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: The carrier core particles for electrophotographic developer include a core composition expressed by a general formula Fe3O4 as a main ingredient and 30 ppm to 400 ppm Na. Such carrier core particles can reduce environmental dependency thereof, while optimizing the resistivity.

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 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: To provide a carrier for two-component electrophotographic developer not only having excellent fluidity but also having proper surface irregularities necessary for imparting electric charge, without generating cracks/chipping of particles even under an influence of stirring stress over a long period of time. A particle surface has raised parts of striped pattern extending almost continuously in a plurality of directions while being superposed on one another, with a surface formed with raised parts of striped pattern occupying 80% or more of the whole surface of a particle. Depths of grooves between the adjacent raised parts are 0.05 ?m or more and 0.2 ?m or less, average surface roughness Ra is 0.1 ?m or more and 0.3 ?m or less, roundness is 0.90 or more, and average particle size is 15 ?m or more and 100 ?m or less, and a carrier core material thus constituted is coated with resin. Thus, the carrier for two-component electrophotographic developer is prepared.

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: A carrier core material for electrophotographic developer containing a soft ferrite, expressed by (MgXMn1-x)Fe2O4 (wherein X is in a range of 0.1?X<1.), wherein an analysis value of P on the surface of the carrier core material is 0.1 mass % or more, an analysis value of Mg is 2 mass % or more, a content of Mg in the carrier core material is 2 mass % or more by EDS, and when the content of Mg in the carrier core material is expressed by M1, and the analysis value of Mg on the surface of the carrier core material by EDS is expressed by M2, a value of M2/M1 exceeds 1.0.

Abstract: To provide a carrier for two-component electrophotographic developer not only having excellent fluidity but also having proper surface irregularities necessary for imparting electric charge, without generating cracks/chipping of particles even under an influence of stirring stress over a long period of time. A particle surface has raised parts of striped pattern extending almost continuously in a plurality of directions while being superposed on one another, with a surface formed with raised parts of striped pattern occupying 80% or more of the whole surface of a particle. Depths of grooves between the adjacent raised parts are 0.05 ?m or more and 0.2 ?m or less, average surface roughness Ra is 0.1 ?m or more and 0.3 ?m or less, roundness is 0.90 or more, and average particle size is 151 ?m or more and 100 ?m or less, and a carrier core material thus constituted is coated with resin. Thus, the carrier for two-component electrophotographic developer is prepared.

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: To provide a carrier for an electrophotographic developer in which high image quality and full colorization are possible while carrier scattering is reduced, and a method for producing the carrier, and an electrophotographic developer including the carrier. A carrier core material for an electrophotographic developer is produced so that the half-value width B of a peak having a maximum intensity in an XRD pattern satisfies B?0.160 (degree). A carrier for an electrophotographic developer and an electrophotographic developer are produced from the carrier core material for an electrophotographic developer.

Abstract: An oxygen absorber for blending in a resin, comprising a mixed powder containing an iron powder, a metal halide and an alkaline substance, and having a half-peak width on a plane (110) of 0.20°/2? (Co—K?) or less as measured by a powder X-ray diffraction method, a specific surface area of 0.5 m2/g or more, and an average particle size of 1 to 40 ?m. The oxygen absorber effectively suppresses the generation of hydrogen, features excellent safety, exhibits excellent oxygen-absorbing capability and offers an advantage of high productivity due to the suppressed occurrence of coarse particles in the step of producing the oxygen absorber. The oxygen-absorbing container has a layer comprising an oxygen-absorbing resin composition containing the oxygen absorber for blending in a resin of the invention, excellently preserves the content, exhibits good appearance with less ruggedness on the surface, and is free from such a probability of swelling or rupturing of the container due to the generation of hydrogen.