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: 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: An image formation process which forms a toner image by the nonmagnetic one-component developing system by bringing an electrically conducting brush impressed with a voltage into contact with a photosensitive material to effect the uniform charging, and forming an electrostatic latent image on the photosensitive material by the exposure to the image-bearing light, wherein the toner that is used as a circularity of from 0.92 to 0.98. The nonmagnetic one-component developing system minimizes irregular electric charging that stems from the use of the electrically conducting brush. This action is obtained even in full-color developing system which effects development many times.

Abstract: There is disclosed a two-component developing agent for use in an mage formation based on electrophotography, which has high developability even at a high speed printing and good developability in the case of the image formation for a long period of time. The two-component developing agent includes a carrier comprising a magnetic particle and an insulating toner. A surface of the magnetic particle is coated with at least a resin. A mean particle size of the magnetic particle is between 30 and 90 &mgr;m and an aggregation degree of said carrier is between 2 and 15%.

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: In a method for forming a color image by using a contact type nonmagnetic one-component developing device, a flat sheet-like blade made of a metal flexible member and having a distal end thereof chamfered is used inside the developing device in combination with a toner having a glass transition point of 55 to 70° C. and a weight average particle diameter of 6.0 to 10.0 &mgr;m, and containing up to 20 number % of particles having particle diameters of 5 &mgr;m or below, as a developer. The developing device is simple in construction, can provide high image quality and can, moreover, provide a highly reliable image formation method.

Abstract: A toner binder comprising a crosslinked polyester resin obtained by using 0.1 to 3 mol % of trimellitic acid and 0.1 to 5 mol % of an epi-bis type epoxy in combination as crosslinking components, said binder having a number average molecular weight (Mn) in the chromatogram determined by a gel permeation chromatography on the non-gel portion of the polyester resin, of 2,000 to 4,000, a ratio (Mw/Mn) of the weight average molecular weight to the number average molecular weight of 10 to 25 and a (percent gel) of the residue unsoluble in tetrahydrofuran solvent of 1 wt % or less. A toner composition for flash fixing comprising the above-described binder as an essential constituent component. The toner and the toner binder exhibit good fixability and void resistance upon flash fixing and produce little fixing odor.

Abstract: A toner binder is disclosed which comprises a polyester resin in which an aliphatic hydrocarbon chain terminated with an ester and/or an ether bond to the aliphatic group contains a constituent element consisting of ethylene in an amount of from 1 to 5 wt % based on the total weight of the resin. Further disclosed is a toner binder using both of a crosslinked polyester having a peak molecular weight of 10,000 or less and a linear polyester having a peak molecular weight of 8,000 or more as binder resins, the peak molecular weight of the linear polyester being greater than the peak molecular weight of the crosslinked polyester.

Abstract: A method for nonmagnetic monocomponent development is intended for use in an electrophotographic copying machine or electrophotographic printer and is capable of producing highly durable prints of high quality during continuous printing operations. In the nonmagnetic monocomponent development, a developer is transported by a development roller to a photoconductor drum. A Doctor blade triboelectrifies the developer and simultaneously regulates the thickness of a layer of the developer. As the developer, a toner is used, which toner is produced by coagulating minute particles having a diameter between 0.1 and 3.0 .mu.m and then heating the minute particles, thereby thermally fusing these particles.

Abstract: A process for producing a wherein an aminium salt infrared light absorber and a positive charge control agent are used in combination while preventing a mutual reaction therebetween. In this toner, the physical contact of the aminium salt compound with the positive charge control agent is avoided (e.g., by separately adding them to respective two separated phases of a binder resin), or alternatively use is made of such a combination of confounds as will not cause a mutual reaction (e.g., a common anion is used).

Abstract: The present specification discloses a toner for electrophotography.This toner comprises two or more kinds of binder resins, and is characterized in that the surface tension of each of the binder resins and the melt viscosity thereof, both at a temperature of 200.degree. C., are respectively below 30 dyne/cm and 100 poises or more, and the melt viscosity thereof and the storage modulus thereof, both at a temperature of 125.degree. C., are respectively below 5000 poises and below 40000 dyne/cm.sup.2, a toner comprising a surface tension reducing agent and a binder resin. Because the melt viscosity of the binder resin at a temperature of 200.degree. C. is 30 poises or more, a toner having an excellent void resistance can be obtained without a worsening of the fixability and blocking resistance thereof.

Abstract: A toner is disclosed wherein an aminium salt infrared light absorber and a positive charge control agent are used in combination while preventing a mutual reaction therebetween. In this toner, the physical contact of the aminium salt compound with the positive charge control agent is avoided (e.g., by separately adding them to respective two separated phases of a binder resin), or alternatively use is made of such a combination of compounds as will not cause a mutual reaction (e.g., a common anion is used).

Abstract: The present specification discloses a toner for electrophotography.This toner comprises two or more kinds of binder resins, and is characterized in that the surface tension of each of the binder resins and the melt viscosity thereof, both at a temperature of 200.degree. C., are respectively below 30 dyne/cm and 100 poises or more, and the melt viscosity thereof and the storage modulus thereof, both at a temperature of 125.degree. C., are respectively below 5000 poises and below 40000 dyne/cm.sup.2, a toner comprising a surface tension reducing agent and a binder resin. Because the melt viscosity of the binder resin at a temperature of 200.degree. C. is 30 poises or more, a toner having an excellent void resistance can be obtained without a worsening of the fixability and blocking resistance thereof.

Abstract: A magnetic brush developer for electrophotography by the reversal development system where a uniform positive charge is imparted to a photoconductive insulator, the insulator is irradiated with a light image to form an electrostatic latent image and the latent image is developed and visualized by a positively charged toner. The developer comprises a carrier of granulated magnetite particles, the surfaces of which are coated with a thermosetting resin containing a fine fluoropolymer powder and a fine magnetite or carbon black powder dispersed therein. When this developer is used, adhesion of the toner to the sleeve is not only prevented at the initial stage of printing but also after continuous printing, and even if continuous printing does conducted, the charge quantity is not reduce, therefore print quality does not degrade.

Abstract: A flash fixing process characterized by using a powdery developing toner comprising at least 80% by weight of a bisphenol A/epichlorohydrin type epoxy resin or a polyester resin as the binder resin, 1 to 10% by weight of a dye or pigment as the colorant and 1 to 10% by weight of a specific aminium compound.