Abstract: The present invention provides: a ferrite carrier core material for an electrophotographic developer, the material having a mesh passing amount of 3 wt % or less as indicated by the ratio of the weight of particles passing through a 16 ?m-mesh to the weight of whole particles constituting a powder, and having a particle strength index of 2 wt % or less as indicated by a difference between the mesh passing amounts before and after crushing; a ferrite carrier which is for an electrophotographic developer and in which the surface of the ferrite carrier core material is coated with a resin; and an electrophotographic developer which includes the ferrite carrier and a toner.

Abstract: A carrier core material is represented by a composition formula MXFe3-XO4 (where M is at least one type of metal element selected from Mg, Mn, Ca, Ti, Cu, Zn and Ni, 0<X<1), in which part of M and/or Fe is substituted with Sr and formed of ferrite particles, and in the carrier core material, a Sr content is equal to or more than 2500 ppm but equal to or less than 12000 ppm, the amount of Sr eluted with pure water at a temperature of 25° C. is equal to or less than 50 ppm, an apparent density is equal to or more than 1.85 g/cm3 but equal to or less than 2.25 g/cm3 and magnetization ?1k when a magnetic field of 79.58×103 A/m (1000 oersteds) is applied is equal to or more than 63 Am2/kg but equal to or less than 75 Am2/kg.

Abstract: A carrier core material formed with ferrite particles, the skewness Rsk of the particle is equal to or more than ?0.40 but equal to or less than ?0.20, and the kurtosis Rku of the particle is equal to or more than 3.20 but equal to or less than 3.50. Here, the maximum height Rz of the particle is equal to or more than 2.20 ?m but equal to or less than 3.50 ?m. Moreover, the ferrite particle contains at least either of Mn and Mg elements. In this way, cracking or chipping in a concave-convex portion of a particle surface is unlikely to occur, and moreover, the amount of coating resin used can be reduced without properties such as electrical resistance being lowered.

Abstract: An electrostatic charge image developing toner includes toner mother particles containing at least a binder resin, elastomer particles including a first oil, and inorganic particles including a second oil, wherein a viscosity of the first oil is equal to or higher than a viscosity of the second oil.

Abstract: Method for the spatially resolved determination of physical, chemical and/or biological properties or state variables and/or the change therein in an examination area of an examination object by determining the change in the spatial distribution and/or the mobility, particularly the mobility in rotation, of magnetic particles in this examination area or in parts thereof as a function of the effect of physical, chemical and/or biological influencing variables on at least a part-area and/or in the physical, chemical and/or biological conditions in at least a part-area of the examination area, by means of the following steps: a) introducing covered and/or coated magnetic particles with at least one solid, viscous and/or liquid shell or coating into at least part of the examination area and/or introducing magnetic particles into at least part of the examination area and/or covering and/or coating at least some of these particles in the examination area, b) generating a magnetic field with a spatial profile of the

Abstract: An image forming apparatus includes an electrophotographic photoreceptor that includes a conductive substrate, an organic photosensitive layer provided on the conductive substrate, and an inorganic protective layer provided on the organic photosensitive layer; a charging unit that charges a surface of the electrophotographic photoreceptor; an electrostatic latent image forming unit that forms an electrostatic latent image on a charged surface of the electrophotographic photoreceptor; a developing unit that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor to thereby form a toner image, by using a developer which contains a toner, and a carrier in which a ratio occupied by carrier particles having a particle diameter of 50 ?m or greater is equal to or smaller than 1% by number; and a transfer unit that transfers the toner image to a surface of a recording medium.

Abstract: A two-component developing agent for developing an electrostatic latent image includes toner particles composed of toner base particles and an exterior additive attached on the toner base particles, and carrier particles composed of carrier core particles and a coating resin provided on the carrier core particles. The coating resin includes a sulfur atom and a resin obtained by polymerizing an isobutyl methacrylate monomer, and the toner base particles include a sulfur atom.

