Canon Kabushiki Kaisha

Nippon Zenn Co. Ltd.

Takaaki Kohtaki

Tadashi Doujo

Makoto Unno

Yushi Mikuriya

Masaaki Taya

Nobuyoshi Sugahara

Yasuhiro Ichikawa

Hiroyuki Kobayashi

Takayuki Itakura

Wakashi Iida

Nozomu Komatsu

Manabu Ohno

Yojiro Hotta

Tetsuya Ida

Koichi Tomiyama

Shunji Suzuki

Nobuyuki Okubo

Kazuhiko Hayami

Tatsuya Nakamura

Masami Fujimoto

Tsuyoshi Takiguchi

Yasutaka Akashi

Yuko Sato

Hiroshi Yusa

Yoichiro Kubo

Masuo Yamazaki

Minoru Shimojo

Toshiyuki Ugai

Takayuki Nagatsuka

Hiromi Mori

Ichiro Ohsaki

Yuichi Mizoh

Kiyomori Oura

Nobuyoshi Sugawara

To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 &#x3bc;m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 &#x3bc;m or more is 0.915 to 0.960; loss tangent tan&#x3b4; (10to 10Hz) of the toner is represented by the following expression:tan&#x3b4; (10to 10Hz)&#x2266;0.0060where the loss tangent tan&#x3b4; is represented by &#x3b5;&#x2033;/&#x3b5;' where &#x3b5;&#x2033; denotes dielectric loss factor and &#x3b5;&#x2032; denotes dielectric constant, and tan&#x3b4; (10to 10Hz) denotes the loss tangent in a frequency range of 10to 10Hz; and a ratio of tan&#x3b4; (10Hz) to tan&#x3b4; (5&#xd7;10Hz) is represented by the following expression:1.05&#x2266;tan&#x3b4; (10Hz)/tan&#x3b4; (5&#xd7;10Hz)&#x2266;1.40where tan&#x3b4; (10Hz) denotes loss tangent at the frequency of 10Hz and tan&#x3b4; (5&#xd7;10Hz) denotes loss tangent at the frequency of 5&#xd7;10Hz.

Black toner with defined loss tangent

To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 &#x3bc;m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 &#x3bc;m or more is 0.915 to 0.960; loss tangent tan &#x3b4; (10to 10Hz) of the toner is represented by the following expression:tan &#x3b4;(10to 10Hz)&#x2266;0.0060where the loss tangent tan &#x3b4; is represented by &#x2208;&#x2033;/&#x2208;' where &#x2208;&#x2033; denotes dielectric loss factor and &#x2208;&#x2032; denotes dielectric constant, and tan &#x3b4; (10to 10Hz) denotes the loss tangent in a frequency range of 10to 10Hz; and a ratio of tan &#x3b4; (10Hz) to tan &#x3b4; (5&#xd7;10Hz) is represented by the following expression:1.05&#x2266;tan &#x3b4;(10Hz)/tan &#x3b4;(5&#xd7;10Hz)&#x2266;1.40where tan &#x3b4; (10Hz) denotes loss tangent at the frequency of 10Hz and tan &#x3b4; (5&#xd7;10Hz) denotes loss tangent at the frequency of 5&#xd7;10Hz.

A toner for electrostatic imaging has a vinyl resin binder with an acid value of 2.5-70 mgKOH/g and (i) a long-chain alcohol with an OH value of 10-120 mg/KOH/g or (ii) a long-chain alkyl carboxylic acid with an acid value of 5-120 mg/KOH/g, wherein the acid value of the resin binder&plus;either (i) OH value of the alcohol or (ii) acid value of the acid>(&frac14;)&times;OH value of the binder.

Toner for developing electrostatic image

A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The toner has viscoelasticity including: a storage modulus at 80&deg; C. (G&prime; ) in a range of 1&times;10 -1&times;10 dN/m , storage moduli at temperatures of 120-180&deg; C. (G&prime; ) in a range of 5&times;10 -1&times;10 dN/m , and loss tangents (tan &dgr;&equals;G&Prime;/G&prime; as a ratio between G&Prime; (loss modulus) and G&prime; (storage molecules)) including a loss tangent at 180&deg; C. (tan &dgr; ) and a minimum of loss tangents over a temperature range of 120-180 &deg; C. (tan &dgr; ) satisfying 1&lE;tan &dgr; /tan &dgr; . The toner further exhibits a thermal behavior providing a heat-absorption curve according to differential scanning calorimetry (DSC) showing a maximum heat-absorption peak temperature in a range of 50-110&deg; C. in a temperature range of 30-200&deg; C.

Toner and full-color image forming method

A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The binder resin comprises a polyester-based resin selected from the group consisting of (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl polymer unit, and (c) a mixture of these resins. The wax is characterized by including a structural unit including an OH group, an amide, or an ester group at a specific position.

Toner

Toner for developing electrostatic image, image forming method and process cartridge

Resin-coated carrier, two-component developer and image forming method

A toner for developing electrostatic images includes a binder resin, a specific long-chain alkyl compound and a specific azo iron complex. The long-chain alkyl compound contains a terminal --OH or --COOH group and from about 35 to 150 (--CH.sub.2 --) groups. The azo iron complex has a cation including 75-98 mol. % of ammonium ion and another ion which is hydrogen, sodium, potassium or mixtures thereof.

