Patents by Inventor Tsuneyoshi Tominaga
Tsuneyoshi Tominaga 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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Publication number: 20230341789Abstract: A toner having both of excellent low-temperature fixability and such high durable developability as to be free from causing any development stripe. The toner is a toner including a toner particle containing a crystalline resin as a binder resin. When a relative permittivity obtained at a time of impedance measurement of the toner under an environment at a temperature of 25° C. and a relative humidity of 50% is represented by ?r, a difference ??r between a relative permittivity ?r(0.01 Hz) at a frequency of 0.01 Hz and a relative permittivity ?r(383 kHz) at a frequency of 383 kHz satisfies a relationship of 0.21?{?r(0.01 Hz)??r(383 kHz)}?0.48.Type: ApplicationFiled: April 13, 2023Publication date: October 26, 2023Inventors: Yuzo Seino, TSUNEYOSHI TOMINAGA, KOKI INOUE, YUKI MASUDA
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Publication number: 20230065610Abstract: A toner comprising a toner particle comprising a binder resin, wherein the binder resin has a side-chain crystalline polymer B having a monomer unit A made of at least one polymerizable monomer A selected from the group consisting of (meth)acrylic acid esters having a linear alkyl group having 18 to 36 carbon atoms, and the toner particle comprises boric acid.Type: ApplicationFiled: August 12, 2022Publication date: March 2, 2023Inventors: Daisuke Yoshiba, Tsuneyoshi Tominaga, Takashi Matsui
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Publication number: 20230051836Abstract: A toner comprising: a toner particle comprising a binder resin and boric acid; wherein the binder resin comprises an amorphous resin and a crystalline polyester resin, a content of the crystalline polyester resin in the toner is 30.00 to 80.00 mass %, and a content of the boric acid in the toner is 0.10 to 10.00 mass %.Type: ApplicationFiled: July 21, 2022Publication date: February 16, 2023Inventors: Tsuneyoshi Tominaga, Daisuke Yoshiba
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Patent number: 11448982Abstract: An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00×1012 ?·cm and not greater than 1.00×1017 ?·cm, the matrix volume resistivity R1 is at least 1.0×105-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.Type: GrantFiled: October 15, 2020Date of Patent: September 20, 2022Assignee: CANON KABUSHIKI KAISHAInventors: Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Noriyoshi Umeda, Masahiro Kurachi, Kazuhiro Yamauchi, Motonari Ito
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Patent number: 11320756Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit has a conductive member contactable with the electrophotographic photosensitive member, and a conductive layer of the conductive member has a matrix-domain structure; at least some of the domains are exposed at the outer surface; a volume resistivity R1 of the matrix and a volume resistivity R2 of the domains satisfy specific relationship; Martens hardness G1 of the matrix and Martens hardness G2 of the domains satisfy relationship G1<G2; the surface roughness Ra of the conductive member is not more than 2.00 ?m; the toner has an external additive having a shape factor SF-1 of not more than 115; and A<Dms is satisfied where A is the number-average diameter of the external additive and Dms is a distance between adjacent walls between the domains.Type: GrantFiled: October 15, 2020Date of Patent: May 3, 2022Assignee: CANON KABUSHIKI KAISHAInventors: Shohei Kototani, Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Noboru Miyagawa, Kazuhiro Yamauchi
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Publication number: 20220128916Abstract: A toner comprises a toner particle comprising a resin A and a resin B, wherein the resin A has a structure represented by a predetermined general formula, and the resin B has a monomer unit represented by a predetermined general formula, and a toner manufacturing method comprises a step of dispersing a toner base particle comprising the resin B in an aqueous medium to obtain a toner slurry, and a step of adding a radical polymerization initiator and a monomer composition comprising a monomer represented by a predetermined general formula to the resulting toner slurry to form the resin A on a surface of the toner base particle.Type: ApplicationFiled: October 15, 2021Publication date: April 28, 2022Inventors: Yu Yoshida, Takashi Matsui, Kenji Aoki, Tsuneyoshi Tominaga, Shohei Shibahara, Mariko Yamashita, Yuna Yamamoto, Kenji Ookubo, Takashi Kenmoku, Taku Shimoda, Masashi Kawamura
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Patent number: 11249408Abstract: A toner including a toner particle including a binder resin, wherein fine particles A and B are present on a surface of the toner particle; the fine particles A are a fatty acid metal salt; the fine particles B have a specific volume resistivity; an average theoretical surface area of the toner particle, an amount of the fine particles A, and a coverage ratio of the toner particle surface by the fine particles A satisfy a specific relationship; the amount of the fine particles B is in a specific range; and a proportion F of an area occupied by a part of the fine particles B embedded in a surface vicinity region of the toner in a total area occupied by the fine particles B present in a cross section of one particle of the toner is 50% by area or more.Type: GrantFiled: June 25, 2020Date of Patent: February 15, 2022Assignee: CANON KABUSHIKI KAISHAInventors: Shohei Tsuda, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
