Abstract: The present invention provides a magnetic mono-component toner which can suppress a selection development on a latent image carrier and can maintain favorable image properties for a long period by using a toner having the coarse powder distribution (S) within a given range in a jumping developing method and an image forming method which uses the toner. In the toner used in the jumping developing method which develops an electrostatic latent image formed on a latent image carrier using a developer carrier, the toner includes toner particles which contain at least a binding resin and a magnetic powder, and the coarse powder distribution (S) of the toner particles satisfies a following formula (1).

Abstract: A two-component developer is provided with cylindrical toner particles and magnetic carrier particles having an average sphericity of 0.95 or more. When such a developer is used in development using a two-component developing method, a clear image can be stably obtained for a long period by suppressing a spent phenomenon and an insufficiency of cleaning.

Abstract: Alloy powder for forming a hard phase for a valve seat material having excellent high temperature wear resistance. The overall composition is consisted of Mo: 48 to 60 mass %, Cr: 3 to 12 mass % and Si: 1 to 5 mass %, and the balance of Co and inevitable impurities.

Abstract: Alloy powder for forming a hard phase for a valve seat material having excellent high temperature wear resistance. The overall composition is consisted of Mo: 48 to 60 mass %, Cr: 3 to 12 mass % and Si: 1 to 5 mass %, and the balance of Co and inevitable impurities.

Abstract: A manufacturing method for wear resistant sintered member is provided. The method includes: compacting a raw powder containing a matrix forming powder and a hard phase forming powder into a green compact, the matrix forming powder containing 90 mass % or more of a powder having the maximum particle diameter of 46 ?m, and the hard phase forming powder being 40 to 70 mass % with respect to the raw powder; and sintering the green compact.

Abstract: A sintered valve seat includes: a matrix; 5 to 40 mass % of a hard phase dispersed in the matrix, the hard phase containing 48 to 60 mass % of Mo; 3 to 12 mass % of Cr; 1 to 5 mass % of Si; and the balance of Co and inevitable impurities; and a structure in which a Cr sulfide is dispersed around the hard phase. The hard phase is formed with a Co base alloy matrix and compounds which are mainly composed of Mo silicides and are integrally precipitated in the Co base alloy matrix.

Abstract: A wear resistant sintered member comprising an Fe base alloy matrix and a hard phase dispersed in the Fe base alloy matrix and having an alloy matrix and hard particles precipitated and dispersed in the alloy matrix. Manganese sulfide particles having particle size of 10 ?m or less are uniformly dispersed in crystal grains of the overall Fe base alloy matrix, and manganese sulfide particles having particle size of 10 ?m or less are dispersed in the alloy matrix of the hard phase.

Abstract: Alloy powder for forming a hard phase for a valve seat material having excellent high temperature wear resistance. The overall composition is consisted of Mo: 48 to 60 mass %, Cr: 3 to 12 mass % and Si: 1 to 5 mass %, and the balance of Co and inevitable impurities.

Abstract: The present invention provides a magnetic mono-component toner which can suppress a selection development on a latent image carrier and can maintain favorable image properties for a long period by using a toner having the coarse powder distribution (S) within a given range in a jumping developing method and an image forming method which uses the toner. In the toner used in the jumping developing method which develops an electrostatic latent image formed on a latent image carrier using a developer carrier, the toner includes toner particles which contain at least a binding resin and a magnetic powder, and the coarse powder distribution (S) of the toner particles satisfies a following formula (1).

Abstract: Alloy powder for forming a hard phase for a valve seat material having excellent high temperature wear resistance. The overall composition is consisted of Mo: 48 to 60 mass %, Cr: 3 to 12 mass % and Si: 1 to 5 mass %, and the balance of Co and inevitable impurities.

Abstract: A valve seat is provided in which wear resistance can be ensured by optimizing the matrix structure without dispersing of expensive hard particles, and therefore the machinability can be improved and the holding down of cost can be achieved. The valve seat exhibits a metallographic structure consisting of only bainite single phase or only a mixed phase of bainite and martensite, has an area ratio of bainite and martensite in cross section of 100:0 to 50:50, and has a matrix hardness of 250 to 850 Hv.

Abstract: A wear resistant sintered member exhibits superior wear resistance at the same level as those of the conventional materials without using a Co-based hard phase is provided. A first hard phase comprising Mo silicide particles dispersed in an Fe-based alloy matrix of the first hard phase and a second hard phase comprising a ferrite phase or a mixed phase of ferrite and austenite having a higher Cr concentration than the Fe-based alloy matrix surrounding a core consisting of Cr carbide particles, are diffused in an Fe-based alloy matrix, the Mo silicide particles are contained in the first hard phase in an amount of 3 to 25 % by area, and the Cr carbide particles are contained in the second hard phase in an amount of 3 to 30 % by area.

