Abstract: A liquid developer which has excellent preservability, storage stability for a long period of time, and fixing characteristic of toner particles and which is also harmless to the environment is provided. The liquid developer contains an insulation liquid and toner particles dispersed in the insulation liquid. The insulation liquid contains a saturated fatty acid and at least one component selected from a group comprising a linolenic acid component, a linoleic acid component and an oleic acid component. The liquid developer may contain an antioxidizing agent and an oxidation polymerization accelerator for accelerating an oxidation polymerization reaction of the linolenic acid component, the linoleic acid component or the oleic acid component during a fixing process.

Abstract: An image forming apparatus which forms an image onto a recording medium using a liquid developer which contains an insulation liquid and toner particles dispersed in the insulation liquid is provided. The image forming apparatus includes a liquid developer storage section for storing the liquid developer therein; a developing section for developing a toner image using the liquid developer supplied from the liquid developer storage section; an image transfer section for transferring the developed toner image formed by the developing section onto the recording medium to form a transferred image thereon; and a fixing section for fixing the transferred image formed on the recording medium onto the recording medium, wherein at least a part of the insulation liquid in the transferred image is oxidized and polymerized to fix the toner particles in the transferred image onto the recording medium. According to the image forming apparatus, it is possible to fix the toner particles onto the recording medium firmly.

Abstract: A liquid developer which has excellent preservability, storage stability for a long period of time, and fixing characteristics of toner particles and which is also harmless to the environment is provided. The liquid developer contains an insulation liquid and toner particles dispersed in the insulation liquid. The insulation liquid contains a saturated fatty acid and at least one of an eicosapentaenoic acid component and a docosahexaenoic acid component. The liquid developer may contain an antioxidizing agent and an oxidation polymerization accelerator for accelerating an oxidation polymerization reaction of the eicosapentaenoic acid component or the docosahexaenoic acid component during a fixing process. Further, an image forming apparatus for use with the liquid developer is also provided.

Abstract: A liquid developer contains an insulation liquid containing as its main component a glyceride of an unsaturated fatty acid, toner particles dispersed in the insulation liquid; and an oxidation polymerization accelerator for accelerating oxidation polymerization reaction of the glyceride during fixing process of the toner particles. The oxidation polymerization accelerator accelerates the oxidation polymerization reaction by supplying oxygen during the fixing process of the toner particles. The liquid developer may further contain an antioxidizing agent. Preferably, the oxidation polymerization accelerator is contained in the insulation liquid being encapsulated.

Abstract: A method of producing a liquid developer which comprises a high insulation solution and toner particles dispersed in the solution is provided. The method comprises the steps of: a kneading step for kneading a material containing a pigment and a resin material to obtain a kneaded material; a water-based emulsion preparing step for preparing a water-based emulsion, the water-based emulsion comprising a dispersoid composed of a material for the toner particles which has been prepared based on the kneading material and a water-based dispersion medium constituted from a water-based liquid in which the dispersoid is dispersed; a dispersion medium removal step for removing the dispersion medium to obtain dry fine particles; and a dispersing step for dispersing the dry fine particles into the high insulation liquid.

Abstract: A method for producing resin particles using a dispersion liquid in which a dispersoid mainly made of a resin material is finely dispersed in a dispersion medium, the method comprising a dispersion liquid ejecting step for ejecting the dispersion liquid in the form of droplets and a dispersion medium removing step for removing the dispersion medium from the dispersion liquid in the form of droplets, wherein a granulation prevention agent for preventing or suppressing fine particles derived from the dispersoid from being agglomerated and then granulated is applied to the dispersion liquid.

Abstract: A method for producing resin particles mainly made of a resin material using a dispersion liquid in which a dispersoid containing the resin material is finely dispersed in a dispersion medium, the method comprising a dispersion medium removing step which comprises ejecting the dispersion liquid from a head portion in the form of droplets into a solidifying portion, conveying the droplets in the solidifying portion to remove the dispersion medium, and obtaining agglomerates each of which is composed of two ore more fine particles derived from the dispersoid, and a bonding step for welding and bonding the fine particles which constitute each of the agglomerates, thereby obtaining resin particles. The resin particles can be used for manufacturing a toner.

Abstract: In a rare-earth bonded magnet of the invention, magnetic powder containing a rare-earth element is bonded together by a binding resin. The rare-earth bonded magnet may further contain an antioxidant and a lubricant. The binding resin contains a high molecular compound comprising the following structure unit; —X—R—X—Y—Ar—Y— (where X is a functional group containing a nitrogen atom, Y is a functional group containing a carbonyl group, R is a normal-chain or branched alkylene group having a carbon number of 6-16, and Ar is an aromatic ring residue).

