoconductive layer and a surface layer on a conductive substrate, ii) a developing means having a toner, and iii) a charging means, the photoconductive layer comprises a non-single-crystal material composed chiefly of silicon, the surface layer comprises a non-single-crystal carbon film containing at least hydrogen and has a dynamic hardness in the range of from 4.90×109 to 1.76×1010 Pa (500 to 1,800 kgf/mm2), the charging means has a charging member kept in contact with the electrophotographic photosensitive member, forming a contact zone therewith, charges the electrophotographic photosensitive member electrostatically upon application of a voltage, and the toner is a magnetic toner having toner particles containing at least a binder resin and a magnetic material, and an inorganic fine powder, having an average circularity of from 0.950 to 1.

Abstract: A two-component developer including at least a magnetic toner and a magnetic carrier having magnetic particles coated with carbon black. The magnetic toner adheres to the magnetic carrier due to the magnetic interaction.

Abstract: A developing material is obtained by performing melting and kneading steps, and then a milling step, for a particulate binder resin material having an average particle size of 250 to 600 &mgr;m and a magnetic powder having an apparent bulk density of 0.3 g/cm3 or more and a compacted bulk density of 2.5 g/cm3 or less.

Abstract: Black magnetic toner comprising: a binder resin; and black magnetic composite particles comprising: magnetic iron oxide particles having an average particle diameter of 0.055 to 0.95 &mgr;m, a coating layer formed on the surface of the magnetic iron oxide particles, comprising at least one organosilicon compound selected from the group consisting of: (1) organosilane compounds obtainable from alkoxysilane compounds, and (2) polysiloxanes or modified polysiloxanes, and a carbon black coat formed on the coating layer comprising the organosilicon compound, in an amount of 26 to 55 parts by weight based on 100 parts by weight of the magnetic iron oxide particles. Such a black magnetic toner can be free from being deteriorated in electric resistance due to the existence of the carbon black coat, and as a result, is suitable as a high-resistant or insulated magnetic toner.

Abstract: A developing agent comprising a toner particle containing a magnetic powder and a binder resin, the kinetic resistance of the developing agent being not higher than 200 M&OHgr;, and the absolute value of the difference &Dgr;V between the maximum value and the minimum value of the surface potential of the developing agent layer on a developing sleeve being not larger than 5V, is used for obtaining satisfactory developing agent image high in image density and low in fogging.

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: 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: A magnetic toner comprising magnetic toner particles containing at least a binder resin, a magnetic material containing a magnetic ion oxide, and a release agent. The magnetic toner has a weight-average particle diameter of from 3 &mgr;m to 10 &mgr;m, a magnetization intensity (saturation magnetization) of from 10 Am2/kg to 50 Am2/kg (emu/g) under application of a magnetic field of 79.6 kA/m (1,000 oersteds), an average circularity of 0.970 or more, a ratio of weight-average particle diameter to number-average particle diameter, of 1.40 or less, iron and an iron compound which stand liberated from the magnetic toner particles at a liberation percentage of from 0.05% to 3.00%, and a resin component having a tetrahydrofuran-insoluble matter in an amount of from 3% by weight to 60% by weight. Also disclosed is an image-forming method making use of the magnetic toner.

Abstract: A circuit-forming charging powder allowing circuit patterns to resist being peeled off a printing object when the powder is used for printing a circuit pattern by an electrophotographic method on the object, wherein the circuit-forming charging powder has a conductive metal powder, a charge control agent and an adhesion reinforcing agent combined with a heat-melt resin and a method for producing the circuit-forming charging powder, as well as printed objects and multilayer wiring boards are described.