Canon Kabushiki Kaisha

Fujita Co., Ltd.

Ryoichi Fujita

Kenji Okado

Makoto Kanbayashi

Tsuyoshi Takiguchi

Toshiyuki Ugai

Wakashi Iida

Takaaki Kaya

Shigeto Tamura

Tetsuya Ida

Yasuhiro Ichikawa

Masaaki Taya

Shinya Yachi

Kazumi Yoshizaki

Makoto Kambayashi

Yoshinobu Baba

Kazuo Terauchi

Takaaki Kotaki

Yuji Moriki

Ayako Sekikawa

Takeshi Ikeda

Tatsuya Nakamura

Kazuo Yoshinaga

Takayuki Itakura

Michihisa Magome

Manabu Ohno

Yuko Sato

Yushi Mikuriya

Tsutomu Shimano

Tatsuhiko Chiba

Nobuyoshi Sugahara

Akihiko Nakazawa

Tsuneyoshi Tominaga

Masanori Shida

Yasukazu Ayaki

Satoshi Yasuda

Koichi Tomiyama

Kazunori Kato

Hiroaki Kawakami

Yasushi Katsuta

Shuichi Aita

Yoshihiko Hyosu

Kenichi Nakayama

Yoshinori Tsuji

Minoru Shimojo

Kiyoshi Mizoe

Fumihiro Arahira

Takeshi Tsujino

Kohji Inaba

Yoshifumi Hano

Yayoi Tazawa

Yuichi Yajima

Hitosi Kanda

A toner having a toner particle including a core particle obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant, a release agent, a polar resin, and a crystalline polyester in an aqueous medium and an outer shell formed by fixing resin fine particles to the surface of the core particle, wherein the resin constituting the resin fine particles is an amorphous resin and the acid value of the resin fine particles is 4.0 to 50.0 mgKOH/g.

Toner and method for manufacturing toner

Provided is a cyan toner which, while being a capsule-type toner having excellent low-temperature fixability, has excellent offset resistance and charging performance and can obtain high-quality images. A cyan toner having at least a resin (a) having a polyester as a main component, a colorant, and a wax, in which glass transition temperatures (&#xb0; C.) Tg(0.5) and Tg(4.0) obtained at a rate of temperature increase of 0.5&#xb0; C./min or 4.0&#xb0; C./min satisfy 40.0&#x2266;Tg(0.5)&#x2266;60.0 and 2.0&#x2266;Tg(4.0)&#x2212;Tg(0.5)&#x2266;10.0, and wherein, when the concentration of the cyan toner in an ethyl acetate dispersion is Cc(mg/ml), and the light absorbance at a wavelength of 712 nm of the dispersion is A(ethyl acetate)712, A(ethyl acetate)712/Cc&#x3c;0.15 is satisfied, and wherein, when the concentration of the cyan toner in a chloroform solution is Cc(mg/ml), and the light absorbance at a wavelength of 712 nm of the solution is A(chloroform)712, 2.00&#x3c;A(chloroform)712/Cc&#x3c;8.15 is satisfied.

Cyan toner

In a black toner having at least a binder resin and an iron-titanium composite oxide as a colorant; the iron-titanium composite oxide is contained in a specific amount; the black toner has a specific weight average particle diameter and a specific saturation magnetization; the black toner has, in X-ray diffraction thereof, a maximum peak at 2&#x3b8;=from 32.5 to 33.1 degrees, having a half width of 0.25 degree or less. The black toner has, in a proportion of less than 30% by number, an iron-titanium composite oxide having, in a sectional photograph of the toner, a maximum frequency of linearity within the range where the linearity is smaller than 2.4 and having a linearity of 3.0 or more, in regard to the number frequency distribution of the linearity of the iron-titanium composite oxide.

Black toner

An object of the present invention is to provide a spherical toner that has a sharp particle size distribution and a small particle diameter. This is a capsule-type toner that exhibits an excellent low-temperature fixability, while at the same time having a high offset resistance and excellent charging properties and having the ability to provide a high-quality image in which the characters, lines, and dots are precisely defined. The object is achieved by a toner comprising a toner particle that comprises at least (a) resin having polyester as the main component, colorant, wax, and (b) urethane resin, wherein the hydroxyl value per specific surface area of the toner particle is fall into the specific range, and wherein a Tg(0.5) and a Tg(4.0)-Tg(0.5) of the toner fall into specific range.

Toner

Provided is magnetic toner including capsule type toner particles each having a surface layer (B) on a surface of a toner base particle (A) containing at least a binder resin (a) mainly formed of a polyester, a magnetic substance, and a wax, in which, the surface layer (B) includes a resin (b), and the resin (b) includes a resin selected from the group consisting of a polyester resin (b1), a vinyl resin (b2), and a urethane resin (b3); a glass transition temperature Tg(a) of the binder resin (a) and a glass transition temperature Tg(b) of the resin (b) satisfy a relationship of Tg(a)&#x3c;Tg(b); a magnetization (&#x3c3;t) in an external magnetic field of 79.6 kA/m of the magnetic toner is 12 Am/kg or more and 30 Am/kg or less; and an average circularity of the toner is 0.960 or more and 1.000 or less.

The color toner has capsule type toner particles each having a surface layer (B) mainly formed of a resin (b) on the surface of a toner base particle (A) containing at least a binder resin (a), a colorant, and a wax, in which (1) a temperature Tp at which a curveobtained by plotting a temperature on an axis of abscissa and the common logarithm of a value obtained by dividing the loss modulus G&#x2033; of the color toner by the unit of the loss modulus on an axis of ordinate shows a maximum is present, and Tp satisfies the relationship of 40&#xb0; C.&#x2266;Tp&#x2266;60&#xb0; C., (2) a temperature Ts at which a curveobtained by differentiating the curvewith respect to the temperature twice shows a local minimum is present in the temperature range of Tp+10(&#xb0; C.) to Tp+40(&#xb0; C.), and (3) a ratio G&#x2033;(Ts)/G&#x2033;(Ts+5) in the curveis larger than 3.0.

