Ricoh Company, Ltd.

Daisuke Misawa

Keisuke Tada

Kenichi Uehara

Hiroshi Endoh

Satoshi Kojima

Shingo Sakashita

Junichi Watanabe

Rintaro Takahashi

Tomoki Murayama

Shoki Matsuda

Fumihiko Chimoto

Hiyori Fujino

Miyuki Hirata

Chihiro Kikuchi

Junya Koeda

Ayumi Oikawa

A yellow toner is provided. The yellow toner comprises toner particles each comprising a binder resin and a colorant, and 1.0% to 15.0% by number of the toner particles have a CH rate of 25.0% or more in absolute value. Here, the CH rate is calculated from the following formula (1):rate (%)=[()/]&#xd7;100&#x2003;&#x2003;Formula (1)where Irepresents an integrated intensity within a wavenumber region of from 2,750 to 3,250 cmwhen an intensity at a wavenumber &#x3bb; within a wavenumber region of from 950 to 3,250 cmis normalized to 1 in a Raman spectrum of each toner particle; and Irepresents an average of the I.

Yellow toner, developer, process cartridge, image forming apparatus, and image forming method

An image forming apparatus, including: photoconductor; charging unit; exposing unit; developing unit containing toner; transfer unit; and fixing unit, wherein the toner includes external additive and base particles containing binder resin, colorant, and release agent, the toner has melt viscosity at 100&#xb0; C. of 500 Pa&#xb7;s to 8,000 Pa&#xb7;s and the release agent has melt viscosity at 100&#xb0; C. of 20 mPa&#xb7;s to 30 mPa&#xb7;s, the fixing unit includes fixing member that has roller or belt shape and contacts toner image transferred onto recording medium, and the fixing member includes release layer on surface thereof that is to be brought into contact with the toner image transferred onto the recording medium, and wherein the release layer satisfies the following expressions:45&#x2266;&#x3b8;1&#x2266;60, and10&#x2266;&#x3b8;1&#x2212;&#x3b8;2,

Image forming apparatus

A method for manufacturing a toner, including at least: dissolving or dispersing a toner material including at least any one of a binder resin and a precursor of a binder resin in an organic solvent which is dispersed in a dispersant-including aqueous medium; forming particles by removing the organic solvent; washing the particles; forming voids in the particles by heating to a temperature T while or after dispersing the particles in an aqueous medium; forming toner base particles by adding a charge controlling agent; and adding an external additive to the toner base particles to obtain toner particles, wherein the T is between a glass transition temperature Tg of the toner particles and Tg+25&#xb0; C., and the toner has a cross-sectional void fraction Sp/St of 0.1% to 15.0%, where St is a cross-sectional area of the toner particles, and Sp is a cross-sectional area of the voids.

Method for manufacturing toner, toner and image forming method

A method of manufacturing toner including preparing a first liquid by dissolving or dispersing toner components including one or both of a binder resin and a precursor thereof in an organic solvent; preparing a second liquid by dispersing the first liquid in a first aqueous medium including a dispersant; producing primary particles by removing the organic solvent from the second liquid; washing the primary particles; preparing a third liquid by dispersing the washed primary particles in a second aqueous medium and heating the second aqueous medium while or after dispersing the washed primary particles therein; and producing toner particles by adding a charge controlling agent to the third liquid. This method satisfies the following inequation:0.60&#x2266;&#x2266;1.00wherein Sa represents a BET specific surface area of the primary particles included in the third liquid and Sb represents that of the toner particles stored for 2 weeks at 40&#xb0; C., 70% RH.

Method of manufacturing toner and toner

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Shizuoka, Japan

Daisuke Misawa