Patents by Inventor Mariko Takii

Mariko Takii 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).

  • Patent number: 9005862
    Abstract: A toner including a crystalline polyester resin (A), an amorphous resin (B), and a composite resin (C) having a condensation polymerization resin unit and an addition polymerization resin unit is provided. A molecular weight distribution of the toner based on THF-soluble contents thereof has a main peak within a molecular weight range from 1,000 to 10,000 and a half bandwidth of the main peak is 15,000 or less. The molecular weight distribution is determined by gel permeation chromatography. The toner includes chloroform-insoluble contents. A ratio C/R of the toner is within a range from 0.03 to 0.55. C and R represent heights of spectrum peaks specific to the crystalline polyester resin (A) and the amorphous resin (B), respectively, determined by a Fourier transform infrared spectroscopic attenuation total reflection method after the toner is stored in a thermostatic chamber at 45° C. for 12 hours.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: April 14, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Masashi Nagayama, Hisashi Nakajima, Saori Yamada, Shinya Hanatani, Mariko Takii, Yoshitaka Sekiguchi
  • Patent number: 8918025
    Abstract: To provide an image forming method, containing: a charging step, a latent electrostatic image forming step, a developing step, a transferring step, and a fixing step, wherein the developing step is developing the latent electrostatic image formed on the latent electrostatic image bearing member with a two-component developer containing a toner and a carrier by a developing element to form a visible image, where the developing contains: stirring the toner and the carrier to prepare the two-component developer to have a flow energy amount of 30 mJ to 70 mJ; and periodically discharging and transporting the stirred two-component to the developer unit by air pressure to thereby supply the two-component developer for the developing.
    Type: Grant
    Filed: July 13, 2012
    Date of Patent: December 23, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Tohmatsu, Shigenori Yaguchi, Hitoshi Iwatsuki, Toyoaki Tano, Koichi Sakata, Mariko Takii
  • Publication number: 20140348550
    Abstract: Toner housing container includes: container body housing a toner; conveying portion conveying the toner from longer direction one end of container body to its other end at which container opening portion is provided; pipe receiving port receiving a conveying pipe fixed to toner conveying device; and uplifting portion moving the toner toward toner receiving port of conveying pipe. Toner has molecular weight distribution having a peak in a range of 103 to 104, and has C/R of from 0.03 to 0.55 between peak height C attributed to crystalline polyester resin and R attributed to non-crystalline resin when measured by FT-IR after stored at 45° C. for 12 hours. Container body includes protruding portion protruding from container body interior side toward the one end. Uplifting portion includes uplifting wall surface extending from container body internal wall surface toward protruding portion. Protruding portion is present between uplifting wall surface and toner receiving port.
    Type: Application
    Filed: May 15, 2014
    Publication date: November 27, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Masashi NAGAYAMA, Hisashi NAKAJIMA, Yoshitaka SEKIGUCHI, Saori YAMADA, Shinya HANATANI, Mariko TAKII, Hiroshi Hosokawa, Shunji KATOH, Shinji TAMAKI, Hiroshi IKEGUCHI, Kenji KIKUCHI, Michiharu SUZUKI
  • Patent number: 8877418
    Abstract: The developing method includes developing an electrostatic latent image on an image bearing member with a two-component developer including a toner and a carrier and born on at least one developer bearing member, whose surface moves at a linear speed of from 300 mm/sec to 2,000 mm/sec. The carrier includes a particulate core material; and a cover layer located on a surface of the core material and including a crosslinked material obtained by crosslinking a resin including a first unit having a specific tris(trialkylsiloxy) silyl group and a second unit having a specific alkoxysilyl group having a crosslinking ability. Each of the first unit and the second unit is included in the resin in a molar ratio of from 0.1 to 0.9 based on all the units included in the resin.
    Type: Grant
    Filed: July 19, 2011
    Date of Patent: November 4, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hisashi Nakajima, Kimitoshi Yamaguchi, Shigenori Yaguchi, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii, Minoru Masuda, Koichi Sakata, Saori Yamada, Hiroyuki Kishida
  • Publication number: 20140255840
    Abstract: A toner is provided. The toner includes a crystalline polyester resin (A); and a non-crystalline resin (B). The toner has a viscoelastic property such that the loss tangent (tan ?) defined as a ratio (G?/G?) of loss elastic modulus (G?) to storage elastic modulus (G?) has at least an inflection point or a local maximal point at a temperature ? in a temperature range of from 65° C. to 80° C. while having a local maximal point at a temperature ? in a temperature range of from 75° C. to 90° C., wherein the loss tangent at the temperature ? is from 1.2 to 2.0, and the loss tangent at the temperature ? is from 1.0 to 2.5, wherein the temperature ? is lower than the temperature ?.