Abstract: A carrier core particle for an electrophotographic developer includes a composition expressed by a general formula: MnxFe3?xO4+y (0<x?1, 0<y), a full width at half maximum z of the most intense peak (311) plane in a powder X-ray diffraction pattern satisfying 0.16 (degree)?z, and a magnetization of 50 emu/g or higher in an external magnetic field of 1000 Oe.

Abstract: A method for reducing toning spacing sensitivity in an electrophotographic process is disclosed. The method includes providing a rotating magnetic member within a conductive non-magnetic development sleeve; providing a developer to the non-magnetic development sleeve for use with the rotating magnetic member including: (i) composite magnetic particles comprising strontium ferrite and lithium ferrite phases and (ii) toner particles. The method further includes moving a charged receiving medium into a toner transfer relationship with the developer on the non-magnetic development sleeve so as to provide a developed image on the receiving medium with reduced toning spacing sensitivity.

Abstract: A porous ferrite core material for an electrophotographic developer wherein the apparent density thereof is 1.5 to 1.9 g/cm3, the shape factor SF-2 thereof is 101 to 110 and the magnetization as measured with a VSM at 1K·1000/4?·A/m is 40 to 60 Am2/kg, a resin-coated ferrite carrier for an electrophotographic developer obtained by coating the surface of the porous ferrite core material with a resin, and an electrophotographic developer using the ferrite carrier.

Abstract: An electrostatic image developing carrier includes a ferrite particle that contains from about 1.0% by weight to about 14.0% by weight of elemental magnesium, wherein an average distribution ratio D of the elemental magnesium in the ferrite particle is from about 1.1 to about 2.0, wherein the average distribution ratio D is defined as an average value of D? of at least 50 ferrite particles, wherein D? is defined as W1/W2, wherein W1 is a weight ratio of elemental magnesium content Mg to elemental iron content Fe, Me/Fe, in a whole cross-section of the ferrite particle, and W2 is a weight ratio of elemental magnesium content Mg to elemental iron content Fe, Me/Fe, in a square, the two opposite vertices of which are located at two points on a diameter of a circle circumscribing the cross-section, each being half a radius distant from the center of the circumscribing circle.

Abstract: It is an object of the present invention to provide a ferrite carrier core material and a ferrite carrier for an electrophotographic developer, which have an excellent charging property, hardly cause carrier scattering due to cracking and chipping of the core material, and have a prolonged life, and methods for manufacturing these, and an electrophotographic developer using the ferrite carrier. For this object, the ferrite carrier core material and a ferrite carrier for an electrophotographic developer, wherein (1) the ferrite composition contains 0.5 to 2.5% by weight of Sr, and the presence amount of Sr—Fe oxides satisfies a specific conditional expression, (2) the distribution in the number of the shape factor SF-2 is in a specific range, (3) the BET specific surface area is 0.15 to 0.30 m2/g, (4) the average particle diameter D50 is 20 to 35 ?m, and (5) the magnetization is 50 to 65 Am2/kg.

Abstract: The present invention provides an image of high image quality by using a magnetic carrier coated with a novel coating resin composition. Further, the present invention stably provides a good image which is hardly influenced by environmental fluctuation and long-term use and has a superior stability of a charging amount when left to stand especially under high temperature and high humidity environments. The present invention also provides a magnetic carrier characterized in that a carrier core surface is coated with a copolymer containing at least, as copolymerization components, an acrylic monomer having a specific structure and an acrylic macromonomer having a specific structure.

Abstract: Provided is a magnetic carrier excellent in leakage, uniformity of a solid image having satisfactory charging stability and developing performance at low electric field. The magnetic carrier is a magnetic carrier comprising: a magnetic substance-dispersed resin carrier core, which contains a magnetic substance and a binding resin, and a coating resin on a surface thereof, wherein: the carrier core has resistivity at 1000 V/cm of 5.0×106-8.0×107 ?·cm, the magnetic substance has a number average particle diameter of 0.20-0.35 ?m; and comprises magnetic-substance particles having vertexes and a particle diameter of 0.53 ?m or more in an amount of 10.0-32.0 vol % based on a total amount of the magnetic substance; and wherein: the carrier core has Fe2O3 content of 98.00% by mass or more; and ZnO content of 0.06-0.50% by mass.