Abstract: The present invention provides a method for manufacturing a rare-earth bonded magnet as follows: A compound 10, prepared by pelletizing a kneaded mixture of a rare-earth-bonded-magnet composition containing a rare-earth magnet powder, a binder resin and an antioxidant, is stored in a hopper 91, and fed into a cylinder 3 through a feeding pipe 92. Meanwhile, piston 81 is extended by driving an oil-hydraulic cylinder 8, and moved downward to compact the compound 10 fed into the cylinder 3 while gradually transferring the compound downward inside the cylinder 3. The cylinder 3 and a heating portion 41 are heated by heaters 5, the compound 10 passing therethrough is heated to become a melted material 11, and the melted material 11 is continuously extruded out from a die 4 in the downward-vertical direction, and is then cooled and solidified when passing through a tip portion 43, thus obtaining a molded body 12 of a rare-earth-bonded-magnet.

Abstract: A pH sensor is provided capable of readily determining the pH of a solution of a small amount. The pH sensor includes a semiconductor substrate, an oxide film provided on the semiconductor substrate, a solution storage part for holding a solution on the oxide film, and an electrode to be in contact with the solution in a vicinity of the oxide film. To determine the pH of a solution, a capacitance-voltage characteristic is initially monitored by the sensor between the electrode in contact with the solution and another electrode provided on the back surface of the semiconductor. Then the pH of the solution is derived from a flat band voltage which is obtained based on the capacitance-voltage characteristic.

Abstract: A composition for a rare earth bonded magnet, the rare earth bonded magnet and the method for manufacturing the rare earth bonded magnet are provided that produce little decline in mechanical strength caused by the addition of a lubricant and have excellent molding properties. The rare earth bonded magnet of the present invention is manufactured from the composition for the magnet that contains rare earth magnetic powder, binding resin containing thermoplastic resin, and fluorine-based resin powder, by compaction molding, extrusion molding or injection molding. The fluorine-based resin powder has the properties of improving mainly lubrication between a molding and a metallic mold. The content of the fluorine-based resin powder in the composition for the rare earth bonded magnet is preferably less than 20 vol % relative to the thermoplastic resin, and the particle diameter of the fluorine-based resin powder is preferably 2-30 &mgr;m.

Abstract: A rare earth bonded magnet comprising a rare earth magnet powder bonded with a binder resin is manufactured by extrusion or injection molding. A rare earth bonded magnet manufactured by extrusion molding has a rare earth magnet powder content of 78.1 to 83.0 percent by volume. A rare earth bonded magnet manufactured by injection molding has a rare earth magnet powder content of 68.0 to 76.0 percent by volume. Preferably, the rare earth metal powder is at least one of Sm--Co alloys, R--Fe--B alloys wherein R is at least one of rare earth elements including Y, and Sm--Fe--N alloys. Preferably, the thermoplastic resin include polyamide, liquid crystal polymer, and Polyphenylene sulfide. Preferably, the rare earth bonded metal has a void ratio of 2 percent by volume or less. A rare earth bonded magnet is manufactured by kneading a rare earth magnetic composition comprising a rare earth magnet powder and a thermoplastic resin, and by extruding or injecting the mixture after kneading.

Abstract: A magnetic powder and a permanent magnet are provided which have magnetic properties enhanced by magnetic interaction. Disclosed are a magnetic powder comprising a mixture of two or more powders including a magnetic powder A (residual magnetic flux density: BrA, coercive force: HcA) and a magnetic powder B (residual magnetic flux density: BrB, coercive force: HcB) of which the residual magnetic flux densities and the coercive forces have the following relationships: BrA>BrB and HcA<HcB, and a bonded magnet or a sintered magnet produced from the magnetic powder, and a method for mixing magnetic powders and a process for producing a magnet.

Abstract: A rare earth-iron series magnet formed from an alloy ingot using a one-step hot working process is provided. The alloy ingot includes between about 8 and 30 atomic percent of at least one rare earth element, between about 2 and 28 atomic percent of boron, less than about 50 atomic percent of cobalt, less than about 15 atomic percent of aluminum and the balance of iron and other impurities that are inevitably included during the preparation process. The alloy is cast to obtain a cast ingot and the hot working is performed on the cast ingot at a temperature of greater than about 500.degree. C. in order to make the crystal grains of the ingot fine and to align the axis of the grains in a desired direction.

