Ricoh Company, Ltd.

Other

Xeikon Manufacturing N.v.

Hachiroh Tosaka

Hiroshi Yamashita

Osamu Uchinokura

Takashi Yoshida

Shinichi Kuramoto

Yoshimichi Katagiri

Tomoyuki Satoh

Masakazu Kinoshita

Hideyuki Yamaguchi

Masae Nakamura

Yoshimi Mizoguchi

Masahide Yamashita

Masanori Suzuki

Hideki Sugiura

Akihiro Kotsugai

Hiroyuki Fushimi

Tomio Kondou

Yuji Natori

Yoshihiro Suguro

Tomiaki Ito

Hitoshi Ueda

Mituo Aoki

Shinichiroh Yagi

Shoichi Sugimoto

A toner is provided including toner particles A having a circularity of greater than 0.93 and not greater than 1.00 and toner particles B having a circularity of from 0.85 to 0.93, wherein the following relationships are satisfied: 70&#x2266;R&#x2266;95, 5&#x2266;R&#x2266;30, 0.014&#x2266;SD&#x2266;0.025, and 0.940&#x2266;ED&#x2266;0.950, wherein R(% by number) represents a ratio of a number of the toner particles A to a total number of toner particles included in the toner, R(% by number) represents a ratio of a number of the toner particles B to the total number of toner particles included in the toner, SD represents a standard deviation of circularity of the toner particles A, and ED represents an average envelope degree of the toner particles B.

Toner, and image forming method and process cartridge using the toner

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

An image formation method for forming an image is proposed, which uses an image formation apparatus capable of performing (1) multi-color image formation and printing by superimposing toner images with different colors by use of a plurality of color toners with different colors, including at least a black toner, and (2) monochrome image formation and printing, using only a black toner, with a maximum transferable amount of each color toner onto the image being in a range of 4&times;10 kg/m to 8&times;10 kg/m , wherein an image glossiness (GKC) obtained by the black toner in the maximum transferable amount thereof at the multi-color image printing, an image glossiness (GCC) obtained by each of the color toners other than the black toner in the maximum transferable amount thereof at the multi-color image printing, and an image glossiness (GKM) obtained by the black toner in the maximum transferable amount thereof at the monochrome image printing satisfy a particular relationship as described in the specification. In addition, the above toners and a printed matter prepared by this image formation method are proposed.

Image formation method, electrophotographic toners, and printed matter

A toner including a binder resin; a colorant; and an external additive, wherein the external additive includes a particulate inorganic material, and a silicone oil, wherein the silicone oil is present on the particulate inorganic material in an amount of Ws by weight and present as a free silicone oil in an amount of Wfs by weight, and a free silicone degree defined as a ratio Wfs/Ws is from 10 to 70%.

Toner, external additive therefor and image forming method using the toner

A toner for developing an electrostatic latent image, which includes ground toner particles having physical properties meeting with at least one of the following conditions (a) and (b):

Toner for developing electrostatic images

A dry toner useful for one component developer developing method is provided which has good image qualities and durability without contamination of developing apparatus. The toner includes a metal oxide in an amount of from about 10 to about 30 parts by weight per 100 parts by weight of the toner and a metal-containing azo dye.

One component developer developing method and dry toner therefor

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Shizuoka, Japan

Hachiroh Tosaka