    Type: Application
    Filed: January 29, 2014
    Publication date: September 11, 2014
    Inventors: Yoshitaka SEKIGUCHI, Hisashi Nakajima, Masashi Nagayama, Saori Yamada, Shinya Hanatani, Mariko Takii
  • Publication number: 20140072910
    Abstract: A carrier for developing an electrostatic latent image of the present invention includes a core material and a coating layer which coats the core material, wherein the coating layer includes a resin and fine particles, wherein the coating layer has an average layer thickness difference of 0.02 ?m to 3.0 ?m, and wherein the carrier for developing an electrostatic latent image has an arithmetic mean surface roughness Ra1 of 0.5 ?m to 0.9 ?m.
    Type: Application
    Filed: June 26, 2013
    Publication date: March 13, 2014
    Inventors: Hitoshi IWATSUKI, Shigenori Yaguchi, Toyoaki Tano, Mariko Takii, Koichi Sakata, Hiroyuki Kishida, Hiroshi Tohmatsu
  • Patent number: 8652735
    Abstract: A carrier including a magnetic core particle and a resin layer covering a surface of the magnetic core particle. The magnetic core particle is a ferrite particle including strontium in an amount of 0.005 to 3% by mass, measured by fluorescent X-ray spectroscopy. The resin layer comprises a resin obtained by heating a copolymer comprising a silicon-containing unit A and another silicon-containing specific unit B.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Koichi Sakata, Shigenori Yaguchi, Toyoshi Sawada, Kimitoshi Yamaguchi, Hitoshi Iwatsuki, Hiroshi Tohmatsu, Hiroyuki Kishida, Toyoaki Tano, Mariko Takii
  • Patent number: 8652738
    Abstract: A contact developing method including supplying a two-component developer to an electrostatic latent image on a rotating image bearing member by rotating a developing sleeve and a rotatable magnet having multiple magnetic poles provided inside the developing sleeve, to develop the electrostatic latent image into a toner image. The developing sleeve and the image bearing member rotate in the same direction while facing each other. The two-component developer comprises a non-magnetic toner and a carrier. The carrier comprises a magnetic core particle and a resin layer covering the magnetic core particle. The resin layer comprises a conductive particle and a resin. The conductive particle comprises an alumina-based material and a conductive layer covering the alumina-based material. The resin is obtained by heating a copolymer comprising a monomer A unit and a monomer B unit.
    Type: Grant
    Filed: July 13, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Hitoshi Iwatsuki, Mariko Takii, Toyoshi Sawada, Toyoaki Tano, Hiroshi Tohmatsu, Koichi Sakata, Hiroyuki Kishida, Saori Yamada
  • Publication number: 20130260299
    Abstract: An image forming method including steps of forming a latent electrostatic image on an image bearing member, developing the latent electrostatic image with a development agent containing toner to obtain a toner image; transferring the toner image onto a transfer medium; fixing the toner image thereon; wherein the fixing is executed by a fixing device containing a heating roller; a fixing roller; a toner heating medium and the fixing roller; and a pressure roller wherein the toner contains a toner binder containing a crystalline resin containing a polyester resin A; a non-crystalline resin containing a non-crystalline resin B and a non-crystalline resin C, and a complex resin, wherein the toner has a main peak in a range of from 1,000 to 10,000 in the molecule weight distribution as measured for a component soluble in tetrahydrofuran by gel permeation chromatography with a half value width of 15,000 or less.
    Type: Application
    Filed: March 13, 2013
    Publication date: October 3, 2013
    Inventors: Hisashi NAKAJIMA, Masashi Nagayama, Saori Yamada, Mariko Takii
  • Publication number: 20130260307
    Abstract: A toner including a crystalline polyester resin (A), an amorphous resin (B), and a composite resin (C) having a condensation polymerization resin unit and an addition polymerization resin unit is provided. A molecular weight distribution of the toner based on THF-soluble contents thereof has a main peak within a molecular weight range from 1,000 to 10,000 and a half bandwidth of the main peak is 15,000 or less. The molecular weight distribution is determined by gel permeation chromatography. The toner includes chloroform-insoluble contents. A ratio C/R of the toner is within a range from 0.03 to 0.55. C and R represent heights of spectrum peaks specific to the crystalline polyester resin (A) and the amorphous resin (B), respectively, determined by a Fourier transform infrared spectroscopic attenuation total reflection method after the toner is stored in a thermostatic chamber at 45° C. for 12 hours.
