Sharp Kabushiki Kaisha Corporation

Katsuru Matsumoto

Yasuhiro Shibai

Keiichi Kikawa

Nobuhiro Maezawa

Satoru Ariyoshi

Yoshitaka Kawase

Ayae Nagaoka

Sayaka Fujita

Mikio Kakui

Hisayuki Utsumi

Koichi Toriyama

Kotaro Fukushima

Toshihiko Murakami

Yoshinori Yamamoto

Eiji Tenjiku

Akiko Uchino

A toner includes a binder resin, a colorant, and a benzilic acid compound. The binder resin contains a polyester resin A obtained by subjecting aromatic dicarboxylic acid, rosin and trivalent or higher-valent alcohol as starting materials to polycondensation, a content of the rosin in a sum of the starting materials being 60% by weight or more, and a polyester resin B obtained by subjecting aromatic dicarboxylic acid and polyhydric alcohol as starting materials to polycondensation.

Toner and method for manufacturing the same

A toner includes a binder resin and a colorant. The binder resin contains a polyester resin A obtained by subjecting aromatic dicarboxylic acid, rosin, and trivalent or higher-valent alcohol as starting materials to polycondensation, a content of the rosin in a sum of the starting materials being 60% by weight or more, and a polyester resin B obtained by subjecting aromatic dicarboxylic acid and polyhydric alcohol as starting materials to polycondensation, the polyester resin B having a viscosity of 10Pa&#xb7;s or more and 10Pa&#xb7;s or less at a softening temperature of the polyester resin A, the polyester resin B being contained in an amount of 50 parts by weight or more and 200 parts by weight or less relative to 100 parts by weight of the polyester resin A.

A toner containing a lignin resin, a carbon-neutral biomass polymer having a low environmental load and taking global environmental protection into account, as a constitutional component of a binder resin, and having a wide fixing non-offset range and an excellent fixing property, is provided. The toner contains at least a binder resin, a colorant, and a release agent. Furthermore, in the toner, the binder resin includes a resin A that is a lignin resin and a resin B that is another resin component, and the resin B has a peak top molecular weight of 10to 10and an acid number of 20 or less.

Toner and method of manufacturing the same, two-component developer, developing device and image forming apparatus

There is provided a method of manufacturing coalesced resin particles for obtaining coalesced resin particles by coalescing aggregated resin particles in a grain boundary-free state in a short period of time while keeping a grain size distribution within a narrow range. In a coalescence process, a slurry of aggregated resin particles is flowed through an inside of a pipe under predetermined heating and pressurizing conditions. In a before-cooling decompression process, a slurry of coalesced resin particles flowing through the inside of the pipe in a heat and pressure-applied state is subjected to pressure reduction before it is cooled down to a predetermined temperature in a cooling process. Then, in a decompression process, a coalesced resin particle slurry that has been cooled in the cooling process while being flowed through the inside of the pipe is decompressed to an atmospheric pressure.

Method of manufacturing coalesced resin particles, coalesced resin particles, toner, two-component developer, developing device, and image forming apparatus

A method of manufacturing a toner in which uneven distribution of toner ingredients by subjecting them to fine dispersion is prevented and which is excellent in transferability, cleaning properties, anti-filming properties, anti-blocking properties, high-temperature offset resisting properties and transparency is provided. Melt-kneaded substances include binder resins, colorants and release agents, respectively. The colorant and the release agent are dispersed in the binder resin. The melt-kneaded substance is negatively charged by an anionic dispersant, whereas the melt-kneaded substance is positively charged by a cationic dispersant. An aggregate is formed by heteroaggregation of the melt-kneaded substances. The aggregate is fused by heating and formed into a spherical toner.

Method of manufacturing toner, toner, two-component developer, developing device and image forming apparatus

A toner capable of forming high quality images of excellent image reproducibility at high definition and high resolution, being decreased for the bleed-out of a wax ingredient to the surface, causing less filming to a photoreceptor and offset phenomenon in a high temperature region, is provided. The toner is manufactured by a method including a preliminary pulverizing step of pulverizing a melt-kneaded product of toner raw materials in a liquid to obtain a coarse powder slurry containing a coarse toner powder, a finely pulverizing step of passing the coarse powder slurry through a pressure resistant nozzle under heating and pressurization thereby further pulverizing the coarse toner powder to obtain a fine powder slurry containing a fine toner powder and in a heated and pressurized state, a cooling step of cooling the fine powder slurry, and a depressurizing step of depressurizing the fine powder slurry.

