Powdertech Co., Ltd.

Mitsui Minings & Melting Co., Ltd.

Other

Mtg Co., Ltd.

Hiromichi Kobayashi

Yuji Sato

Tsuyoshi Itagoshi

Toshio Honjo

Takao Sugiura

Takeshi Gondo

Kanao Kayamoto

Issei Shinmura

Takashi Hikichi

Koji Aga

Yoichi Kamikoriyama

Kenji Suzuoka

Tomoyuki Suwa

Kazuya Kinoshita

Takashi Nakashima

Takeshi Naito

Yasuhiko Kataoka

Tsuyoshi Matsushita

Yasushige Nakamura

Yoshimichi Katagiri

Tetsuya Uemura

Seijiro Ishimaru

Toru Iwata

Masahiro Ogata

Tadashi Harayama

Shinichi Matsuda

A magnetic powder to be included in a cosmetic agent being removable by a magnetic attraction force from the cosmetic agent applied to the skin. The magnetic powder comprises a ferromagnetic ferrite, a mean volume particle diameter of 50 to 75 &#x3bc;m when determined from a particle size distribution obtained by a laser diffraction scattering method, a content of particles with a particle diameter of less than 37 &#x3bc;m of 15% by mass or less, and a content of particles with a particle diameter of 105 &#x3bc;m or more of 5% by mass or less. The magnetic powder preferably has a saturation magnetization of 80 Am/kg or more.

Magnetic powder for cosmetic agent

A ferrite core material for a resin-filled type carrier, and a resin-filled type carrier which is used as an electrophotographic developer by mixing a toner, sufficiently secure the image density, have no carrier adhesion and can maintain high-quality images over a long period, and an electrophotographic developer using the carrier, are provided. A ferrite core material for a resin-filled type carrier characterized in a void fraction of 10 to 60%, a resin-filled type carrier filled in the carrier core material with a resin, and an electrophotographic developer composed of the resin-filled type carrier and a toner, are provided.

Ferrite core material for resin-filled type carrier, resin-filled type carrier, and electrophotographic developer using the carrier

Disclosed are a resin-filled ferrite carrier core material for an electrophotographic developer, including a porous ferrite particle, wherein the composition of the porous ferrite particle is represented by the following formula (1), and part of (MgO) and/or (FeO) in the following formula (1) is replaced with SrO; a ferrite carrier obtained by filling a resin in the voids of the ferrite carrier core material; and an electrophotographic developer using the ferrite carrier: 

Resin-filled ferrite carrier core material for electrophotographic developer, ferrite carrier and electrophotographic developer using the ferrite carrier

A resin-filled carrier for an electrophotographic developer obtained by filling resin into voids of a porous ferrite core material, wherein the porous ferrite core material has a pore volume of 0.055 to 0.16 mL/g and a peak pore size of 0.20 to 0.7 &#x3bc;m, and an electrophotographic developer using this resin-filled carrier.

Resin-filled carrier for electrophotographic developer, and electrophotographic developer using the resin-filled carrier

Employed are a resin-filled ferrite carrier for an electrophotographic developer filled with a resin in voids of a porous ferrite core material, wherein the resin filled in the voids is a silicone resin which has a softening point of 40&#xb0; C. or above and is cured at or above such softening point, and the filled amount is 7 to 30 parts by weight based on 100 parts by weight of the core material, a method for producing thereof band an electrophotographic developer using this ferrite carrier.

Resin-filled ferrite carrier for electrophotographic developer, production method thereof and electrophotographic developer using the ferrite carrier

A resin-filled carrier for an electrophotographic developer obtained by filling resin into voids of a porous ferrite core material, wherein the porous ferrite core material has a pore volume of 0.04 to 0.16 mL/g and a peak pore size of 0.9 to 2.0 &#x3bc;m, and an electrophotographic developer using this resin-filled carrier.

Disclosed are a ferrite carrier for electrophotographic developer and an electrophotographic developer using the ferrite carrier, wherein: the ferrite carrier is a composite ferrite composed of Li and Mg; when the composition of the ferrite is calculated as a mixture of a Li ferrite having a stoichiometric composition and a Mg ferrite having a stoichiometric composition, the excessive amount of FeOis less than 5 mol %, or the total excessive amount of LiO and MgO is less than 1 mol %; the content of the elements other than Li, Mg, Fe and O is 2 % by weight or less; and further, the content of Mn in terms of element is 1000 to 9000 ppm.

Ferrite carrier for electrophotographic developer and electrophotographic developer

A granulating method for forming a particle with a continuous ink-jet method using a liquid material, in which the liquid material containing a solid component and a binder component is supplied into one or more ink-jet nozzles of a continuous ink-jet device, a droplet is formed by having the supplied liquid material flow out the ink-jet nozzle, the droplet is carried in to drying means for drying the droplet, and the carried droplet is dried so as to obtain a granulated particle(s), the granulated particle(s) and a granulating device.

