Patents by Inventor Yasuaki Iwamoto
Yasuaki Iwamoto 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: 20200026210Abstract: A toner is provided. The toner comprises a binder resin, a metal-containing azo dye, and a quaternary ammonium salt, has an average circularity of from 0.85 to 0.95, and is free of a tin compound having Sn—C bond.Type: ApplicationFiled: April 30, 2019Publication date: January 23, 2020Inventors: Yu HIRAI, Masayuki Ishii, Hyo Shu, Masayuki Kakimoto, Yoshitaka Sekiguchi, Shohta Kobayashi, Shinya Hanatani, Kohtaroh Ogino, Yasuaki Iwamoto
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Patent number: 9625848Abstract: A toner, wherein the toner is obtained by washing a toner particle dispersion liquid which is obtained by adding cellulase to a dispersion slurry, and the dispersion slurry is obtained from a dispersion liquid or an emulsion of a toner material-containing oil phase in an aqueous medium, and wherein the dispersion liquid or the emulsion contains a cellulosic dispersion stabilizing agent.Type: GrantFiled: June 26, 2013Date of Patent: April 18, 2017Assignee: Ricoh Company, Ltd.Inventors: Yousuke Suzuki, Sayaka Yuasa, Sayuri Kojima, Takahiro Kadota, Yasuaki Iwamoto
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Publication number: 20150030976Abstract: A black toner for developing a latent electrostatic image, including: a toner base containing a pigment, a binder resin, a releasing agent, a compound containing fluorine and a compound containing sulfur; and an external additive, wherein the toner contains the external additive on a surface of the toner base, and wherein an amount of the fluorine in the toner base is 200 ppm by mass to 600 ppm by mass as measured by combustion-ion chromatography, and an amount of the sulfur in the toner base is 1,000 ppm by mass to 1,500 ppm by mass as measured by the combustion-ion chromatography.Type: ApplicationFiled: February 28, 2013Publication date: January 29, 2015Inventors: Kei Yokokawa, Yasuaki Iwamoto, Takahiro Kadota
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Patent number: 8835086Abstract: An electrostatic image developing toner including: a binder resin; a colorant; and a wax, wherein the intensity ratio of an absorbance at 2,850 cm?1 derived from the wax to an absorbance at 828 cm?1 derived from the binder resin, represented by “absorbance derived from the wax/absorbance derived from the binder resin”, is in the range of 0.1 to 0.5, where the absorbances are measured by FTIR-ATR, and the intensity ratio serves as a value for determining the amount of the wax present within 0.3 ?m in depth from surfaces of particles of the toner after the toner has been heated to 140° C. and then cooled, and wherein the toner has a storage elastic modulus of 5,000 Pa or greater at 140° C.Type: GrantFiled: December 1, 2010Date of Patent: September 16, 2014Assignee: Ricoh Company, Ltd.Inventors: Naohiro Watanabe, Naohito Shimota, Yasuaki Iwamoto, Masana Shiba, Satoshi Kojima
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Publication number: 20140072911Abstract: A toner, wherein the toner is obtained by washing a toner particle dispersion liquid which is obtained by adding cellulase to a dispersion slurry, and the dispersion slurry is obtained from a dispersion liquid or an emulsion of a toner material-containing oil phase in an aqueous medium, and wherein the dispersion liquid or the emulsion contains a cellulosic dispersion stabilizing agent.Type: ApplicationFiled: June 26, 2013Publication date: March 13, 2014Inventors: Yousuke SUZUKI, Sayaka Yuasa, Sayuri Kojima, Takahiro Kadota, Yasuaki Iwamoto
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Patent number: 8377618Abstract: A toner is provided including a mother toner including a crystalline polyester resin, an amorphous resin, and a wax, and an external additive in an amount of from 0.30 to 0.55 parts by weight based on 100 parts by weight of the mother toner. The toner satisfies the following equation 0.36?(2.77×C/R+1.97×W/R)/X?1.85, wherein each of C, W, and R represents a height of an absorbance peak specific to the crystalline polyester resin, the wax, and the amorphous resin, respectively, measured by a FT-IR ATR method, and X represents an amount (parts by weight) of the external additive. An image forming method and apparatus using the toner are also provided.Type: GrantFiled: September 15, 2008Date of Patent: February 19, 2013Assignee: Ricoh Company LimitedInventors: Hyo Shu, Yasuaki Iwamoto, Yasutada Shitara, Minoru Masuda
