Patents by Inventor Takeshi Kaburagi
Takeshi Kaburagi 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: 7371494Abstract: The present invention provides a magnetic toner which is hardly influenced by an environment, and with which an image with high quality and excellent resolution can be stably even under low humidity. In the magnetic toner of present invention: I) a ratio of an iron element content to a carbon element content present on the toner particle surface is less than 0.0010; II) 50 number % or more of toner particles satisfy a relationship of D/C?0.02 (C: projected area diameter of toner particles, D: minimum value for a distance between a magnetic iron oxide fine particle and the toner particle surface); and III) 40-95 number % of toner particles satisfy a structure where 70 number % or more of the magnetic iron oxide fine particles in the respective toner particles are present up to a depth of 0.2 time as far as C from the toner particle surface.Type: GrantFiled: September 13, 2004Date of Patent: May 13, 2008Assignee: Canon Kabushiki KaishaInventors: Tatsuhiko Chiba, Michihisa Magome, Eriko Yanase, Takeshi Kaburagi
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Publication number: 20070231718Abstract: A toner includes toner particles containing at least a binder resin and a colorant, and inorganic fine particles. The shape factor SF-1 of the toner particles is in a specific range. The toner has a storage elastic modulus at 140° C., G? (140° C.), in a specific range the toner comes to have a viscosity of 1.0×103 Pa·s according to a flow tester heating method at a temperature of from 115° C. or more to less than 130° C.Type: ApplicationFiled: June 5, 2007Publication date: October 4, 2007Applicant: CANON KABUSHIKI KAISHAInventors: Yuji Moriki, Shinya Yachi, Yushi Mikuriya, Keiji Komoto, Kenichi Nakayama, Takeshi Kaburagi, Emi Tosaka
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Patent number: 7241546Abstract: A toner includes toner particles containing at least a binder resin and a colorant, and inorganic fine particles. The shape factor SF-1 of the toner particles is in a specific range. The toner has a storage elastic modulus at 140° C., G? (140° C.), in a specific range the toner comes to have a viscosity of 1.0×103 Pa·s according to a flow tester heating method at a temperature of from 115° C. or more to less than 130° C.Type: GrantFiled: June 25, 2004Date of Patent: July 10, 2007Assignee: Canon Kabushiki KaishaInventors: Yuji Moriki, Shinya Yachi, Yushi Mikuriya, Keiji Komoto, Kenichi Nakayama, Takeshi Kaburagi, Emi Tosaka
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Patent number: 7160663Abstract: A toner includes toner particles and an inorganic fine powder mixed with the toner particles. The toner particles contain a binder resin, a coloring agent, a releasing agent, and a sulfur-containing resin. The toner particles contain at least one element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum, and phosphorus and satisfy the relationship: 4?T/S?30 wherein T represents the total content of the element in ppm, and S represents the content of sulfur in ppm. The weight-average particle diameter (D4) of the toner is in the range of 3 to 10 ?m. The average circularity of the toner is within the range of 0.950 to 0.995.Type: GrantFiled: March 25, 2004Date of Patent: January 9, 2007Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Yasushi Katsuta, Yushi Mikuriya, Takeshi Kaburagi, Emi Tosaka
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Patent number: 7153625Abstract: In a process for producing toner particles by dispersing in an aqueous medium a polymerizable monomer composition containing at least a polymerizable monomer and a colorant and carrying out polymerization by the use of a polymerization initiator, the concentration of alcohol having 4 to 6 carbon atoms in the aqueous medium is so adjusted as to be from 500 ppm to 2,000 ppm when the polymerization conversion of the polymerizable monomer composition is 30%, and to be from 2,300 ppm to 10,000 ppm when the polymerization conversion of the polymerizable monomer composition is 97%.Type: GrantFiled: April 11, 2005Date of Patent: December 26, 2006Assignee: Canon Kabushiki KaishaInventors: Takeshi Kaburagi, Yushi Mikuriya, Keiji Komoto, Yasushi Katsuta, Kenichi Nakayama
