Abstract: An electrophotographic magenta toner which comprises a binder resin and a colorant comprising (a) 0.5 to 15 parts by weight of C.I. Pigment Red 57:1 and (b) 0.5 to 15 parts by weight of C.I. Pigment Red 81 or C.I. Pigment Red 122, per 100 parts by weight of the toner. A magenta developer comprising the magenta toner, and a full color image forming method using the magenta toner or developer are also disclosed.

Abstract: Disclosed is a developing agent comprising toner particles including a binder resin mainly containing an ethylene-norbornene copolymer and a coloring agent mainly containing a cyanine dye and an organic boron ammonium salt. The developing agent can be decolored by irradiation with light having a predetermined wavelength region.

Abstract: A toner for developing an electrostatic image is disclosed. The toner contains an amount of not less than 0.1% by weight of an element selected from elements of the Groups of 1B, 2B, 4B, 5B, 6B, 7B, 8, 3A and 4A of the fourth and fifth periodic of the long periodic table of the elements, and the isolation ratio of the element is not more than 10% by number.

Abstract: A flash fixing color toner for use in an image forming process includes a binder resin and a hue-altering coloring agent, wherein the hue-altering coloring agent alters, at a time of irradiation of flash light, an initial hue of the color toner into a secondary hue, so that the color toner is fixed to a recording medium by the irradiation of flash light, and a color image is substantially formed with the secondary hue of the color toner.

Abstract: In a toner containing at least a binder resin, a pigment and a pigment dispersant, the pigment dispersant has a structure wherein a quinacridone molecular skeleton which is readily adsorptive on the colorant pigment and an oligomer or polymer which has good affinity for the solvent and for the resin serving as a toner binder are covalently bonded. Also disclosed is a process for producing the toner.

Abstract: An optical fixing toner includes an infrared ray absorbing agent which is made of one element or a mixture of a plurality of elements selected from a group of elements consisting of oxides, sulfides, halides, complex salts and acid chlorides of lanthanoide.

Abstract: A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The binder resin comprises a polyester-based resin selected from the group consisting of (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl polymer unit, and (c) a mixture of these resins. The wax is characterized by including a structural unit including an OH group, an amide, or an ester group at a specific position.

Abstract: The present invention discloses a flash fixing color toner for use in an image forming process, which comprises a binder resin, a coloring agent, and an infrared absorbent, wherein negative ions form part of the infrared absorbent, and the negative ions include toluenesulfonic acid ion (C6H4(CH3)SO3−), nitric acid ion (NO3−) or hexafluorophosphoric acid ion (PF6−). Further, the present invention discloses an image forming process, which is characterized by using the flash fixing color toner.

Abstract: A flash fixing toner includes a binder resin, a coloring agent, a charge control agent, a wax, and an infrared ray absorbing agent. The infrared ray absorbing agent is held within the wax, so as to suppress contact between the infrared ray absorbing agent and the charge control agent.

Abstract: An external additive for electrostatically charged image developing toner is provided. The additive includes spherical hydrophobic fine silica particles having primary particles with a particle diameter of from 0.01 to 5 &mgr;m and having been treated with a compound selected from the group consisting of a quaternary ammonium salt compound, a fluoroalkyl-group-containing betaine compound and a silicone oil.

Abstract: Disclosed are marking particles comprising a first polymer, a second polymer, a chelating agent, and a spiropyran material of the formula wherein n is an integer representing the number of repeat —CH2— units and R is —H or —CH═CH2. The marking particles comprise a core containing the first polymer in which is dispersed the chelating agent and the spiropyran and encapsulated within a shell of the second polymer formulated by an interfacial polymerization.

Abstract: A magenta toner containing at least a binder resin and a colorant; the magenta toner having a storage elastic modulus at a temperature of 80° C., G′80, in the range of from 1×106 dN/m2 to 1×108 dN/m2 and a storage elastic modulus at a temperature of from 120° C. to 180° C., G′120-180, in the range of from 2×103 dN/m2 to 1×106 dN/m2, and containing at least a compound selected from the group consisting of compounds represented by the following Formulas (1) and (2) and a compound represented by the following Formula (3).

Abstract: Disclosed are marking particles comprising a resin, a chelating agent, and a spiropyran material which is of the formula The marking particles are prepared by an emulsion aggregation process.

Abstract: A yellow toner comprising fine resin particles and an external additive being added to surfaces of the fine resin particles, wherein the fine resin particles comprise (a) a resin binder comprising a polyester obtained by polycondensing an alcohol component comprising a compound represented by the formula (I), with a carboxylic acid component comprising a dicarboxylic acid compound and a tricarboxylic or higher polycarboxylic acid compound; (b) a colorant comprising a compound represented by the formula (II); and (c) a charge control agent comprising a compound selected from the group consisting of metal compounds of a salicylic acid derivative represented by the formula (III); and metal compounds of a benzilic acid derivative represented by the formula (IV); and wherein the external additive comprises silica having an average particle size of from 35 to 350 nm.

Abstract: A sepiomelanine pigment is employed as a coloring agent in a developing agent for forming sepia color, black color and full color images without employing carbon black.

Abstract: Charge control agent comprising a base particle containing at least a charge control substance, and a granulating agent, said base particle being granulated using said granulating agent, and said granulating agent being at least one selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, natural water-soluble high molecular compounds and synthetic water-soluble high molecular compounds; manufacturing process thereof; and toner for developing electrostatic images containing the charge control agent for the purpose of charge control, and also containing a coloring agent and a resin.

Abstract: A toner for electrophotography is disclosed. The toner comprises a binder resin and a colorant and a wax in amount of 0.5 to 8 percent by weight, and adhesion power index of wax particles to toner particles is between 0.7 and 2.2. The toner improves the durability of the developer material and a photoreceptor, minimizes image smear at high temperature and humidity, and exhibits excellent fixation as well as offsetting resistance.