Toner for developing electrostatic image, image forming method and

A toner for developing an electrostatic image is constituted by toner particles containing at least a binder resin and a colorant, and particles containing at least one double oxide. The double oxide includes a double oxide (A) represented by the following formula (1):

Toner for developing electrostatic image containing specified double

A toner for developing an electrostatic image is constituted by a resin composition and a colorant. The resin composition includes a high-softening point polyester resin (I) having a softening point of 120.degree.-180.degree. C. a low-softening point polyester resin (II) having a softening point of 80.degree.-120.degree. C., and a long-chain alkyl compound selected from the group consisting of-a long-chain alkyl alcohol principally comprising long-chain alkyl alcohol components having long-chain alkyl groups of 23 to 252 carbon atoms and a long-chain alkyl carboxylic acid principally comprising long-chain alkyl carboxylic acid components having long-chain alkyl groups of 22 to 251 carbon atoms. The resin composition preferably includes a tetrahydrofuran (THF)-soluble content providing a gel permeation chromatogram showing a weight-average molecular weight (Mw) of at least 10.sup.5, a ratio of Mw to number-average molecular weight (Mn) of at least 35 and an areal percentage of at least 5% of a region of molecular weight of at least 2.times.10.sup.5.

A toner for developing an electrostatic image is constituted by a binder resin and a colorant. The toner is characterized by a percentage change .sub.G' of at most 50% as calculated by the following formula (1):

A developer for developing an electrostatic image is constituted by an insulating magnetic toner, inorganic fine powder and a flowability-improving agent having a BET specific surface area of at least 30 m.sup.2 /g. The insulating magnetic toner has a weight-average particle size (t-D.sub.4) of 4-14 .mu.m, a number-average particle size (t-D.sub.1) of 1-10 .mu.m, and a ratio (t-D.sub.4)/(t-D.sub.1) of 1.01-2. The inorganic fine powder has a weight-average particle size (m-D.sub.4) of 0.6-5 .mu.m, a number-average particle size (m-D.sub.1) of 0.5-4 .mu.m, and a ratio (m-D.sub.4)/(m-D.sub.1) which is in the range of 1.0-2.4 and is equal to or larger than the ratio (t-D.sub.4)/(t-D.sub.1). The inorganic fine powder is contained in an amount which is 2-8 times that of the flowability-improving agent by weight. The developer is able to retain stable developing performances by effecting suppressing preferential consumption of a particular particle size fraction in a long term of successive copying.

Developer containing insulating magnetic toner flowability-improving

An image forming apparatus and a process cartridge includes a toner for developing an electrostatic image that is constituted by at least a binder resin and a charge control agent. The binder resin has an acid value of 5-50. The charge control agent includes an iron complex represented by the following formula: ##STR1## wherein X.sub.1 and X.sub.2 independently denote hydrogen atom, lower alkyl group, lower alkoxy group, nitro group or halogen atom; m and m' denote an integer of 1-3; R.sub.1 and R.sub.3 independently denote hydrogen atom, C.sub.1-18 alkyl or alkenyl, sufonamide, mesyl, sulfonic acid group, carboxy ester group, hydroxy, C.sub.1-18 alkoxy, acetylamino, benzoylamino or halogen atom; n and n' denote an integer of 1-3; R.sub.2 and R.sub.4 denote hydrogen atom or nitro group; and A.sup.+ denotes hydrogen ion, sodium ion, potassium ion or ammonium ion. The toner has a weight-average particle size (D.sub.4) of 4-9 .mu.m and including toner particles having a particle size of 5 .mu.m or smaller at 3-90% by number, toner particles having a particle size of 6.35-10.08 .mu.m at 1-80% by number and toner particles having a particle size of 12.7 .mu.m or larger at a percentage by volume of at most 2.0%, wherein the toner particles having a particle size of 5.0 .mu.m or smaller are contained at N % by number and at V % by volume satisfying a relationship:

Toner for developing electrostatic image, forming apparatus and process

A toner for developing an electrostatic image is constituted by at least a binder resin and a charge control agent. The binder resin has an acid value of 5-50. The charge control agent comprises an iron complex represented by the following formula: ##STR1## wherein X.sub.1 and X.sub.2 independently denote hydrogen atom, lower alkyl group, lower alkoxy group, nitro group or halogen atom; m and m' denote an integer of 1-3; R.sub.1 and R.sub.3 independently denote hydrogen atom, C.sub.1-18 alkyl or alkenyl, sufonamide, mesyl, sulfonic acid group, carboxy ester group, hydroxy, C.sub.1-18 alkoxy, acetylamino, benzoylamino or halogen atom; n and n' denote an integer of 1-3; R.sub.2 and R.sub.4 denote hydrogen atom or nitro group; and A.sup.+ denotes hydrogen ion, sodium ion, potassium ion or ammonium ion. The toner has a weight-average particle size (D.sub.4) of 4-9 .mu.m and including toner particles having a particle size of 5 .mu.m or smaller at 3-90% by number, toner particles having a particle size of 6.35-10.08 .mu.m at 1-80% by number and toner particles having a particle size of 12.7 .mu.m or larger at a percentage by volume of at most 2.0%, wherein the toner particles having a particle size of 5.0 .mu.m or smaller are contained at N % by number and at V % by volume satisfying a relationship:

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Yokohama, Japan

Takaaki Kohtaki