Color toner

A magnetic carrier includes a magnetic material-dispersed resin core containing at least a magnetic material and a binder resin. The surface of the magnetic material-dispersed resin core is coated with a coating material containing at least a fluorine resin and 1 to 40 parts by weight of fine particles based on 100 parts by weight of the fluorine resin. The coating material is in an amount of 0.3 to 4.0 parts by weight based on 100 parts by weight of the magnetic material-dispersed resin core. The magnetic carrier has a contact angle of 95 to 125&#xb0;. A two-component developer is also provided which makes use of the magnetic carrier.

Magnetic carrier and two-component developer

The present invention provides a toner: comprising a binder resin comprising a polyester unit, a colorant, a releasing agent, and inorganic fine particles; has a weight average particle diameter of 3.0&#x2013;6.5 &#x3bc;m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 &#x3bc;m or more of 0.920&#x2013;0.945; has a BET specific surface area of 2.1&#x2013;3.5 m/g; and has a permeability of light of a wavelength of 600 nm in a liquid having dispersed the toner in a 45 vol % methanol aq. of 30&#x2013;80%. The present invention also provides a two-component developer: comprising the toner and a magnetic carrier comprising magnetic core particles coated by a coating layer; and has a number average particle diameter of 15&#x2013;80 &#x3bc;m. Using the toner and the two-component developer enables a high-quality image to be formed at a high speed even in an oilless fixing system.

Toner and two-component developer

A process for producing toner particles, in which toner particles are produced by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer in an aqueous medium in a vessel, is provided. In this process, a resin composition containing a THF-insoluble resin component, which is a resin component generated in the process for producing toner particles, is kneaded. Then, the kneaded material and the polymerizable monomer are mixed together, and the resulting polymerizable monomer is polymerized to produce toner particles. For the resin composition, toner particles different from those having desired property, deposits on the vessel where the polymerization reaction occurred, or the like is used.

Process for producing toner particles

Toner, toner production process, and image-forming method

When a pressure plate of a clutch for motorcycles and the like is moved to engage and disengage driving friction plates and driven friction plates, a rod driver connected to an operation rod is constructed such that a pair of operation members is assembled so as to face a plurality of guide grooves formed on a surface of interposing balls, wherein the plurality of guide grooves is formed along an imaginary circle having a radius of about 19.3 mm on the faces of each of the operation members, and the balls have a diameter of about 9.5 mm. One of the operation members is rotated with respect to the other operation member to separate the operation members because bottom surfaces of the guide grooves are slanted by an angle of between 13.7&deg; through 14.4&deg; from the faces, and centers of the guide grooves are most deep, as much as about 3.872 mm, in the guide grooves, whereby the clutch is securely disengaged in use by a small force.

Clutch for motorcycles

A two-component type developer has a negatively chargeable toner having toner particles and an external additive and a magnetic-fine-particle-dispersed resin carrier. The magnetic-fine-particle-dispersed resin carrier has composite particles containing at least inorganic compound particles and a binder resin. The inorganic compound particles have been surface-treated with a lipophilic-treating agent having at least one type of functional group (A) selected from the group consisting of an epoxy group, an amino group, a mercapto group, an organic acid group, an ester group, a ketone group, an alkyl halide group and an aldehyde group, or a mixture of the agent. The composite particles have been surface-coated with at least one type of coupling agent having at least one type of functional group (B) different from the functional group (A) the lipophilic-treating agent. The functional group (B) the coupling agent has being a functional group or groups selected from the group consisting of an epoxy group, an amino group and a mercapto group. The negatively chargeable toner has a weight-average particle diameter of from 3 &mgr;m to 9 &mgr;m.

Two-component type developer and image forming method

An electrophotographic apparatus includes an electrophotographic photosensitive member, and (i) a charger, (ii) an imagewise exposure device, (iii) a developing device and (iv) a transfer device, disposed in this order opposite to the photosensitive member. The charger includes a charging member including magnetic particles disposed in contact with the photosensitive member so as to charge the photosensitive member based on a voltage received thereby. The magnetic particles are surface-coated with a coupling agent having a linear alkyl group having a least 6 carbon atoms. The developing device also functions to recover residual toner remaining on the photosensitive member processing by the transfer device and the charger. Because of the coating with such a specific coupling agent, the charging magnetic particles can exhibit good triboelectric changeability for the transfer residual toner for a long period.

Electrophotographic apparatus, image forming method, and process cartridge for developing an image with toner containing an external additive

A yellow toner suitable for electrophotography is formed by dispersing a yellow colorant mixture in a binder resin. The yellow colorant mixture is formed of at least a pigment of formula (1) or (2) below, and a dye of formula (3) below:

Yellow toner, process for producing the tower and image forming method using the toner

In the image forming machine of the invention, a two-component type developer has a spherical magnetic powder dispersion type carrier, which has a weight average particle diameter of from 15 to 60 .mu.m. The external additive is present in the form of particles on the toner particle, and comprises inorganic oxide fine particles A having a shape factor SF-1 of from 100 to 130, and non-spherical inorganic oxide fine particles B, having a shape factor SF-1 larger than 150 and particles B having been obtained by combining a plurality of component particles.

Image forming method and image forming apparatus using specific

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Kawasaki, Japan

Ryoichi Fujita