Canon Kabushiki Kaisha

Kazuo Terauchi

Takeshi Yamamoto

Yojiro Hotta

Takayuki Itakura

Tetsuya Ida

Yoshinobu Baba

Masami Fujimoto

Koji Nishikawa

Motohide Shiozawa

Takeshi Naka

Naoki Okamoto

Keisuke Tanaka

Koh Ishigami

Kosuke Fukudome

Shuhei Moribe

Shohei Tsuda

Noriyoshi Umeda

Takaaki Furui

Ryo Nagata

Satoshi Mita

Katsuhisa Yamazaki

Manami Haraguchi

Kenta Kubo

Takuya Mizuguchi

Hirohide Tanikawa

Yuko Sato

Nobuyoshi Sugahara

Kazuyuki Sato

Ryoichi Fujita

Yu Yoshida

Yusuke Kosaki

Takaaki Kotaki

Hiroyuki Fujikawa

Kunihiko Nakamura

Takaaki Kaya

Shingo Ito

Tsuneyoshi Tominaga

Akane Masumoto

Yasukazu Ikami

Ryuichiro Matsuo

Kousuke Yamamoto

A toner including a toner particle; and an external additive, wherein the external additive contains strontium titanate particle, and when in a projected image of the strontium titanate particle photographed using a scanning electron microscope, a standard deviation of a distance from a center of the projected image to an outline of the projected image is Ds, and a circle-equivalent diameter of the projected image is Da, a value CV calculated by Equation (1) is 0.07 or less,/(/2)&#x2003;&#x2003;(1).

Toner

A toner contains toner particles, titanate fine particles having a Group II element, and hydrotalcite compound fine particles as an external additive and satisfying 10&#x2264;Lt&#x2264;80 and 100&#x2264;Lh&#x2264;Weight average particle diameter (D4) of toner particles&#xd7;0.50, when the number average particle diameter (D1) of primary particles of the titanate fine particles is defined as Lt (nm) and the number average particle diameter (D1) of primary particles of the hydrotalcite compound fine particles is defined as Lh (nm).

A toner including a toner particle and an external additive, wherein the external additive contains an inorganic fine particle A and a silica fine particle; in a surface of the toner observed using a scanning electron microscope, a number-average particle diameter of primary particle of the silica fine particle is from 5 nm to 50 nm, a number-average particle diameter of primary particle of the inorganic fine particle A is at least 10 nm and less than 60 nm, a coverage ratio X1 of the toner surface covered by the silica fine particle is from 60 area % to 95 area %, the inorganic fine particle A is a fine particle of a titanate having a Group 2 element, and a coverage ratio X2 of the toner surface covered by the inorganic fine particle A is from 5 area % to 40 area %.

Provided is toner that contains a toner particle, and an external additive containing a strontium titanate particle, wherein the toner has an average circularity of at least 0.935 and not more than 0.995, the strontium titanate particle has a number-average primary particle diameter of at least 10 nm and not more than 60 nm, the strontium titanate particle has a peak in the range of 39.700&#xb0;&#xb1;0.150&#xb0; and a peak in the range of 46.200&#xb0;&#xb1;0.150&#xb0; in a CuK&#x3b1; x-ray diffraction spectrum obtained in the 2&#x3b8; range of at least 10&#xb0; and not more than 90&#xb0; where &#x3b8; is the Bragg angle, and the ratio of the area Sb of the peak at 46.200&#xb0;&#xb1;0.150&#xb0; to the area Sa of the peak at 39.700&#xb0;&#xb1;0.150&#xb0; is at least 1.80 and not more than 2.30.

A toner comprising an external additive A, and a toner particle containing a binder resin and a colorant, wherein the external additive A: i) is an external additive that has a charge control agent on the surface thereof; ii) has a wall friction angle &#x3b8; calculated from the following formula (1) of not more than 25.0&#xb0;&#x3b8;=&#x3c4;/5.0&#x2003;&#x2003;formula (1);iii) has a number-average particle diameter (D1) of primary particles of at least 70 nm and not more than 500 nm; and iv) has a solidity as given by the following formula (2) of at least 0.40 and not more than 0.90solidity=area of external additive/area of region encompassed by envelope for external additive&#x2003;&#x2003; formula (2).

Toner and method of producing toner

A toner comprising: a toner particle containing a toner base particle containing a binder resin and a colorant, and a resin particle fixed to a surface of the toner base particle; and an inorganic fine particle A, wherein the surface of the toner particle has protruded portions originating in the resin particle, an average length (D) of long sides of the protruded portions is 50 nm to 300 nm, an average Height (H) of the protruded portions is 25 nm to 250 nm, the average long-side length and the average height of the protruded portions satisfies a specific relationship, and an average value of a compactness of the inorganic fine particle A is 0.40 to 0.80, and the attachment rate of the inorganic fine particles A is 0.1% to 5.0% by area.

A toner having compatibility between transfer properties and cleaning properties is provided. A toner wherein a fine particle A containing a primary particle having a number average particle diameter (D1) of 80 nm or more and 400 nm or less is present on the surface of a toner particle at a coverage ratio of 5 to 40%, a fixing rate of 30 to 90% by mass, and a variation coefficient of 0.1 to 0.5 in a region of 0.5 &#x3c0;&#x3bc;m.

Toner and imaging method

The toner comprising a toner particle containing a binder resin and a colorant, an iron oxide particle and an organic-inorganic composite fine particle, wherein the organic-inorganic composite fine particle comprises a vinyl resin particle, and inorganic fine particles which are embedded in the vinyl resin particle, and at least a part of which is exposed at surface of the organic-inorganic composite fine particle; the organic-inorganic composite fine particle has convexes derived from the inorganic fine particles, and wherein: a coverage ratio of the surface of the organic-inorganic composite fine particle with the inorganic fine particle is 20-70%; and the content of the iron oxide particle present on a surface of the toner particle is 0.1-5.0 mass % based on the mass of the toner particle.

