Kyocera Document Solutions Inc.

Toshiki Takemori

Yukinori Nakayama

Hiroki Uemura

Masaki Okita

Masanori Sugahara

Takamichi Mori

Kohei Yamauchi

Yoshio Ozawa

Hiroaki Moriyama

Masashi Tamagaki

Masashi Yamashita

Masami Tujihiro

A toner includes a plurality of toner particles and a plurality of lubricant particles. The lubricant particles each include a core and a coat layer covering a surface of the core. The core contains stearic acid, palmitic acid, or a combination thereof. The coat layer has a thickness of at least 10 nm and no greater than 50 nm.

Toner, image forming apparatus, and image forming method

Toner particles each contain a binder resin and a releasing agent. The releasing agent includes an ester mixture. The ester mixture includes an ester and a fatty acid. The ester includes at least one monoester. The monoester is a dehydration condensation product of a monovalent linear saturated carboxylic acid and a monovalent linear saturated alcohol. The fatty acid includes at least one monovalent linear saturated carboxylic acid. The fatty acid includes a monovalent linear saturated carboxylic acid having a carbon number of at least 14 and no greater than 24 but does not include a monovalent linear saturated carboxylic acid having a carbon number of less than 14 or a monovalent linear saturated carboxylic acid having a carbon number of greater than 24. The fatty acid has a melting point of 60&#xb0; C. to 80&#xb0; C. The fatty acid accounts for 5% by mass to 20% by mass of the ester mixture.

Toner

Toner particles of a toner contain a non-crystalline polyester resin, a crystalline polyester resin, a styrene-acrylic acid-based resin, and an ester wax. The crystalline polyester resin has a repeating unit derived from an acrylic acid-based monomer and a repeating unit derived from a styrene-based monomer. The styrene-acrylic acid-based resin has a repeating unit derived from an acrylic acid-based monomer having an amino group and a repeating unit derived from a styrene-based monomer. An amino group ratio in the styrene-acrylic acid-based resin is at least 40% and no greater than 60%. The toner has a storage elastic modulus of at least 1.00&#xd7;10Pa and no greater than 5.00&#xd7;10Pa at 90&#xb0; C. The ester wax has a melting point of at least 60&#xb0; C. and no higher than 80&#xb0; C. A dispersion diameter of the ester wax in the toner particles is at least 500 nm and no greater than 1,000 nm.

Electrostatic latent image developing toner

An electrostatic latent image developing toner includes a plurality of toner particles containing a non-crystalline polyester resin and a crystalline polyester resin. The toner particles contain as the crystalline polyester resin a dispersoid of crystallized crystalline polyester resin (CPES) domains. The CPES domains of the CPES dispersoid have an aspect ratio of at least 3.40 and no greater than 10.0 in terms of number average value. The toner particles have a roundness of at least 0.950 and no greater than 0.970 in terms of number average value. In a cross-sectional image of each of the toner particles, a ratio of a total area occupied by the CPES dispersoid to a cross-sectional area of the toner particle is at least 10.0% and no greater than 30.0%. The non-crystalline polyester resin includes a repeating unit derived from alkenyl succinic anhydride. The crystalline polyester resin includes a repeating unit derived from n-butyl methacrylate.

Toner particles each have a toner core, a shell layer covering a surface of the toner core, and first resin particles containing a melamine resin. A shell layer coverage is 60% to 80%. The first resin particles each have an embedded portion and a protrusion portion. The embedded portions are embedded beneath the surface of the toner core. The protrusion portions protrude outward from the surface of the toner core in a radial direction of the toner particle. An average value Wd of thicknesses b of the shell layers, a number average value Dp of embedment depths c of the first resin particles, and a number average value Pd of primary particle diameters d of the first resin particles satisfy relations (1) to (3) shown below.0.2&#x2264;&#x2264;0.8&#x2003;&#x2003;(1)()&#x3e;&#x2003;&#x2003;(2)0.10 &#x3bc;m&#x2264;&#x2264;1.00 &#x3bc;m&#x2003;&#x2003;(3)

