Abstract: The present invention relates to a carrier for electrophotographic developers, a developer containing the carrier, a container for the developer, a image forming apparatus using the developer, an image forming method using the same, and a method of making the carrier.

Abstract: A carrier for an image developer for electrophotography, including core particles, and a coating layer covering each of the core particles, wherein the core particles have a weight average particle diameter of Dv which is 25–45 ?m and a number average particle diameter of Dp which meets with the following condition: 1?Dv/Dp?1.3, wherein the core particles have such a particle size distribution that particles having a particle diameter of less than 44 ?m is at least 70% by weight and particles having a particle diameter of less than 22 ?m is not more than 7% by weight.

Abstract: The present invention relates to an image forming method including: a charging step; an electrostatic latent image forming step; a developing step; a transfer step; a fixing step; and a cleaning step, wherein an electrostatic latent image developing agent comprises a toner and a carrier, wherein particles which have a volume resistivity of at least 1×1014 ?cm and an average primary particle diameter of 50 nm or less has a higher covering ratio than other particles on the toner particle surfaces, a shape factor SF1 of the toner is in the range of from 100 to 140, the carrier is a resin coated carrier, and at least a coating resin layer comprises a positively charging resin and a quaternary ammonium salt compound.

Abstract: The present invention provides a toner: comprising a binder resin comprising a polyester unit, a colorant, a releasing agent, and inorganic fine particles; has a weight average particle diameter of 3.0–6.5 ?m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 ?m or more of 0.920–0.945; has a BET specific surface area of 2.1–3.5 m2/g; and has a permeability of light of a wavelength of 600 nm in a liquid having dispersed the toner in a 45 vol % methanol aq. of 30–80%. The present invention also provides a two-component developer: comprising the toner and a magnetic carrier comprising magnetic core particles coated by a coating layer; and has a number average particle diameter of 15–80 ?m. Using the toner and the two-component developer enables a high-quality image to be formed at a high speed even in an oilless fixing system.

Abstract: A developing method of the present invention is practicable with a developing unit of the type including a rotatable, nonmagnetic sleeve and a rigid metering member. A two ingredient type developer made up of magnetic carrier grains and toner grains is magnetically deposited on the sleeve. The metering member meters the amount of the developer deposited on the sleeve. The sleeve has surface roughness Rz ranging from 5 ?m to 20 ?m. The carrier grains each are covered with a coating layer containing at least binder resin and grains. The ratio of the diameter D of the individual grain contained in the coating layer to the thickness h of the binder resin layer lies in the range of 1<D/h<10. The carrier grains have a weight-mean grain size ranging from 20 ?m to 60 ?m.

Abstract: In the two-component developer for use in electrophotography containing a toner and a carrier, said toner contains a magnetic powder as an external additive, said carrier is a resin coated magnetic carrier of 6.0 to 8.0 in true specific gravity, and the coating resin is a silicone based resin containing a crosslinking agent having phenyl groups and an aminosilane coupling agent. The crossliking agent in the coating resin for the carrier has phenyl groups in a content ratio of 0.2 to 15% by number.

Abstract: Carrier comprised of a mixture of a first carrier and a second carrier, and wherein the first carrier is comprised of a steel core and the second carrier is comprised of a magnetite.

Abstract: A carrier develops latent electrostatic images in corporation with a toner and one particle of the carrier includes a magnetic particle, and a coating layer covering the magnetic particle. The coating layer includes a crosslinked condensation product of a composition containing (i) an N-alkoxyalkylated polyamide and (ii) at least one resin that is reactive with the alkoxyalkylated polyamide and includes a silicone having a silanol group and/or a hydrolyzable group.

Abstract: An electrostatic latent image on an image-bearing member is developed with a two-component developer comprising a toner and a carrier stored in a developer vessel while supplying as required a replenishing developer to the developer vessel. The replenishing developer comprises 1 wt. part of a carrier and 2-50 wt. parts of a toner, wherein the carrier is a magnetic fine particle-dispersed resin carrier comprising at least inorganic compound particles and a carrier binder resin, and the toner has a weight-average particle size of 3 to 10 ?m and contains 1 to 40 wt. % of solid wax.