    Type: Application
    Filed: March 14, 2013
    Publication date: October 3, 2013
    Inventors: Masashi Nagayama, Hisashi Nakajima, Saori Yamada, Shinya Hanatani, Mariko Takii, Yoshitaka Sekiguchi
  • Publication number: 20130260302
    Abstract: A toner, including: crystalline resin; non-crystalline resin; and a composite resin, wherein the crystalline resin is crystalline polyester resin (A), the non-crystalline resin comprises: non-crystalline resin (B) containing chloroform insoluble matter; and non-crystalline resin (C) having a softening temperature (T½) lower than that of the non-crystalline resin (B) by 25° C. or more, an absolute value |Tgc?Tgb| of a difference between a glass transition temperature (Tgc) of non-crystalline resin (C) and a glass transition temperature (Tgb) of non-crystalline resin (B) is 10° C. or lower, wherein the composite resin is composite resin (D) containing a condensation polymerization resin unit and an addition polymerization resin unit, and the toner has a molecular weight distribution having a main peak in 1,000 to 10,000 and a half width of 15,000 or less, where the molecular weight distribution is obtained by gel permeation chromatography (GPC) of tetrahydrofuran (THF) soluble matter of the toner.
    Type: Application
    Filed: March 14, 2013
    Publication date: October 3, 2013
    Inventors: Hisashi Nakajima, Saori Yamada, Masashi Nagayama, Mariko Takii, Shinya Hanatani
  • Publication number: 20130252160
    Abstract: A toner for forming an electrophotographic image is provided, wherein the toner includes at least four types of binder resins, wherein the binder resins includes at least: a crystalline polyester resin (A); a non-crystalline resin (B); a non-crystalline resin (C); and a composite resin (D) which includes a condensation polymerization resin unit and an addition polymerization resin unit, wherein the non-crystalline resin (B) includes a chloroform insoluble matter, wherein the non-crystalline resin (C) has a softening temperature (T½) lower than that of the non-crystalline resin (B) by 25° C. or more, and wherein the toner has a main peak between 1,000 to 10,000 in a molecular weight distribution obtained by GPC from a tetrahydrofuran soluble matter, and the toner has a half-value width of the molecular weight distribution of 15,000 or less.
    Type: Application
    Filed: September 14, 2012
    Publication date: September 26, 2013
    Inventors: Masashi NAGAYAMA, Mitsuo Aoki, Hisashi Nakajima, Saori Yamada, Mariko Takii
  • Publication number: 20130244162
    Abstract: A toner, including: a binder resin; and a colorant, wherein the binder resin contains: a crystalline polyester resin (A); a non-crystalline resin (B); and a composite resin (C), where the composite resin (C) contains a condensation polymerization resin unit and an addition polymerization resin unit, wherein the toner contains chloroform insoluble matter in an amount of 1% by mass to 30% by mass, wherein the toner has a molecular weight distribution having a main peak in a range of 1,000 to 10,000 and a half width of 15,000 or less, where the molecular weight distribution is obtained through gel permeation chromatography (GPC) of tetrahydrofuran soluble matter of the toner, and wherein the toner has an endothermic peak in a range of 90° C. to 130° C. in measurement through differential scanning calorimetry (DSC).
    Type: Application
    Filed: March 14, 2013
    Publication date: September 19, 2013
    Inventors: Saori Yamada, Hisashi Nakajima, Masashi Nagayama, Shinya Hanatani, Mariko Takii, Yoshitaka Sekiguchi
  • Patent number: 8518626
    Abstract: The carrier is used for a two-component developer for developing an electrostatic latent image, and includes a particulate magnetic core material; and a cover layer located on a surface of the particulate magnetic core material and including a crosslinked material. The crosslinked material is formed by hydrolyzing a copolymer including at least a unit (A) having a specific acrylic siloxane structure including a tris(trialkylsiloxy)silanyl group and a unit (B) having a specific acrylic silicone structure to form a material having a silanol group, and subjecting the material having a silanol group to a condensation reaction using an organic zirconium-containing catalyst.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: August 27, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Saori Yamada, Minoru Masuda, Hisashi Nakajima, Kimitoshi Yamaguchi, Koichi Sakata, Hitoshi Iwatsuki, Yutaka Takahashi, Toyoaki Tano, Mariko Takii
  • Patent number: 8512928
    Abstract: A carrier comprising a magnetic core particle having a shape factor SF-2 of 130 to 160 and a resin layer covering a surface of the magnetic core particle. The resin layer comprises a conductive particle and a resin obtained by heating a copolymer comprising a silicon-containing A unit and another silicon-containing B unit.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: August 20, 2013
    Assignee: Rocoh Company, Ltd.