Abstract: A carrier core particle for an electrophotographic developer including a core composition expressed by a general formula: (MnxMgyCaz) FeWO4+V (x+y+z+w=3, ?0.003<v) as a main ingredient, wherein 0.05?y?0.35 and 0.005?z?0.024.

Abstract: A carrier core particle for an electrophotographic developer includes a core composition expressed by a general formula: MnxFe3?xO4+y (0<x?1, 0<y) as a main ingredient, 0.1 wt % or more of Si, and 0.03 wt % or more of at least one metal element selected from the group consisting of Ca, Sr and Mg.

Abstract: Provided is a method for manufacturing carrier core particles for electrophotographic developer capable of stably maintaining high chargeability over a long time. The method for manufacturing carrier core particles includes a granulation step of granulating a mixture of raw materials containing manganese, iron, strontium, and calcium and a firing step of firing the mixture granulated in the granulation step. The firing step includes a heating process of heating the granular mixture with an increase in temperature to a predetermined degree and a cooling process of cooling the granular mixture, after the heating process, in an atmosphere with an oxygen concentration ranging from 5000 ppm to 20000 ppm. The molar ratio of the sum of strontium and calcium to the sum of the manganese, iron, strontium, and calcium is 0.0026 to 0.013.

Abstract: A carrier for developing an electrostatic charge image comprising a core material and a coating resin layer that covers the core material, wherein the core material is a ferrite particle having a Brunauer-Emmitt-Teller (BET) specific surface area of from about 0.12 m2/g to about 0.20 m2/g, and having a fluidity of from about 26 sec/50 g to about 30 sec/50 g.

Abstract: The present invention relates to a two-component developer which comprises a toner, and a carrier having a surface of a core material particle coated with a resin having a unit of general formula (1). The present invention provides a two-component developer which has enhanced environmental stability of carrier charging performance.

Abstract: A carrier for developing an electrostatic latent image, including a particulate core material having a magnetism having developed spontaneous magnetization; and a covering layer comprising an electroconductive material, covering the surface of the particulate core material, wherein the carrier has an electrical resistivity Log R [?cm] of from 8.0 to 12.0 when measured by a method, including filling the carrier in a cell containing a pair of facing electrodes, each having a surface area of 2×4 [cm2] with a gap of 2 [mm] therebetween; and applying a DC voltage of 1,000 [V] therebetween to measure a DC resistivity, and a weight-average particle diameter (Dw) of from 25 to 45 ?m.

Abstract: A two-component developing agent includes toner and a carrier including carrier particles. The toner includes a binding resin. The carrier particle includes a porous ferrite core particle and a resin covering layer. The resin covering layer covers the porous ferrite core particle. The resin covering layer includes ferrite particles. An average particle diameter of the ferrite particles ranges from 0.1 to 1.0 ?m.

Abstract: A porous ferrite core material for an electrophotographic developer, the porous ferrite core material including Mg in a content of 0.3 to 3% by weight, Ti in a content of 0.4 to 3% by weight and Fe in a content of 60 to 70% by weight, and the porous ferrite core material having a pore volume of 0.04 to 0.16 ml/g, a peak pore size of 0.4 to 1.6 ?m, a saturation magnetization of 40 to 80 Am2/kg, a remanent magnetization of less than 7 Am2/kg and a coercive force of less than 43 A/m; a resin-filled ferrite carrier for an electrophotographic developer obtained by filling a resin in the voids of the porous ferrite core material; and an electrophotographic developer using the ferrite carrier.

Abstract: An image forming method using a two component developing system is provided in which a print speed is not less than 300 mm/s, a peak-to-peak voltage of an AC component in a developing bias is not more than 1.3 kV, a sufficient image density can be ensured, and a recorded image having a small amount of magnetic carrier remaining on the image and having high image quality can be obtained. A magnetic carrier that forms a two component developer contains a magnetic core and a resin. The magnetic core is a ferrite containing Sr and Ca inside thereof at the same time, having a small crystal grain diameter, a high density crystal-grain boundary structure, and an extremely large capacitance of the grain boundary. Use of the ferrite can provide the above method.

