Patents by Inventor Takayuki Itakura
Takayuki Itakura 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: 10409186Abstract: A toner is provided, where good cleanability is exhibited, abrasion variations of the photo conductor surface is reduced, and contamination of a charge member is reduced. The toner includes toner particles and organic-inorganic composite fine particles on the toner particle surfaces, wherein each of the organic-inorganic composite fine particles is a particle in which inorganic fine particles are exposed at the surfaces of vinyl based resin particles in such a way that convex portions derived from the inorganic fine particles are formed on the surfaces, the average circularity of the toner is 0.960 or more, and the absolute value Q of the amount of triboelectricity of the toner measured by a two-component method and the electrostatic adhesion F of the toner satisfy 0.003?F/Q2?0.040.Type: GrantFiled: July 30, 2014Date of Patent: September 10, 2019Assignee: Canon Kabushiki KaishaInventors: Yojiro Hotta, Shohei Tsuda, Taiji Katsura, Masaharu Miura, Yoshinobu Baba, Takayuki Itakura
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Patent number: 10039698Abstract: An object of the present invention is to provide a tooth-cleaning composition having a high remineralizing effect on demineralized dental enamel. The tooth-cleaning composition contains a wax and a calcium phosphate, wherein a content of the calcium phosphate is 0.001 to 33% by mass.Type: GrantFiled: January 14, 2016Date of Patent: August 7, 2018Assignee: KABUSHIKI KAISHA SANGIInventors: Takayuki Itakura, Rimiko Takikawa, Mariko Obuki, Rie Takamatsu
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Patent number: 9715188Abstract: 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.Type: GrantFiled: July 30, 2014Date of Patent: July 25, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Kazuo Terauchi, Koji Nishikawa, Shohei Tsuda, Yojiro Hotta, Katsuhisa Yamazaki, Takayuki Itakura, Takeshi Naka, Motohide Shiozawa
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Publication number: 20170189287Abstract: An object of the present invention is to provide a tooth-cleaning composition having a high remineralizing effect on demineralized dental enamel. The tooth-cleaning composition contains a wax and a calcium phosphate, wherein a content of the calcium phosphate is 0.001 to 33% by mass.Type: ApplicationFiled: January 14, 2016Publication date: July 6, 2017Inventors: Takayuki ITAKURA, Rimiko Takikawa, Mariko Obuki, Rie Takamatsu
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Patent number: 9594323Abstract: A toner having toner particles, each of which contains a binder resin, a wax and inorganic fine particles, wherein the inorganic fine particles are fixed at the surface of the toner particles as a result of a surface treatment by hot air, and the degree of uneven distribution of wax in the toner is controlled in a depth direction of the toner, from the toner surface towards a toner central portion.Type: GrantFiled: January 25, 2016Date of Patent: March 14, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Kosuke Fukudome, Yoshiaki Shiotari, Takayuki Itakura
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Patent number: 9588450Abstract: 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.Type: GrantFiled: July 30, 2014Date of Patent: March 7, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Shohei Tsuda, Koji Nishikawa, Katsuhisa Yamazaki, Yojiro Hotta, Kazuo Terauchi, Motohide Shiozawa, Takeshi Naka, Takuya Mizuguchi, Takayuki Itakura
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Patent number: 9575425Abstract: 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.Type: GrantFiled: July 29, 2014Date of Patent: February 21, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Takeshi Naka, Kazuo Terauchi, Motohide Shiozawa, Yojiro Hotta, Shohei Tsuda, Katsuhisa Yamazaki, Koji Nishikawa, Takayuki Itakura
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Publication number: 20160202621Abstract: A toner is provided, where good cleanability is exhibited, abrasion variations of the photo conductor surface is reduced, and contamination of a charge member is reduced. The toner includes toner particles and organic-inorganic composite fine particles on the toner particle surfaces, wherein each of the organic-inorganic composite fine particles is a particle in which inorganic fine particles are exposed at the surfaces of vinyl based resin particles in such a way that convex portions derived from the inorganic fine particles are formed on the surfaces, the average circularity of the toner is 0.960 or more, and the absolute value Q of the amount of triboelectricity of the toner measured by a two-component method and the electrostatic adhesion F of the toner satisfy 0.003?F/Q2?0.040.Type: ApplicationFiled: July 30, 2014Publication date: July 14, 2016Inventors: Yojiro Hotta, Shohei Tsuda, Taiji Katsura, Masaharu Miura, Yoshinobu Baba, Takayuki Itakura