Abstract: A carrier including a magnetic core material and a layer located on a surface of the magnetic core material, wherein the carrier satisfies the following relationships (1) to (3): 0.90≦(&sgr;a/&sgr;b)<1.00 (1); 200≦(&sgr;b·&rgr;c)≦400 (2); 10≦(&sgr;b/&rgr;c)≦20 (3), wherein &sgr;b represents a magnetization of the carrier at 1,000 Oe, &sgr;a represents a magnetization of the carrier after frictionized with a cylindrical sleeve under a specific condition and &rgr;c represents a true specific gravity of the carrier, wherein the carrier has a weight-average particle diameter of about 25 to about 65 &mgr;m and includes carrier particles having a weight-average particle diameter not greater than about 12 &mgr;m in an amount of not greater than about 0.3% by weight, wherein a ratio between the weight-average particle diameter and a number-average particle diameter of the carrier is about 1 to about 1.3, and wherein an electric resistance is from about 1.0×109 to about 1.

Abstract: A magnetic carrier includes a magnetic material-dispersed resin core containing at least a magnetic material and a binder resin. The surface of the magnetic material-dispersed resin core is coated with a coating material containing at least a fluorine resin and 1 to 40 parts by weight of fine particles based on 100 parts by weight of the fluorine resin. The coating material is in an amount of 0.3 to 4.0 parts by weight based on 100 parts by weight of the magnetic material-dispersed resin core. The magnetic carrier has a contact angle of 95 to 125°. A two-component developer is also provided which makes use of the magnetic carrier.

Abstract: A carrier for electrophotographic developer comprising carrier particles, each carrier particle having at least one surface-coating layer by resin material, wherein the surface-coating layer containing an acrylic resin and a silicone resin, the acrylic resin is in an amount ranging 10 to 90 wt. % based on the total amount of resin coating ingredients. The carrier shows no accumulation of toner-spents, therefore can obtain a stable electric charge, and has no layer scraping in binder resin layer, therefore can obtain a stable electric resistance, hence occurs no deterioration of images reproduced, by using acrylic resin having high anti-abrasive and high surface energy, whereas it has strong adhesiveness and high fragility, in combination use of silicone resin having poor anti-abrasive and small adhesiveness but has low fragility, thus is hard to cause a toner spent and hard to integrate the spent constituents due to its low surface energy.

Abstract: The present invention relates to an image forming method including: a charging step; an electrostatic latent image forming step; a developing step; a transfer step; a fixing step; and a cleaning step, wherein an electrostatic latent image developing agent comprises a toner and a carrier, wherein particles which have a volume resistivity of at least 1×1014 &OHgr;cm and an average primary particle diameter of 50 nm or less has a higher covering ratio than other particles on the toner particle surfaces, a shape factor SF1 of the toner is in the range of from 100 to 140, the carrier is a resin coated carrier, and at least a coating resin layer comprises a positively charging resin and a quaternary ammonium salt compound.

Abstract: An apparatus and method for non-interactive, dry powder development of electrostatic images includes an image bearing member bearing an electrostatic image; two component developer comprising toner and permanently magnetized thickly coated carrier beads, the coated carrier beads having magnetizable core radius r, average radius a, and magnetization Mb, with the ratio r/a being given as K; a developer transporting member having a thickness t for transporting a developer layer of the two component developer, wherein the layer is spaced close to and out of contact with the image bearing member, a multipole magnet member disposed in close proximity to the transporting member and moving relative to it so as to sweep poles across its surface, the magnet member having a periodic magnetization of spatial frequency k and a peak magnetization M0 wherein Mb, t, k, and M0, are chosen such that Mb is sufficiently large to prevent the escape of developer, a quantity C in the equation C = 2.

Abstract: Of developing agents each having a binder containing a polyester resin having an acidic value, wax having a softening point higher than that of the binder, and wax having a softening point lower than that of the binder, the acidic value of a black developing agent is made higher than that of a color developing agent.

Abstract: Carrier comprised of a mixture of a first carrier and a second carrier, and wherein the first carrier is comprised of a steel core and the second carrier is comprised of a magnetite.