Abstract: The invention relates to an iron-based high-temperature wear-resistant sintered alloy. This alloy contains 3.74-13.36 wt % W, 0.39-5.58 wt % V, 0.2-5.78 wt % Cr, 0.1-0.6 wt % Si, 0.39-1.99 wt % Mn, 0.21-1.18 wt % S, and up to 2.16 wt % C. This alloy includes 20-80 wt % of a first phase and 80-20 wt % of a second phase, each distributed therein, in the form of spots. The first phase contains 3-7 wt % W, up to 1 wt % Cr, 0.1-0.6 wt % Si, 0.2-1 wt % Mn, 0.1-0.6 wt % S, and up to 2.2 wt % C. The first phase may contain 0.5-1.5 wt % V, and in this case the vanadium content of the alloy becomes 0.79-5.88 wt %. The second phase contains 7-15 wt % W, 2-7 wt % V, 1-7 wt % Cr, 0.1-0.6 wt % Si, 0.2-1 wt % Mn, 0.1-0.6 wt % S, and up to 2.2 wt % of C. Each phase contains 0.3-1.6 wt % MnS and a carbide of at least tungsten, which are dispersed therein. The second phase further contains 10-20 areal % tungsten carbide (particle diameter: ≧1 &mgr;m) dispersed therein. The alloy further contains 0.

Abstract: A valve seat is provided in which wear resistance can be ensured by optimizing the matrix structure without dispersing of expensive hard particles, and therefore the machinability can be improved and the holding down of cost can be achieved. The valve seat exhibits a metallographic structure consisting of only bainite single phase or only a mixed phase of bainite and martensite, has an area ratio of bainite and martensite in cross section of 100:0 to 50:50, and has a matrix hardness of 250 to 850 Hv.

Abstract: A carrier for use in development of an electrostatic latent image and an image forming apparatus using the carrier, with which a stable charging ability is maintained for a long period of time, and a high density image free from fog can be formed. The carrier has magnetic material particles coated with a coating resin. The coating resin is a thermoplastic resin, with a hardness of rank F to B in the terms of the pencil scratch test, and is present in an amount of 0.5 to 5 parts by weight to 100 parts by weight of the magnetic material particles.

Abstract: A sintered alloy having superb wear resistance consisting, percent by weight of, as a whole, Ni in the amount of 1.35 to 19.61%, Cr in the amount of 0.9 to 11.05%, Mo in the amount of 1.44 to 9.09%, Co in the amount of 3.6 to 20.05%, V in the amount of 0.018 to 0.26%, Si in the amount of 0.1 to 0.75%, C in the amount of 0.35 to 1.5%, and the balance of Fe, and the sintered alloy exhibiting a metallographic structure in which the following hard phases are dispersed in a mixed structure of martensite, sorbite, and austenite: a first hard phase comprising, a hard phase as a core mainly consisting of Mo suicide, and a diffused phase including diffused Co surrounding the hard phase; and a second hard phase comprising, a hard phase as a core consisting of Cr carbide, and a mixed phase of ferrite and austenite surrounding the hard phase.

Abstract: The invention relates to a sintered alloy. This sintered alloy includes 3-13.4 wt % of W, 0.4-5.6 wt % or 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. The sintered alloy includes first and second phase which are distributed therein, in a form of spots, respectively. The second phase is in an amount of from 20 to 80 wt %, based on the total weight of the first and second phases. The first phase contains 3-7 wt % of W, 0.5-1.5 wt % of optional V, up to 1 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. The second phase contains 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. When the manganese contents of the first and second phases and the total of the sintered alloy are respectively in a range of from 0.2 to 1.

Abstract: A magnetic carrier for electrophotographic developing agent wherein the surfaces of the magnetic core particles are partly coated with a thermosetting resin and a small amount of a low-melting or low-softening thermoplastic resin or wax, and at least recessed portions of the core particles are filled with these coating materials. The magnetic carrier has an electric resistance that is maintained within a range that is suited for forming the image, and suppresses the occurrence of spent toner.

Abstract: Disclosed is a sintered iron alloy and a method of manufacturing the same. The sintered alloy comprises: an alloy matrix and a lead phase for imparting lubricability to the sintered alloy. The alloy matrix comprises a first alloy phase being composed of 0.5 to 3% nickel by weight, 0.5 to 3% molybdenum by weight, 5.5 to 7.5% cobalt by weight, 0.6 to 1.2% carbon by weight, and the balance iron, and a second alloy phase being composed of 26 to 30% molybdenum by weight, 7 to 9% chromium by weight, 1.5 to 2.5% silicon by weight, and the balance cobalt. The content of the lead phase in the sintered alloy is not more than 3.5% by weight. The lead phase is dispersed in the alloy matrix and a pore which is formed in the alloy matrix. The ratio of the lead dispersed in the alloy matrix to the total lead phase is 60% by weight or more, and the lead phase dispersed in the alloy matrix is particles in which the maximum particle size is 10 .mu.m or less.

Abstract: An electrophotographic developer includes a toner and a carrier, in which the carrier is provided on the surface of a core material thereof with a resin coating layer. The coating layer is made of cured body of a methyl silicone resin containing not less than 70% by weight of T-units and a methylated melamine resin having a molecular weight of not less than 700. This developer is not lowered in flowability, generates no spent particles and presents stable electric charging characteristics. Accordingly, the developer of the present invention is suitably used where a toner is used containing no electric charge controlling agent.