Method of manufacturing toner, toner, two-component developer, developing device, and image forming apparatus

A method of manufacturing toner particles capable of decreasing the manufacturing costs by simplifying the manufacturing apparatus and by decreasing the number of the steps, as well as to provide toner particles, a two-component developer, a developing apparatus and an image forming apparatus are provided. A high-pressure homogenizer is constituted by a tank, a feed pump, a high-pressure pump, a heat exchanger, a nozzle, a first depressurizing module, a cooling unit, a second depressurizing module and a take-out port arranged in this order. A flow path constituted in the first depressurizing module has a straight portion tilted with respect to a direction in which the aqueous slurry passes and a portion for relaxing the flow of the aqueous slurry.

Method of manufacturing toner particles, toner particles, two-component developer, developing device and image forming apparatus

The toner includes a plurality of toner particles containing a binder resin and a colorant. In toner particles, according to measurement by a flow particle image analyzer, the content of small size particles having a circle-equivalent diameter of 0.5 to 2.0 &#x3bc;m is 5% by number or less based on the entire toner particles, the content of medium size particles having a circle-equivalent diameter of more than 2.0 &#x3bc;m and 4.0 &#x3bc;m or less is 20% by number or more and 30% by number or less based on the entire toner particles, and the content of large size particles having a circle-equivalent diameter of more than 4.0 &#x3bc;m and 6.0 &#x3bc;m or less is 50% by number or more and 70% by number or less based on the entire toner particles, and the shape factor of the toner particles SFis 130 or more and 140 or less.

Toner, method of manufacturing toner, developer, two-component developer, developing device, and image forming apparatus

A functional particle is manufactured by a method including an aggregating step, a depressurizing step, and a cooling step. In the aggregating step, the functional particle is obtained by flowing a mixed slurry containing a core particle and a shell particle through a coiled pipeline while heating the mixed slurry to a glass transition temperature or higher of the core particle, to deposit the shell particles on the surface of the core particle. In the depressurizing step, the grain size of the functional particle is controlled and the coarse particle is pulverized to make the grain size of the functional particles uniform. In the cooling step, re-aggregation of the functional particles with unified grain size is prevented.

Functional particle and manufacturing method thereof

A toner in form of aggregate of resin-containing particles is manufactured by aggregating the resin-containing particles which contain binder resin and the colorant, with the aid of an aggregate dispersant containing a polymer in which anionic polar groups are bonded to a main chain. To be specific, salt of divalent or higher valent metal is added to a slurry of the resin-containing particles so that a metal ion and the anionic polar group are bonded to each other, and a temperature of the slurry is increased so that a bond between the anionic polar group and a water molecule is broken. This decreases water-solubility of the polymer so that the resin-containing particles are aggregated.

Aggregate dispersant, method of manufacturing aggregate of resin-containing particles, toner, developer, developing apparatus, and image forming apparatus

A method of manufacturing aggregate particles capable of obtaining aggregate particles having high mechanical strength, small particle size, with narrow particle size distribution width by preventing interfusion of bubbles in the aggregate particles during stirring is provided. Aggregate particles are manufactured by stirring a resin particle slurry including resin particles dispersed in an aqueous medium and contained in a stirring vessel by a stirring section having a impeller and two or more screen members disposed so as to surround the impeller in the stirring vessel and each formed with a plurality of slits and aggregating the resin particles.

Method of manufacturing aggregate particles and toner

There is provided a capsulated toner which has low-temperature fixing ability, good storage stability, excellent charge stability, high fixing strength to a sheet paper, and low consumption, and is capable of forming a color image of high-definition, high-gloss, and high-density. The capsulated toner for electrophotography includes a shell layer containing a cycloolefin copolymer resin and a core particle including a synthetic resin different from the cycloolefin copolymer resin, wherein the capsulated toner has a core/shell type structure.

Capsulated toner having fine particle cycloolefin copolymer resin shell

The aggregated particles are manufactured through a method of manufacturing aggregated particles, which includes an aggregating step, a depressurizing step, and a cooling step. In the aggregating step, a slurry is prepared which contains aggregated particles obtained by flowing an aqueous slurry of resin fine particles having a volume average particle diameter in the range of 0.4 &#x3bc;m to 3 &#x3bc;m through a coiled piping in a heated and pressurized state and thereby aggregating the resin fine particles. In the depressurizing step, the slurry containing the aggregated particles is depressurized, and a particle size control is conducted by disintegrating coarse particles so as to homogenize particle diameters of the aggregated particles. In the cooling step, the slurry containing the aggregated particles of which particle diameters have been homogenized is cooled.

Method of manufacturing aggregated particles

A toner manufacturing method that allows production of toner having desired characteristics with stability in accordance with fusion emulsification technique for obtaining a toner by granulating a resin kneaded product while dispersing it in an aqueous medium. A resin kneaded product containing at least a binder resin and a colorant is mixed with a dispersant/water-containing aqueous medium. The resultant admixture is stirred by an stirring apparatus including a screen with an admixture discharge hole disposed internally of a vessel and a rotor disposed in an stirring space created by the screen.

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Nara, Japan

Katsuru Matsumoto