Patents by Inventor Toyoshi Sawada

Toyoshi Sawada 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).

  • Publication number: 20080254378
    Abstract: The object of the present invention is to provide a toner characterized in that the toner comprises a first binder resin and a second binder resin, the first binder resin is an amorphous resin and the second binder resin is a crystalline resin, and the glass-transition temperature of the toner (TgA) is lower than the glass-transition temperature expressed by the following equation (1) (TgC). TgC = ? i = 1 n ? ? b i / ? i = 1 n ? ? ( b i TgB i ) Equation ? ? ( 1 ) In the above equation (1), “TgBi” represents the glass-transition temperature of the amorphous resin, “n” represents the number of amorphous resins, and “b” represents the content of the amorphous resin (part by mass). Examples of the preferred aspect of the present invention includes the one that at least a part of the amorphous resin and a part of the crystalline resin are compatible each other, and the one that the glass-transition temperature of the toner (TgA) is 10° C.
    Type: Application
    Filed: June 17, 2008
    Publication date: October 16, 2008
    Inventors: Keiko Matsumoto, Toyoshi Sawada
  • Publication number: 20080227015
    Abstract: A toner, including at least a binder resin; a colorant; and a modified layered inorganic mineral in which at least a part of ions between the layers are modified with an organic material ion, wherein the toner includes at least one external additive having an average primary particle diameter of from 80 to 180 nm and an aspect ratio of from 0.7 to 0.95.
    Type: Application
    Filed: February 22, 2008
    Publication date: September 18, 2008
    Inventors: Tsuneyasu NAGATOMO, Toyoshi Sawada, Takuya Seshita, Satoshi Kojima, Tomomi Suzuki
  • Patent number: 7413839
    Abstract: The object of the present invention is to provide a toner characterized in that the toner comprises a first binder resin and a second binder resin, the first binder resin is an amorphous resin and the second binder resin is a crystalline resin, and the glass-transition temperature of the toner (TgA) is lower than the glass-transition temperature expressed by the following equation (1) (TgC). TgC = ? i = 1 n ? b i / ? i = 1 n ? ( b i TgB i ) Equation ? ? ( 1 ) In the above equation (1), “TgBi” represents the glass-transition temperature of the amorphous resin, “n” represents the number of amorphous resins, and “b” represents the content of the amorphous resin (part by mass). Examples of the preferred aspect of the present invention includes the one that at least a part of the amorphous resin and a part of the crystalline resin are compatible each other, and the one that the glass-transition temperature of the toner (TgA) is 10° C.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: August 19, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Keiko Matsumoto, Toyoshi Sawada
  • Patent number: 7386266
    Abstract: An image removing method including bringing an outermost layer of a removing member into contact with an image fixed on an image support without applying a liquid to the image while heating the image and the outermost layer; and separating the removing member from the image support to remove the image from the image support, wherein the removing member includes a substrate and the outermost layer which is located overlying the substrate and which includes a thermoplastic resin, and wherein the image includes a removing agent which can decrease adhesion force of the image to the image support when heated.
    Type: Grant
    Filed: February 10, 2006
    Date of Patent: June 10, 2008
    Assignee: Ricoh Company Limited
    Inventors: Masashi Nagayama, Motoharu Tanaka, Toyoshi Sawada, Keiko Shiraishi, Tadashi Saitoh
  • Patent number: 7379696
    Abstract: A toner including toner particles including a colorant; a binder resin; and a release agent, wherein the binder resin includes a polyester resin (A) having a crystallinity and a specific formula (1), wherein a molar ratio of the ester bond of the crystalline polyester resin to total ester bonds included in the binder resin is not less than 0.60, and wherein the toner has a weight average particle diameter of from 3.0 to 9.0 ?m, and includes toner particles having a particle diameter not greater than 5 ?m in an amount of from 60 to 90% by quantity. A fixing method in which a toner image of the toner is fixed with a fixing device including a fixing roller having a thickness not greater than 1.0 mm and a pressure roller, wherein the fixing pressure is not greater than 1.5×105 Pa. An image forming method and a process cartridge using the toner are also provided.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: May 27, 2008
    Assignee: Ricoh Company Limited
    Inventors: Toyoshi Sawada, Keiko Matsumoto
  • Publication number: 20080076055
    Abstract: To provide a developer that includes a carrier and a toner having base particles each containing a binder resin and a paraffin wax, wherein the base particle has a paraffin wax-originated endotherm from 2.0 J/g to 5.5 J/g at an endothermic peak as measured by DSC, an average circularity from 0.94 to 1.00, and a contact area-to-whole projected area ratio from 15% to 40%.