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Patent number: 7112393Abstract: In a non-magnetic toner having non-magnetic toner particles containing at least a binder resin and a colorant, and an inorganic fine powder, the non-magnetic toner particles contain at least one ether compound having a specific structure, and the ether compound is in a content of from 5 ppm to 1,000 ppm.Type: GrantFiled: January 27, 2004Date of Patent: September 26, 2006Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Yushi Mikuriya, Yuji Moriki, Yasushi Katsuta, Kenichi Nakayama, Takeshi Kaburagi, Emi Tosaka, Yasuhiro Hashimoto
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Publication number: 20060204876Abstract: In a process for producing toner particles by dispersing in an aqueous medium a polymerizable monomer composition containing at least a polymerizable monomer and a colorant and carrying out polymerization by the use of a polymerization initiator, the concentration of alcohol having 4 to 6 carbon atoms in the aqueous medium is so adjusted as to be from 500 ppm to 2,000 ppm when the polymerization conversion of the polymerizable monomer composition is 30%, and to be from 2,300 ppm to 10,000 ppm when the polymerization conversion of the polymerizable monomer composition is 97%.Type: ApplicationFiled: May 11, 2006Publication date: September 14, 2006Applicant: CANON KABUSHIKI KAISHAInventors: Takeshi Kaburagi, Yushi Mikuriya, Keiji Komoto, Yasushi Katsuta, Kenichi Nakayama
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Publication number: 20060166120Abstract: In a toner having toner particles containing at least a binder resin, a colorant and a release agent, the toner has a loss tangent (tan ?) which has a minimum value 1 and a maximum value 1 at from 70° C. or more to less than 110° C. and has a maximum value 2 at from 140° C. or more to less than 200° C. and has a loss elastic modulus at 140° C., G?(140° C.), which is: 1.0×104 dN/m2?G?(140° C.)?2.0×105 dN/m2; and the binder resin is chiefly composed of a vinyl type copolymer. This can provide a toner with which images kept to have gloss within a preferable state can be obtained without changing fixing speed and fixing temperature even when transfer materials of different types are used.Type: ApplicationFiled: December 23, 2005Publication date: July 27, 2006Applicant: CANON KABUSHIKI KAISHAInventors: Yuji Moriki, Keiji Komoto, Yasushi Katsuta, Takeshi Kaburagi, Tomoaki Igarashi
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Patent number: 7043175Abstract: In an image forming system, an image-bearing member having a photoconductor layer comprising an Si-based non-single crystal material is charged at a relatively low potential of 250 to 600 volts by a contact charging member in the presence of electroconductive fine powder. An electrostatic latent image formed on the image-bearing member is developed with a magnetic toner which includes magnetic toner particles comprising at least a binder resin and a magnetic iron oxide, and inorganic fine powder and electroconductive fine powder present at the surface of the magnetic toner particles. The magnetic toner has a weight-average particle size of 3-10 ?m and an average circularity of 0.950 to 0.995, and contains 0.05 to 3.00% of isolated iron-containing particles.Type: GrantFiled: November 15, 2001Date of Patent: May 9, 2006Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi
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Patent number: 7029813Abstract: In a toner having toner particles containing at least a colorant, a release agent and a polar resin, and an inorganic fine powder, the polar resin contains a polyester resin obtained by carrying out polymerization in the presence of a titanium chelate compound as a catalyst, and has an acid value in a specific range. The toner particles are granulated in an aqueous medium and have a weight-average particle diameter in a specific range.Type: GrantFiled: November 21, 2003Date of Patent: April 18, 2006Assignee: Canon Kabushiki KaishaInventors: Yushi Mikuriya, Yasushi Katsuta, Keiji Komoto, Takeshi Kaburagi, Emi Tosaka
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Publication number: 20050238984Abstract: In a process for producing toner particles by dispersing in an aqueous medium a polymerizable monomer composition containing at least a polymerizable monomer and a colorant and carrying out polymerization by the use of a polymerization initiator, the concentration of alcohol having 4 to 6 carbon atoms in the aqueous medium is so adjusted as to be from 500 ppm to 2,000 ppm when the polymerization conversion of the polymerizable monomer composition is 30%, and to be from 2,300 ppm to 10,000 ppm when the polymerization conversion of the polymerizable monomer composition is 97%.Type: ApplicationFiled: April 11, 2005Publication date: October 27, 2005Applicant: CANON KABUSHIKI KAISHAInventors: Takeshi Kaburagi, Yushi Mikuriya, Keiji Komoto, Yasushi Katsuta, Kenichi Nakayama
