Kyocera Document Solutions Inc.

Masaki Okita

Hiroki Uemura

Yukinori Nakayama

Toshiki Takemori

Takamichi Mori

Masashi Yamashita

A positively chargeable toner includes a plurality of toner particles. The toner particles each contain a crystalline polyester resin, a non-crystalline polyester resin, a carnauba wax, and a quaternary ammonium salt. The crystalline polyester resin has an SP value of at least 10.0 (cal/cm)and no greater than 10.1 (cal/cm). An amount of the crystalline polyester resin is at least 5 parts by mass and no greater than 19 parts by mass relative to 100 parts by mass of the toner particles. An amount of the carnauba wax is at least 21.0% by mass and no greater than 42.0% by mass relative to a total mass of the crystalline polyester resin, the quaternary ammonium salt, and the carnauba wax.

Positively chargeable toner

Cores of toner particles contain a non-crystalline polyester resin, a carnauba wax, and a crystalline polyester resin (polymer of monomers including alcohol, carboxylic acid, styrene-based monomer, and acrylic acid-based monomer) having an SP value ((cal/cm)) of at least 10 and no greater than 11. Shell layers each include a resin film mainly constituted by a complex of resin particles having a glass transition point of at least 50&#xb0; C. and no greater than 100&#xb0; C. A Ru-dyed ratio of the toner particles in a state in which no external additive is present is at least 50% and no greater than 80%. An intensity of an absorbency peak around a wavenumber of 701 cmis at least 0.0100 and no greater than 0.0250. Surface adsorption forces (F: coated regions, F: exposed regions) satisfy '0 nN&#x3c;F', '50 nN&#x2264;F&#x2264;70 nN', and &#x201c;35 nN&#x2264;F&#x2212;F&#x2264;65 nN&#x201d;.

Electrostatic latent image developing toner

Toner particles contain a non-crystalline polyester resin, a crystalline polyester resin, a styrene-acrylic acid-based resin, and a releasing agent. An amount of the releasing agent contained in the toner is at least 7.5% by mass and no greater than 12.5% by mass. An amount of the styrene-acrylic acid-based resin contained in the toner is at least 50 parts by mass and no greater than 100 parts by mass relative to 100 parts by mass of the releasing agent. The crystalline polyester resin includes an acrylic acid-based unit and a styrene-based unit. The styrene-acrylic acid-based resin includes an acrylic acid-based unit that has an epoxy group and a styrene-based unit. A peak top molecular weight of the toner in a differential molecular weight distribution curve is at least 8,000 and no greater than 12,000. A mass average molecular weight of the toner is at least 40,000 and no greater than 65,000.

A positively chargeable toner for electrostatic latent image development includes toner particles. The toner particles each include a toner core containing boron nitride and a shell layer disposed over a surface of the toner core. The boron nitride is contained in an amount of no less than 0.05% by mass and no greater than 35% by mass relative to total mass of the toner core. The boron nitride has a thermal conductivity of no less than 40 W/m&#xb7;K and no greater than 220 W/m&#xb7;K.

Positively chargeable toner for electrostatic latent image development

An electrostatic latent image developing toner includes a plurality of toner particles each containing a binder resin. The toner particles each contain as the binder resin, a crystalline polyester resin and a non-crystalline polyester resin. An FT-IR spectrum of the electrostatic latent image developing toner obtained through FT-IR analysis based on an ATR method has an absorbency peak of at least 0.0100 and no greater than 0.0250 in a wave number range of 701 cm&#xb1;1 cm.

An electrostatic latent image developing toner includes toner particles that each include a toner core containing a binder resin and a shell layer disposed over a surface of the toner core. The binder resin includes a crystalline polyester resin and an amorphous polyester resin. The crystalline polyester resin has a melting point of at least 80&#xb0; C. and no greater than 120&#xb0; C. When the electrostatic latent image developing toner is measured using a differential scanning calorimeter, a glass transition point is observed in a first run but is not observed in a second run. The shell layer contains a resin including a thermosetting component and a thermoplastic component.

An electrostatic latent image developing toner includes toner particles. Each of the toner particles includes a toner core containing a binder resin and a releasing agent, and a shell layer coating the toner core. The releasing agent has a melting point Mpof no less than 50&#xb0; C. and no greater than 100&#xb0; C. The releasing agent has a number average dispersion diameter of no less than 30 nm and no greater than 500 nm. The shell layer is made from a resin including a unit derived from a monomer of a thermosetting resin. The thermosetting resin is one or more amino resins from among a melamine resin, a urea resin, and a glyoxal resin.

A toner for developing an electrostatic latent image, the toner comprising: a releasing agent; and a binder resin, wherein: the releasing agent includes at least a first releasing agent material and a second releasing agent material, the first releasing agent material having a different melting point compared to the second releasing agent material; and a differential scanning calorimetric curve, obtained by measuring the toner for developing the electrostatic latent image by means of a differential scanning calorimeter, exhibits a shoulder at a temperature in a range of 50&#xb0; C. to 53&#xb0; C. corresponding to a glass transition temperature of the toner for developing the electrostatic latent image, and also exhibits a local maximum point at a temperature in a range of 90&#xb0; C. to 95&#xb0; C.

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Osaka, Japan

Masaki Okita