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Publication number: 20120264043Abstract: An electrostatic image developing toner including: a binder resin; a colorant; and a wax, wherein the intensity ratio of an absorbance at 2,850 cm?1 derived from the wax to an absorbance at 828 cm?1 derived from the binder resin, represented by “absorbance derived from the wax/absorbance derived from the binder resin”, is in the range of 0.1 to 0.5, where the absorbances are measured by FTIR-ATR, and the intensity ratio serves as a value for determining the amount of the wax present within 0.3 ?m in depth from surfaces of particles of the toner after the toner has been heated to 140° C. and then cooled, and wherein the toner has a storage elastic modulus of 5,000 Pa or greater at 140° C.Type: ApplicationFiled: December 1, 2010Publication date: October 18, 2012Inventors: Naohiro Watanabe, Naohito Shimota, Yasuaki Iwamoto, Masana Shiba, Satoshi Kojima
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Patent number: 8084176Abstract: The present invention provides a toner which includes at least a binder resin, and a colorant, wherein the toner has a concentration of radioactive carbon isotope C-14 of 10.8 pMC or higher.Type: GrantFiled: May 22, 2009Date of Patent: December 27, 2011Assignee: Ricoh Company, Ltd.Inventors: Yasuaki Iwamoto, Shinya Nakayama, Yasutada Shitara, Hiroyuki Kishida
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Publication number: 20110255899Abstract: A toner, including a binder; a colorant; and a wax including a molecular chain constituted of only a C—H bond and a C—C bond, and having a melting point of from 50 to 78° C. and a melt viscosity of from 5 to 15 mPa·S at 140° C., wherein the toner has a weight reduction rate of from 0.001 to 0.1% by weight/min when measured by TGA (Thermogarvimetric Analysis) method in an atmosphere at 165° C. for 10 min.Type: ApplicationFiled: April 13, 2011Publication date: October 20, 2011Applicant: RICOH COMPANY, LTD.Inventors: Yasuaki Iwamoto, Naohito Shimota, Naohiro Watanabe, Satoshi Kojima, Masana Shiba
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Patent number: 8034526Abstract: A method for manufacturing a toner, including: dissolving or dispersing toner constituents including a resin, a colorant, a release agent, and a graft polymer including a polyolefin resin unit and a vinyl resin unit in a solvent, to prepare a toner constituent liquid; supplying the toner constituent liquid to a retention part configured to retain the toner constituent liquid; discharging the toner constituent liquid from the retention part to a granulation space through plural holes arranged on the retention part, while exciting the toner constituent liquid by a vibration means in contact with a part of the retention part, so that the discharged columnar toner constituent liquid is constricted to form liquid droplets; and converting the liquid droplets into solid toner particles; together with a toner manufactured by the above method.Type: GrantFiled: September 7, 2007Date of Patent: October 11, 2011Assignee: Ricoh Company LimitedInventors: Yohichiroh Watanabe, Shinji Ohtani, Yoshihiro Norikane, Yasuaki Iwamoto, Yasutada Shitara, Kazumi Suzuki, Takahiro Honda
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Patent number: 8012659Abstract: An image forming apparatus including a fixing device to fix a toner image on a recording medium including a heat roller and an oil applicator to apply a silicone oil to the heat roller, having a system speed of from 500 to 1700 mm/sec, and using a toner including a binder resin including a crystalline polyester resin and an amorphous polyester resin; a fatty acid amide compound; and a colorant, wherein a ratio (W/R) of a height (W) of a peak at a wavenumber of 1638 cm?1, specific to the fatty acid amide compound, to a height (R) of a peak at a wavenumber of 829 cm?1, specific to the amorphous polyester resin, is from 0.010 to 0.040 in an absorption spectrum obtained by an ATR method (total reflectance method) using a Fourier transform infrared (FT-IR) spectrophotometer.Type: GrantFiled: December 14, 2007Date of Patent: September 6, 2011Assignee: Ricoh Company LimitedInventors: Hyo Shu, Minoru Masuda, Yasuaki Iwamoto, Yasutada Shitara