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Publication number: 20050089785Abstract: The present invention provides a magnetic toner which is hardly influenced by an environment, and with which an image with high quality and excellent resolution can be stably even under low humidity. In the magnetic toner of present invention: I) a ratio of an iron element content to a carbon element content present on the toner particle surface is less than 0.0010; II) 50 number % or more of toner particles satisfy a relationship of D/C?0.02 (C: projected area diameter of toner particles, D: minimum value for a distance between a magnetic iron oxide fine particle and the toner particle surface); and III) 40-95 number % of toner particles satisfy a structure where 70 number % or more of the magnetic iron oxide fine particles in the respective toner particles are present up to a depth of 0.2 time as far as C from the toner particle surface.Type: ApplicationFiled: September 13, 2004Publication date: April 28, 2005Applicant: CANON KABUSHIKI KAISHAInventors: Tatsuhiko Chiba, Michihisa Magome, Eriko Yanase, Takeshi Kaburagi
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Patent number: 6879793Abstract: To provide a method for forming images in which the image bearing member and the toner carrying member are arranged with a gap of 100 ?m to 250 ?m, and the equation (1) and equation (2) are satisfied. (1) 22?(the frequency of the alternating current component of the alternating electric field/the peripheral speed of the toner carrying member)×the maximum electric field intensity at the time of developing?1.20. (2) 8?(the frequency of the alternating current component of the alternating electric field/the peripheral speed of toner carrying member)×(the fluidity index of Carr/the floodability index of Carr)?50. According to the method for forming images of the present invention, it is possible to obtain a high quality image without generating fog and light shielding while attaining a uniform halftone with a high image density even over long-term.Type: GrantFiled: June 18, 2003Date of Patent: April 12, 2005Assignee: Canon Kabushiki KaishaInventors: Tatsuhiko Chiba, Michihisa Magome, Keiji Komoto, Kaori Hiratsuka, Takeshi Kaburagi
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Publication number: 20050026062Abstract: In a non-magnetic toner having non-magnetic toner particles containing at least a binder resin and a colorant, and an inorganic fine powder, the non-magnetic toner particles contain at least one ether compound having a specific structure, and the ether compound is in a content of from 5 ppm to 1,000 ppm.Type: ApplicationFiled: January 27, 2004Publication date: February 3, 2005Inventors: Keiji Komoto, Yushi Mikuriya, Yuji Moriki, Yasushi Katsuta, Kenichi Nakayama, Takeshi Kaburagi, Emi Tosaka, Yasuhiro Hashimoto
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Publication number: 20050026061Abstract: In a toner having toner particles containing at least a colorant, a release agent and a polar resin, and an inorganic fine powder, the polar resin contains a polyester resin obtained by carrying out polymerization in the presence of a titanium chelate compound as a catalyst, and has an acid value in a specific range. The toner particles are granulated in an aqueous medium and have a weight-average particle diameter in a specific range.Type: ApplicationFiled: November 21, 2003Publication date: February 3, 2005Inventors: Yushi Mikuriya, Yasushi Katsuta, Keiji Komoto, Takeshi Kaburagi, Emi Tosaka
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Publication number: 20050026055Abstract: A toner includes toner particles containing at least a binder resin and a colorant, and inorganic fine particles. The shape factor SF-1 of the toner particles is in a specific range. The toner has a storage elastic modulus at 140° C., G? (140° C.), in a specific range the toner comes to have a viscosity of 1.0×103 Pa·s according to a flow tester heating method at a temperature of from 115° C. or more to less than 130° C.Type: ApplicationFiled: June 25, 2004Publication date: February 3, 2005Applicant: CANON KABUSHIKI KAISHAInventors: Yuji Moriki, Shinya Yachi, Yushi Mikuriya, Keiji Komoto, Kenichi Nakayama, Takeshi Kaburagi, Emi Tosaka