Granulating method, granulated particle(s) and granulating device

An object of the present invention is to provide a quality inspection method for obtaining a specifying factor which can more reliably indicate powder characteristics of a core material for an electrophotographic ferrite carrier. The method includes measuring an impedance of the core material for the electrophotographic ferrite carrier to obtain a Cole-Cole plot in which a real number impedance is arranged in an X-axis and an imaginary number impedance is arranged in a Y-axis, and evaluating characteristics of particles of the core material for the electrophotographic ferrite carrier using the Cole-Cole plot.

Method for inspecting quality of core material for electrophotographic ferrite carrier

It is contemplated to provide irregular shaped ferrite carrier which has a lower resistance, a high specific surface area, a low specific gravity and a longer operational life, and an electrophotographic developer comprising the ferrite carrier which prevents the toner scattering, has a high image density, and is responsive to high-speed and color imaging. The irregular shaped ferrite carrier is characterized in that the carrier particles are irregular shaped, and 40 percent by number or more of the particles have a rock candy sugar shape and/or an oyster shell shape, and that the shape factor (SF-1=R/S&#xd7;&#x3c0;/4&#xd7;100, wherein R is a maximum length and S is a projected area.) is 140 to 250, and the distribution width (&#x3b4;) is 60 or less.

Irregular shaped ferrite carrier and electrophotographic developer using the ferrite carrier

A carrier for an electrophotographic developer which is used as an electrophotographic developer in a mixture with a toner and which secures sufficiently the image density and can maintain high-quality images for a long period, and an electrophotographic developer using the carrier, are provided. A resin-filled ferrite carrier for electrophotographic developer obtained by filling, with a resin, avoid of a porous ferrite core whose void continues from the surface to reach the interior of the core, the carrier comprising a plurality of three-dimensional laminate structures in which resin layers and ferrite layers are alternately present, and an electrophotographic developer including the carrier and a toner, are employed.

Carrier for electrophotographic developer, and electrophotographic developer using the same

A carrier core material containing at least one metal oxide (MO) having a melting point of not higher than 1000&#xb0; C. and at least one metal oxide (MO) having a melting point of not lower than 1800&#xb0; C., wherein the metal (M) for constituting the metal oxide (MO) has an electrical resistivity of not less than 10&#x3a9;&#xb7;cm. Also disclosed is a two-component developing agent comprising a coated carrier, which comprises the carrier core material coated with a resin, and toner particles. Further disclosed is an image forming method comprising developing an electrostatic latent image formed on a photosensitive member with the two-component developing agent using an alternating electric field. The carrier core material and the coated carrier have high magnetization and are free from occurrence of leakage of electric charge over a wide range of electric field from low electric field to high electric field. According to the two-component developing agent, an excellent image can be formed.

Carrier core material, coated carrier, and two-component developing agent for electrophotography

A carrier for electrophotographic developer comprises a resin carrier core comprising a binder resin and magnetic powder dispersed in the binder resin, and a coating layer comprising a coating resin on a surface of the core, the binder resin being a silicone resin obtained by curing of a polysiloxane compound (A) having an epoxy group and a polysiloxane compound (B) having a group capable of reacting with the epoxy group, due to a ring-opening addition reaction; the binder resin containing a functional group which is an epoxy group and/or a group capable of reacting with an epoxy group; the coating resin containing a functional group capable of reacting with the functional group of the binder resin; the functional group of the coating resin and the function group of the binder resin forming a chemical bond.

Carrier for electrophotographic developer and two-component electrophotographic developer

A ferrite carrier for the electrophotographic developer containing 40 to 500 ppm of zirconium; a method for preparing a ferrite carrier for the electrophotographic developer, comprising the steps for weighing, mixing, and pulverizing ferrite raw materials, and for granulating, drying, and firing the obtained slurry; wherein a zirconium raw material is added so that the zirconium content after firing becomes 40 to 500 ppm; and an electrophotographic developer using the ferrite carrier.

Ferrite carrier for electrophotographic developer and method for preparing the same, and electrophotographic developer using the same

Provided are a carrier for electrophotography developers prepared by generating a slight amount of byproducts such as water, alcohol, etc, which carrier is free from release of a magnetic powder, has excellent mechanical strength and durability, and good environmental stability, and further can restrain occurrence of toner spent condition and has favorable fluidity and excellent capability of imparting charging to a toner, a two-component developer comprising the carrier and a method for forming an image using the developer. The carrier for electrophotography developers comprises a magnetic powder dispersed binder resin, the binder resin material comprises (A) a polysiloxane compound having an epoxy group as a functional group and (B) a polysiloxane compound having a group capable of ring-opening addition reaction with the epoxy group of the polysiloxane compound (A), and the binder resin is a silicone resin prepared by curing with ring-opening addition reaction of the epoxy resin. The developer comprises the carrier for electrophotography developers and the toner particle. The method for forming an image comprises developing a static latent image by the developer with an alternating electric field.

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Kashiwa, Japan

Hiromichi Kobayashi