Patents by Inventor Ryoichi Fujita
Ryoichi Fujita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8524434Abstract: 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.Type: GrantFiled: June 9, 2011Date of Patent: September 3, 2013Assignee: Canon Kabushiki KaishaInventors: Tsuneyoshi Tominaga, Ryoichi Fujita, Tsutomu Shimano
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Patent number: 8460845Abstract: 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 (° C.) Tg(0.5) and Tg(4.0) obtained at a rate of temperature increase of 0.5° C./min or 4.0° C./min satisfy 40.0?Tg(0.5)?60.0 and 2.0?Tg(4.0)?Tg(0.5)?10.0, and wherein, when the concentration of the cyan toner in an ethyl acetate dispersion is Cc1 (mg/ml), and the light absorbance at a wavelength of 712 nm of the dispersion is A(ethyl acetate)712, A(ethyl acetate)712/Cc1<0.15 is satisfied, and wherein, when the concentration of the cyan toner in a chloroform solution is Cc2 (mg/ml), and the light absorbance at a wavelength of 712 nm of the solution is A(chloroform)712, 2.00<A(chloroform)712/Cc2<8.15 is satisfied.Type: GrantFiled: November 12, 2009Date of Patent: June 11, 2013Assignee: Canon Kabushiki KaishaInventors: Takaaki Kaya, Ayako Sekikawa, Ryoichi Fujita, Shigeto Tamura, Makoto Kambayashi
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Publication number: 20110305984Abstract: 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.Type: ApplicationFiled: June 9, 2011Publication date: December 15, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Tsuneyoshi Tominaga, Ryoichi Fujita, Tsutomu Shimano
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Patent number: 7943281Abstract: 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?=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.Type: GrantFiled: April 14, 2006Date of Patent: May 17, 2011Assignee: Canon Kabushiki KaishaInventors: Takaaki Kaya, Yasukazu Ayaki, Shigeto Tamura, Yayoi Tazawa, Ryoichi Fujita, Yuichi Yajima
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Publication number: 20100273102Abstract: The color toner has capsule toner particles each having a surface layer (B) mainly formed of a resin (b) on the surface of a toner base particle (A), the 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 curve 1 obtained by plotting a temperature on an axis of abscissa and the common logarithm of a value obtained by dividing the loss modulus G? 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° C.?Tp?60° C., (2) a temperature Ts at which a curve 2 obtained by differentiating the curve 1 with respect to the temperature twice shows a local minimum is present in the temperature range of Tp+10 (° C.) to Tp+40 (° C.), and (3) a ratio G?(Ts)/G?(Ts+5) in the curve 1 is larger than 3.0.Type: ApplicationFiled: July 8, 2010Publication date: October 28, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Shigeto Tamura, Takaaki Kaya, Ryoichi Fujita, Makoto Kambayashi
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Patent number: 7794908Abstract: 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)<Tg(b); a magnetization (?t) in an external magnetic field of 79.6 kA/m of the magnetic toner is 12 Am2/kg or more and 30 Am2/kg or less; and an average circularity of the toner is 0.960 or more and 1.000 or less.Type: GrantFiled: March 2, 2009Date of Patent: September 14, 2010Assignee: Canon Kabushiki KaishaInventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Makoto Kambayashi, Takeshi Ikeda
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Patent number: 7794909Abstract: 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.Type: GrantFiled: July 6, 2009Date of Patent: September 14, 2010Assignee: Canon Kabushiki KaishaInventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Ayako Sekikawa, Makoto Kambayashi
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Patent number: 7776501Abstract: 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 curve 1 obtained by plotting a temperature on an axis of abscissa and the common logarithm of a value obtained by dividing the loss modulus G? 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° C.?Tp?60° C., (2) a temperature Ts at which a curve 2 obtained by differentiating the curve 1 with respect to the temperature twice shows a local minimum is present in the temperature range of Tp+10(° C.) to Tp+40(° C.), and (3) a ratio G?(Ts)/G?(Ts+5) in the curve 1 is larger than 3.0.Type: GrantFiled: October 3, 2008Date of Patent: August 17, 2010Assignee: Canon Kabushiki KaishaInventors: Shigeto Tamura, Takaaki Kaya, Ryoichi Fujita, Makoto Kambayashi
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Publication number: 20100062355Abstract: 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 (° C.) Tg(0.5) and Tg(4.0) obtained at a rate of temperature increase of 0.5° C./min or 4.0° C./min satisfy 40.0?Tg(0.5)?60.0 and 2.0?Tg(4.0)?Tg(0.5)?10.0, and wherein, when the concentration of the cyan toner in an ethyl acetate dispersion is Cc1 (mg/ml), and the light absorbance at a wavelength of 712 nm of the dispersion is A(ethyl acetate)712, A(ethyl acetate)712/Cc1<0.15 is satisfied, and wherein, when the concentration of the cyan toner in a chloroform solution is Cc2 (mg/ml), and the light absorbance at a wavelength of 712 nm of the solution is A(chloroform)712, 2.00<A(chloroform)712/Cc2<8.15 is satisfied.Type: ApplicationFiled: November 12, 2009Publication date: March 11, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Takaaki Kaya, Ayako Sekikawa, Ryoichi Fujita, Shigeto Tamura, Makoto Kambayashi
