Mita Industrial Co., Ltd.

Kazushige Inoue

Toru Takatsuna

Takashi Nagai

Yumiko Sano

Yoshihisa Kuramae

Yukihiro Mori

Akiyoshi Urano

Kazuhito Takaoka

Seiji Kado

Hiroko Higuchi

Masatoshi Uehara

Etsuro Nakagawa

This invention provides an electrophotographic toner comprising the polyester resin being fixing resin and the electric charge control resin having the functional group that endows positively charging property to the toner, in which the polyester resin has an acid value of not more than 10 mgKOH/g and a hydroxyl value of not more than 40 mgKOH/g, and the functional group is present in 2 to 5 mol % in the electric charge control resin. This electrophotographic toner has stable positively charging property, so that good image is obtainable.

Electrophotographic toner and contact development method using the toner

There is disclosed a positive charging type electrophotographic toner comprising a fixing resin, and a colorant and an electric charge controlling material, which are contained in the fixing resin, the electric charge controlling material being an electric charge controlling resin comprising a polymer which is compatible with the fixing resin, a molecular-weight distribution of the polymer resembling a molecular-weight distribution of a weight-average molecular weight of not more than 20,000 in the molecular-weight distribution of the fixing resin, and a group corresponding to a quaternary ammonium salt being contained at the side chain of the polymer. This toner is superior in charging properties, fixing properties, offset resistance and strength, because a resin having a quaternary ammonium salt group is used as the electric charge controlling material.

Electrophotographic toner

The present invention provides a toner 1 for non-magnetic one-components developments to be used for a method for non-magnetic one-component contact type development, wherein an apparent density is not less than 0.32 g/cc and when supplying to a developing roller 2 immediately after the consumption at the black solid part, a charged amount is not less than 7 .mu.C/g at an absolute value. This toner is suitable for using in combination with an organic photoconductor and can prevent that a residual image of the black solid part is remained at the half tone part immediately after the development of the black solid part.

Toner for non-magnetic one-component development and method for contact

A black photoconductive toner having sensitivity to light in the wavelength range of semiconductor lasers, the toner containing a resinous binder, photoconductive material, a sensitizer, and a perylene black pigment or yellow, magenta, or cyan quinone dyes.

Black photoconductive toner having sensitivity to light in the

Disclosed is an image forming apparatus in which photosensitive toner remaining on an electrically-conductive drum after the formation of an image is collected and then used again for the subsequent process of forming an image. The apparatus comprises a toner storage unit including a toner feed system and a toner collecting system both disposed within a single housing. The toner feed system feeds toner onto an electrically-conductive drum for the formation of an image. The toner collecting system includes a blade for removing the toner remaining on the conductive drum after the formation of the image, and also includes a transporting paddle or a feeder for delivering the removed toner back to the toner feed system, the toner then being supplied again onto the electrically-conductive drum for the subsequent image-forming process.

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Osaka, Japan

Kazushige Inoue