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Publication number: 20160139523Abstract: A toner having toner particles, each of which contains a binder resin, a wax and inorganic fine particles, wherein the inorganic fine particles are fixed at the surface of the toner particles as a result of a surface treatment by hot air, and the degree of uneven distribution of wax in the toner is controlled in a depth direction of the toner, from the toner surface towards a toner central portion.Type: ApplicationFiled: January 25, 2016Publication date: May 19, 2016Inventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Kosuke Fukudome, Yoshiaki Shiotari, Takayuki Itakura
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Publication number: 20160091809Abstract: 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.Type: ApplicationFiled: July 30, 2014Publication date: March 31, 2016Inventors: Shohei Tsuda, Koji Nishikawa, Katsuhisa Yamazaki, Yojiro Hotta, Kazuo Terauchi, Motohide Shiozawa, Takeshi Naka, Takuya Mizuguchi, Takayuki Itakura
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Publication number: 20160070192Abstract: 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.Type: ApplicationFiled: July 30, 2014Publication date: March 10, 2016Inventors: Kazuo Terauchi, Koji Nishikawa, Shohei Tsuda, Yojiro Hotta, Katsuhisa Yamazaki, Takayuki Itakura, Takeshi Naka, Motohide Shiozawa
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Patent number: 9256148Abstract: A toner having toner particles, each of which contains a binder resin, a wax and inorganic fine particles, wherein the inorganic fine particles are fixed at the surface of the toner particles as a result of a surface treatment by hot air, and the degree of uneven distribution of wax in the toner is controlled in a depth direction of the toner, from the toner surface towards a toner central portion.Type: GrantFiled: November 24, 2011Date of Patent: February 9, 2016Assignee: CANON KABUSHIKI KAISHAInventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Kosuke Fukudome, Yoshiaki Shiotari, Takayuki Itakura
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Patent number: 9034549Abstract: A toner is provided that exhibits a satisfactory heat-resistant storability and an excellent low-temperature fixability. The toner has toner particles each of which contains at least a binder resin and a wax, and is characterized in that this toner is obtained by attaching a metal compound to the surface of the toner particle and thereafter performing a surface treatment with a hot air current; the binder resin contains at least a polyester resin; and the metal compound is formed by coordinating or bonding a specific aromatic oxycarboxylic acid to a metal.Type: GrantFiled: December 9, 2011Date of Patent: May 19, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Yoshiaki Shiotari, Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Kosuke Fukudome, Takayuki Itakura
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Publication number: 20150125790Abstract: A magnetic toner having a toner particle containing a binder resin and a magnetic member, a first inorganic fine particle and an organic-inorganic composite particle on the surface of the toner particle, wherein the organic-inorganic composite particle i) has a structure in which a second inorganic fine particle is embedded in a resin particle, and ii) is contained in an amount of 0.5 mass % or more and 3.0 mass % or less based on the mass of the toner; the first inorganic fine particle contains an inorganic oxide fine particle selected from the group consisting of a silica fine particle, a titanium oxide fine particle and an alumina fine particle; has a number average particle diameter (D1) of 5 nm or more and 25 nm or less, and contains the silica fine particle in an amount of 85 mass % or more based on the inorganic oxide fine particle.Type: ApplicationFiled: January 13, 2015Publication date: May 7, 2015Inventors: Yojiro Hotta, Koji Nishikawa, Shohei Tsuda, Motohide Shiozawa, Takeshi Naka, Kazuo Terauchi, Katsuhisa Yamazaki, Takayuki Itakura
