Abstract: A method for producing a developing agent including heating a dispersion of a toner particle material containing a binder resin fine particle, a coloring agent particle and a dispersion medium at a temperature of a glass transition point of the binder resin or higher and adding a coagulating agent in the heated dispersion of a toner particle material to coagulate a toner material containing the binder resin fine particle and the coloring agent particle, thereby forming a coagulated particle is disclosed.

Abstract: A developing agent comprises first and second resin fine particles containing a colorant and a release agent and different in weight average molecular weight, and a concentration of the release agent which is softened at a low temperature in the second resin fine particles having the high weight average molecular weight is higher than a concentration of the release agent in the first resin fine particles, whereby thermal properties dependent on the weight average molecular weight of the resin fine particles are made uniform and fixability of the developing agent is improved.

Abstract: A method for manufacturing a developing agent by mixing a coarsely granulated mixture containing a binder resin and a coloring agent with an aqueous medium and mechanically stirring the resulting mixed solution to finely granulate the coarsely granulated mixture, thereby forming a fine particle.

Abstract: In a manufacturing method of a resin for developing agent, a first polymerization agent is added in an aqueous medium; a radical polymerizable monomer is polymerized in the presence of a chain transfer agent to form a low molecular substance resin particle; after consuming the chain transfer agent, a second polymerization initiator is added in the aqueous medium; and the remaining monomer is polymerized to form a high molecular substance resin particle, thereby improving fixability of the developing agent.

Abstract: The present invention is directed to a steam turbine rotor which comprises an iron base alloy containing 0.05 to 0.2 wt % of carbon, 0.1 wt % or less of silicon, 0.05 to 1.5 wt % of manganese, more than 8.0 wt % to less than 13 wt % of chromium, less than 1.5 wt % of nickel, 0.1 to 0.3 wt % of vanadium, 0.01 to 0.1 wt % of niobium, 0.01 to 0.1 wt % of nitrogen, 0.02 wt % or less of aluminum, less than 0.50 wt % of molybdenum and 0.9 to 3.0 wt % of tungsten; contents of molybdenum Mo and tungsten W satisfying the following formulae0.75.ltoreq.1/2W+Mo and3.ltoreq.W/Mo;a .delta.-ferrite phase and a large grain boundry carbide being scarcely contained basically in the metallic structure; a matrix of martensite being formed therein.