Patents by Inventor Daichi Hisakuni
Daichi Hisakuni 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: 20230185210Abstract: A glittering toner includes: a flat metallic pigment having a surface coated with a resin; a polyester-styrene acrylic composite resin; and a polyester resin. When a solubility parameter of the polyester-styrene acrylic composite resin is represented by SP1 (cal/cm3)1/2 and a solubility parameter of the polyester resin is represented by SP2 (cal/cm3)1/2, the SP1 and the SP2 satisfy a relational expression (1): [SP2?SP1>0.3] and the SP1 satisfies a relational expression (2): [10<SP1].Type: ApplicationFiled: December 12, 2022Publication date: June 15, 2023Inventors: Tsukiko TAKAHASHI, Kohsuke SATOH, Kazumi SUZUKI, Daichi HISAKUNI, Kazuoki FUWA
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Patent number: 11340540Abstract: Provided is an image forming apparatus including an image bearer, a developing unit configured to develop with a toner, an intermediate transfer member, and a transferring unit, wherein the intermediate transfer member is a laminate including a base layer and an elastic layer including particles at a surface thereof to form convex-concave shapes at the surface, the particles have volume resistivity of from 1×100 ohm*cm through 1×109 ohm*cm, the toner includes additive, an amount of the additive separated from the toner is from 20 percent by mass through 35 percent by mass relative to a total amount of the additive in the toner when a toner dispersion liquid in which the toner is dispersed in a dispersant is irradiated with ultrasonic wave vibration with an irradiation energy dose of 4 kJ, and the toner has a dielectric constant of 2.6 or greater but 3.9 or less.Type: GrantFiled: December 21, 2018Date of Patent: May 24, 2022Assignee: Ricoh Company, Ltd.Inventors: Akio Takei, Daisuke Inoue, Daichi Hisakuni, Hidetaka Kubo, Masahiro Ohmori, Junichi Awamura
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Patent number: 11079700Abstract: An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m2. The toner satisfies a relation 0.13?X/Dn?0.16, where X [?m] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10?4 N at a loading rate of 3.0×10?5 N/sec under an environment of 32 degrees C. and 40% RH, and Dn [?m] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.Type: GrantFiled: March 6, 2020Date of Patent: August 3, 2021Assignee: Ricoh Company, Ltd.Inventors: Keiji Makabe, Tsuneyasu Nagatomo, Kohsuke Satoh, Daichi Hisakuni, Kousuke Suzuki, Shintaro Akiyama
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Patent number: 11061343Abstract: A toner including: a plate-shaped pigment containing a metal as a main component; and a binder resin containing polyester resin (A) that is insoluble in THF, wherein: a weight average molecular weight (Mw) of a tetrahydrofuran (THF)-soluble component of the toner as determined by gel permeation chromatography (GPC) is 5,000 or higher but 14,000 or lower; and a glass transition temperature (Tg) of a THF-insoluble component of the toner as determined from a differential scanning colorimetry (DSC) curve at first heating in DSC is ?60° C. or higher but 10° C. or lower.Type: GrantFiled: February 18, 2020Date of Patent: July 13, 2021Assignee: Ricoh Company, Ltd.Inventors: Yuka Mizoguchi, Ryota Inoue, Hiroshi Yamashita, Minoru Masuda, Daichi Hisakuni, Tomomi Harashima
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Patent number: 11061345Abstract: A toner including toner particles, each toner particle including a toner base particle, and inorganic particles, wherein the inorganic particles include particles of a fluorine-containing aluminium compound, and a liberation ratio of the inorganic particles is 10% or greater but 60% or less.Type: GrantFiled: February 24, 2020Date of Patent: July 13, 2021Assignee: Ricoh Company, Ltd.Inventors: Kohsuke Satoh, Tsuneyasu Nagatomo, Keiji Makabe, Daichi Hisakuni
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Publication number: 20210063916Abstract: Provided is an image forming apparatus including an image bearer, a developing unit configured to develop with a toner, an intermediate transfer member, and a transferring unit, wherein the intermediate transfer member is a laminate including a base layer and an elastic layer including particles at a surface thereof to form convex-concave shapes at the surface, the particles have volume resistivity of from 1×100 ohm*cm through 1×109 ohm*cm, the toner includes additive, an amount of the additive separated from the toner is from 20 percent by mass through 35 percent by mass relative to a total amount of the additive in the toner when a toner dispersion liquid in which the toner is dispersed in a dispersant is irradiated with ultrasonic wave vibration with an irradiation energy dose of 4 kJ, and the toner has a dielectric constant of 2.6 or greater but 3.9 or less.Type: ApplicationFiled: December 21, 2018Publication date: March 4, 2021Inventors: Akio TAKEI, Daisuke INOUE, Daichi HISAKUNI, Hidetaka KUBO, Masahiro OHMORI, Junichi AWAMURA
