Canon Kabushiki Kaisha

Masatsugu Fujiwara

Hirohide Tanikawa

Hiroaki Kawakami

Satoshi Yoshida

Toshiaki Nakahara

Kiichiro Sakashita

Kazunori Kato

Yasuo Mitsuhashi

Tsutomu Onuma

Shinji Doi

Naoki Matsushige

Keita Nozawa

Masashi Jinbo

Masayoshi Shimamura

Kuniko Kobayashi

Masashi Jimbo

Ichirou Osaki

Toner for developing electrostatic images and heat fixing method

A toner for developing electrostatic images has toner particles containing a binder resin and a colorant, and fine titanium oxide particles or fine alumina particles. The surfaces of the fine titanium oxide particles or fine alumina particles have been subjected to an organic treatment and have a methanol wettability half value of 55% or more.

Developing method, image forming method, and heat fixing method, with

Toner for developing electrostatic images, two component type developer,

A toner for developing electrostatic images contains toner particles containing at least a binder resin and a colorant as well as a fine powder comprised of base particles on which crystalline low resistance tin oxide films are formed. The crystalline low resistance tin oxide contains less than 100 ppm of antimony, arsenic and phosphorus, and has an oxygen deficiency structure. The toner is excellent in strength and can consistently give high quality images under any environmental conditions.

Toner for developing electrostatic images and image forming method

An image forming process is disclosed which uses a non-magnetic one-component type developer comprising a finder resin and a releasing agent having specific properties. The developer has such advantages as being excellent in low-temperature fixability as well as anti-offset property.

Image forming process, image-forming apparatus, apparatus unit, and

A toner for developing an electrostatic image is constituted by a binder resin and a hydrocarbon wax having a weight-average molecular weight of 800 to 3600. The toner is provided with good fixation characteristics including low-temperature fixability and anti-high temperature offsetting if the toner shows a storage modulus of at least 1.times.10.sup.3 dyn/cm.sup.2, a loss modulus in the range of 5.times.10.sup.2 -5.times.10.sup.4 dyn/cm.sup.2 and a ratio of loss modulus/storage modulus (loss tangent) of below 0.9 as measured under conditions of a frequency of 0.1 Hz and a temperature of 200.degree. C.; and the toner provides a DSC curve, as measured by a differential scanning calorimeter, showing an onset temperature of heat absorption of at most 105.degree. C. and a heat-absorption peak temperature in the range of 90.degree.-120.degree. C. on temperature increase, and a heat evolution peak temperature in the range of 62.degree.-75.degree. C. and a heat evolution peak intensity ratio of at least 2.times.10.sup.-3 on temperature decrease.

Toner for developing electrostatic image

A toner for developing electrostatic images is prepared from a binder resin and a hydrocarbon wax. The toner is provided with improved fixability and anti-offset characteristic by controlling the thermal characteristic of the hydrocarbon wax so as to provide a DSC (differential scanning calorimeter) curve, showing an onset temperature of heat absorption in the range of 50.degree.-110.degree. C. and at least one heat absorption peak P1 in the range of 70.degree.-130.degree. C. giving a peak temperature T.sub.P1 on temperature increase, and showing a maximum heat evolution peak temperature in the range of T.sub.P1 .+-.9.degree. C. on temperature decrease. Correspondingly, the toner provides a DSC curve showing a rising temperature of heat absorption of at least 80.degree. C., an onset temperature of heat absorption of at most 105.degree. C. and a heat absorption peak temperature in the range of 100.degree.-120.degree. C., respectively on temperature increase, and showing a heat evolution peak temperature in the range of 62.degree.-75.degree. C. and a heat evolution peak intensity ratio of at least 5.times.10.sup.-3 on temperature decrease.

Toner for developing electrostatic image and heat-fixing method

A positively chargeable magnetic toner comprises positively chargeable magnetic toner particles having at least a binder resin, a magnetic substance and a charge controlling agent; wherein the binder resin contains (A) a vinyl polymer having carboxyl groups, acid anhydride groups, partial esters thereof or mixtures of the groups and having and an acid value of 5 to 30, and (B) a copolymer obtained by polymerizing at least a diolefin monomer and a vinyl monomer; and wherein the charge controlling agent contains (C) a quaternary ammonium salt and (D) a nigrosine dye or a triphenylmethane dye, the ratio by weight among the components (A), (B), (C) and (D) being within the range of (A):(B):(C):(D)=80 to 30:70 to 20:2.0 to 0.5: 2.0 to 0.1 relative to 100 parts of the total weight of the components (A) and (B). The present invention also provides an image forming process, an image forming apparatus and a facsimile apparatus, all of which use the positively chargeable magnetic toner.

Positively chargeable magnetic toner, image forming process image

A developer for developing electrostatic latent images, comprising a mixture of toner and fine powder of silicic acid wherein the mixture has a ratio of B/A of 0.9 or larger provided that the mixture contains A wt. % thereof of the silicic acid fine powder, and contains B wt. % thereof of the silicic acid fine powder after the mixture has been passed through a 200 mesh-sieve.

Developer with surface treated silicic acid for developing electrostatic

A developer for developing electrostatic images, containing a magnetic toner having a binder resin and magnetic powder, the developer containing 17-60% by number of magnetic toner particles of 5 microns or smaller, containing 1-23% by number of magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of magnetic toner particles of 16 microns or larger; wherein the magnetic toner has a volume-average particle size of 4-9 microns, and the magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following:

Developer in an image forming device having a binding resin and magnetic

An image forming method, comprising the steps of: providing an electrophotographic photosensitive member comprising an organic photoconductor, and a toner-carrying member carrying thereon a magnetic toner disposed opposite to the photosensitive member with a predetermined clearance in a developing region; the photosensitive member comprising at least two species of charge-generating substances and carrying thereon a digital and an analog electrostatic images; carrying the magnetic toner on the toner-carrying member to the developing region while regulating the magnetic toner so as to provide a thickness smaller than the clearance, the magnetic toner having a specific particle size distribution and a volume-average particle size of 4-10 microns; and developing the electrostatic images with the magnetic toner.

Electrophotographic analog and digital imaging and developing using

A developer for developing electrostatic images, comprising a non-magnetic toner, the toner containing 17-60% by number of non-magnetic toner particles of 5 microns or smaller, containing 1-30% by number of non-magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of nonmagnetic toner particles of 16 microns or larger; wherein the non-magnetic toner has a volume-average particle size of 4-10 microns, and the non-magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following formula:

Non-magnetic toner

A developer for developing electrostatic images, comprising a magnetic toner comprising a binder resin and magnetic powder, the developer containing 17-60% by number of magnetic toner particles of 5 microns or smaller, containing 1-23% by number of magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of magnetic toner particles of 16 microns or larger; wherein the magnetic toner has a volume-average particle size of 4-9 microns, and the magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following formula:

Growing community of inventors

Yokohama, Japan

Masatsugu Fujiwara