Canon Kabushiki Kaisha

Other

Keiji Komoto

Akira Hashimoto

Takeshi Kaburagi

Tatsuhiko Chiba

Michihisa Magome

Satoshi Handa

Tsuyoshi Takiguchi

Manabu Ohno

Tsutomu Kukimoto

Yushi Mikuriya

Yasukazu Ayaki

Emi Tosaka

Satoshi Yoshida

Yasushi Katsuta

Kenichi Nakayama

Yuji Moriki

Tatsuya Nakamura

Kenji Okado

Masanori Ito

Shinya Yachi

Eriko Yanase

Atsuyoshi Abe

Hiroaki Kawakami

Yasuhiro Hashimoto

Kaori Hiratsuka

Kiyokazu Suzuki

A toner includes toner particles containing at least a binder resin and a colorant, and inorganic fine particles. The shape factor SF-1 of the toner particles is in a specific range. The toner has a storage elastic modulus at 140&#xb0; C., G' (140&#xb0; C.), in a specific range the toner comes to have a viscosity of 1.0&#xd7;10Pa&#xb7;s according to a flow tester heating method at a temperature of from 115&#xb0; C. or more to less than 130&#xb0; C.

Toner, and image forming method

A toner includes toner particles and an inorganic fine powder mixed with the toner particles. The toner particles contain a binder resin, a coloring agent, a releasing agent, and a sulfur-containing resin. The toner particles contain at least one element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum, and phosphorus and satisfy the relationship:4&#x2266;&#x2266;30wherein T represents the total content of the element in ppm, and S represents the content of sulfur in ppm. The weight-average particle diameter (D) of the toner is in the range of 3 to 10 &#x3bc;m. The average circularity of the toner is within the range of 0.950 to 0.995.

Toner

In a process for producing toner particles by dispersing in an aqueous medium a polymerizable monomer composition containing at least a polymerizable monomer and a colorant and carrying out polymerization by the use of a polymerization initiator, the concentration of alcohol having 4 to 6 carbon atoms in the aqueous medium is so adjusted as to be from 500 ppm to 2,000 ppm when the polymerization conversion of the polymerizable monomer composition is 30%, and to be from 2,300 ppm to 10,000 ppm when the polymerization conversion of the polymerizable monomer composition is 97%.

Process for producing toner particles, and toner

In a non-magnetic toner having non-magnetic toner particles containing at least a binder resin and a colorant, and an inorganic fine powder, the non-magnetic toner particles contain at least one ether compound having a specific structure, and the ether compound is in a content of from 5 ppm to 1,000 ppm.

Non-magnetic toner

A toner having a favorable fixability, excelling in charge stability, and capable of forming a image of retaining a high image density and a high resolution in long-term use is provided. That is, the toner of the present invention is a toner obtained by polymerizing a polymerizable monomer composition comprising a polymerizable monomer and a colorant, in which the polymerizable monomer composition is polymerized using a polymerization initiator comprising a redox initiator which includes an organic peroxide with a 10-hour half-life temperature of 86&#xb0; C. or higher and an reducing agent; the toner has a ratio of a weight-average particle diameter to a number-average particle diameter of 1.40 or less; and the toner has top of a main-peak in a molecular weight range of 5,000 to 50,000 in a molecular weight distribution measured using GPC of the THF-soluble part thereof, including t-butanol with a content of 0.1 to 1,000 ppm.

In an image forming system, an image-bearing member having a photoconductor layer comprising an Si-based non-single crystal material is charged at a relatively low potential of 250 to 600 volts by a contact charging member in the presence of electroconductive fine powder. An electrostatic latent image formed on the image-bearing member is developed with a magnetic toner which includes magnetic toner particles comprising at least a binder resin and a magnetic iron oxide, and inorganic fine powder and electroconductive fine powder present at the surface of the magnetic toner particles. The magnetic toner has a weight-average particle size of 3-10 &#x3bc;m and an average circularity of 0.950 to 0.995, and contains 0.05 to 3.00% of isolated iron-containing particles.

Image forming method and apparatus

In a toner having toner particles containing at least a colorant, a release agent and a polar resin, and an inorganic fine powder, the polar resin contains a polyester resin obtained by carrying out polymerization in the presence of a titanium chelate compound as a catalyst, and has an acid value in a specific range. The toner particles are granulated in an aqueous medium and have a weight-average particle diameter in a specific range.

To provide a method for forming images in which the image bearing member and the toner carrying member are arranged with a gap of 100 &#x3bc;m to 250 &#x3bc;m, and the equation (1) and equation (2) are satisfied. (1) 22&#x2266;(the frequency of the alternating current component of the alternating electric field/the peripheral speed of the toner carrying member)&#xd7;the maximum electric field intensity at the time of developing&#x2266;1.20. (2) 8&#x2266;(the frequency of the alternating current component of the alternating electric field/the peripheral speed of toner carrying member)&#xd7;(the fluidity index of Carr/the floodability index of Carr)&#x2266;50. According to the method for forming images of the present invention, it is possible to obtain a high quality image without generating fog and light shielding while attaining a uniform halftone with a high image density even over long-term.