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Patent number: 10895816Abstract: An image forming apparatus is provided that includes: first and second electrostatic latent image bearers; first and second electrostatic latent image forming devices; first and second developing devices configured to develop first and second electrostatic latent images with a colored toner and a special-color toner to form a colored toner image and a special-color toner image, respectively; a primary transfer device configured to transfer the colored toner image and the special-color toner image onto an intermediate image bearer in an overlapping manner to form a composite toner image; a secondary transfer device configured to transfer the composite toner image onto a recording medium; and a fixing device configured to fix the composite toner image thereon. The special-color toner comprises plate-like and/or film-like pigments. An absolute difference in volume resistivity between the special-color toner and the colored toner is 0.30 log ? cm or less.Type: GrantFiled: September 12, 2019Date of Patent: January 19, 2021Assignee: Ricoh Company, Ltd.Inventors: Minoru Masuda, Hiroshi Yamashita, Ryota Inoue, Yuka Mizoguchi, Daichi Hisakuni, Tomomi Harashima
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Publication number: 20200301308Abstract: An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m2. The toner satisfies a relation 0.13?X/Dn?0.16, where X [?m] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10?4 N at a loading rate of 3.0×10?5 N/sec under an environment of 32 degrees C. and 40% RH, and Dn [?m] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.Type: ApplicationFiled: March 6, 2020Publication date: September 24, 2020Inventors: Keiji MAKABE, Tsuneyasu NAGATOMO, Kohsuke SATOH, Daichi HISAKUNI, Kousuke SUZUKI, Shintaro AKIYAMA
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Publication number: 20200301298Abstract: A toner for developing an electrostatic image is provided. The toner comprises a binder resin and a glitter pigment having an average surface roughness Ra of 100 nm or less.Type: ApplicationFiled: March 18, 2020Publication date: September 24, 2020Inventors: Ryota INOUE, Hiroshi Yamashita, Minoru Masuda, Yuka Mizoguchi, Daichi Hisakuni
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Publication number: 20200285167Abstract: A toner including: a plate-shaped pigment containing a metal as a main component; and a binder resin containing polyester resin (A) that is insoluble in THF, wherein: a weight average molecular weight (Mw) of a tetrahydrofuran (THF)-soluble component of the toner as determined by gel permeation chromatography (GPC) is 5,000 or higher but 14,000 or lower; and a glass transition temperature (Tg) of a THF-insoluble component of the toner as determined from a differential scanning colorimetry (DSC) curve at first heating in DSC is ?60° C. or higher but 10° C. or lower.Type: ApplicationFiled: February 18, 2020Publication date: September 10, 2020Inventors: Yuka MIZOGUCHI, Ryota INOUE, Hiroshi YAMASHITA, Minoru MASUDA, Daichi HISAKUNI, Tomomi HARASHIMA
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Publication number: 20200272066Abstract: A toner including toner particles, each toner particle including a toner base particle, and inorganic particles, wherein the inorganic particles include particles of a fluorine-containing aluminium compound, and a liberation ratio of the inorganic particles is 10% or greater but 60% or less.Type: ApplicationFiled: February 24, 2020Publication date: August 27, 2020Inventors: Kohsuke Satoh, Tsuneyasu Nagatomo, Keiji Makabe, Daichi Hisakuni
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Publication number: 20200089140Abstract: An image forming apparatus is provided that includes: first and second electrostatic latent image bearers; first and second electrostatic latent image forming devices; first and second developing devices configured to develop first and second electrostatic latent images with a colored toner and a special-color toner to form a colored toner image and a special-color toner image, respectively; a primary transfer device configured to transfer the colored toner image and the special-color toner image onto an intermediate image bearer in an overlapping manner to form a composite toner image; a secondary transfer device configured to transfer the composite toner image onto a recording medium; and a fixing device configured to fix the composite toner image thereon. The special-color toner comprises plate-like and/or film-like pigments. An absolute difference in volume resistivity between the special-color toner and the colored toner is 0.30 log ? cm or less.Type: ApplicationFiled: September 12, 2019Publication date: March 19, 2020Inventors: Minoru MASUDA, Hiroshi YAMASHITA, Ryota INOUE, Yuka MIZOGUCHI, Daichi HISAKUNI, Tomomi HARASHIMA