    Type: Application
    Filed: September 17, 2007
    Publication date: March 27, 2008
    Inventors: Toyoshi Sawada, Masahide Yamada, Akinori Saitoh, Tomomi Suzuki, Junichi Awamura, Takuya Seshita
  • Publication number: 20080070148
    Abstract: A toner including a binder resin; a colorant; a release agent; and a modified layered inorganic material in which at least part of interlayer ions is modified with an organic ion, wherein the toner has a volume average particle diameter (Dv) of 3 to 7 ?m and a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) of the toner of 1.00 to 1.30, and wherein the release agent is included in the toner in an amount (A) of 1 to 10% by weight, and the ratio (B/A) of the amount (A) to the amount (B) of the release agent included in a classified toner in units of percent by weight is 0.7 to 1.3, wherein the classified toner satisfies the relationship (Dv?/Dn??1)/(Dv/Dn?1)?3/4 wherein Dv? and Dn? respectively represent the volume and number average particle diameters of the classified toner.
    Type: Application
    Filed: September 14, 2007
    Publication date: March 20, 2008
    Inventors: Junichi AWAMURA, Akinori Saitoh, Masahide Yamada, Toyoshi Sawada, Takuya Seshita, Tomomi Suzuki
  • Publication number: 20070218385
    Abstract: A toner is provided including a binder resin and a colorant, wherein the toner has an average shape factor SF-1 of from 130 to 160, and includes toner particles having a shape factor SF-1 of from 100 to 115 in an amount of not greater than 2% by number, and wherein the toner is prepared by a wet granulation method, along with an image forming apparatus and process cartridge using the toner.
    Type: Application
    Filed: March 19, 2007
    Publication date: September 20, 2007
    Inventors: Satoshi Kojima, Toyoshi Sawada, Tsuneyasu Nagatomo, Takuya Seshita, Tomomi Suzuki
  • Publication number: 20070218383
    Abstract: An image forming apparatus including an image bearer; a charging device charging the image bearer; a light irradiating device irradiating the charged image bearer with light to form an electrostatic image; a developing device developing the electrostatic image with a developer including a toner to form a toner image on the image bearer; a transfer device transferring the toner image; and a cleaning device cleaning the image bearer, wherein the volume average particle diameter of the toner is greater than 5.0 ?m and less than 5.5 ?m, the content of toner particles having a particle diameter of not greater than 4.0 ?m is not higher than 20% by number, the ratio of the first shape factor SF-1 to the second shape factor SF-2 is from 1.00 to 1.15, and the content of toner particles having a SF-2 of not less than 115 is not less than 67.8% by number.