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Publication number: 20090263738Abstract: 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.Type: ApplicationFiled: July 6, 2009Publication date: October 22, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Ayako Sekikawa, Makoto Kambayashi
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Publication number: 20090170021Abstract: 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)<Tg(b); a magnetization (?t) in an external magnetic field of 79.6 kA/m of the magnetic toner is 12 Am2/kg or more and 30 Am2/kg or less; and an average circularity of the toner is 0.960 or more and 1.000 or less.Type: ApplicationFiled: March 2, 2009Publication date: July 2, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Makoto Kambayashi, Takeshi Ikeda
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Publication number: 20090035685Abstract: 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 curve 1 obtained by plotting a temperature on an axis of abscissa and the common logarithm of a value obtained by dividing the loss modulus G? 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° C.?Tp?60° C., (2) a temperature Ts at which a curve 2 obtained by differentiating the curve 1 with respect to the temperature twice shows a local minimum is present in the temperature range of Tp+10(° C.) to Tp+40(° C.), and (3) a ratio G?(Ts)/G?(Ts+5) in the curve 1 is larger than 3.0.Type: ApplicationFiled: October 3, 2008Publication date: February 5, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Shigeto Tamura, Takaaki Kaya, Ryoichi Fujita, Makoto Kambayashi
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Publication number: 20090011353Abstract: 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?=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.Type: ApplicationFiled: April 14, 2006Publication date: January 8, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Takaaki Kaya, Yasukazu Ayaki, Shigeto Tamura, Yayoi Tazawa, Ryoichi Fujita, Yuichi Yajima
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Patent number: 7244539Abstract: 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°. A two-component developer is also provided which makes use of the magnetic carrier.Type: GrantFiled: April 29, 2004Date of Patent: July 17, 2007Assignee: Canon Kabushiki KaishaInventors: Yoshinobu Baba, Ryoichi Fujita, Takaaki Kaya, Kazuo Terauchi
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Patent number: 7144668Abstract: 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 3.0–6.5 ?m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 ?m or more of 0.920–0.945; has a BET specific surface area of 2.1–3.5 m2/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 30–80%. 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 15–80 ?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.Type: GrantFiled: March 5, 2004Date of Patent: December 5, 2006Assignee: Canon Kabushiki KaishaInventors: Yoshinobu Baba, Yuko Sato, Ryoichi Fujita, Takaaki Kotaki, Nobuyoshi Sugahara, Kazuo Terauchi, Takayuki Itakura
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Patent number: 6953648Abstract: 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.Type: GrantFiled: April 24, 2003Date of Patent: October 11, 2005Assignee: Canon Kabushiki KaishaInventors: Takeshi Tsujino, Hitosi Kanda, Ryoichi Fujita, Yoshinori Tsuji
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Publication number: 20040253529Abstract: 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°. A two-component developer is also provided which makes use of the magnetic carrier.Type: ApplicationFiled: April 29, 2004Publication date: December 16, 2004Applicant: CANON KABUSHIKI KAISHAInventors: Yoshinobu Baba, Ryoichi Fujita, Takaaki Kaya, Kazuo Terauchi
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Publication number: 20040175643Abstract: 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 3.0-6.5 &mgr;m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 &mgr;m or more of 0.920-0.945; has a BET specific surface area of 2.1-3.5 m2/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 30-80%. 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 15-80 &mgr;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.Type: ApplicationFiled: March 5, 2004Publication date: September 9, 2004Inventors: Yoshinobu Baba, Yuko Sato, Ryoichi Fujita, Takaaki Kotaki, Nobuyoshi Sugahara, Kazuo Terauchi, Takayuki Itakura
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Publication number: 20030232269Abstract: 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.Type: ApplicationFiled: April 24, 2003Publication date: December 18, 2003Inventors: Takeshi Tsujino, Hitosi Kanda, Ryoichi Fujita, Yoshinori Tsuji
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Patent number: 6346356Abstract: A toner is comprised of toner particles containing at least a binder resin, a colorant, a wax component and an oxycarboxylic acid. The toner satisfies the following conditions: 1.05≦A/B≦3.00, and 0.15≦B≦3.50 wherein A (mg) is a weight of oxycarboxylic acid extracted with methanol from 1 g of the toner, and B (mg) is a weight of oxycarboxylic acid extracted with an aqueous 0.1 mol/liter sodium hydroxide solution from 1 g of the toner.Type: GrantFiled: May 17, 2000Date of Patent: February 12, 2002Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Toshiyuki Ugai, Ryoichi Fujita, Shinya Yachi, Yasushi Katsuta, Kenichi Nakayama