Abstract: Provided is a magnetic carrier excellent in leakage, uniformity of a solid image having satisfactory charging stability and developing performance at low electric field. The magnetic carrier is a magnetic carrier comprising: a magnetic substance-dispersed resin carrier core, which contains a magnetic substance and a binding resin, and a coating resin on a surface thereof, wherein: the carrier core has resistivity at 1000 V/cm of 5.0×106-8.0×107 ?·cm, the magnetic substance has a number average particle diameter of 0.20-0.35 ?m; and comprises magnetic-substance particles having vertexes and a particle diameter of 0.53 ?m or more in an amount of 10.0-32.0 vol % based on a total amount of the magnetic substance; and wherein: the carrier core has Fe2O3 content of 98.00% by mass or more; and ZnO content of 0.06-0.50% by mass.

Abstract: A material expressed as a composition formula MXFe3-XO4 (where M is at least one of Mg and Mn, and 0?X?1) is a main component, and as a total amount, 0.1 to 2.5 weight percent of at least one of a Sr element and a Ca element is contained. Here, when ferrite particles are used as a carrier, in terms of obtaining a higher image density, the fluidity of the ferrite particles magnetized under a magnetic field of 1000/(4?) kA/m (1000 oersteds) is preferably 40 seconds or more. The residual magnetization ?r is preferably 3 Am2/kg or more.

Abstract: The carrier core particles 11 for electrophotographic developer contain lithium as a core composition. When the carrier core particles 11 are immersed in pure water at a weight ratio of 1 part core particles 11 to 10 parts pure water and shaken, the amount of lithium that leaches out to the pure water is 0.10 ppm or lower.

Abstract: The present invention provides a magnetic carrier that can stably impart charge to a toner on a long term basis and that exhibits an excellent toner separation property and thus exhibits an excellent developing performance. This magnetic carrier is a magnetic carrier in which a vinyl resin coats the surface of a resin-filled core in which a resin is filled in pores of a porous ferrite particle, wherein the resistivity, Mg content, and total content of Sr and Ca oxides of the porous ferrite particle exhibit prescribed values and the magnetic carrier has a total area—in the backscattered electron projection image obtained by observation using a scanning electron microscope at an acceleration voltage of 2.0 kV—for a region originating with the porous ferrite particle of from at least 0.2 area % to not more than 5.0 area % with reference to the projected area of the magnetic carrier.

Abstract: The invention provides a developer for developing an electrostatic latent image, the developer having at least: a transparent toner; and a carrier. The carrier contains at least: a magnetic particle; and a resin coating layer. The resin coating layer coats the surface of the magnetic particle and has cyan color. The invention further provides a developer cartridge storing the developer. The invention further provides a process cartridge storing the developer. The invention further provides an image formation apparatus having at least a color toner image-forming unit, a transparent toner image-forming unit that uses the developer to form a transparent toner image, and a fixing unit.

Abstract: To provide a carrier for electrophotographic developer, capable of realizing a high image quality and full colorization and reducing carrier scattering, and a manufacturing method of the same, and an electrophotographic developer containing the carrier. A carrier core material for electrophotographic developer, with a general formula expressed by MgxMn(1-x)FeyO4 (where 0<x<1, and 1.6?y?2.4), wherein a half-value width B of a peak having a maximum intensity in a powder XRD pattern satisfies B?0.180 (degree), is manufactured and from this carrier core material for electrophotographic developer, the carrier for electrophotographic developer and the electrophotographic developer are manufactured.

Abstract: An electrostatic image developing carrier includes a ferrite particle that contains magnesium element in an amount of about 3.0 wt % or more and about 10.0 wt % or less and manganese element in an amount of about 0.2 wt % or more and less than about. 1.0 wt %; and a resin layer that covers the ferrite particle.