    Type: Application
    Filed: March 16, 2007
    Publication date: September 20, 2007
    Inventors: Takuya Seshita, Toyoshi Sawada, Tomomi Suzuki, Tsuneyasu Nagatomo, Satoshi Kojima
  • Patent number: 7235338
    Abstract: A toner prepared by a method of dissolving or dispersing toner constituents comprising a modified resin capable of reacting with an active hydrogen and a colorant which is a black metallic material to prepare a solution or a dispersion; and reacting the solution or dispersion with at least one of a crosslinking agent and an elongation agent in an aqueous medium including a resin particulate material.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: June 26, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Takada, Masahiro Ohki, Toyoshi Sawada, Keiko Shiraishi, Masashi Nagayama
  • Patent number: 7217485
    Abstract: A toner for electrophotography contains a binder resin, a charge control agent, and a colorant. The colorant is a black iron oxide compound containing 10 to 45% by weight of titanium component calculated in terms of Ti atom in relation to Fe atom when measured by wavelength dispersive X-ray fluorescence spectrometry. Peaks at Bragg angle 2? of the toner to CuK? X-ray are peak A at 32.9 degrees ±0.3 degrees and peak B at 35.5 degrees ±0.3 degrees, and X ray intensity ratio between peaks A and B (A/B) is in the range of 0.3 to 2.0 at a scan speed of 0.5 to 4 degrees/min.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: May 15, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Kumi Hasegawa, Mitsuo Aoki, Bing Shu, Toyoshi Sawada, Keiko Shiraishi, Masashi Nagayama, Shinichi Kuramoto
  • Patent number: 7163774
    Abstract: A toner including a binder resin including a crystalline polyester and a non-crystalline resin; a release agent; and a black metal-containing material having a saturation magnetization not greater than 50 emu/g. A toner container containing the toner. A fixing method including passing a support with the toner image thereon through a nip between two cylindrical rollers while applying a pressure not greater than 1×105 Pa to the two cylindrical rollers, wherein one of the cylindrical rollers which contacts the toner image has a thickness not greater than 1.0 mm. An image forming method including developing an electrostatic image with the toner to form a toner image; transferring the toner image onto a receiving material; and fixing the toner image by the fixing method mentioned above. A process cartridge including an image bearing member and a developing device using the toner.
    Type: Grant
    Filed: February 6, 2004
    Date of Patent: January 16, 2007
    Assignee: Ricoh Company Limited
    Inventors: Keiko Shiraishi, Toyoshi Sawada, Masashi Nagayama, Shinichi Kuramoto, Mitsuo Aoki, Kumi Hasegawa, Bing Shu
  • Patent number: 7132210
    Abstract: An image-forming color toner contains at least a colorant, a resin (A), a modified resin (B) and a wax (a) as a mold releasing agent, the image-forming color toner having a phase separated structure comprising the modified resin (B) as a domain in the resin (A) as a continuous phase, and wax (a) being effectively contained the modified resin (B). The modified resin (B) has a wax part containing a wax component (b), and a modified part formed of a vinyl monomer unit and an average ester group concentration of 8% by weight to 30% by weight.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: November 7, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Masanori Suzuki, Yohichiroh Watanabe, Keiko Shiraishi, Toyoshi Sawada, Takuya Saito, Masashi Nagayama
  • Publication number: 20060222987
    Abstract: An image-forming color toner contains at least a colorant, a resin (A), a modified resin (B) and a wax (a) as a mold releasing agent, the image-forming color toner having a phase separated structure comprising the modified resin (B) as a domain in the resin (A) as a continuous phase, and wax (a) being effectively contained the modified resin (B). The modified resin (B) has a wax part containing a wax component (b), and a modified part formed of a vinyl monomer unit and an average ester group concentration of 8% by weight to 30% by weight.
    Type: Application
    Filed: June 2, 2006
    Publication date: October 5, 2006
    Inventors: Masanori Suzuki, Yohichiroh Watanabe, Keiko Shiraishi, Toyoshi Sawada, Takuya Saito, Masashi Nagayama
  • Publication number: 20060127152
    Abstract: An image removing method including bringing an outermost layer of a removing member into contact with an image fixed on an image support without applying a liquid to the image while heating the image and the outermost layer; and separating the removing member from the image support to remove the image from the image support, wherein the removing member includes a substrate and the outermost layer which is located overlying the substrate and which includes a thermoplastic resin, and wherein the image includes a removing agent which can decrease adhesion force of the image to the image support when heated.