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Patent number: 8007974Abstract: A toner that is excellent in low-temperature fixing property, offset resistance, storage stability, charge rising property, charge stability with time and pulverizability and allows for forming high-quality images over a long period of time. The toner contains at least a binder resin, a colorant and a charge controlling agent, wherein the charge controlling agent contains an aromatic oxycarboxylic acid metal compound having a trivalent or more central metal, the binder resin comprises a polyester resin (A) having a softening point Tm (A) of 120° C. to 160° C. and a polyester resin (B) having a softening point Tm (B) of 80° C. to less than 120° C., and at least any one of the polyester resins (A) and (B) contains 1,2-propane diol at 65 mol % or more in a divalent alcohol component and can be obtained by condensation polymerizing an alcohol component substantially composed of only an aliphatic alcohol with a carboxylic acid component.Type: GrantFiled: November 21, 2007Date of Patent: August 30, 2011Assignee: Ricoh Company, Ltd.Inventors: Shinya Nakayama, Akihiro Kotsugai, Yasuaki Iwamoto, Yasutada Shitara
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Publication number: 20110091245Abstract: An image forming method including electrostatic image forming step, developing step, transferring step, fixing step and oil application step for applying an oil to a fixing member, wherein the toner includes a binder resin, a colorant and a wax, and the relationship (A2/A1)×100<200 is satisfied, wherein A1 represents the area of the oil dropped on a pellet of the toner measured 30 seconds after dropping the oil, and A2 represents the area of the dropped oil measured 24 hours after dropping the oil. Alternatively, the relationships (X1?X2)<0.5 atomic percent, X1>1.0 atomic percent, and X2>1.0 atomic percent, are satisfied, wherein X1 and X2 represent amounts of Si atoms of the silicone oil measured by subjecting the toner image to X-ray photoelectron spectroscopy at times 5 minutes and 24 hours, respectively, after fixing the toner image.Type: ApplicationFiled: December 28, 2010Publication date: April 21, 2011Inventors: Yasutada SHITARA, Minoru Masuda, Yasuaki Iwamoto, Hyo Shu
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Patent number: 7901861Abstract: An image forming method including electrostatic image forming step, developing step, transferring step, fixing step and oil application step for applying an oil to a fixing member, wherein the toner includes a binder resin, a colorant and a wax, and the relationship (A2/A1)×100<200 is satisfied, wherein A1 represents the area of the oil dropped on a pellet of the toner measured 30 seconds after dropping the oil, and A2 represents the area of the dropped oil measured 24 hours after dropping the oil. Alternatively, the relationships (X1?X2)<0.5 atomic percent, X1>1.0 atomic percent, and X2>1.0 atomic percent, are satisfied, wherein X1 and X2 represent amounts of Si atoms of the silicone oil measured by subjecting the toner image to X-ray photoelectron spectroscopy at times 5 minutes and 24 hours, respectively, after fixing the toner image.Type: GrantFiled: December 4, 2007Date of Patent: March 8, 2011Assignee: Ricoh Company LimitedInventors: Yasutada Shitara, Minoru Masuda, Yasuaki Iwamoto, Hyo Shu
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Patent number: 7892718Abstract: Provided are image forming apparatuses, image forming methods, and process cartridges using a toner that is excellent in low temperature fixing ability, hot offset resistance, and storage stability, and also generate less odor, and thus that can provide high quality images with superior fixing ability, far from tone change with time, and less likely to occur abnormal images such as density-drop and background smear. The image forming apparatuses comprise a latent electrostatic image bearing member, a charging unit, an exposing unit, a developing unit, a transfer unit, and a fixing unit, wherein the toner comprises a binder resin and a colorant, the binder resin comprises a polyester resin prepared by condensation polymerization between an alcohol component that contains an aliphatic polyvalent alcohol and a carboxylic acid component that contains (meth)acrylic acid-modified rosin.Type: GrantFiled: April 20, 2007Date of Patent: February 22, 2011Assignee: Ricoh Company, Ltd.Inventors: Yasuaki Iwamoto, Yohichiroh Watanabe, Yasutada Shitara
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Publication number: 20110033794Abstract: A toner containing a binder, a colorant, and a wax having a molecular chain consisting of C—H bond and C—C bond, wherein the mass reduction of the wax at 165° C. is 10% by mass or less, and the total amount of the wax in the toner measured by a DSC method is 1% by mass to 8% by mass, wherein a ratio, Sbet/SF, of a BET specific surface area (Sbet) of the toner to an average circularity (SF) of the toner is 1.0 m2/g or more to less than 3.6 m2/g, wherein the toner is obtained through a process which contains at least emulsifying or dispersing a toner material liquid in an aqueous medium containing a surfactant, and wherein the toner material liquid is a liquid containing toner-forming materials which contains at least the binder, the colorant and the wax.Type: ApplicationFiled: August 2, 2010Publication date: February 10, 2011Inventors: Naohiro WATANABE, Naohito SHIMOTA, Yasuaki IWAMOTO, Masana SHIBA, Satoshi KOJIMA, Masaki WATANABE, Tsuneyasu NAGATOMO, Hyo SHU
