Ricoh Company, Ltd.

Tomiaki Ito

Yuji Natori

Hachiro Tosaka

Tomio Kondou

Hidehiro Mochizuki

Hachiroh Tosaka

Hitoshi Ueda

The toner according to the present invention may be produced from a toner raw composition which comprises a foaming agent, a binder resin and a colorant, wherein the colorant comprises a black metal compound, the foaming agent has a volume-average particle diameter of 2 &#x3bc;m to 50 &#x3bc;m, the toner raw composition turns into a porous mixture while the foaming agent expands at melting and kneading the toner raw composition, and the toner obtained through milling and classifying the porous mixture has a specific density of 1.0 g/cmto 1.3 g/cm, wherein the specific density is determined as follows: 1 gram of toner is pressed at 400 kgf/cmfor five minutes in a discal cavity having a diameter of 20 mm, then the discal toner is removed; the discal toner volume (V) is calculated from the diameter and height, measured at 10 minutes after releasing the pressure on the discal toner, and the discal toner mass (W) is measured; then the specific density is determined from the following formula: Specific Density (&#x3c1;)=W/V.

Toner, developer, container containing toner, process, cartridge, image forming apparatus and process

A toner for developing an electrostatic latent image, including toner particles each containing a black colorant and a binder resin, wherein the black colorant comprises a metal oxide having a number average particle diameter in the range of 20 to 100 nm in an amount of 10 to 40% by weight based on a total weight of the toner particles.

Black toner, image forming method and image forming apparatus using the toner

A continuous crushing method including at least feeding a toner block into a crusher through a screw feeder thereof having a crushing capacity while cyclically increasing and decreasing a feeding amount of the toner block; and crushing the toner block to prepare a toner, in which the feeding amount of the toner block in the increasing cycle is larger than the crushing capacity.

Continuous crushing method and apparatus

A toner having a half melting temperature not greater than 115&deg; C. has good fixability without filming, even in an image forming method using a non-contact fixing method; has good fixability and color reproducibility, even in an image forming method reproducing multi-colored images by combining two or more toner layers of different color; has good heat resistance without impairing fixability and color reproducibility; and produces high quality images without impairing fixability and color reproducibility.

Growing community of inventors

Tagata-gun, Japan

Tomiaki Ito