    Type: Application
    Filed: February 10, 2006
    Publication date: June 15, 2006
    Inventors: Masashi Nagayama, Motoharu Tanaka, Toyoshi Sawada, Keiko Shiraishi, Tadashi Saitoh
  • Patent number: 7060407
    Abstract: An image removing method including bringing an outermost layer of a removing member into contact with an image fixed on an image support without applying a liquid to the image while heating the image and the outermost layer; and separating the removing member from the image support to remove the image from the image support, wherein the removing member includes a substrate and the outermost layer which is located overlying the substrate and which includes a thermoplastic resin, and wherein the image includes a removing agent which can decrease adhesion force of the image to the image support when heated.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: June 13, 2006
    Assignee: Ricoh Company, Limited
    Inventors: Masashi Nagayama, Motoharu Tanaka, Toyoshi Sawada, Keiko Shiraishi, Tadashi Saitoh
  • Patent number: 7052815
    Abstract: A color toner including toner particles including a colorant, a binder resin, and a wax; and an external additive including at least one of an inorganic particulate material and a particulate resin, wherein the binder resin includes a polyester resin (A) having a crystallinity and a formula (—O—CO—CR1=CR2-CO—O—(CH2)n—)m, wherein R1 and R2 independently represents a hydrocarbon, and n and m are repeating numbers; a resin (B); and a resin (C), wherein the resins (B) and (C) and the wax have an island-sea structure such that the resin (C) is present like islands in a sea of the resin (B) and the wax is substantially included in the resin (C). A toner container, an image forming method, an image forming apparatus and a process cartridge including the color toner are also provided.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: May 30, 2006
    Assignee: Ricoh Company, Limited
    Inventors: Toyoshi Sawada, Masanori Suzuki, Kohki Katoh, Yohichiroh Watanabe, Keiko Shiraishi, Takuya Saito, Masashi Nagayama
  • Patent number: 7049037
    Abstract: A color toner composition including at least toner particles including at least a binder resin; a colorant and a release agent dispersed in the binder resin; and a titania as an external additive, wherein the colorant has an average dispersion particle diameter not greater than 0.5 ?m; the release agent and the binder resin are insoluble to each other; the toner particles satisfy the relationship: 0.05?Dw/D4?0.4, wherein Dw represents an average dispersion particle diameter of the release agent and D4 represents a weight-average particle diameter of the toner particles; and the titania has a segregation rate of from 0.5 to 5%.
    Type: Grant
    Filed: August 6, 2004
    Date of Patent: May 23, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohki Katoh, Masanori Suzuki, Yohichiro Watanabe, Masahide Yamashita, Akihiro Kotsugai, Toyoshi Sawada, Keiko Shiraishi
  • Patent number: 6977129
    Abstract: A charge control agent containing a calcium salt of a sulfoisophthalic acid compound. A toner for developing an electrostatic latent image including the above charge control agent, a binder resin and a colorant.
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: December 20, 2005
    Assignees: Ricoh Company, Ltd., Takemoto Yushi Kabushiki Kaisha
    Inventors: Takuya Saito, Masanori Suzuki, Yohichiroh Watanabe, Keiko Shiraishi, Toyoshi Sawada, Tatsuhiko Osaki, Satoshi Aratani, Hiroki Ogiso
  • Publication number: 20050277046
    Abstract: A color toner including toner particles including a colorant, a binder resin, and a wax; and an external additive including at least one of an inorganic particulate material and a particulate resin, wherein the binder resin includes a polyester resin (A) having a crystallinity and a formula (—O—CO—CR1?CR2—CO—O—(CH2)n—)m, wherein R1 and R2 independently represents a hydrocarbon, and n and m are repeating numbers; a resin (B); and a resin (C), wherein the resins (B) and (C) and the wax have an island-sea structure such that the resin (C) is present like islands in a sea of the resin (B) and the wax is substantially included in the resin (C). A toner container, an image forming method, an image forming apparatus and a process cartridge including the color toner are also provided.
    Type: Application
    Filed: August 4, 2005
    Publication date: December 15, 2005
    Inventors: Toyoshi Sawada, Masanori Suzuki, Kohki Katoh, Yohichiroh Watanabe, Keiko Shiraishi, Takuya Saito, Masashi Nagayama