Abstract: A two component developer comprising a magnetic toner containing a binder resin and a magnetic particle, and a magnetic carrier containing a magnetic particle, wherein the magnetic toner has an average particle diameter of 4.0 to 10.0 &mgr;m, and contains 5 to 80 No. % of toner particles having particle diameter of 5 &mgr;m or less, and exhibits magnetization of 10 to 25 emu/g under magnetic field of 5 kiloersteds.

Abstract: The present invention provides an electrophotographic developer which reduces toner contamination on the surface of a developer carrier even when a development effective range is narrowed and which is stabilized in an image quality in every environmental situation and has a long life and a low cost and an image-forming method using the same.

Abstract: A carrier develops latent electrostatic images in corporation with a toner and one particle of the carrier includes a magnetic particle, and a coating layer covering the magnetic particle. The coating layer includes a crosslinked condensation product of a composition containing (i) an N-alkoxyalkylated polyamide and (ii) at least one resin that is reactive with the alkoxyalkylated polyamide and includes a silicone having a silanol group and/or a hydrolyzable group.

Abstract: A carrier comprised of a core and thereover a polymer coating, and which coating is generated by the emulsion polymerization of one or more monomers and a surfactant, and wherein said polymer coating is of a diameter of equal to or less than about 100 nanometers.

Abstract: An apparatus and method for non-interactive, dry powder development of electrostatic images includes an image bearing member bearing an electrostatic image; two component developer comprising toner and permanently magnetized thickly coated carrier beads, the coated carrier beads having magnetizable core radius r, average radius a, and magnetization Mb, with the ratio r/a being given as K; a developer transporting member having a thickness t for transporting a developer layer of the two component developer, wherein the layer is spaced close to and out of contact with the image bearing member, a multipole magnet member disposed in close proximity to the transporting member and moving relative to it so as to sweep poles across its surface, the magnet member having a periodic magnetization of spatial frequency k and a peak magnetization M0 wherein Mb, t, k, and M0, are chosen such that Mb is sufficiently large to prevent the escape of developer, a quantity C in the equation 1 C = 2.

Abstract: A development system having a magnetic developer material that features novel coated carrier particles. In embodiments of the invention, the coated carrier particles incorporate a coating of sufficiently resilient characteristic so as to maintain the encapsulation of the respective carrier core while withstanding the mechanical action of a development material stripping device which would otherwise cause fragmentation of the carrier particles. Preferably, the carrier coating is of a sufficiently thick and/or a resilient nature such that the desired encapsulation is maintained.

Abstract: A carrier for electrophotographic developer essentially consisting of a core material of magnetic particles and thereon provided a resinous coating layer, wherein a weight-average particle-diameter(Dw) of the carrier ranges from 25 to 45 &mgr;m, the content of particles having diameter less than 44 &mgr;m is more than or equal to 75% by weight, the content of particles having diameter more than or equal to 62 &mgr;m is less than one percent by weight, the content of particles having diameter less than 22 &mgr;m is less than or equal to 7.0% by weight, the magnetic moment of the carrier at 1 kilo Oe of magnetic field is more than or equal to 76 emu/g. The carrier shows high optical density of image with no smearing of background area, good reproducibility in developing of small dots in image with no carrier deposition.

Abstract: A carrier is composed of carrier particles, each carrier particle having a core particle containing at least a magnetic material and a surface coating layer provided on the core particle containing at least a resin, the surface coating layer being constituted of a plurality of regions, the regions being separately formed and joined together to form a complex configuration, and having different phase lags when the surface coating layer is subjected to scanning by phase imaging measurement using a scanning probe microscope in a tapping mode, wherein a region having a phase lag over the average phase lag obtained from Eavg=&Sgr;(E(i)·S(i))/&Sgr;S(i) has an area SO, and SO and &Sgr;S(i) are in a relationship of 10%≦SO/&Sgr;S(i)×100≦90% when each region comprises a component A(i) having an area S(i) and a phase lag E(i), in which i represents the number of regions with different phase lags. A two-component developer employs the above-mentioned carrier.

