Mitsubishi Chemical Corporation

Teruki Senokuti

Teruyuki Mitsumori

Hiroaki Takamura

Kozo Ishio

Shiro Yasutomi

Shiho Sano

Masakazu Sugihara

Yumi Hirabaru

Takeshi Oowada

Masaya Oota

Masaya Ota

A method of forming an image including an electrophotographic photoreceptor and a toner, wherein a photosensitive layer in the electrophotographic photoreceptor includes an undercoat layer including metal oxide particles, a charge generation layer including hydroxygallium phthalocyanine, and a charge transport layer, and the toner contains toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 &#x3bc;m to 7.0 &#x3bc;m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 &#x3bc;m to 3.56 &#x3bc;m satisfies&#x2014;0.0517EXP(22.4/Dv50)&#x2266;Dns&#x2266;0.233EXP(17.3/Dv50) where Dv50 is the volume median diameter (&#x3bc;m) of the toner, and Dns is the percentage in number of toner particles having a particle diameter of from 2.00 &#x3bc;m to 3.56 &#x3bc;m.

Method of image forming with a photoreceptor and toner

An image forming apparatus comprising an electrophotographic photoreceptor having a photosensitive layer on an electroconductive substrate, and a toner for developing an electrostatic charge image, wherein the photosensitive layer of the electrophotographic photoreceptor contains a phthalocyanine obtained via an acid paste step; the toner for developing an electrostatic charge image is a toner for developing an electrostatic charge image containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 &#x3bc;m to 7.0 &#x3bc;m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 &#x3bc;m to 3.56 &#x3bc;m satisfies the following formula (1):&#x2266;0.233 EXP(17.3/50)&#x2003;&#x2003;(1).

Image forming apparatus

To provide an image forming apparatus which is able to improve image quality while suppressing soiling of image white parts, scattering in the apparatus, streaks, fading, etc. due to non-uniformity in the particle size distribution of a toner or mismatching between a toner and a photoreceptor, and which has good cleaning properties, and even when a high speed printing machine is used, is able to reduce a problem of soiling, etc. in long-term use and provide excellent image stability. An image forming apparatus comprising an electrophotographic photoreceptor having a photosensitive layer on an electroconductive substrate, and a toner for developing an electrostatic charge image, wherein the photosensitive layer of the electrophotographic photoreceptor contains a phthalocyanine obtained via an acid paste step; the toner for developing an electrostatic charge image is a toner for developing an electrostatic charge image containing toner matrix particles formed in an aqueous medium; the toner has a volume median diameter (Dv50) of from 4.0 &#x3bc;m to 7.0 &#x3bc;m; and the relationship between the volume median diameter (Dv50) and the percentage in number (Dns) of toner particles having a particle diameter of from 2.00 &#x3bc;m to 3.56 &#x3bc;m satisfies the following formula (1):&#x2266;0.233 EXP(17.3/50)&#x2003;&#x2003;(1).

Growing community of inventors

Joetsu, Japan

Teruki Senokuti