    Inventors: Hiroyuki Kishida, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii
  • Patent number: 8475989
    Abstract: The carrier is used for a two-component developer for developing an electrostatic latent image, and includes a particulate magnetic core material; and a cover layer located on a surface of the core material and including a crosslinked material and barium sulfate. The cover layer is formed by applying a coating medium including barium sulfate, a copolymer including a unit (A) having a specific acrylic siloxane structure including a tris(trialkylsiloxy)silanyl group and a unit (B) having a specific acrylic silicone structure having a crosslinking ability, and a condensation reaction catalyst, heating the applied medium to a temperature of from 100° C. to 230° C. so that the copolymer is hydrolyzed to produce a material having a silanol group, and the material and the catalyst are subjected to a condensation reaction to form the crosslinked material.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: July 2, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Yutaka Takahashi, Minoru Masuda, Kimitoshi Yamaguchi, Hisashi Nakajima, Koichi Sakata, Hitoshi Iwatsuki, Saori Yamada, Toyoaki Tano, Mariko Takii
  • Publication number: 20130016999
    Abstract: To provide an image forming method, containing: a charging step, a latent electrostatic image forming step, a developing step, a transferring step, and a fixing step, wherein the developing step is developing the latent electrostatic image formed on the latent electrostatic image bearing member with a two-component developer containing a toner and a carrier by a developing element to form a visible image, where the developing contains: stirring the toner and the carrier to prepare the two-component developer to have a flow energy amount of 30 mJ to 70 mJ; and periodically discharging and transporting the stirred two-component to the developer unit by air pressure to thereby supply the two-component developer for the developing.
    Type: Application
    Filed: July 13, 2012
    Publication date: January 17, 2013
    Inventors: Hiroshi Tohmatsu, Shigenori Yaguchi, Hitoshi Iwatsuki, Toyoaki Tano, Koichi Sakata, Mariko Takii
  • Publication number: 20120064451
    Abstract: A carrier comprising a magnetic core particle having a shape factor SF-2 of 130 to 160 and a resin layer covering a surface of the magnetic core particle. The resin layer comprises a conductive particle and a resin obtained by heating a copolymer comprising a silicon-containing A unit and another silicon-containing B unit having.
    Type: Application
    Filed: September 6, 2011
    Publication date: March 15, 2012
    Inventors: Hiroyuki Kishida, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii
  • Publication number: 20120058423
    Abstract: A contact developing method including supplying a two-component developer to an electrostatic latent image on a rotating image bearing member by rotating a developing sleeve and a rotatable magnet having multiple magnetic poles provided inside the developing sleeve, to develop the electrostatic latent image into a toner image. The developing sleeve and the image bearing member rotate in the same direction while facing each other. The two-component developer comprises a non-magnetic toner and a carrier. The carrier comprises a magnetic core particle and a resin layer covering the magnetic core particle. The resin layer comprises a conductive particle and a resin. The conductive particle comprises an alumina-based material and a conductive layer covering the alumina-based material. The resin is obtained by heating a copolymer comprising a monomer A unit and a monomer B unit.
    Type: Application
    Filed: July 13, 2011
    Publication date: March 8, 2012
    Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Hitoshi Iwatsuki, Mariko Takii, Toyoshi Sawada, Toyoaki Tano, Hiroshi Tohmatsu, Koichi Sakata, Hiroyuki Kishida, Saori Yamada
  • Publication number: 20120057898
    Abstract: A carrier including a magnetic core particle and a resin layer covering a surface of the magnetic core particle. The magnetic core particle is a ferrite particle including strontium in an amount of 0.005 to 3% by mass, measured by fluorescent X-ray spectroscopy. The resin layer comprises a resin obtained by heating a copolymer comprising a silicon-containing unit A and another silicon-containing specific unit B.
    Type: Application
    Filed: August 19, 2011
    Publication date: March 8, 2012
    Inventors: Koichi Sakata, Shigenori Yaguchi, Toyoshi Sawada, Kimitoshi Yamaguchi, Hitoshi Iwatsuki, Hiroshi Tohmatsu, Hiroyuki Kishida, Toyoaki Tano, Mariko Takii