Sharp Kabushiki Kaisha Corporation

Satoru Ariyoshi

Yasuhiro Shibai

Katsuru Matsumoto

Yoshitaka Kawase

Kiyoshi Toizumi

Nobuhiro Maezawa

Junichiro Nakayama

Kunio Kojima

Keiichi Kikawa

Yoritaka Tsubaki

Masahiko Kubo

Takanori Kamoto

Yoshinori Yamamoto

Yoshihiro Yamamoto

Tadashi Une

Kensuke Goto

Yoshihiko Minamiyama

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 having good dispersibility of a pigment and a release agent therein and having excellent low temperature fixability is provided. The toner includes a binder resin, a pigment and a release agent, and the binder resin includes a graft polymer in which abietic acids and an unsaturated fatty acid are grafted to a vinyl resin. An image is formed using such a toner.

Toner

A toner capable of ensuring cleanness and the amount of specific charge for extended periods of time and having excellent charge stability and fixing property, a two-component developer, a developing device and an image forming apparatus are provided. A toner includes toner particles containing at least a binding resin and a coloring agent, and fine silicon-containing oxide particles having an average primary particle size of not smaller than 70 nm but not larger than 150 nm and containing water in an amount of not larger than 2.0% by weight, the fine silicon-containing oxide particles being externally added to the toner particles.

Toner, two-component developer, developing device and image forming apparatus

A toner comprising: a component consisting of a thermoplastic resin containing an amorphous plant-derived resin having a carboxyl group; a component consisting of a crystalline epoxy resin having a glycidyl group; a component consisting of a cross-linked resin generated through a reaction between the carboxyl group of the plant-derived resin and the glycidyl group of the crystalline epoxy resin; and a colorant.

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

A toner in which even a toner containing crystalline polyester exhibits excellent fixing property, chargeability, color reproducibility, and long-term stability, as well as a two-component developer, a developing device, and an image forming apparatus are provided. The toner includes toner base particles which contain a colorant and a binder resin containing at least crystalline polyester and an amorphous resin; and a mixed oxide of aluminum oxide and silicon dioxide externally added to the toner base particles, and the toner is so adjusted that the binder resin contains 20% by weight to 50% by weight of the crystalline polyester and that a compositional proportion of aluminum oxide in the mixed oxide of aluminum oxide and silicon dioxide falls within a range of 35% by weight or more and less than 50% by weight.

Toner, two-component developer, developing device, and image forming apparatus

A toner has columnar particles manufactured through: a kneading step of melt-kneading toner raw materials including at least binder resin, colorant and a release agent to prepare a kneaded product; a spinning step of extruding the kneaded product from orifices disposed at the tip of a spinning nozzle to prepare a fibrous kneaded product; and a pulverizing step of cutting or pulverizing the fibrous kneaded product, the toner matrix particles each having an aspect ratio of 0.5 to 5.0 and a d/dvalue of 0.5 or above and contain an external additive composed of large particles and small particles having a volume average particle size smaller than that of the large particles, as well as to provide each of the columnar particles with each having 10 or less reentrants whose apertures have a longer length in a minor axis thereof than a radius of the respective large 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.

Toner manufacturing method

There is provided a method of manufacturing a toner, using a shearing force for granulation, in which bubbles are prevented from arising upon application of the shearing force, thus manufacturing a diameter-reduced toner having a particle diameter of about 5 &#x3bc;m which is favorable for enhancement in definition and resolution of images. Upon granulating after a kneaded product of toner raw material is mixed with water dispersion, an interior part of granulating system is heated and pressurized and moreover, both of the shearing force and collision force are applied to the kneaded product of toner raw material by use of a high-speed rotating dispersion type granulator composed of a cylindrical pressure-resistant container, a spinning rotor, following screens, and a fixed screen.

Method of manufacturing toner

A kneaded material obtained by heating and melt-kneading a toner composition and a water-based medium containing water are put into a container of a granulating apparatus, and heated by a heater while agitating, to disperse the kneaded material into the water-based medium in its softened state. A temperature at which a loss tangent value of the kneaded material reaches a predetermined loss tangent value A, specifically, 0.5 or more and less than 5.0, is inputted to a granulating temperature input section as a setting granulating temperature T. The heater is then controlled by a control section so that a granulating temperature as a temperature of the water-based medium measured by a thermometer reaches the setting granulating temperature Tinputted to the input section. Accordingly, the granulating temperature as a temperature of the water-based medium, and thus a temperature of the kneaded material in the water-based medium is adjusted to T

Method for manufacturing toner

Resin particles containing at least binding resin and wax particles having a diameter of 30 to 600 nm are coagulated, and a resulting coagulated product is heated. Such wax particles are manufactured, for example, by way of a coarse particle preparing step, a slurry preparing step, a pulverizing step, a cooling step, and a depressurizing step. Slurry of wax coarse particles obtained by way of the coarse particle preparing step and the slurry preparing step is directed under heat and pressure through a pressure-resistant nozzle whereby the wax coarse particles are pulverized into the wax particles at the pulverizing step. The cooling step and the depressurizing step are disposed just after the pulverizing step to prevent the wax particles from coarsening.

Method for manufacturing toner and toner

A toner of excellent anti-hot offsetting property, with no variety of the charging performance and suitable as a toner for the development of electrostatic images, and a manufacturing method thereof are provided. At first, a crosslinked resin at least containing a tetrahydrofuran insoluble component and a colorant are dry-kneaded. Next, the obtained kneaded resin product is mixed with an aqueous dispersant solution prepared in advance and they are heated, to form colorant-containing resin particles in a liquid mixture of the kneaded resin product and the aqueous dispersant solution. Then, the liquid mixture is cooled and the colorant-containing resin particles are separated from the liquid mixture.

Toner and manufacturing method thereof

A method of manufacturing a toner for developing static charges in an aqueous system is provided which includes preparation step for a resin kneaded product, preparation step for the aqueous dispersion of a less water-soluble alkaline earth metal salt, preparation step for synthetic resin particles, removal step for the less water-soluble alkaline earth metal salt, and separation-cleaning-drying step. At preparation step Sfor synthetic resin, an ionic material for decomposing the less water-soluble alkaline earth metal salt is admixed with a mixture of the resin kneaded product and the aqueous dispersion of the less water-soluble alkaline earth metal salt.

Method of manufacturing a toner

Cross-linked type organic fine particles are used as organic fine particles having a core-shell structure to be attached to a base particle, and the cross-linking degree of the core part is made higher than that of the shell part. A toner is manufactured by mixing cross-linked type organic fine particles having a core-shell structure with a solution containing a neutralizer, dispersing a composition for forming a base particle, which contains a releasing agent and a colorant, into the solution in which the organic fine particles are mixed, and separating the composition from the solution.

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Nara, Japan

Satoru Ariyoshi