Patents by Inventor Yayoi Tazawa
Yayoi Tazawa 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: 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: 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: 7049039Abstract: A coloring agent for use in toners which comprises coloring particles modified with a surface modifier having in one molecule a hydrophilic moiety, a hydrophobic moiety, and a reactive moiety between the hydrophilic moiety and the hydrophobic moiety. Also disclosed is a toner comprising toner particles containing at least a binder resin and a coloring agent comprising the above surface-modified coloring particles.Type: GrantFiled: May 21, 2002Date of Patent: May 23, 2006Assignee: Canon Kabushiki KaishaInventors: Yayoi Tazawa, Yasukazu Ayaki
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Patent number: 6808855Abstract: A toner production process comprising the step of polymerizing a polymerizable monomer in the presence of (i) base particles containing at least a binder resin and (ii) a polymerization initiator. The polymerization initiator has in one molecule a hydrophilic moiety and a hydrophobic moiety and a reactive moiety between them, and the base particles are enlarged and/or surface-modified upon polymerization of the polymerizable monomer. Also disclosed is a toner having a circularity of from 0.92 to 1.0, which is produced by this process.Type: GrantFiled: May 23, 2002Date of Patent: October 26, 2004Assignee: Canon Kabushiki KaishaInventors: Yasukazu Ayaki, Hitoshi Itabashi, Yayoi Tazawa
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Patent number: 6566028Abstract: A toner is comprised of toner particles composed of at least a binder resin and a clorant, wherein the toner particles each have a coating layer formed on their surfaces in a state of particulate matters being stuck to one another. The particulate matters contains at least a silicon compound.Type: GrantFiled: July 16, 2001Date of Patent: May 20, 2003Assignee: Canon Kabushiki KaishaInventors: Yayoi Tazawa, Takeshi Ikeda, Yoshinobu Baba, Hitoshi Itabashi, Yuzo Tokunaga, Yasukazu Ayaki
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Publication number: 20030073020Abstract: A toner production process comprising the step of polymerizing a polymerizable monomer in the presence of (i) base particles containing at least a binder resin and (ii) a polymerization initiator. The polymerization initiator has in one molecule a hydrophilic moiety and a hydrophobic moiety and a reactive moiety between them, and the base particles are enlarged and/or surface-modified upon polymerization of the polymerizable monomer. Also disclosed is a toner having a circularity of from 0.92 to 1.0, which is produced by this process.Type: ApplicationFiled: May 23, 2002Publication date: April 17, 2003Inventors: Yasukazu Ayaki, Hitoshi Itabashi, Yayoi Tazawa
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Publication number: 20030027071Abstract: A coloring agent for use in toners which comprises coloring particles modified with a surface modifier having in one molecule a hydrophilic moiety, a hydrophobic moiety, and a reactive moiety between the hydrophilic moiety and the hydrophobic moiety. Also disclosed is a toner comprising toner particles containing at least a binder resin and a coloring agent comprising the above surface-modified coloring particles.Type: ApplicationFiled: May 21, 2002Publication date: February 6, 2003Inventors: Yayoi Tazawa, Yasukazu Ayaki
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Publication number: 20020197551Abstract: A toner is comprised of toner particles composed of at least a binder resin and a clorant, wherein the toner particles each have a coating layer formed on their surfaces in a state of particulate matters being stuck to one another. The particulate matters contains at least a silicon compound.Type: ApplicationFiled: July 16, 2001Publication date: December 26, 2002Inventors: Yayoi Tazawa, Takeshi Ikeda, Yoshinobu Baba, Hitoshi Itabashi, Yuzo Tokunaga, Yasukazu Ayaki
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Patent number: 6358658Abstract: A toner is comprised of toner particles composed of at least a binder resin and a clorant, wherein the toner particles each have a coating layer formed on their surfaces in a state of particulate matters being stuck to one another. The particulate matters contains at least a silicon compound.Type: GrantFiled: November 18, 1999Date of Patent: March 19, 2002Assignee: Canon Kabushiki KaishaInventors: Yayoi Tazawa, Takeshi Ikeda, Yoshinobu Baba, Hitoshi Itabashi, Yuzo Tokunaga, Yasukazu Ayaki
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Patent number: 6106990Abstract: A process for producing toner particles is conducted by:preparing toner precursor particles containing at least binder resin and coloring agent; andspherizing the toner precursor particles to obtain toner particles;wherein spherizing steps include;(1) dispersing the toner precursor particles in an aqueous medium containing a dispersant, thereby preparing a disperse system (a);(2) dispersing oil droplet particles containing a softening agent into an aqueous medium, thereby preparing a disperse system (b);(3) preparing a mixed disperse system (c) by adding the disperse system (a) to the disperse system (b), and causing the softening agent to be absorbed by the toner precursor particles in the mixed disperse system (c); and(4) removing the softening agent from the toner precursor particles.Type: GrantFiled: July 29, 1999Date of Patent: August 22, 2000Assignee: Canon Kabushiki KaishaInventors: Yayoi Tazawa, Yoshinobu Baba, Hitoshi Itabashi, Yuzo Tokunaga, Yasukazu Ayaki