A plurality of toner particles each include a toner core, a shell layer covering a surface of the toner core, and a plurality of magnetic particles penetrating the shell layer. Each of the magnetic particles has an embedded portion and a protrusion portion. The embedded portions are embedded in the surface of the toner core. The protrusion portions are located further outward than the embedded portions in a radial direction of the toner particle and protrude outward from a surface of the shell layer in the radial direction of the toner particle. An average Heywood diameter X of the magnetic particles, a shell layer thickness Y, and an average value Z of protrusion heights of the respective magnetic particles satisfy relation (1) and relation (2) shown below.0&#x3c;&#x2264;(/2)&#x2003;&#x2003;(1)10 nm&#x2264;&#x2264;50 nm&#x2003;&#x2003;(2)

Toner, one-component developer, and two-component developer

An electrostatic latent image developing toner includes a plurality of toner particles each having: a sea-like domain substantially formed from a plurality of resins including at least a polyester resin containing an alcohol component having a carbon number of 2-6; and a plurality of island-like domains distributed in an island-like pattern in the sea-like domain. The island-like domains are substantially formed from a resin containing a nigrosine pigment. A dispersion diameter of the island-like domains is 0.1-1.0 &#x3bc;m. The polyester resin containing the alcohol component having a carbon number of 2-6 is contained in the sea-like domain in an amount of 5-50% by mass relative to a total amount of constituent resins (the plurality of resins). A ratio of an SP value of the resins forming the sea-like domain to an SP value of the resin forming the island-like domain is no greater than 0.98 or at least 1.20.

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 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.

Electrostatic latent image developing toner includes at least a binder resin and a releasing agent. In the electrostatic latent image developing toner, a maximum thermal expansion coefficient difference (Sw&#x2212;Sr), which is a difference between a maximum value (Sw) of a thermal expansion coefficient of the releasing agent and a maximum value (Sr) of a thermal expansion coefficient of the binder resin, is 1 or more, and a temperature at which the thermal expansion coefficient of the releasing agent reaches a maximum is 60&#xb0; C. or more to 75&#xb0; C. or less.

A magnetic toner for developing an electrostatic latent image of the present disclosure includes toner particles each having a toner core containing a binder resin and a magnetic powder, and a shell layer coating a surface of the toner core. The shell layer contains a unit derived from a monomer of a thermosetting resin and a unit derived from a thermoplastic resin. The thermosetting resin is one or more resins selected from the group of amino resins consisting of a melamine resin, a urea resin, and a glyoxal resin. The amount of iron eluted from the toner core (iron concentration in a filtrate) measured by a specified method is 10 mg/L or less.

Magnetic toner for developing electrostatic latent image

A toner for developing electrostatic images contains a binder resin, a colorant, a release agent, and a charge control agent. The release agent contains a wax having a polar group. The toner for developing electrostatic images has tan &#x3b4; of 1 to 2 at a temperature of 80&#xb0; C. to 145&#xb0; C. as measured with a viscoelasticity measuring apparatus at a frequency of 10 Hz and a shear stress of 500 Pa, and has a breaking point of 180&#xb0; C. or less in a temperature-tan &#x3b4; curve.

Toner for developing electrostatic images

Domains of a charge control resin are formed by dispersing a charge control resin containing a quaternary ammonium salt functional group-containing resin of a copolymer of an addition-polymerizable monomer having a quaternary ammonium salt functional group and a styrene and/or acrylic monomer into a polyester resin as binder resin, and the proportion of the number of domains of the charge control resin with a domain diameter of no less than 0.01 &#x3bc;m to less than 0.3 &#x3bc;m versus the number of domains of the charge control resin with a domain diameter of no less than 0.01 &#x3bc;m, which is measured by a predetermined method, is adjusted to no less than 98% by number.

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Osaka, Japan

Toshiki Takemori