Patents by Inventor Ryuuta Yoshida
Ryuuta Yoshida 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: 20230147363Abstract: A toner includes: toner base particles each containing a binder resin; and resin particles on a surface of each of the toner base particles. A glass transition temperature (Tg) of the toner at the first heating in differential scanning calorimetry (DSC) is 20° C. or higher and 50° C. or lower. A glass transition temperature of a tetrahydrofuran (THF)-insoluble component of the toner at the first heating in DSC is ?40° C. or higher and 10° C. or lower. An average circularity of the toner is 0.970 or more and 0.985 or less. A standard deviation of the average circularity is 0.020 or less.Type: ApplicationFiled: November 8, 2022Publication date: May 11, 2023Inventors: Ryuuta YOSHIDA, Akio TAKEI, Ryohei YAMAGUCHI, Toma TAKEBAYASHI
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Publication number: 20230109578Abstract: A toner includes toner base particles each containing a binder resin and a release agent, and resin particles on a surface of each of the toner base particles. A ratio (Iw/Ir) is 0.10 or more and 0.30 or less, where Ir is a peak height of the binder resin and Iw is a peak height of the release agent, as measured through attenuated total reflection (ATR). A standard deviation ? (nm) of distances L (nm) between the resin particles that are adjacent to each other on the surface of each of the toner base particles is 150 nm or more and 500 nm or less.Type: ApplicationFiled: September 29, 2022Publication date: April 6, 2023Inventors: Kazumasa TABATA, Akio TAKEI, Hiroshi YAMADA, Toma TAKEBAYASHI, Ryuuta YOSHIDA
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Publication number: 20220342330Abstract: A toner includes toner base particles. Each of the toner base particles includes a binder resin, a colorant, and inorganic filler. An atomic concentration % of Al in the toner base particles as measured by XRF is 0.35 or greater but 0.85 or less. The toner satisfies 0.8<(M1/M2)/(M3/M4)<1.2. M1 is an atomic concentration % of Al in the toner base particles as measured by XPS, M2 is the atomic concentration % of Al in the toner base particles as measured by XRF, and M3 is an atomic concentration % of Al in particles as measured by XPS, and M4 is an atomic concentration % of Al in the particles as measured by XRF. The particles are particles obtained by classifying the toner base particles into 6/5 Dv, and Dv is a volume average particle diameter of the toner base particles.Type: ApplicationFiled: April 18, 2022Publication date: October 27, 2022Applicant: Ricoh Company, Ltd.Inventors: Ryohei YAMAGUCHI, Ryuuta Yoshida, Yoshiyasu Adachi, Kazumasa Tabata, Akira Tanaka
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Publication number: 20220137525Abstract: The present disclosure provides a toner having excellent low-temperature fixing, heat-resistant-storage property, cleaning performance, and filming resistance. A toner containing toner base particles having a crystalline polyester resin and an amorphous polyester resin includes a plurality of organic particles disposed at least partially embedded in a surface of the toner base particles. A percentage of the crystalline polyester resin occupying the surface of the toner base particles is 4% to 20%, a volume average particle size of the organic particles is 10 nm to 40 nm, and a standard deviation of a distance between adjacent particles of the organic particles that are not in contact is 500 nm or less.Type: ApplicationFiled: November 2, 2021Publication date: May 5, 2022Applicant: Ricoh Company, Ltd.Inventors: Ryuuta Yoshida, Toma Takebayashi, Akio Takei, Yasuo Kamada
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Patent number: 10073366Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.Type: GrantFiled: June 14, 2017Date of Patent: September 11, 2018Assignee: Ricoh Company, Ltd.Inventors: Kohsuke Nagata, Ryuuta Yoshida, Shinya Nakayama, Tsuyoshi Sugimoto, Akinori Saitoh, Hideyuki Santo, Suzuka Karato, Koh Ohnuma, Takahiro Kadota, Shinsuke Nagai, Akihiro Takeyama
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Publication number: 20170363980Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.Type: ApplicationFiled: June 14, 2017Publication date: December 21, 2017Inventors: Kohsuke NAGATA, Ryuuta YOSHIDA, Shinya NAKAYAMA, Tsuyoshi SUGIMOTO, Akinori SAITOH, Hideyuki SANTO, Suzuka KARATO, Koh OHNUMA, Takahiro KADOTA, Shinsuke NAGAI, Akihiro TAKEYAMA
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Patent number: 9201326Abstract: A toner including: a binder resin containing a non-crystalline resin and a crystalline resin; a colorant; and, a releasing agent, wherein the releasing agent has a melting point of 55° C. to 80° C., and wherein the toner satisfies the following Expressions 1 and 2: (Expression 1): 20,000 Pa·s?G1?50,000 Pa·s; and (Expression 2): (G4/G2)/(G3/G1) 1.00, where G1 is a storage modulus, G2 is a loss modulus, G3 is a storage modulus and G4 is a loss modulus, and the storage modulus G1 and the loss modulus G2 are measured at 80° C. when the toner is heated from 70° C. to 150° C. and the storage modulus G3 and the loss modulus G4 are measured at 80° C. when the toner heated to 150° C. is cooled to 70° C.Type: GrantFiled: December 28, 2012Date of Patent: December 1, 2015Assignee: Ricoh Company, Ltd.Inventors: Ryuuta Yoshida, Takahiro Honda, Junichi Awamura, Osamu Uchinokura, Masaki Watanabe, Daisuke Inoue, Tomoki Murayama, Mamoru Hozumi