Abstract: There is provided a ferrite core material for an electrophotographic developer, the ferrite core material having a ferrite particle composition represented by the formula (1) shown below, containing SrO replacing a part of (MnO) and/or (MgO) in the formula (1) shown below, and having a Cl concentration of 0.1 to 100 ppm, as measured by an elution method of the ferrite core material: (MnO)x(MgO)y(Fe2O3)z??(1) wherein x=35 to 45 mol %, y=5 to 15 mol %, z=40 to 60 mol %, and x+y+z=100 mol %.

Abstract: A resin coated carrier is provided that can stably charge a toner having added thereto an external additive having a large particle size over a long period of time and can prevent blocking of a developer. The resin coated carrier satisfies the following formula (1): log(Mb/Ma)>2??(1) in which Ma is a weight average molecular weight of a silicone resin having the minimum weight average molecular weight, contained in a resin coating layer, and Mb is a weight average molecular weight of a silicone resin having the maximum weight average molecular weight, and the following formula (2) is satisfied: 0.5??log(A/B)?2.5??(2) in which A is a volume resistance (?/cm) under electric field of 1,000 V/cm obtained by conducting a stirring test, and B is a volume resistance (?/cm) under electric field of 1,000 V/cm before the stirring test.

Abstract: In a method for coating electrophotographic carrier core surfaces with a resin composition by rotating a rotator having a plurality of agitating blades on its surface in a casing; a coating treatment material that is introduced to a space defined between the rotator and the casing is in a packing of from 50% to 98% by volume; at the time of coating treatment, the electrophotographic carrier core surfaces are coat-treated with the resin composition while being put forward and put backward; and the electrophotographic carrier cores and the resin composition are, at the time of coating treatment, temperature-controlled at a specific temperature T (° C.) or below. This method enables the electrophotographic carrier core surfaces to be more uniformly coated with a coating resin.

Abstract: An objective is to provide a carrier exhibiting stable charge providing ability in which sufficient charge can be provided to toner having a small particle diameter, and no image contamination such as fog caused by toner scattering via lack of electrification is generated. Another objective is to provide a carrier capable of maintaining a charging level of no interference for image formation even under the image forming condition at which a charging level for printing a number of prints continuously is difficult to be maintained. Disclosed is a carrier comprising a core particle made of ferrite possessing Mg and coated thereon, a resin, wherein the core particle has a ratio of the number of irregular-shaped core particles of at most 5%, based on the total number of core particles, and a surface of the core particle has grains having a maximum grain diameter of 2-5 ?m.

Abstract: A carrier for developing an electrostatic charge image comprising a core material and a coating resin layer that covers the core material,wherein the core material is a ferrite particle having a Brunauer-Emmitt-Teller (BET) specific surface area of from about 0.12 m2/g to about 0.20 m2/g, and having a fluidity of from about 26 sec/50 g to about 30 sec/50 g.

Abstract: An electrostatic latent image developing carrier is provided which comprises a core particle and a resin coating layer containing conductive particles dispersed therein, the carrier having a volume average particle diameter of 25 to 60 ?m and an average degree of circularity of 0.975 or more, wherein the core particle has a BET specific surface area of 0.1 to 0.3 m2/g and an internal void ratio of 10% or less.

Abstract: A carrier core material for an electrophotographic developer including Li ferrite, maghemite, and Fe3O4, wherein a part thereof is substituted with Mn, Li content is 1 to 2.5% by weight, Mn content is 2 to 7.5% by weight, and silicon content is 25 to 10,000 ppm, the following equation (1) is satisfied when respective integrated strengths of spinel crystal structure (110), (210), (211), and (311) faces in X-ray diffraction are respectively I110, I210, I211, and I311, a resistivity R50 of 50 V across a 6.5 mm gap is 5×107 to 7×108?, and a resistivity R1000 of 1,000 V across a 6.5 mm gap is 1×107 to 8×108?. 2<100×(I110+I210+I211)/I311<14??(1).