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Patent number: 7873304Abstract: To provide an image forming apparatus including: a latent electrostatic image bearing member; a charging unit configured to charge the surface of the latent electrostatic image bearing member; an exposing unit configured to expose the charged surface of the latent electrostatic image to form a latent electrostatic image thereon; a developing unit configured to develop the latent electrostatic image with a toner to form a visualized image; a transferring unit configured to transfer the visualized image onto a recording medium; and a fixing unit configured to fix the visualized image transferred onto the recording medium, wherein the toner includes a binder resin and a coloring agent, and the binder resin includes a polyester resin obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing a (meth)acrylic acid modified rosin.Type: GrantFiled: April 20, 2007Date of Patent: January 18, 2011Assignee: Ricoh Company, Ltd.Inventors: Yasuaki Iwamoto, Yohichiroh Watanabe, Yasutada Shitara
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Patent number: 7862973Abstract: Provided is a toner that comprises a binder resin, a releasing agent, and a colorant, wherein the mass average particle diameter of the toner is 3 ?m to 8 ?m, the content of particles having a particle diameter of no more than 5 ?m is from 60% by number to 90% by number, the binder resin comprises a polyester resin (A) having a softening temperature Tm(A) from no lower than 120° C. to no higher than 160° C. and a polyester resin (B) having a softening temperature Tm(B) from no lower than 80° C. to lower than 120° C., and at least one of the polyester resins (A) and (B) is prepared by condensation polymerization between an alcohol component and a carboxylic acid component, and the alcohol component comprises divalent alcohol of 1,2-propanediol in a content of no less than 65% by mole and consists substantially of aliphatic alcohol; and also provided is a developer that comprises the toner and a carrier.Type: GrantFiled: November 21, 2007Date of Patent: January 4, 2011Assignee: Ricoh Company, Ltd.Inventors: Shinya Nakayama, Akihiro Kotsugai, Yasuaki Iwamoto, Yasutada Shitara, Yohichiroh Watanabe
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Patent number: 7749674Abstract: A toner including toner particles including a binder resin, a colorant, and an inorganic particulate material present on a surface of the toner particles. The toner particles have a surface roughness (Ra) of from 1 to 30 nm, a standard deviation of the surface roughness of from 10 to 90 nm and include 1 to 20 convexities per 1 ?m, which have a height not less than 10 nm.Type: GrantFiled: July 30, 2007Date of Patent: July 6, 2010Assignee: Ricoh Company, Ltd.Inventors: Hideki Sugiura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Kazuhiko Umemura, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi
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Patent number: 7718340Abstract: To provide an image forming apparatus, image forming method and process cartridge, which are excellent in low-temperature fixation properties, storage stability, durability and filming resistance, can reduce generation of odor, and are capable of forming an extremely high quality image. The apparatus includes: a latent electrostatic image bearing member; a charging unit; an exposing unit; a developing unit; a transferring unit; and a fixing unit; wherein the toner comprises a binder resin and coloring agent, and the binder resin comprises a polyester-based resin (A) and polyester-based resin (B) having a melting point at least 10° C. higher than that of the polyester-based resin (A), and at least one of the polyester-based resins (A) and (B) is a resin derived from a (meth)acrylic acid modified rosin and includes a polyester unit obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing a (meth)acrylic acid modified rosin.Type: GrantFiled: May 30, 2007Date of Patent: May 18, 2010Assignee: Ricoh Company, Ltd.Inventors: Yasuaki Iwamoto, Yohichiroh Watanabe, Yasutada Shitara