Abstract: A method of developing a latent electrostatic image using a two-component developer system, having a ratio (Vr/Vp) ranges 1.2<(Vr/Vp)<3 where the (Vp) is a linear speed (Vp)[m/sec] of a photosensitive member and the (Vr) is a linear speed (Vr) [m/sec] of a developing sleeve, and applying a biased direct-current (VB) [by volt] wherein; a developing gap(Gp)[cm] as a distance at the nearest point between a photosensitive member and a developing sleeve is less than or equal to 0.6 mm, a ratio(&rgr;p/&rgr;a) satisfies an expression (&rgr;p/&rgr;a)<0.

Abstract: A resin-coated carrier to be mixed with a polymer toner obtained by suspension polymerization or emulsion polymerization to provide an electrophotographic developer, which exposes 2 to 20% of the surface area of the core thereof, the average exposed area ratio per exposed part of the core being 0.03% or less.

Abstract: A carrier for the development of an electrostatic latent image, comprising a core material and a resin coating the core material therewith, wherein the coating resin comprises a copolymer of at least four kinds of monomers including: (1) a monomer containing a carboxyl group; (2) an acrylic acid alkylester monomer or methacrylic acid alkylester monomer, containing a C1-C3 linear alkyl group; (3) an acrylic acid alkylester monomer or methacrylic acid alkylester monomer, containing a C4-C10 linear alkyl group or C3-C10 branched alkyl group; and (4) a monomer containing fluorine. Also disclosed is a two-component developer for the development of an electrostatic latent image, comprising a toner and the carrier.

Abstract: A carrier for a two-component developer for developing a latent electrostatic image is composed of carrier particles, each of the carrier particles having a core particle and a coating layer provided on the surface of the core particle, with the coating layer containing an amino-group-containing modified silicone resin. A two-component developer is composed of a toner and the above-mentioned carrier.

Abstract: A carrier for use with a toner as a two-component type developer for developing an electrostatic image, comprising spherical magnetic core particles, and a resin layer covering each of said core particles and containing at least two resistance controlling materials having different specific resistances, wherein each of the resistance controlling materials is in the form of particles having a number average particle diameter of no more than {fraction (1/10)} of a number average particle diameter of the toner.

Abstract: The present invention provides a carrier for electrophotography, which is capable of charging the toner in the developer very rapidly to a target electrostatic charge and at the same time, is capable of maintaining the target electrostatic charge during printing, so that the chemical fogging related to the slow charging rate can be eliminated and the image density related to the maintenance of the electrostatic charge can be preserved during printing. The charging rate and the charge maintenance of the electrophotographic carrier can be preserved if the carrier composed of magnetic core particles and the resin coat satisfies the following equation (B)>[(−19.4)×(A)+31], wherein (A) represents a carbon content (weight %) of the carrier and (B) represents a ratio of the square root of the number of emitted photoelectrons ((CPS)½) and the photon energy (eV).

Abstract: A carrier for an image developer for electrophotography, including core particles, and a coating layer covering each of the core particles, wherein the core particles have a weight average particle diameter of Dv which is 25-45 &mgr;m and a number average particle diameter of Dp which meets with the following condition:

Abstract: A developer for a trickle developing method is used in formation of a full color image and is made of a mixture of a toner and a carrier. The toner contains inorganic fine particles as an internal additive and an external additive, a volume average particle diameter D50v of the toner is between 5.0 and 9.0 &mgr;m, a true specific gravity of the carrier is between 3.00 and 4.60, a volume average particle diameter of the carrier is between 15 and 60 &mgr;m, and the ratio of the volume average particle diameter of the carrier to the volume average particle diameter of the toner is between 3.00 and 7.00, and an image forming method using the developer.

Abstract: A carrier is composed of carrier particles, each carrier particle having a core particle containing at least a magnetic material and a surface coating layer provided on the core particle containing at least a resin, the surface coating layer being constituted of a plurality of regions, the regions being separately formed and joined together to form a complex configuration, and having different phase lags when the surface coating layer is subjected to scanning by phase imaging measurement using a scanning probe microscope in a tapping mode, wherein a region having a phase lag over the average phase lag obtained from Eavg=&Sgr;(E(i)·S(i))/&Sgr;S(i) has an area SO, and SO and &Sgr;S(i) are in a relationship of 10%≦SO/&Sgr;S(i)×100≦90% when each region comprises a component A(i) having an area S(i) and a phase lag E(i), in which i represents the number of regions with different phase lags. A two-component developer employs the above-mentioned carrier.

