Canon Kabushiki Kaisha

Kazuhiko Hayami

Nozomu Komatsu

Yasuhiro Ichikawa

Takayuki Itakura

Hirohide Tanikawa

Wakashi Iida

Yojiro Hotta

Tetsuya Ida

Akira Hashimoto

Takaaki Kaya

Nobuyoshi Sugahara

Takaaki Kotaki

Hiroyuki Fujikawa

Takaaki Kohtaki

Koh Ishigami

Takakuni Kobori

The present invention relates to a toner which has good property such as fixability, coloring power, developability, durability, and environmental stability and so on. More specifically, the present invention relates to a color toner containing at least a binder resin, a colorant, and a wax, in which: a wax concentration of an extract obtained by dispersing the toner into n-hexane at a concentration of 15 mg/cmat 23&#xb0; C. and by subjecting the resultant dispersion to extraction treatment at 23&#xb0; C. for 1 minute is in the range of 0.080 to 0.500 mg/cm; an average circularity of particles each having a circle-equivalent diameter of 3 &#x3bc;m or more in the toner is in the range of 0.925 to 0.965; and a content of the wax is in the range of 1 to 15 parts by mass with respect to 100 parts by mass of the binder resin.

Color toner and two-component developer

The present invention provides a yellow toner which is excellent in transparency of an image formed on an OHP sheet, excellent in color reproducibility even when a light-pressure fixing unit is employed, excellent in coloring power and charge property, and is reduced in occurrence of filming. The present invention also provides a yellow toner having excellent durability and capable of contributing to the simplification or miniaturization of the constitution of an image forming apparatus. The yellow toner of the invention comprises a binder resin and a colorant, the binder resin contains at least a polyester unit, and the toner in the powder state has a lightness L* satisfying the relationship of L*&#x3e;87 and has a chromaticity b* satisfying the relationship of 106&#x3c;b*&#x3c;120.

Yellow toner, image forming apparatus and a method for producing a toner

A color toner that comprises at least a binder resin, a colorant and a release agent, wherein the binder resin has at least a polyester unit and is synthesized in the presence of a tin compound as a catalyst represented by the general formula (1):(RCOO)Sn&#x2003;&#x2003;(1)wherein, R is an alkyl group of 5 to 15 carbon atoms. The toner is excellent in charge build-up, resistance to high temperature offset, color reproducibility and transparency.

Color toner

A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.

Color toner, and full-color image-forming method

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

In a color toner having toner particles which have toner base particles containing a binder resin, a colorant and a wax, and inorganic fine particles, (i) in the toner base particles, particles having a circle-equivalent diameter of 3.00 &#x3bc;m or more as measured with a flow type particle image analyzer have an average circularity of from 0.920 or more to less than 0.950, (ii) in the particles having a circle-equivalent diameter of 3.00 &#x3bc;m or more in the toner base particles, particles having a circularity of 0.960 or more are in a number frequency cumulative value of 40% or less; and (iii) in the particles having a circle-equivalent diameter of 3.00 &#x3bc;m or more in the toner base particles, particles having a circularity of 0.920 or less are in a number frequency cumulative value of 30% or less. Also disclosed is a full-color image forming method making use of the toner.

A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the. wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.

Color toner, and full-color image forming method

A toner having toner particles each comprising at least a binder resin, a wax, and a colorant is used in an image forming apparatus which has a fixing means comprising a belt-shaped heating member and a pressurizing member. The binder resin contains a resin formed by a reaction between an epoxy group of a vinyl resin (A) having the epoxy group and a carboxyl group of a resin (B) having at least a polyester unit and the carboxyl group. The toner has a storage elastic modulus at a temperature of 80&#xb0; C. (G' 80) in the range of 1&#xd7;10to 1&#xd7;10Pa and has a storage elastic modulus at a temperature of 160&#xb0; C. (G&#x2032; 160) in the range of 1&#xd7;10to 1&#xd7;10Pa.

Toner and image forming apparatus

Provided is toner which is excellent in developing property, transferring property, and fixing property, hardly affected by its surrounding, and has good endurance. The toner has a peak temperature of maximum endothermic peak in the range of 60 to 100&#xb0; C. in an endothermic curve of differential scanning calorimetry (DSC) measurement;

Toner

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.

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Shizuoka, Japan

Kazuhiko Hayami