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Patent number: 8999618Abstract: A toner set, including: at least one chromatic toner containing a colorant; and a transparent toner containing no colorant, wherein the chromatic toner and the transparent toner each include a releasing agent and a binder resin, and wherein an amount of a tetrahydrofuran insoluble matter in the transparent toner is smaller than an amount of a tetrahydrofuran insoluble matter in the chromatic toner.Type: GrantFiled: May 20, 2013Date of Patent: April 7, 2015Assignee: Ricoh Company, Ltd.Inventors: Ryuuta Yoshida, Satoshi Ogawa, Masaki Watanabe, Hyo Shu, Naohiro Watanabe
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Patent number: 8778588Abstract: To provide a toner, which contains a binder resin, a colorant, and a releasing agent, wherein the binder resin contains a low molecular weight resin component, where the low molecular weight resin component has a resin softening coefficient (A), represented by the following formula (1), satisfying A>0.165, and has storage elastic modulus (dyne/cm2) G?(Tfb) satisfying G?(Tfb)?1×104 where Tfb is a flow onset temperature (° C.) of the low molecular weight resin component as measured by a capillary rheometer: A=|[(r1)?ln G?(r2)]/(T1?T2)|??Formula (1) (where T1 is temperature (° C.) at which storage elastic modulus G?(r1) is 1×105 (dyne/cm2) and T2 is temperature (° C.) at which storage elastic modulus G?(r2) is 1×103 (dyne/cm2) as measured by means of a viscoelasticity measuring device with measuring frequency of 1 Hz, and measuring distortion of 1 deg; and | | represents an absolute value.).Type: GrantFiled: October 12, 2011Date of Patent: July 15, 2014Assignee: Ricoh Company, Ltd.Inventors: Teruki Kusahara, Junichi Awamura, Tsuyoshi Sugimoto, Hyo Shu, Tomomi Suzuki, Osamu Uchinokura, Takahiro Honda, Satoshi Kojima, Satoshi Ogawa, Daisuke Inoue, Koshi Sato, Daisuke Ito, Ryuuta Yoshida, Syouko Satoh
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Publication number: 20130316280Abstract: A toner set, including: at least one chromatic toner containing a colorant; and a transparent toner containing no colorant, wherein the chromatic toner and the transparent toner each include a releasing agent and a binder resin, and wherein an amount of a tetrahydrofuran insoluble matter in the transparent toner is smaller than an amount of a tetrahydrofuran insoluble matter in the chromatic toner.Type: ApplicationFiled: May 20, 2013Publication date: November 28, 2013Inventors: Ryuuta YOSHIDA, Satoshi OGAWA, Masaki WATANABE, Hyo SHU, Naohiro WATANABE
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Publication number: 20130196260Abstract: A toner including: a binder resin containing a non-crystalline resin and a crystalline resin; a colorant; and, a releasing agent, wherein the releasing agent has a melting point of 55° C. to 80° C., and wherein the toner satisfies the following Expressions 1 and 2: (Expression 1): 20,000 Pa·s?G1?50,000 Pa·s; and (Expression 2): (G4/G2)/(G3/G1) 1.00, where G1 is a storage modulus, G2 is a loss modulus, G3 is a storage modulus and G4 is a loss modulus, and the storage modulus G1 and the loss modulus G2 are measured at 80° C. when the toner is heated from 70° C. to 150° C. and the storage modulus G3 and the loss modulus G4 are measured at 80° C. when the toner heated to 150° C. is cooled to 70° C.Type: ApplicationFiled: December 28, 2012Publication date: August 1, 2013Inventors: Ryuuta YOSHIDA, Takahiro HONDA, Junichi AWAMURA, Osamu UCHINOKURA, Masaki WATANABE, Daisuke INOUE, Tomoki MURAYAMA, Mamoru HOZUMI
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Publication number: 20130022371Abstract: To provide a toner, which contains a binder resin, a colorant, and a releasing agent, wherein the binder resin contains a low molecular weight resin component, where the low molecular weight resin component has a resin softening coefficient (A), represented by the following formula (1), satisfying A>0.165, and has storage elastic modulus (dyne/cm2) G?(Tfb) satisfying G?(Tfb)?1×104 where Tfb is a flow onset temperature (° C.) of the low molecular weight resin component as measured by a capillary rheometer: A=|[ln G?(r1)?ln G?(r2)]/(T1?T2)|??Formula (1) (where T1 is temperature (° C.) at which storage elastic modulus G?(r1) is 1×105 (dyne/cm2) and T2 is temperature (° C.) at which storage elastic modulus G?(r2) is 1×103 (dyne/cm2) as measured by means of a viscoelasticity measuring device with measuring frequency of 1 Hz, and measuring distortion of 1 deg; and ? represents an absolute value.Type: ApplicationFiled: October 12, 2011Publication date: January 24, 2013Applicant: Ricoh Company, Ltd.Inventors: Teruki Kusahara, Junichi Awamura, Tsuyoshi Sugimoto, Hyo Shu, Tomomi Suzuki, Osamu Uchinokura, Takahiro Honda, Satoshi Kojima, Satoshi Ogawa, Daisuke Inoue, Koshi Sato, Daisuke Ito, Ryuuta Yoshida, Syouko Satoh