Abstract: The addition of a chelating agent or a chelating agent and an antioxidant in combination to a rare-earth bonded magnet composition and a rare-earth bonded magnet comprising a rare-earth magnetic powder and a resin component can provide improved moldability and magnets having high performance and high corrosion resistance. Further, the regulation of property values of the magnet composition enables the occurrence of troubles to be avoided during molding, resulting in improved productivity. Furthermore, the use of at least two resins as a resin component in an extruding composition contributes to improvement in moldability and consequently increase in throughput. Furthermore, the use of extrusion, involving setting by cooling, and not compression molding in the production of magnets can provide high-density, high-performance magnets.

Abstract: A rare earth bonded magnet formed by bonding a rare earth magnet powder with a binding resin contains the rare earth magnet powder, and a thermoplastic resin serving as the binding resin in an amount within a range of from 1 to 5 wt. %, and preferably further contains an oxidation inhibitor. As the rare earth magnet powder, for example, at least one of an Sm--Co alloy, an R--Fe--B alloy (where, R represents at least a kind of rare earth elements including Y) and an Sm--Fe--N alloy can be appropriately used. As the thermoplastic resin, for example, polyamide, a liquid crystal polymer, or a PPS is appropriately employed. As the oxidation inhibitor, a chelating agent is appropriately applicable. In such a rare earth bonded magnet, the thermoplastic resin covers the outer surface of the rare earth magnet powder 2, and is present so as to prevent particles of the magnet powder from coming into contact with each other. Such a rare earth bonded magnet should preferably have a void ratio of no more than 2 vol. %.

Abstract: A die for extrusion molding a resin bonding magnet. In the production of the magnet, a molten mixture of a magnetic powder and a resin are introduced into a cavity between an outer die and a mandril to which a magnetic field is applied. A steep temperature gradient along the die axis direction of the molten mixture and the cavity is achieved by making the outer die of a multiple layer structure along the die axis direction, utilizing two or more axially adjacent blocks or sheets made of the same or different materials whereby fluidity of the molten mixture is sufficiently high at the inlet of the cavity to enable the magnetic powder in the molten mixture to be sufficiently orientated in the direction of the magnetic field and then the molten mixture is cooled to a solidified state so that the orientation of the magnetic powder is not disturbed, thereby producing a magnetic having high magnetic properties.

Abstract: A magnetic powder and a permanent magnet are provided which have magnetic properties enhanced by magnetic interaction. Disclosed are a magnetic powder comprising a mixture of two or more powders including a magnetic powder A (residual magnetic flux density: BrA, coercive force: HcA) and a magnetic powder B (residual magnetic flux density: BrB, coercive force: HcB) of which the residual magnetic flux densities and the coercive forces have the following relationships: BrA>BrB and HcA<HcB, and a bonded magnet or a sintered magnet produced from the magnetic powder, and a method for mixing magnetic powders and a process for producing a magnet.

Abstract: A rare earth iron permanent magnet including at least one rare earth element, iron and boron as primary ingredients. The magnet can have an average grain diameter of less than or equal to about 150 .mu.m and a carbon content of less than or equal to about 400 ppm and a oxygen content of less than or equal to about 1000 ppm. The permanent magnet is prepared by casting a molten alloy. In one embodiment, the cast body is heat treated at a temperature of greater than or equal to about 250.degree. C. Alternatively, the material can be cast and hot worked at a temperature of greater than or equal to about 500.degree. C. Finally, the material can be cast, hot worked at a temperature of greater than or equal to about 500.degree. C. and then heat treated at a temperature of greater than or equal to about 250.degree. C. The magnets provided in accordance with the invention are relatively inexpensive to produce an have excellent performance characteristics.

Abstract: A rare earth iron permanent magnet including at least one rare earth element, iron and boron as primary ingredients. The magnet can have an average grain diameter of less than or equal to about 150 .mu.m and a carbon content of less than or equal to about 400 ppm and a oxygen content of less than or equal to about 1000 ppm. The permanent magnet is prepared by casting a molten alloy. In one embodiment, the cast body is heat treated at a temperature of greater than or equal to about 250.degree. C. Alternatively, the material can be cast and hot worked at a temperature of greater than or equal to about 500.degree. C. Finally, the material can be cast, hot worked at a temperature of greater than or equal to about 500.degree. C. and then heat treated at a temperature of greater than or equal to about 250.degree. C. The magnets provided in accordance with the invention are relatively inexpensive to produce an have excellent performance characteristics.