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Patent number: 10303072Abstract: A toner is provided. The toner contains a polyester resin. The toner has a glass transition temperature (Tg1st) at first temperature rising of differential scanning calorimetry (DSC) of from 45° C. to 65° C. The toner includes a component insoluble in tetrahydrofuran (THF) having two glass transition temperatures (Tga1st and Tgb1st) at the first temperature rising of DSC, where Tga1st is in a range of ?45° C. to 5° C. and Tgb1st is in a range of 45° C. to 70° C. The toner includes a component soluble in THF having a glass transition temperature (Tg2nd) at second temperature rising of DSC of from 40° C. to 65° C.Type: GrantFiled: February 6, 2018Date of Patent: May 28, 2019Assignee: Ricoh Company, Ltd.Inventors: Akira Tanaka, Hiroyuki Takeda, Junichi Awamura, Hiroshi Yamada, Daichi Hisakuni, Yasuo Kamada
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Publication number: 20180224763Abstract: A toner is provided. The toner contains a polyester resin. The toner has a glass transition temperature (Tg1st) at first temperature rising of differential scanning calorimetry (DSC) of from 45° C. to 65° C. The toner includes a component insoluble in tetrahydrofuran (THF) having two glass transition temperatures (Tga1st and Tgb1st) at the first temperature rising of DSC, where Tga1st is in a range of ?45° C. to 5° C. and Tgb1st is in a range of 45° C. to 70° C. The toner includes a component soluble in THF having a glass transition temperature (Tg2nd) at second temperature rising of DSC of from 40° C. to 65° C.Type: ApplicationFiled: February 6, 2018Publication date: August 9, 2018Inventors: Akira TANAKA, Hiroyuki TAKEDA, Junichi AWAMURA, Hiroshi YAMADA, Daichi HISAKUNI, Yasuo KAMADA
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Patent number: 9804516Abstract: A toner includes a base particle; and an external additive covering the base particle. The toner includes a tetrahydrofuran (THF)-insoluble component having a glass transition temperature determined from a DSC curve when heated for the second time of from ?50° C. to 10° C. and an average circularity not greater than 0.98, and satisfies the following relation: Bt?0.025×Ct?1.80 wherein Bt represents a BET specific surface area [m2/g]; and Ct represents a coverage [%] of the external additive covering the base particle.Type: GrantFiled: April 21, 2016Date of Patent: October 31, 2017Assignee: Ricoh Company, Ltd.Inventors: Keiji Makabe, Tsuneyasu Nagatomo, Kohsuke Satoh, Junichi Watanabe, Kenji Yoneda, Daichi Hisakuni
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Patent number: 9791794Abstract: A toner includes a base particle comprising a crystalline polyester resin; and an external additive which is a group of silica particles having a number-average particle diameter of from 0.01 ?m to 0.11 ?m on the surface of the toner. A number ratio of the silica particles having a circularity not less than 0.8 is 20% or more in the total number of the silica particles.Type: GrantFiled: February 24, 2016Date of Patent: October 17, 2017Assignee: Ricoh Company, Ltd.Inventors: Junichi Watanabe, Kenji Yoneda, Kohsuke Satoh, Tsuneyasu Nagatomo, Keiji Makabe, Daichi Hisakuni
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Publication number: 20160334722Abstract: A toner includes a base particle; and an external additive covering the base particle. The toner includes a tetrahydrofuran (THF)-insoluble component having a glass transition temperature determined from a DSC curve when heated for the second time of from ?50° C. to 10° C. and an average circularity not greater than 0.98, and satisfies the following relation: Bt?0.025×Ct?1.80 wherein Bt represents a BET specific surface area [m2/g]; and Ct represents a coverage [%] of the external additive covering the base particle.Type: ApplicationFiled: April 21, 2016Publication date: November 17, 2016Inventors: Keiji MAKABE, Tsuneyasu Nagatomo, Kohsuke Satoh, Junichi Watanabe, Kenji Yoneda, Daichi Hisakuni
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Publication number: 20160266507Abstract: A toner includes a base particle comprising a crystalline polyester resin; and an external additive which is a group of silica particles having a number-average particle diameter of from 0.01 ?m to 0.11 ?m on the surface of the toner. A number ratio of the silica particles having a circularity not less than 0.8 is 20% or more in the total number of the silica particles.Type: ApplicationFiled: February 24, 2016Publication date: September 15, 2016Inventors: Junichi WATANABE, Kenji Yoneda, Kohsuke Satoh, Tsuneyasu Nagatomo, Keiji Makabe, Daichi Hisakuni