Ricoh Company, Ltd.

Tomomi Harashima

Hiroshi Yamashita

Yuka Mizoguchi

Minoru Masuda

Ryota Inoue

Daichi Hisakuni

Hiroshi Yamada

Junichi Watanabe

Akinori Saitoh

Akio Takei

Toma Takebayashi

Masahiro Yukikawa

A toner includes toner base particles and external additives deposited on a surface of the toner base particle. The toner base particle includes an amorphous polyester resin, a crystalline polyester resin, a release agent, and resin particles. An abundance ratio of the crystalline polyester resin in the surface of the toner base particle as observed by TEM is 2.5% or greater but 25% or less. The resin particles are deposited at the surface of the toner base particle as observed by SEM. A ratio of aggregates of the resin particles occupying the surface of the toner base particle is 1% or greater but 70% or less, where R is a major axis of the minimum particle of the resin particles, and the resin particle having a major axis of 3R or greater is determined as the aggregate.

Toner, developer, toner storage unit, image forming apparatus, and image forming method

A toner includes a crystalline polyester resin and an amorphous polyester resin. A ratio of the storage modulus of the toner G' (T) at a temperature Tto the storage modulus of the toner G′ (T+3) at a temperature T+3 is greater than or equal to 10, in a case where the temperature Tis within a range from 50° C. to 65° C.

Toner, method of manufacturing toner, toner storage unit, image forming apparatus and method of forming image

A toner including: a plate-shaped pigment containing a metal as a main component; and a binder resin containing polyester resin (A) that is insoluble in THF, wherein: a weight average molecular weight (Mw) of a tetrahydrofuran (THF)-soluble component of the toner as determined by gel permeation chromatography (GPC) is 5,000 or higher but 14,000 or lower; and a glass transition temperature (Tg) of a THF-insoluble component of the toner as determined from a differential scanning colorimetry (DSC) curve at first heating in DSC is &#x2212;60&#xb0; C. or higher but 10&#xb0; C. or lower.

Toner, toner stored unit, and image forming apparatus

An image forming apparatus is provided that includes: first and second electrostatic latent image bearers; first and second electrostatic latent image forming devices; first and second developing devices configured to develop first and second electrostatic latent images with a colored toner and a special-color toner to form a colored toner image and a special-color toner image, respectively; a primary transfer device configured to transfer the colored toner image and the special-color toner image onto an intermediate image bearer in an overlapping manner to form a composite toner image; a secondary transfer device configured to transfer the composite toner image onto a recording medium; and a fixing device configured to fix the composite toner image thereon. The special-color toner comprises plate-like and/or film-like pigments. An absolute difference in volume resistivity between the special-color toner and the colored toner is 0.30 log &#x3a9; cm or less.

Image forming apparatus and toner set

Growing community of inventors

Kanagawa, Japan

Tomomi Harashima