Abstract: A process which comprises mixing a carrier core with a polymer core and polymer shell and wherein the polymer shell is present as a coating on said core and said polymer core, wherein said polymer core is generated by emulsification of and heating of monomer forming a seed latex; adding a portion of said seed latex to said emulsification mixture, followed by heating and adding another second portion of said seed latex; and wherein said shell is generated by emulsion polymerization of a monomer, followed by heating.

Abstract: An image formation method which remarkably extends developer life while providing size reduction and high speed coloring. Also, a replenishing toner and a method of producing the same, and a toner cartridge. In the image formation method, conducting image formation by an image formation apparatus having a plurality of xerography units, the developer apparatus of at least one xerography unit has a developer recovering mechanism appropriately replenishing a replenishing toner composed of a toner and a carrier into the developer apparatus and recovering an excess portion of a developer from the equipment. The above-mentioned replenishing toner has a carrier content in the range of 5 to 40% by weight, the above-mentioned carrier is a carrier coated with a resin having a specific composition, and/or the above-mentioned toner is in a specific shape. The replenishing toner may be produced using the above-mentioned recovered developer.

Abstract: An electrostatic latent image on an image-bearing member is developed with a two-component developer comprising a toner and a carrier stored in a developer vessel while supplying as required a replenishing developer to the developer vessel. The replenishing developer comprises 1 wt. part of a carrier and 2-50 wt. parts of a toner, wherein the carrier is a magnetic fine particle-dispersed resin carrier comprising at least inorganic compound particles and a carrier binder resin, and the toner has a weight-average particle size of 3 to 10 &mgr;m and contains 1 to 40 wt. % of solid wax.

Abstract: A resin-coated carrier to be mixed with a polymer toner obtained by suspension polymerization or emulsion polymerization to provide an electrophotographic developer, which exposes 2 to 20% of the surface area of the core thereof, the average exposed area ratio per exposed part of the core being 0.03% or less.

Abstract: An electrostatic latent image developer is provided which has an improved durability and a longer life-time by preventing the toner spent. The electrostatic latent image developer comprises a resin-coated magnetic carrier and a toner. Said resin-coated magnetic carrier consists of a magnetic ferrite carrier core and a coating layer formed thereon by polymerizing a high molecular weight polyethylene resin directly on the surface of said carrier core. Said toner does not contain polyethylene wax but polypropylene wax and/or polyester wax having an average molecular weight of 10,000 as the wax component or components in an amount of from 0.1 to 20 wt. %.

Abstract: In the two-component developer for use in electrophotography containing a toner and a carrier, said toner contains a magnetic powder as an external additive, said carrier is a resin coated magnetic carrier of 6.0 to 8.0 in true specific gravity, and the coating resin is a silicone based resin containing a crosslinking agent having phenyl groups and an aminosilane coupling agent. The crossliking agent in the coating resin for the carrier has phenyl groups in a content ratio of 0.2 to 15% by number.

Abstract: A method for coating carrier particles wherein the carrier particles are stirred mechanically and wherein the volume of the coating solution is in the same order of magnitude as the volume of the carrier particles to be coated.

Abstract: A two component developer comprising a magnetic toner containing a binder resin and a magnetic particle, and a magnetic carrier containing a magnetic particle, wherein the magnetic toner has an average particle diameter of 4.0 to 10.0 &mgr;m, and contains 5 to 80 No. % of toner particles having particle diameter of 5 &mgr;m or less, and exhibits magnetization of 10 to 25 emu/g under magnetic field of 5 kiloersteds.

Abstract: There is disclosed a two-component developing agent for use in an mage formation based on electrophotography, which has high developability even at a high speed printing and good developability in the case of the image formation for a long period of time. The two-component developing agent includes a carrier comprising a magnetic particle and an insulating toner. A surface of the magnetic particle is coated with at least a resin. A mean particle size of the magnetic particle is between 30 and 90 &mgr;m and an aggregation degree of said carrier is between 2 and 15%.

