Toyo Ink Manufacturing Company

Fujimi Incorporated

Toyo Ink Mfg. Co., Ltd.

Japan U-pica Company, Ltd.

Yasushi Nakanishi

Hirofumi Iemura

Takaaki Hikosaka

Akira Yamane

Yoshinori Onose

Shigehiro Hayashi

A polyester resin for toner, wherein an acid component of the polyester comprises (1) disproportionated rosin and (2) terephthalic acid and/or isophthalic acid, an alcohol component of the polyester comprises (3) glycidyl ester of tertiary fatty acid and (4) an aliphatic diol containing from 2 to 10 carbon atoms, and a cross-linking component of the polyester comprises a polycarboxylic acid having three or more carboxyl groups and/or a polyol having three or more hydroxyl groups, with the molar ratio of the acid component (1) to the acid component (2), (1)/(2), being from 0.2 to 0.6 and the molar ratio of the alcohol component (3) to the alcohol component (4), (3)/(4), being from 0.05 to 0.4. A toner for developing an electrostatic charge image contains the polyester resin for a toner (binder resin), a colorant and a charge control agent. Further, the invention also relates to an image-forming method using the toner for developing an electrostatic charge image.

Polyester resin for toner, toner for developing electrostatic charge image and method for forming image

An image-forming process, which comprises steps of developing an electrostatic latent image on an inorganic photoreceptor with an electrostatic image developer containing 0.1 to 5.0% by weight, based on the toner particles, of silicon carbide fine powder of 0.2 to 1.5 &#x3bc;m in average primary particle size, 10 to 50 m/g in specific surface area and 10 to 60% in amount of agglomerated particles, said silicon carbide fine powder being contained in an amount of 0.1 to 5.0% by weight, transferring the developed image to a transfer member, then removing residual toner particles on the photoreceptor by means of a cleaning blade.

Electrostatic image developer and image-forming process

An electrostatic image developing toner comprising at least a binder resin and a releasant, wherein the binder resin comprises a petroleum resin and a styrene-based copolymer or styrene-based homopolymer in an amount of 5:5 to 7:3 by weight in terms of the ratio of the petroleum resin:styrene-based copolymer or styrene-based homopolymer and has the maximum molecular weight value (P ) based on the petroleum resin in a range of from 5&times;10 to 2&times;10 and the maximum molecular weight value (P ) based on the styrene-based copolymer or styrene-based homopolymer in a range of from 1&times;10 to 4.5&times;10 in the chromatogram obtained by measuring the binder resin through gel permeation chromatography and the releasant is a wax having a melt viscosity at 140&deg; C. of 10 mPa/s (cp) or less and is added in an amount of 1 to 7 parts by weight per 100 parts by weight of the toner.

Electrostatic image developing toner and image-forming method using the same

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Tokyo, Japan

Yasushi Nakanishi