Abstract: The present invention can provide small-diameter core material particles for electro photographic carrier, the particles that can prevent occurrences of carrier adhesions and reduce toner spent, have excellent durability and cause little fluctuations in image density with a narrow particle diameter distribution, and an efficient, cost-effective production method thereof. That is, the core material particles for electro photographic carrier are particles wherein the weight average particle diameter, Dw, is in the range of 22 ?m to 32 ?m, the ratio of Dw to the number average particle diameter, Dp, satisfies the condition, 1<Dw/Dp<1.20, the content of particles smaller than 20 ?m in diameter is in the range of 0% by mass to 7% by mass and smaller than 36 ?m is in the range of 90% by mass to 100% by mass, and the BET specific surface area is in the range of 300 cm2/g to 900 cm2/g.

Abstract: A core material of a ferrite carrier for an electrophotographic developer, the core material being composed of a ferrite particle containing at least one or more temperature compensation-type dielectric components selected from Mg2TiO4, MgTiO3 and MgTi2O4, a ferrite carrier for an electrophotographic developer, the ferrite carrier being prepared by coating a surface of the carrier core material with a resin, and an electrophotographic developer using the ferrite carrier.

Abstract: A ferrite carrier for an electrophotographic developer having a compression breaking strength of 150 MPa or more, a rate of compressive change of 15.0% or more and a shape factor SF-1 of 100 to 125, a method for producing the same, and an electrophotographic developer containing the ferrite carrier.

Abstract: A carrier core material for an electrophotographic developer containing Li ferrite, maghemite, and Fe3O4, wherein a part thereof is substituted with Mn, a Li content is 1 to 2.5% by weight, a Mn content is 2 to 7.5% by weight, and a silicon content is 25 to 10,000 ppm, a compression breaking strength is 130 MPa or more, an SF-1 is 125 to 145, respective cumulative strengths of respective spinel crystal structure faces in X-ray diffraction satisfy a certain equation, a vacuum resistivity R500 across a 2 mm gap when a measurement voltage of 500 V is applied is 1×106 to 5×109 ?, and a vacuum resistivity R1000 across a 6.5 mm gap when a measurement voltage of 1,000 V is applied is 5×107 to 1×1010 ?.

Abstract: In a method for recycling a double component developer that contains a carrier and a toner used for an image forming device such as office automation equipment, an economic value of recycling is increased, thereby allowing a company to carry out an active and sustainable environmental activity. Material components of a carrier are completely utilized, so that a process of removing and disposing part of components of the carrier, which is present in the conventional technology of a carrier recycling, is omitted from a recycling system, and in consequence, a cost of recycling is minimized. Furthermore, as well as a subject of the recycling, i.e. a carrier itself, a more valuable material, i.e. a platinum group metal, is utilized for the recycling.

Abstract: A developer for an electrophotographic tandem image forming method is provided that contains a toner; and a carrier, wherein the toner has a shape factor SF-1 of from 120 to 160, an average circularity of form 0.93 to 0.98, a weight-average particle diameter (D4) of from 3.0 to 8.0 ?m, and a ratio (D4/Dn) of the weight-average particle diameter (D4) to a number-average particle diameter (Dn) of from 1.01 to 1.20, and wherein the carrier is almost a spherical ferrite coated with a resin wherein alumina is dispersed, which has an average particle diameter of from 20 to 45 ?m and the following formula: (MgO)x(MnO)y(Fe2O3)z wherein x is from 1 to 5 mol %, y is from 5 to 55 mol % and z is from 45 to 55 mol %.

Abstract: A resin coated carrier for electrophotography and a two-component developer for electrophotography made therefrom, in which electrostatic charge giving ability to toner is high, anti-spent property is superior, charging property is stable even if a large number sheets are continuously printed, initial electrostatic charge increasing ability and electrostatic charge maintaining ability after leaving are also superior, and fogging at supplying toner and fogging after leaving are not generated. In a resin coated carrier for electrophotography comprising a coating material and a core material, in which the coating material covers the surface of the core material, the coating material contains a resin component and a conductive agent, the core material is ferrite, and electric resistance of the carrier at an applied voltage of 100 V set to be 1.0×103 to 1.0×106 ?·cm, or breakdown voltage is set to be 120 to 280 V.