Provided is a magnetic toner in which enhancement of initial transfer efficiency and transfer efficiency that is stable during a long-term use are achieved by simultaneously suppressing the friction force between the toner and a drum and the cohesion between toners, and further the degradation in chargeability and fluidity caused by the deterioration of the toner. The magnetic toner includes: a magnetic toner particle; a first external additive; and a second external additive. The first external additive includes an organic-inorganic composite fine particle, a plurality of convexes derived from an inorganic fine particle being present on a surface of the organic-inorganic composite fine particle, and has a number-average particle diameter of 50 nm or more and 500 nm or less. The second external additive includes a silica fine particle and has a number-average particle diameter of 5 nm or more and 30 nm or less. A shear load calculated from a rotation torque is 0.50 kPa or more and 2.00 kPa or less when a disc-shaped disc is pressed against a surface of a magnetic toner powder layer, the magnetic toner powder layer being produced by applying a vertical load of 9.0 kPa to the magnetic toner, under a vertical load of 5.0 kPa, and the disc which is being pressed is rotated, and an absolute value |&#x3b6;(T)&#x2212;&#x3b6;(A1)| of a difference between a zeta potential &#x3b6;(T) of the magnetic toner particle dispersed in water and a zeta potential &#x3b6;(A1) of the first external additive dispersed in water is 50 mV or less.

Magnetic toner

A toner is provided including large particle-diameter external additives with sweep to the concaves of a toner particle suppressed, so that the large particle-diameter external additives function as spacer particles for a long period. The toner includes toner particles which contain a binder resin and magnetic material, and organic-inorganic composite fine particles having a structure including inorganic fine particles embedded in a vinyl resin particle. The presence state of the magnetic material on the toner particle surface satisfies specific conditions and the presence state of the organic-inorganic composite fine particles on the toner surface satisfies specific conditions.

The toner includes toner particles containing a polyester resin A, a polyester resin B and a colorant, the polyester resin A has a polyester portion including a segment capable of forming a crystal structure and a crystal nucleating agent segment, which is bonded to an end of the polyester portion, and the polyester resin B is a resin which is free of any segments capable of forming a crystal structure, the polyester resin B has a weight average molecular weight Mwb by GPC of a THF soluble matter of 3000 or more and 100000 or less, and an SP value Sa ((cal/cm)) of the polyester portion of the polyester resin A and an SP value Sb ((cal/cm)) of the polyester resin B satisfy the following relationships:9.00&#x2266;&#x2266;10.50&#x2212;0.40&#x2266;&#x2266;0.80.

The toner of the present invention includes toner particles containing polyester resins A and B and a colorant, the A has a polyester portion including a portion capable of forming a crystal structure and a crystal nucleating agent portion, which is bonded to an end of the polyester portion, the B is free from any portions capable of forming a crystal structure, in a chart obtained as a result of GPC of a THF-soluble matter of the B, a ratio of a component having a molecular weight of 1500 or less in the B is 5.0 to 15.0% by area, and when an SP value of the polyester portion of the A is represented by Sa ((cal/cm)) and an SP value of the B is represented by Sb ((cal/cm)), the SP values Sa and Sb satisfy the following relationships:9.50&#x2266;Sa&#x2266;11.00&#x2212;0.65&#x2266;&#x2266;0.70.

Provided is a toner exhibiting satisfactory fixability even in high-speed fixing process involving a double-sided printing mechanism, keeping stable toner image even after a conveyance step, and doesn't cause curling to a fixing roller even in thin paper. In a toner including toner particles, each of which contains polyester resins A and B, a coloring agent, and a resin composition C, the resin A includes a crystal nucleating agent bonded to a polyester molecular chain including a moiety capable of forming a crystalline structure. The resin B doesn't include a moiety capable of forming a crystalline structure. The composition C is obtained by copolymerizing a vinyl-based resin component with a polyolefin resin component. SP values the resin A, the resin B, the agent, the polyolefin component, and the vinyl-based component satisfy the particular relationships.

Provided is the following magnetic carrier. The magnetic carrier maintains high developing performance even when the number of sheets to be output is large. Its charge-providing performance hardly reduces even when toner or an external additive is spent on the magnetic carrier. In addition, the magnetic carrier is strong in resistance against standing. The magnetic carrier includes a magnetic carrier core and a resinous coating layer formed on a surface of the magnetic carrier core, in which the resinous coating layer contains a resin composition and silica-alumina composite particles.

Magnetic carrier

Provided is a toner satisfying low-temperature fixing performance and long-term storage stability of fixed images. Further, provided is a toner capable of obtaining toner images excellent in long-term storage stability irrespective of use environments even in the case where images are formed by a high-speed fixing system having low internal pressure of a fixing nip of a fixing device and a high printing speed. The toner includes toner particles containing a binder resin having a resin A and B, and a coloring agent, in which the resin A includes a resin including a moiety capable of forming a crystalline structure; the resin B includes a resin free of a moiety capable of forming a crystalline structure; and &#x394;Hand &#x394;Hsatisfy the expressions:2&#x2266;&#x394;H&#x2266;453[%]&#x2266;{(&#x394;)/&#x394;}&#xd7;100&#x2266;70[%]where &#x394;Hand &#x394;Hrepresent a heat of melting derived from the binder resin measured at a temperature increase speed of 100&#xb0; C./min and 10&#xb0; C./min, respectively.

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Numazu, Japan

Kazuo Terauchi