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Patent number: 11169460Abstract: A toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the organosilicon polymer has a structure represented by at least one selected from the group consisting of RaSiO3/2 and Rb2SiO2/2 (wherein Ra and Rb represent organic groups), and in the number particle size distribution of the toner as measured within a particle size range of from 2 to 60 ?m, the number-average particle diameter T-D50n at which the accumulation from the smallest diameter is 50% is from 6 to 12 ?m, the number ratio of toner 4 ?m or less in size is from 2% to 5% of the total toner, and the number ratio of toner 3 ?m or less in size as a percentage of the total toner 4 ?m or less in size is from 25% to 50%.Type: GrantFiled: December 27, 2019Date of Patent: November 9, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
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Patent number: 11061342Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00×1012 ?·cm and is 1.0×105 times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0×103 to 1.0×1010 ?·cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0×1011 to 1.0×1017 ?·cm.Type: GrantFiled: October 15, 2020Date of Patent: July 13, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Masahiro Kurachi, Kazuhiro Yamauchi, Hideo Kihara
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Patent number: 11003105Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the external additive contains composite particles of an organosilicon polymer fine particle and a fatty acid metal salt.Type: GrantFiled: December 27, 2019Date of Patent: May 11, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura
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Patent number: 11003104Abstract: Provided is a toner including a toner particle and an external additive, wherein the external additive includes a composite particle including a hydrotalcite particle covered on the surface with an organosilicon polymer fine particle, a coverage ratio of the hydrotalcite particle surface by the organosilicon polymer fine particle is from 1% to 50%, and given A (nm) as the number-average particle diameter of the primary particles of the organosilicon polymer fine particle and B (nm) as the number-average particle diameter of the primary particles of the hydrotalcite particle, the toner satisfies the following formula (I) and formula (II): A<B??(I) 20?A?350??(II).Type: GrantFiled: December 27, 2019Date of Patent: May 11, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka
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Publication number: 20210116828Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00×1012 ?·cm and is 1.0×105 times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0×103 to 1.0×1010 ?·cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0×1011 to 1.0×1017 ?·cm.Type: ApplicationFiled: October 15, 2020Publication date: April 22, 2021Inventors: Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Masahiro Kurachi, Kazuhiro Yamauchi, Hideo Kihara
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Publication number: 20210116831Abstract: An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00×1012 ?·cm and not greater than 1.00×1017 ?·cm, the matrix volume resistivity R1 is at least 1.0×105-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.Type: ApplicationFiled: October 15, 2020Publication date: April 22, 2021Inventors: Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Noriyoshi Umeda, Masahiro Kurachi, Kazuhiro Yamauchi, Motonari Ito
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Publication number: 20210116832Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit has a conductive member contactable with the electrophotographic photosensitive member, and a conductive layer of the conductive member has a matrix-domain structure; at least some of the domains are exposed at the outer surface; a volume resistivity R1 of the matrix and a volume resistivity R2 of the domains satisfy specific relationship; Martens hardness G1 of the matrix and Martens hardness G2 of the domains satisfy relationship G1<G2; the surface roughness Ra of the conductive member is not more than 2.00 ?m; the toner has an external additive having a shape factor SF-1 of not more than 115; and A<Dms is satisfied where A is the number-average diameter of the external additive and Dms is a distance between adjacent walls between the domains.Type: ApplicationFiled: October 15, 2020Publication date: April 22, 2021Inventors: Shohei Kototani, Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Noboru Miyagawa, Kazuhiro Yamauchi