Abstract: It is contemplated to provide irregular shaped ferrite carrier which has a lower resistance, a high specific surface area, a low specific gravity and a longer operational life, and an electrophotographic developer comprising the ferrite carrier which prevents the toner scattering, has a high image density, and is responsive to high-speed and color imaging. The irregular shaped ferrite carrier is characterized in that the carrier particles are irregular shaped, and 40 percent by number or more of the particles have a rock candy sugar shape and/or an oyster shell shape, and that the shape factor (SF-1=R2/S×?/4×100, wherein R is a maximum length and S is a projected area.) is 140 to 250, and the distribution width (?) is 60 or less.

Abstract: A carrier core material for an electrophotographic developer containing Li ferrite, maghemite, and Fe3O4, wherein a part thereof is substituted with Mn, a Li content is 1 to 2.5% by weight, a Mn content is 2 to 7.5% by weight, and a silicon content is 25 to 10,000 ppm, a compression breaking strength is 130 MPa or more, an SF-1 is 125 to 145, respective cumulative strengths of respective spinel crystal structure faces in X-ray diffraction satisfy a certain equation, a vacuum resistivity R500 across a 2 mm gap when a measurement voltage of 500 V is applied is 1×106 to 5×109?, and a vacuum resistivity R1000 across a 6.5 mm gap when a measurement voltage of 1,000 V is applied is 5×107 to 1×1010?.

Abstract: A carrier core material for an electrophotographic developer including Li ferrite, maghemite, and Fe3O4, wherein a part thereof is substituted with Mn, Li content is 1 to 2.5% by weight, Mn content is 2 to 7.5% by weight, and silicon content is 25 to 10,000 ppm, the following equation (1) is satisfied when respective integrated strengths of spinel crystal structure (110), (210), (211), and (311) faces in X-ray diffraction are respectively I110, I210, I211, and I311, a resistivity R50 of 50 V across a 6.5 mm gap is 5×107 to 7×108?, and a resistivity R1000 of V across a 6.5 mm gap is 1×107 to 8×108?.

Abstract: A carrier for electrostatic latent image developer, including a core material and at least two or more resin-coated layers formed on the surface of the core material, wherein the resin-coated layers include a siloxane bond-containing coating resin containing an organic metal compound and a conductive material, the metal contained in the organic metal compound in the innermost resin-coated layer has an ionization potential of less than 7 eV, and the metal contained in the organic metal compound in the outermost resin-coated layer has an ionization potential of 7 eV or more.

Abstract: The invention discloses an electrostatic latent image developer including a toner and a carrier. The carrier has cores and a coating resin including an electrically conductive material on the surface of each of the cores. The coating resin has an inner portion and an outermost portion, and the outermost portion is made of a cross-linked resin. The content of the electrically conductive material in the outermost portion is lower than that in the inner portion. The toner has toner mother particles, and, on the surface of each of the toner mother particles, inorganic particles and resin particles, and the resin particles are made of a non-cross-linking resin.

Abstract: A carrier core material containing at least one metal oxide (MLO) having a melting point of not higher than 1000° C. and at least one metal oxide (MHO) having a melting point of not lower than 1800° C., wherein the metal (MH) for constituting the metal oxide (MHO) has an electrical resistivity of not less than 10?5 ?·cm. Also disclosed is a two-component developing agent comprising a coated carrier, which comprises the carrier core material coated with a resin, and toner particles. Further disclosed is an image forming method comprising developing an electrostatic latent image formed on a photosensitive member with the two-component developing agent using an alternating electric field. The carrier core material and the coated carrier have high magnetization and are free from occurrence of leakage of electric charge over a wide range of electric field from low electric field to high electric field. According to the two-component developing agent, an excellent image can be formed.