Method for forming image

A toner suitable for use in electrophotography, etc., is composed of toner particles each containing a binder resin, a colorant and a wax component. The toner has a number-average particle size of 2-6 &mgr;m and a standard deviation in particle size of below 2.6 &mgr;m based on a number-basis distribution of circle-equivalent diameters, an average circularity of 0.970-0.995 and a standard deviation in circularity of below 0.030 based on a circularity frequency distribution, and a residual monomer content of at most 500 ppm. The toner particles have such a microtexture as to provide a particle cross section as observed through a transmission electron microscope (TEM) exhibiting a matrix of the binder resin and a particle of the wax dispersed in a discrete form in the matrix of the binder resin.

Toner for developing electrostatic images and image forming method

A magnetic toner exhibiting stable performances under various environmental conditions is formed of toner particles each comprising at least a binder resin and iron oxide dispersed therein. Relative to the dry specific gravity (A) of the magnetic toner, the magnetic toner is characterized by a specific gravity distribution of toner particle fractions obtainable through wet sedimentation and including: at most 15 wt. % of a fraction having a specific gravity of above (A)&times;1.000 and at most (A)&times;1.025, 0.1-20 wt. % of a fraction having a specific gravity of above (A)&times;0.975 and at most (A)&times;1.000, at least 30 wt. % of a fraction having a specific gravity of above (A)&times;0.950 and at most (A)&times;0.975, 0.1-20 wt. % of a fraction having a specific gravity of above (A)&times;0.925 and at most (A)&times;0.950, and at most 15 wt. % of a fraction having a specific gravity of above (A)&times;0.900 and at most (A)&times;0.925.

Magnetic toner

A magnetic toner is formed of magnetic toner particles each comprising a binder resin, an iron oxide, a sulfur-containing polymer, and inorganic fine powder blended with the magnetic toner particles, the toner having a weight-average particle size (D4) of 3-10 &mgr;m, and either (a) an average circularity of at least 0.970, and a magnetization of 10-50 Am /kg (emu/g) at a magnetic field of 79.6 kA/m (1000 oersted), or (b) toner particles which retain carbon in an amount of A and iron in an amount of B at surfaces thereof, satisfying: B/A<0.001, and containing at least 50% by number of magnetic toner particles of D/C&lE;0.02, wherein C represents a particle projection area-equivalent circle diameter and D represents a minimum distance between a surface of the magnetic toner particle and iron oxide particles contained therein.

A dry toner has toner particles containing at least a binder resin, a colorant and a wax component and an external additive. The binder resin contains a component derived from a monomer selected from butadiene, isoprene and chloroprene. The toner has a main Tg from 40&deg; C. to 70&deg; C. When specific surface area measured by the BET method in an environment of 23&deg; C. atmospheric temperature and 65% relative humidity is represented by A (m /g) and specific surface area measured by the BET method in an environment of 50&deg; C. atmospheric temperature and 3% relative humidity is represented by B (m /g), the toner satisfies the following relationship: 0.8&lE;A&lE;4.0, 0.80&lE;(B/A)&lE;1.05. The toner has a circle-corresponding number-average particle diameter D1 from 2 to 10 &mgr;m, an average circularity from 0.950 to 0.995 and a circularity standard deviation less than 0.040. The toner has a main-peak molecular weight from 2,000 to 100,000 and contains a THF-insoluble matter from 5 to 60% by weight.

Dry toner, dry toner production process, and image forming method

A toner is comprised of a binder resin, a colorant and a wax. The binder resin has a polycarbonate resin in an amount of from 0.1% by weight to 50.0% by weight and a resin other than the polycarbonate resin in an amount of from 50.0% by weight to 99.9% by weight, based on the weight of the binder resin. In molecular weight distribution as measured by gel permeation chromatography of tetrahydrofuran-soluble matter, the toner contains in an amount of 15.0% by weight or less based on the weight of the toner a component which has in its structure a repeating unit of the polycarbonate resin and is contained in components having a molecular weight of 1,000 or less.

Toner and image forming method

A magnetic toner comprising magnetic toner particles containing at least a binder resin, a magnetic material containing a magnetic iron oxide, and a release agent. The magnetic toner has a weight-average particle diameter of from 3 &mgr;m to 10 &mgr;m, a magnetization intensity (saturation magnetization) of from 10 Am /kg to 50 Am /kg (emu/g) under application of a magnetic field of 79.6 kA/m (1,000 oersteds), an average circularity of 0.970 or more, a ratio of weight-average particle diameter to number-average particle diameter, of 1.40 or less, iron and an iron compound which stand liberated from the magnetic toner particles at a liberation percentage of from 0.05% to 3.00%, and a resin component having a tetrahydrofuran-insoluble matter in an amount of from 3% by weight to 60% by weight. Also disclosed is an image-forming method making use of the magnetic toner.

Growing community of inventors

Numazu, Japan

Keiji Komoto