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Publication number: 20050026063Abstract: A toner includes toner particles and an inorganic fine powder mixed with the toner particles. The toner particles contain a binder resin, a coloring agent, a releasing agent, and a sulfur-containing resin. The toner particles contain at least one element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum, and phosphorus and satisfy the relationship: 4?T/S?30 wherein T represents the total content of the element in ppm, and S represents the content of sulfur in ppm. The weight-average particle diameter (D4) of the toner is in the range of 3 to 10 ?m. The average circularity of the toner is within the range of 0.950 to 0.995.Type: ApplicationFiled: March 25, 2004Publication date: February 3, 2005Inventors: Keiji Komoto, Yasushi Katsuta, Yushi Mikuriya, Takeshi Kaburagi, Emi Tosaka
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Publication number: 20040018028Abstract: To provide an method for forming image in which the image bearing member and the toner carrying member are arranged with a gap of 100 &mgr;m to 250 &mgr;m; equation (1) and equation (2) are satisfied: (1) 22≦(the frequency of the alternating current component of the alternating electric field/the peripheral speed of the toner carrying member)×the maximum electric field intensity at the time of developing≦120; (2) 8≦(the frequency of the alternating current component of the alternating electric field/the peripheral speed of toner carrying member)×(the fluidity index of Carr/the floodability index of Carr)≦50. According to method for forming image of the present invention, it is possible to obtain a high quality image without generating fog and light shielding while attaining a uniform halftone with a high image density even in a long-term use.Type: ApplicationFiled: June 18, 2003Publication date: January 29, 2004Applicant: CANON KABUSHIKI KAISHAInventors: Tatsuhiko Chiba, Michihisa Magome, Keiji Komoto, Kaori Hiratsuka, Takeshi Kaburagi
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Patent number: 6653035Abstract: A magnetic toner exhibiting stable performances under various environmental conditions is formed of toner particles each comprising at least a binder resin and iron oxide dispersed therein. Relative to the dry specific gravity (A) of the magnetic toner, the magnetic toner is characterized by a specific gravity distribution of toner particle fractions obtainable through wet sedimentation and including: at most 15 wt. % of a fraction having a specific gravity of above (A)×1.000 and at most (A)×1.025, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.975 and at most (A)×1.000, at least 30 wt. % of a fraction having a specific gravity of above (A)×0.950 and at most (A)×0.975, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.925 and at most (A)×0.950, and at most 15 wt. % of a fraction having a specific gravity of above (A)×0.900 and at most (A)×0.925.Type: GrantFiled: July 26, 2002Date of Patent: November 25, 2003Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Tatsuya Nakamura, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi, Eriko Yanase
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Patent number: 6638674Abstract: A magnetic toner is formed of magnetic toner particles each comprising a binder resin, an iron oxide, a sulfur-containing polymer, and inorganic fine powder blended with the magnetic toner particles, the toner having a weight-average particle size (D4) of 3-10 &mgr;m, and either (a) an average circularity of at least 0.970, and a magnetization of 10-50 Am2/kg (emu/g) at a magnetic field of 79.6 kA/m (1000 oersted), or (b) toner particles which retain carbon in an amount of A and iron in an amount of B at surfaces thereof, satisfying: B/A<0.001, and containing at least 50% by number of magnetic toner particles of D/C≦0.02, wherein C represents a particle projection area-equivalent circle diameter and D represents a minimum distance between a surface of the magnetic toner particle and iron oxide particles contained therein.Type: GrantFiled: July 25, 2001Date of Patent: October 28, 2003Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi, Eriko Yanase