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Patent number: 8986914Abstract: An object of the present invention is to improve resistance to wraparound during fixing while achieving both low-temperature fixability and resistance to hot offset. A further object is to suppress image density variations and fogging in white background regions during use at high print coverage rate at high temperature and high humidity. A toner containing inorganic fine particles and toner particles containing a binder resin and a wax being provided, the toner being characterized in that the binder resin contains a polyester resin A obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aromatic diol and a polyester resin B obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aliphatic diol, and in that the degree of segregation of the wax in the toner depth direction from the toner surface toward the toner center is controlled.Type: GrantFiled: September 15, 2011Date of Patent: March 24, 2015Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Yoshiaki Shiotari, Koh Ishigami, Kentaro Kamae, Takayuki Itakura
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Publication number: 20150037719Abstract: 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.Type: ApplicationFiled: July 29, 2014Publication date: February 5, 2015Inventors: Takeshi Naka, Kazuo Terauchi, Motohide Shiozawa, Yojiro Hotta, Shohei Tsuda, Katsuhisa Yamazaki, Koji Nishikawa, Takayuki Itakura
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Publication number: 20150037720Abstract: Provided is magnetic toner capable of favorably maintain fluidity of the magnetic toner in a developing unit even after a large number of image formation. The magnetic toner to which an external additive that has 1) a number average particle diameter of 70 or more and 200 or less, 2) a shape factor SF-1 of 100 or more and 250 or less, and 3) a shape factor SF-2 of 105 or more and 250 or less, is added, and a covering rate by silica on the surfaces of toner particles is 40.0% or more and 70.0% or less, and the magnetic toner has specific fluidity.Type: ApplicationFiled: July 29, 2014Publication date: February 5, 2015Inventors: Shohei Tsuda, Yojiro Hotta, Kouji Nishikawa, Shotaro Nomura, Katsuhisa Yamazaki, Masami Fujimoto, Takayuki Itakura
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Publication number: 20150003875Abstract: An object of the present invention is to provide a two-component developer which can achieve a high-definition image with a smaller toner laid-on level than a conventional one, provides a color gamut comparable to that of printing, can respond to an increase in printing speed, and allows an image with a stable tinge to be formed even in long-term use. The object can be achieved by a two-component developer containing a cyan toner and a magnetic carrier, the two-component developer being characterized in that the cyan toner has the following characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.Type: ApplicationFiled: July 10, 2014Publication date: January 1, 2015Inventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Publication number: 20140113228Abstract: A toner has a weight-average particle diameter (D4) of 3.0 ?m or more and 8.0 ?m or less, wherein the average circularity analyzed by dividing particles of the toner having an equivalent circle diameter of 1.98 ?m or more and less than 200.00 ?m into 800 in a range of a circularity of 0.200 or more and 1.000 or less is 0.960 or more and 0.985 or less, the proportion of particles A having a circularity of 0.990 or more and 1.000 or less is 25.0% or less on a basis of the number of particles, and the ratio of particles B having an equivalent circle diameter of 0.50 ?m or more and less than 1.98 ?m to the total particles having an equivalent circle diameter of 0.50 ?m or more and less than 200.00 ?m is 10.0% or less on a basis of the number of particles.Type: ApplicationFiled: May 30, 2012Publication date: April 24, 2014Applicant: CANON KABUSHIKI KAISHAInventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura
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Publication number: 20130288174Abstract: A toner is provided that exhibits a satisfactory heat-resistant storability and an excellent low-temperature fixability. The toner has toner particles each of which contains at least a binder resin and a wax, and is characterized in that this toner is obtained by attaching a metal compound to the surface of the toner particle and thereafter performing a surface treatment with a hot air current; the binder resin contains at least a polyester resin; and the metal compound is formed by coordinating or bonding a specific aromatic oxycarboxylic acid to a metal.Type: ApplicationFiled: December 9, 2011Publication date: October 31, 2013Applicant: CANON KABUSHIKI KAISHAInventors: Yoshiaki Shiotari, Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Kosuke Fukudome, Takayuki Itakura