Abstract: A process which comprises mixing a carrier core with a polymer core and polymer shell and wherein the polymer shell is present as a coating on said core and said polymer core, wherein said polymer core is generated by emulsification of and heating of monomer forming a seed latex; adding a portion of said seed latex to said emulsification mixture, followed by heating and adding another second portion of said seed latex; and wherein said shell is generated by emulsion polymerization of a monomer, followed by heating.

Abstract: A carrier for electrophotographic developer essentially consisting of a core material of magnetic particles and thereon provided a resinous coating layer, wherein a weight-average particle-diameter(Dw) of the carrier ranges from 25 to 45 &mgr;m, the content of particles having diameter less than 44 &mgr;m is more than or equal to 75% by weight, the content of particles having diameter more than or equal to 62 &mgr;m is less than one percent by weight, the content of particles having diameter less than 22 &mgr;m is less than or equal to 7.0% by weight, the magnetic moment of the carrier at 1 kilo Oe of magnetic field is more than or equal to 76 emu/g. The carrier shows high optical density of image with no smearing of background area, good reproducibility in developing of small dots in image with no carrier deposition.

Abstract: An electrophotographic image formation method for developing a latent electrostatic image formed on a latent image bearing member with toner to a toner image, using a two-component developer including a carrier and a toner. The zoner is held on a developer bearing member, with a gap between the facing surfaces of the latent image bearing member and the developer bearing member being set in a range of 0.1 mm to 0.5 mm. The carrier includes carrier particles, each carrier particle including a core material and a coating material which is coated on the surface of the core material The coating material includes a polysiloxane resin including at least an oxygen atom (O) and a silicon atom as constituent elements therefor, with an atomic ratio of the constituent elements, O/Si, being in a range of 2.1 to 4.0, and the carrier having a specific resistivity of 109 to 1016 &OHgr;·cm.

Abstract: A method of developing a latent electrostatic image using a two-component developer system, having a ratio (VrNVp) ranges 1.2<(Vr/Vp)<3 where the (Vp) is a linear speed (Vp) [m/sec] of a photosensitive member and the (Vr) is a linear speed (Vr) [m/sec] of a developing sleeve, and applying a biased direct-current (VB) [by volt] wherein; a developing gap(Gp)[cm] as a distance at the nearest point between a photosensitive member and a developing sleeve is less than or equal to 0.6 mm, a ratio(&rgr;p/&rgr;a) satisfies an expression (&rgr;p/&rgr;a)<0.

Abstract: A carrier for use in electrophotography provided by the present invention satisfies such conditions that when (i) the porosity of the surface of a core particle is A %(A≦40) and (ii) the resin-coated rate of the porous part of the surface the core particle is B %, (iii) A×B/100 is 15 or more and further (ix) the resin-coated rate of the smooth part, besides the porous part, is 20% or less.

Abstract: A carrier for an image developer for electrophotography, including core particles, and a coating layer covering each of the core particles, wherein the core particles have a weight average particle diameter of Dv which is 25-45 &mgr;m and a number average particle diameter of Dp which meets with the following condition:

Abstract: Carrier comprised of a core, a number of the pores thereof containing a polymer, and thereover a coating.

Abstract: An electrostatic charge regulator capable of holding an electric charge in a stable state and superior in environmental stability, as well as a method for making the electrostatic charger regulator and an image forming method using the electrostatic charge regulator, are disclosed. The electrostatic charge regulator has a surface layer containing a non-linear resistor on a base member such as a carrier, a developer sleeve, a developer blade, or a transfer belt. The electrostatic charge regulator is obtained by forming on the base member a surface layer by using a thin film of a composite metal oxide or by using dispersion of powder of the composite metal oxide in a high molecular compound, the composite metal oxide being prepared using at least one metal selected from Group A metals (Zn, Ti, Si, Al, Zr) and at least one metal selected from Group B metals (Bi, Sb, C, Y, La, Pr, Sc, Ce, Sn, Pb). The image forming method uses the above electrostatic charge regulator to form an image.