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Patent number: 10976679Abstract: A toner containing: a toner particle that contains a binder resin and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the binder resin contains an amorphous resin and a crystalline polyester resin, a content of the crystalline polyester resin in the binder resin is from 5 to 30 mass %, and the crystalline polyester resin contains from 5 to 25 mass % of a component having a molecular weight of not more than 2,500.Type: GrantFiled: December 27, 2019Date of Patent: April 13, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga
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Patent number: 10942466Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the toner particle contains a polyvalent metal compound, the polyvalent metal compound is at least one selected from the group consisting of aluminum compounds, iron compounds and magnesium compounds, a content of a metal element derived from the polyvalent metal compound in the toner particle is from 0.080 to 20.000 ?mol/g, the external additive contains an organosilicon polymer particle having a hydroxyl group, a ratio of a number-average particle diameter of the organosilicon polymer particle to a number-average particle diameter of the toner particle is from 0.0160 to 0.0650, and a content of the organosilicon polymer particle is at least 0.10 mass parts per 100.00 mass parts of the toner particle.Type: GrantFiled: December 27, 2019Date of Patent: March 9, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki
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Publication number: 20210003932Abstract: A toner including a toner particle including a binder resin, wherein fine particles A and B are present on a surface of the toner particle; the fine particles A are a fatty acid metal salt; the fine particles B have a specific volume resistivity; an average theoretical surface area of the toner particle, an amount of the fine particles A, and a coverage ratio of the toner particle surface by the fine particles A satisfy a specific relationship; the amount of the fine particles B is in a specific range; and a proportion F of an area occupied by a part of the fine particles B embedded in a surface vicinity region of the toner in a total area occupied by the fine particles B present in a cross section of one particle of the toner is 50% by area or more.Type: ApplicationFiled: June 25, 2020Publication date: January 7, 2021Inventors: Shohei Tsuda, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
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Patent number: 10845721Abstract: A toner has a toner particle that has a binder resin and a release agent, wherein when the temperature when G?=1.0×105 Pa in a dynamic viscoelastic measurement on the toner is denoted by Ta, and the glass transition temperature in a differential scanning calorimetric measurement on the toner is denoted by Tg, the Ta and the Tg satisfy the following formulas: 40° C.?Tg?70° C., 60° C.?Ta?90° C., and 0° C.?Ta?Tg?35° C.; and the toner has a storage elastic modulus G? having a minimum value in the range from 110° C. to 150° C. in a dynamic viscoelastic measurement on the toner.Type: GrantFiled: October 14, 2019Date of Patent: November 24, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Masatake Tanaka, Tsuneyoshi Tominaga, Noriyoshi Umeda, Satoshi Otsuji, Shinsuke Mochizuki
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Publication number: 20200209773Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the toner particle contains a polyvalent metal compound, the polyvalent metal compound is at least one selected from the group consisting of aluminum compounds, iron compounds and magnesium compounds, a content of a metal element derived from the polyvalent metal compound in the toner particle is from 0.080 to 20.000 ?mol/g, the external additive contains an organosilicon polymer particle having a hydroxyl group, a ratio of a number-average particle diameter of the organosilicon polymer particle to a number-average particle diameter of the toner particle is from 0.0160 to 0.0650, and a content of the organosilicon polymer particle is at least 0.10 mass parts per 100.00 mass parts of the toner particle.Type: ApplicationFiled: December 27, 2019Publication date: July 2, 2020Inventors: Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki
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Publication number: 20200209774Abstract: Provided is a toner including a toner particle and an external additive, wherein the external additive includes a composite particle including a hydrotalcite particle covered on the surface with an organosilicon polymer fine particle, a coverage ratio of the hydrotalcite particle surface by the organosilicon polymer fine particle is from 1% to 50%, and given A (nm) as the number-average particle diameter of the primary particles of the organosilicon polymer fine particle and B (nm) as the number-average particle diameter of the primary particles of the hydrotalcite particle, the toner satisfies the following formula (I) and formula (II): A<B??(I) 20?A?350??(II).Type: ApplicationFiled: December 27, 2019Publication date: July 2, 2020Inventors: Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka