Chemically Or Physically Identified Binder Or Coating Resin For Magnetic Carrier Patents (Class 430/111.35)
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Patent number: 8293446Abstract: A resin-coated carrier is provided. A resin-coated carrier includes a carrier core and a resin coating layer formed on a surface of the carrier core. The carrier core is composed of a porous material having surface fine pores formed on a surface thereof, and has an apparent density of 1.6 to 2.0 g/cm3. The resin coating layer contains cross-linked fine resin particles. Additionally, the resin-coated carrier is configured such that a volume average particle size of the cross-linked fine resin particles contained in the resin coating layer and an area average diameter of the surface fine pores satisfy a predetermined relational expression.Type: GrantFiled: April 28, 2010Date of Patent: October 23, 2012Assignee: Sharp Kabushiki KaishaInventors: Osamu Wada, Takanori Kamoto, Nobuyuki Yoshioka, Ayae Nagaoka, Tadashi Iwamatsu
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Publication number: 20120251942Abstract: There are provided a resin-coated carrier for an electrophotographic developer, in which a magnetic particle is coated with a resin on its surface, and the coating resin contains a carbon nanotube having a carbon content of 75% by weight or more, and an electrophotographic developer using the resin-coated carrier.Type: ApplicationFiled: March 28, 2012Publication date: October 4, 2012Applicant: POWDERTECH CO., LTD.Inventors: Tetsuya UEMURA, Makoto ISHIKAWA
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Patent number: 8263302Abstract: A carrier for electrophotographic developer, including a core material; and a layer comprising a binder resin, located overlying the core material, wherein the binder resin includes a segment including one or more polymerizable vinyl monomers as a structural unit; and another segment including a partial cleavage structure of polyhedral oligomeric silsesquioxane and/or another partial cleavage structure of polyhedral oligomeric silsesquioxane as a structural unit.Type: GrantFiled: September 8, 2009Date of Patent: September 11, 2012Assignee: Ricoh Company, Ltd.Inventors: Yoshihiro Moriya, Akihiro Kotsugai, Toyoshi Sawada, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita
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Patent number: 8257896Abstract: A carrier which is capable of avoiding excess blocking of the carrier particles at the time of forming a covering layer and is excellent in durability, a developer containing the carrier, and a developer container containing the developer, as well as an image forming method and a process cartridge which use the developer are provided. A carrier including at least a core material particle and a covering layer, a surface of the core material particle being covered with the covering layer, wherein the covering layer contains a condensate which is obtained by condensation of a silicone resin having at least one of a silanol group and a functional group which can be converted to the silanol group by hydrolysis, using a titanium diisopropoxy bis(ethylaceto-acetate) catalyst.Type: GrantFiled: March 10, 2010Date of Patent: September 4, 2012Assignee: Ricoh Company, Ltd.Inventors: Minoru Masuda, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano
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Publication number: 20120214097Abstract: Provided are a magnetic carrier and a two-component developer comprising the magnetic carrier. The magnetic carrier comprises magnetic carrier particles, each of which comprises a magnetic carrier core, the surface of which is coated with a charge control agent and further coated with a resin coat layer containing a resin composition.Type: ApplicationFiled: August 24, 2011Publication date: August 23, 2012Applicant: CANON KABUSHIKI KAISHAInventors: Takeshi Naka, Yoshinobu Baba, Koh Ishigami
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Publication number: 20120214098Abstract: A carrier for a two-component developer, includes: magnetic particles and a resin coating layer that is coated on the magnetic particles, the resin coating layer containing metal nitride particles having a volume average primary particle diameter of from about 300 to about 2,000 nm.Type: ApplicationFiled: September 2, 2011Publication date: August 23, 2012Applicant: FUJI XEROX CO., LTD.Inventors: Norihito FUKUSHIMA, Toshiaki HASEGAWA, Yosuke TSURUMI
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Patent number: 8247150Abstract: A carrier for developing an electrostatic latent image which includes a core material and a resin coating layer provided on the core material. The resin coating layer includes a resin and a particulate tin oxide, and the surface of the particulate tin oxide is coated with carbon.Type: GrantFiled: September 17, 2009Date of Patent: August 21, 2012Assignee: Ricoh Company, Ltd.Inventors: Hitoshi Iwatsuki, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata
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Patent number: 8247149Abstract: To provide an electrophotographic developer carrier including a carrier core material, and a coat layer containing a binder resin and conductivity-imparted microparticles which are produced by imparting conductivity to inorganic microparticles, the coat layer being formed over the carrier core material, wherein the electrophotographic developer carrier has a static resistivity of 10 [Log (?·cm)] or higher and a dynamic resistivity of 9 [Log (?)] or lower, and is used in an electrophotographic developer together with a negatively chargeable toner having an average circularity of 0.925 to 0.970, and wherein the toner includes a resin, a colorant and an inorganic layered mineral in which at least part of interlayer ions is modified with organic ions, and is granulated by dispersing and/or emulsifying an oil phase and/or a monomer phase containing at least a toner composition and/or a toner composition precursor in an aqueous medium.Type: GrantFiled: December 2, 2008Date of Patent: August 21, 2012Assignee: Ricoh Company, Ltd.Inventors: Shinichiro Yagi, Kousuke Suzuki, Masashi Nagayama
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Publication number: 20120202147Abstract: An anisotropic magnetic material-dispersed resin carrier including: fine magnetic particles; and a binder resin in which at least the fine magnetic particles are dispersed, wherein the anisotropic magnetic material-dispersed resin carrier has a magnetic anisotropy where magnetic fields of the fine magnetic particles are orientated in the same direction, and wherein the anisotropic magnetic material-dispersed resin carrier has a saturation magnetization of 16 emu/g to 30 emu/g, a coercive force of 15 kA/m to 40 kA/m, and a number average particle diameter of 15 ?m or more but less than 100 ?m.Type: ApplicationFiled: January 31, 2012Publication date: August 9, 2012Applicant: RICOH COMPANY, LTD.Inventors: Kazumi SUZUKI, Masaki Yoshino, Hisao Kurosu, Tatsuya Morita, Tomoko Kino, Shingo Sakashita
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Patent number: 8227163Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core having a polymeric coating on at least a portion thereof. The polymer coating possesses cation binding groups. Processes for coating such carriers with the polymeric coatings are also provided.Type: GrantFiled: March 23, 2010Date of Patent: July 24, 2012Assignee: Xerox CorporationInventors: Richard P. N. Veregin, Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy
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Patent number: 8216759Abstract: The present invention provides an electrophotographic carrier which includes a core particle, a first resin layer containing a charge-generating material for coating the core particle, and a second resin layer containing a hole-transporting material for coating the first resin layer. The invention also provides a two-component developer comprising said carrier, and an image-forming process and apparatus using said developer. According to the invention, high quality images can be formed, with excellent image density (especially when developing solid images) and less fogging.Type: GrantFiled: June 23, 2009Date of Patent: July 10, 2012Assignee: Sharp Kabushiki KaishaInventor: Keigo Mitamura
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Patent number: 8213833Abstract: An image forming apparatus including at least an image bearer; a charger charging the image bearer; an irradiator irradiating the image bearer to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a developer comprising a toner and a carrier to form a toner image on the image bearer; a developer feeder feeding a supplemental developer including the toner and the carrier into the image developer; and a developer collector collecting the developer in the image developer, wherein the developer feeder includes a cylindrical supplemental developer container containing the supplemental developer, including a spiral developer guide race on the inner circumferential surface thereof; and a sub-hopper configured to store the supplemental developer, and wherein the carrier includes a core material; and a layer coated on the core material, including a binder resin and non-black or a non-color inorganic particulate material.Type: GrantFiled: January 11, 2008Date of Patent: July 3, 2012Assignee: Ricoh Company, Ltd.Inventors: Shinichiro Yagi, Tomio Kondou, Masashi Nagayama, Hltoahi Iwatsuki
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Patent number: 8211610Abstract: The carrier includes a particulate core material having magnetism; and a resin layer located on the surface of the particulate core material. The resin layer is prepared by forming a layer including a copolymer, which includes a unit (A) having a specific acrylic siloxane structure, a unit (B) having a specific acrylic silicone structure having a crosslinking ability, and a unit (C) having a specific acrylic structure in a specific ratio, on the particulate core material, and then subjecting the layer to a heat treatment to crosslink the layer.Type: GrantFiled: March 1, 2010Date of Patent: July 3, 2012Assignee: Ricoh Company LimitedInventors: Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano
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Patent number: 8187781Abstract: Employed are a resin-filled ferrite carrier for an electrophotographic developer filled with a resin in voids of a porous ferrite core material, wherein the resin filled in the voids is a silicone resin which has a softening point of 40° C. or above and is cured at or above such softening point, and the filled amount is 7 to 30 parts by weight based on 100 parts by weight of the core material, a method for producing thereof band an electrophotographic developer using this ferrite carrier.Type: GrantFiled: March 4, 2008Date of Patent: May 29, 2012Assignee: Powdertech Co., Ltd.Inventors: Hiromichi Kobayashi, Takao Sugiura
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Publication number: 20120129087Abstract: The present invention relates to a magnetic carrier for an electrophotographic developer comprising spherical magnetic composite particles comprising a phenol resin as a binder and ferromagnetic iron oxide particles bonded to each other through the phenol resin, wherein the spherical magnetic composite particles have a ten-point mean roughness Rz of 0.3 to 2.0 ?m. The magnetic carrier for an electrophotographic developer according to the present invention exhibits an excellent durability against peeling-off and abrasion of coating resins formed thereon and a high stability to mechanical stress exerted onto the carrier, is free from occurrence of spent toner, can be stably held over a long period of time without occurrence of fogging and unevenness in density of toner images, and can keep high-quality images with an excellent gradation for a long period of time.Type: ApplicationFiled: June 4, 2010Publication date: May 24, 2012Inventors: Katsuji Iwami, Shigenori Harada, Eiichi Kurita, Kaori Kinoshita
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Publication number: 20120122028Abstract: A carrier for developing an electrostatic image, includes: magnetic core material particles and a coated layer coated on the magnetic core material particles, the coated layer containing a resin having a monomer unit represented by formula (A): wherein R1 represents a hydrogen atom or a methyl group; R2 to R4 each independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group; R5 independently represents an alkyl group, an aryl group or an aralkyl group; n represents an integer of from 0 to 7; and L1 represents a single bond or an alkylene group, provided that at least one of R3 and R4 is not a hydrogen atom.Type: ApplicationFiled: April 21, 2011Publication date: May 17, 2012Applicant: FUJI XEROX CO., LTD.Inventors: Yasuaki HASHIMOTO, Yosuke TSURUMI
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Patent number: 8178273Abstract: To provide (1) a method for manufacturing a carrier, including: dissolving a coating material composed of a plurality of types of materials in a fluid containing at least one of a supercritical fluid and a subcritical fluid; and lowering the solubility of the solution by controlling at least one of pressure and temperature to form a coating layer on a core surface, or (2) a method for manufacturing a carrier, including: dispersing or dissolving a coating material in a fluid containing at least one of a supercritical fluid and a subcritical fluid; and lowering solubility of the solution by controlling at least one of pressure and temperature to form a coating layer on a core surface, wherein the coating material contains at least a silicone resin, and the silicone resin has a weight-average molecular weight (Mw) of 800 to 5,000.Type: GrantFiled: September 11, 2007Date of Patent: May 15, 2012Assignee: Ricoh Company, Ltd.Inventors: Ryota Inoue, Chiaki Tanaka, Shinichi Kuramoto
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Publication number: 20120115078Abstract: The present invention relates to a magnetic carrier for an electrophotographic developer comprising spherical composite particles comprising spherical composite core particles comprising at least ferromagnetic iron oxide fine particles and a cured phenol resin and having an average particle diameter of 1 to 100 ?m, and a melamine resin coating layer formed on the respective core particles, wherein a ratio of R100 to R300 (R100/R300) in which R100 is an electric resistance value as measured when applying a voltage of 100 V to the magnetic carrier; and R300 is an electric resistance value as measured when applying a voltage of 300 V to the magnetic carrier, is controlled to lie within the range of 1 to 50.Type: ApplicationFiled: June 15, 2010Publication date: May 10, 2012Inventors: Kaori Kinoshita, Shinji Uemoto, Eiichi Kurita
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Patent number: 8142971Abstract: An electrostatic charge developer includes a carrier having a core material and a resin coating layer covering the surface of the core material, and a toner having a binder resin that contains a non-crystalline polyester resin and a crystalline polyester resin. The resin coating layer contains a copolymer that contains a nitrogen-containing acrylic ester or nitrogen-containing methacrylic ester and an alicyclic acrylic ester or alicyclic methacrylic ester. The non-crystalline polyester resin contains at least an alkyl succinic acid or an anhydride or lower alkyl ester thereof, or an alkenyl succinic acid or an anhydride or lower alkyl ester thereof. The crystalline polyester resin is an aliphatic polyester resin.Type: GrantFiled: October 14, 2008Date of Patent: March 27, 2012Assignee: Fuji Xerox Co., Ltd.Inventors: Noriyuki Mizutani, Yasuhiro Arima, Fusako Kiyono, Susumu Yoshino
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Publication number: 20120052435Abstract: A tin-zinc complex oxide powder includes particles containing a tin-zinc complex oxide and having a volume resistivity of about 1×105 ?·cm or less.Type: ApplicationFiled: May 17, 2011Publication date: March 1, 2012Applicant: FUJI XEROX CO., LTD.Inventors: Kazunori ANAZAWA, Tomoko MIYAHARA, Kaoru TORIKOSHI
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Patent number: 8114562Abstract: A two-component developer containing a yellow toner and a magnetic carrier, wherein the yellow toner has the characteristics: (i) when the concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and the absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the relationship of 6.00<A422/Cy<14.40; (ii) the lightness L* and chroma C* of the yellow toner determined in a powder state satisfy the relationships of 85.0?L*?95.0 and 100.0?C*?115.0; and (iii) the absolute value for the triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: GrantFiled: March 3, 2010Date of Patent: February 14, 2012Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Patent number: 8067136Abstract: To provide: a charge control agent having negative chargeability, which contributes to environmental conservation and the like to an increased degree, has high performance (high charge amount, quick rise-up of charge, excellent stability with time, and high environmental stability), and has improved dispersibility; a toner for developing an electrostatic charge image containing the charge control agent; and an image forming method and an image forming apparatus each using the toner for developing an electrostatic charge image. A charge control agent for controlling a charged state of powder, characterized by including one or more units each represented by the following chemical formula (1) in a molecule.Type: GrantFiled: June 9, 2005Date of Patent: November 29, 2011Assignee: Canon Kabushiki KaishaInventors: Tetsuya Yano, Takashi Kenmoku, Tatsuki Fukui, Ako Kusakari, Chieko Mihara
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Patent number: 8062822Abstract: An electrostatic latent image developing carrier is provided which comprises a core particle and a resin coating layer containing conductive particles dispersed therein, the carrier having a volume average particle diameter of 25 to 60 ?m and an average degree of circularity of 0.975 or more, wherein the core particle has a BET specific surface area of 0.1 to 0.3 m2/g and an internal void ratio of 10% or less.Type: GrantFiled: December 7, 2005Date of Patent: November 22, 2011Assignee: Fuji Xerox Co., Ltd.Inventors: Satoshi Inoue, Masahiro Takagi, Koutarou Yoshihara
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Patent number: 8053073Abstract: A process for producing resin-coated metal particles includes coating surfaces of metal particles with silica; allowing a polymerizable group to adsorb onto the surfaces of the silica-coated particles by the use of a silane coupling agent; and coating the surfaces of the silica-coated particles with a polymeric resin by mixing the particles to which the polymerizable groups have been adsorbed, a polymerizable monomer, a polymerization initiator, and a dispersant to polymerize the polymerizable monomer and the polymerizable groups.Type: GrantFiled: September 15, 2004Date of Patent: November 8, 2011Assignee: Murata Manufacturing Co., Ltd.Inventors: Kiyoko Ueda, Ichiro Nakamura, Kiyoyasu Sakurada
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Patent number: 8043785Abstract: The present invention provides a method for producing a carrier that includes dissolving at least a coating material in carbon dioxide in a liquid state, and forming a coating layer on a core material surface by reducing the solubility of the liquid with at least the coating material dissolved therein through control of at least any one of the pressure and temperature. The present invention also provides a carrier produced by the method for producing a carrier.Type: GrantFiled: November 23, 2007Date of Patent: October 25, 2011Assignee: Ricoh Company, Ltd.Inventors: Ryota Inoue, Chiaki Tanaka, Masayuki Ishii, Yoshihiro Moriya, Shingo Sakashita
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Patent number: 8039184Abstract: Provided is a two-component developer with which degradation of development is inhibited even in the case of prolonged use, and thereby a high quality image exhibiting high resolution and sufficient image density can be formed for a long duration. Also disclosed is a two-component developer possessing a carrier and a toner, wherein the carrier in which magnetic material powder is dispersed in a binder resin containing a phenol formaldehyde resin has a shape coefficient SF-1 of 1.0-1.2, a shape coefficient SF-2 of 1.1-2.5 and a volume-based median particle diameter of 10-100 ?m, and the toner possesses a colored particle and an external additive particle, wherein the external additive particle comprises a titanic acid compound and iron, and the iron content is 100-1,000 ppm, based on the titanic acid compound.Type: GrantFiled: March 5, 2009Date of Patent: October 18, 2011Assignee: Konica Minolta Business Technologies, Inc.Inventors: Masahiro Anno, Masahiko Nakamura, Tsuyoshi Uchida, Kenichi Onaka, Junya Onishi, Naoya Tonegawa
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Patent number: 8039189Abstract: The present invention can provide small-diameter core material particles for electro photographic carrier, the particles that can prevent occurrences of carrier adhesions and reduce toner spent, have excellent durability and cause little fluctuations in image density with a narrow particle diameter distribution, and an efficient, cost-effective production method thereof. That is, the core material particles for electro photographic carrier are particles wherein the weight average particle diameter, Dw, is in the range of 22 ?m to 32 ?m, the ratio of Dw to the number average particle diameter, Dp, satisfies the condition, 1<Dw/Dp<1.20, the content of particles smaller than 20 ?m in diameter is in the range of 0% by mass to 7% by mass and smaller than 36 ?m is in the range of 90% by mass to 100% by mass, and the BET specific surface area is in the range of 300 cm2/g to 900 cm2/g.Type: GrantFiled: April 17, 2007Date of Patent: October 18, 2011Assignee: Ricoh Company, Ltd.Inventors: Kimitoshi Yamaguchi, Naoki Imahashi, Masashi Nagayama
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Publication number: 20110236820Abstract: An electrostatic charge image development carrier includes magnetic core particles and a resin coating layer that contains titanium dioxide particles doped with niobium and coats each of the magnetic core particles.Type: ApplicationFiled: August 26, 2010Publication date: September 29, 2011Applicant: FUJI XEROX CO., LTD.Inventors: Toshiaki HASEGAWA, Takeshi SHOJI, Sakon TAKAHASHI, Fusako KIYONO
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Publication number: 20110236815Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core having a polymeric coating on at least a portion thereof. The polymer coating possesses cation binding groups. Processes for coating such carriers with the polymeric coatings are also provided.Type: ApplicationFiled: March 23, 2010Publication date: September 29, 2011Applicant: XEROX CORPORATIONInventors: Richard P.N. Veregin, Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy
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Patent number: 8026032Abstract: A carrier for use in an image forming apparatus in which a toner and a carrier are fed to an image developer thereof and an extra developer including the toner and the carrier in the image developer is discharged therefrom, wherein at least one of the carrier fed to the image developer and a carrier readily contained therein includes a core material; and a coated film coating the core material, and wherein the coated film includes a binder resin and a particulate material having a ratio of an average particle diameter thereof to an average thickness of the coated film of from 0.01 to 1, and includes concavities and convexities having an average difference of elevation of from 0.02 to 3.0 ?m.Type: GrantFiled: October 11, 2007Date of Patent: September 27, 2011Assignee: Ricoh Company, Ltd.Inventors: Hitoshi Iwatsuki, Tomio Kondou, Shinichiro Yagi, Masashi Nagayama
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Publication number: 20110229817Abstract: 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: ApplicationFiled: March 1, 2011Publication date: September 22, 2011Inventors: Saori YAMADA, Minoru Masuda, Hisashi Nakajima, Kimitoshi Yamaguchi, Koichi Sakata, Hitoshi Iwatsuki, Yutaka Takahashi, Toyoaki Tano, Mariko Takii
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Patent number: 7981582Abstract: A toner having a crystalline or semi-crystalline polyester resin, an amorphous resin and a colorant. The toner preferably exhibits a resistivity of at least 1×1011 ohm-cm. A developer may be produced including the toner and optionally a carrier. If a carrier is included, the carrier preferably exhibits a resistivity of greater than 1×107 ohm-cm. An electrophotographic machine includes the toner exhibiting high resistivity.Type: GrantFiled: June 23, 2005Date of Patent: July 19, 2011Assignee: Xerox CorporationInventors: Richard P. N. Veregin, Michael S. Hawkins, Vladislav Skorokhod, Valerie M. Farrugia
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Patent number: 7964330Abstract: There are adopted an electrophotographic resin-coated ferrite carrier having a carrier core coated with a resin, wherein a product of an apparent density ? (g/cm3), average particle size d (?m) and BET specific surface area S (m2/g) of the carrier core satisfies the following condition, a method for producing the same, and an electrophotographic developer. 4.5??×d×S?8.Type: GrantFiled: March 30, 2007Date of Patent: June 21, 2011Assignee: Powertech Co., Ltd.Inventors: Issei Shinmura, Kanao Kayamoto
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Patent number: 7939233Abstract: A magnetic carrier and a two-component developer are provided which have remedied blank areas, fog after leaving, carrier sticking during running, and image density variations before and after running. The magnetic carrier has magnetic carrier particles having at least porous magnetic core particles and a resin. The magnetic carrier particles satisfying the specific conditions (a), (b) and (c) where, in a reflected electron image of cross sections of the magnetic carrier particles as photographed with a scanning electron microscope, straight lines that divide a cross section of a magnetic carrier particle into 72 at intervals of 5° are drawn from a reference point of the cross section thereof toward the surface of the magnetic carrier particle; the magnetic carrier particles being contained in an amount of 60% by number or more.Type: GrantFiled: January 21, 2010Date of Patent: May 10, 2011Assignee: Canon Kabushiki KaishaInventors: Chika Inoue, Hiroyuki Fujikawa, Koh Ishigami, Kunihiko Nakamura, Nozomu Komatsu, Tomoko Endo, Yoshinobu Baba, Takayuki Itakura
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Patent number: 7939232Abstract: A toner or two-component developer is obtained by mixing, aggregating, and heating resin particles, colorant particles, and wax particles in an aqueous medium. A gel permeation chromatography (GPC) measurement of the resin particles shows that a weight-average molecular weight is 10000 to 60000, and the ratio of the weight-average molecular weight to a number-average molecular weight is 1.5 to 6. The wax particles include at least a first wax and a second wax. An endothermic peak temperature (melting point Tmw1 (° C.)) of the first wax based on a DSC method is 50° C. to 90° C. An endothermic peak temperature (melting point Tmw2 (° C.)) of the second wax based on the DSC method is at least 5° C. to 50° C. higher than Tmw1. Thus, the toner can have a smaller particle size and a sharp particle size distribution without requiring a classification process, can achieve a longer life, and can suppress transfer voids or scattering during transfer.Type: GrantFiled: November 1, 2005Date of Patent: May 10, 2011Assignee: Panasonic CorporationInventors: Yasuhito Yuasa, Hidekazu Arase, Masahisa Maeda
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Patent number: 7939234Abstract: An image forming apparatus, including a latent image-holding member, a developing unit, a transfer unit, a cleaning unit, and a recycling unit, wherein the developer includes a toner having an external-additive adhesiveness index SA in the range of approximately 50% to approximately 95% and: a carrier containing magnetic particles and a coating layer coating the surface of the magnetic particles and having a total energy of approximately 1,420 to approximately 2,920 mJ; or a carrier containing magnetic powder-dispersed particles and a coating layer coating the surface of the magnetic powder-dispersed particles and having a total energy of, approximately 890 to approximately 1,390 mJ.Type: GrantFiled: May 30, 2007Date of Patent: May 10, 2011Assignee: Fuji Xerox Co., Ltd.Inventors: Akira Matsumoto, Akihiro Iizuka, Fusako Kiyono
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Publication number: 20110097662Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core, having a dry powder polymer coating. The polymer coating possesses a carbon to oxygen from about 3:1 to about 8:1. In embodiments, the coating may also include a colorant, such as carbon black. Processes for coating such carriers with the dry powder polymer coatings are also provided.Type: ApplicationFiled: October 22, 2009Publication date: April 28, 2011Applicant: XEROX CORPORATIONInventors: Daryl W. Vanbesien, Michael S. Hawkins, Suxia Yang, Richard P.N. Veregin, Karen Ann Moffat
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Publication number: 20110091802Abstract: 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: ApplicationFiled: October 4, 2010Publication date: April 21, 2011Inventors: Yutaka TAKAHASHI, Minoru Masuda, Kimitoshi Yamaguchi, Hisashi Nakajima, Koichi Sakata, Hitoshi Iwatsuki, Saori Yamada, Toyoaki Tano, Mariko Takii
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Patent number: 7927775Abstract: Provided is a magnetic carrier giving a high quality image free of density variation without the occurrence of fogging or carrier adhesion and having excellent dot reproducibility even during long-term use. The magnetic carrier has magnetic carrier particles produced by filling pores of porous magnetic core particles with a resin. The magnetic carrier contains 80% by number or more of the magnetic carrier particles satisfying the specific conditions (a) and (b) when 18 straight lines passing through a reference point of a cross section of the magnetic carrier particle are drawn at intervals of 10° in a reflected electron image of the cross section of the magnetic carrier particle photographed by a scanning electron microscope.Type: GrantFiled: January 21, 2010Date of Patent: April 19, 2011Assignee: Canon Kabushiki KaishaInventors: Nozomu Komatsu, Koh Ishigami, Hiroyuki Fujikawa, Kunihiko Nakamura, Chika Inoue, Yoshinobu Baba, Takayuki Itakura, Tomoko Endo
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Publication number: 20110086307Abstract: A carrier, including a magnetic particulate core material and a resin layer on the core material, wherein the resin layer includes a resin obtained by heat treatment of a copolymer including a site derived from a monomer component having the following formula (1) and a site derived from a monomer component having the following formula (2), and includes a cross-linked material obtained by hydrolysis of the copolymer to produce a silanol group and condensation using an organotitanium compound: wherein R1 represents a hydrogen atom or a methyl group; m represents an alkylene group having 1 to 8 carbon atoms; R2 represents an alkyl group having 1 to 4 carbon atoms; R3 represents an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; X represents 10 to 90 mol %; and Y represents 10 to 90 mol %.Type: ApplicationFiled: October 1, 2010Publication date: April 14, 2011Inventors: Hisashi NAKAJIMA, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Saori Yamada, Toyoaki Tano
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Patent number: 7914964Abstract: An image forming method of forming images on both sides of a recording sheet; comprising the steps of: fixing a first toner image on a first surface a recording sheet; and fixing a second toner image on a second surface of the recording sheet; wherein in two-component developer includes toner particles each containing a binder resin having a glass transition temperature Tg° C. and a colorant and carrier particles in each on which magnetic powder is dispersed in a binder resin including a phenol formaldehyde obtained by a polymerization process, and the first toner image is fixed with first heat in such a way that the surface temperature of the first surface of the recording sheet is a temperature in a range of Tg° C. or more and lower than 100° C.Type: GrantFiled: July 20, 2007Date of Patent: March 29, 2011Assignee: Konica Minolta Business Technologies, Inc.Inventors: Hiroshi Yamazaki, Ken Ohmura
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Publication number: 20110070540Abstract: The present disclosure provides carriers for use with toner compositions. In embodiments, a carrier may include a core, having a dry powder polymer coating. In embodiments, the coating may also include a colorant, such as carbon black. Processes for coating such carriers with the dry powder polymer coatings are also provided.Type: ApplicationFiled: September 21, 2009Publication date: March 24, 2011Applicant: XEROX CORPORATIONInventors: Daryl W. Vanbesien, Michael S. Hawkins, Corey L. Tracy, Richard P.N. Veregin, Karen Ann Moffat, Biby Esther Abraham
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Patent number: 7906262Abstract: A two-component developer containing a cyan toner and a magnetic carrier, wherein the cyan toner has the characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.0; and (iii) the absolute value for the triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: GrantFiled: March 3, 2010Date of Patent: March 15, 2011Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Publication number: 20110020747Abstract: An electrophotographic carrier includes a magnetic core material and a resin layer that coats the magnetic core material, the resin layer comprising a resistance control agent and a polymer including a repeating unit derived from an alicyclic group-containing methacrylic ester, the resin layer including a monomer as a base material of the repeating unit in the polymer in an amount of from about 0.5% by weight to about 3.0% by weight relative to the total amount of the resin layer.Type: ApplicationFiled: March 18, 2010Publication date: January 27, 2011Applicant: FUJI XEROX CO., LTD.Inventors: Fusako Kiyono, Takeshi Shoji, Yosuke Tsurumi, Akihiro Iizuka
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Patent number: 7867683Abstract: A toner that when the complex elastic modulus measured at an angular frequency of 6.28 rad/sec., and a strain amount of 0.3% is 1×106 Pa or more and 1×108 Pa or less, the tangent loss is 0.5 or more and 1.8 or less.Type: GrantFiled: April 20, 2007Date of Patent: January 11, 2011Assignee: Fuji Xerox Co., Ltd.Inventors: Masanobu Ninomiya, Toyofumi Inoue, Masataka Kuribayashi, Masashi Ikeda, Takafumi Koide
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Patent number: 7862977Abstract: A method to form an image using a trickle developing system, wherein (a) the toner comprises colorant particles with a volume median diameter of 3 to 8 ?m having first inorganic particles on surfaces of the colorant particles to form toner particles; (b) the carrier comprises magnetic particles with a weight average particle diameter (D4) of 20 to 40 ?m having second inorganic particles on surfaces of the magnetic particles to form carrier particles; and (c) an area ratio of element (A) based on a total area of surfaces of the carrier particles is 0.5 to 3.0 area % determined by using an X-ray analysis, provided that element (A) represents one or more elements commonly contained in the first inorganic particles and in the second inorganic particles.Type: GrantFiled: April 3, 2007Date of Patent: January 4, 2011Assignee: Konica Minolta Business Technologies, Inc.Inventors: Makoto Kobayashi, Yoshiyasu Matsumoto
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Patent number: 7858283Abstract: A magnetic carrier which has magnetic carrier particles each having at least porous magnetic core particles and a resin, in which, in a backscattered electron image of the magnetic carrier particles, photographed with a scanning electron microscope as taken at an accelerating voltage of 2.0 kV, magnetic carrier particles having area proportion S1 found from a specific expression (1) of from 0.5 area % or more to 8.0 area % or less are in a proportion of 8.0% by number or more in the magnetic carrier, an average proportion Av1 of the total area of portions having a high luminance which come from a metal oxide on the magnetic carrier particles to the total projected area of the magnetic carrier particles is from 0.5 area % or more to 8.0 area % or less, and an average proportion Av2 found from a specific expression (2) is 10.0 area % or less.Type: GrantFiled: January 21, 2010Date of Patent: December 28, 2010Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Chika Inoue, Tomoko Endo, Yoshinobu Baba, Takayuki Itakura
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Patent number: 7846631Abstract: Provided is a toner including toner particles each containing at least a binder resin, a colorant, and a wax component, and an inorganic fine powder, the toner being wherein: in a microscopic compression test on the toner, a recovery ratio Z(25) and the gradient of a load-displacement curve R(25) each satisfy a specific range; and the toner has a glass transition temperature (TgA) measured with a differential scanning calorimeter (DSC) in a specific range and a temperature (P1) of the highest endothermic peak measured with the DSC in a specific range, and the temperature (P1) of the highest endothermic peak and the glass transition temperature (TgA) satisfy a specific relationship.Type: GrantFiled: January 20, 2009Date of Patent: December 7, 2010Assignee: Canon Kabushiki KaishaInventors: Yasushi Katsuta, Koji Inaba, Ken-ichi Nakayama, Kenta Kamikura
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Publication number: 20100273103Abstract: The present invention provides an image of high image quality by using a magnetic carrier coated with a novel coating resin composition. Further, the present invention stably provides a good image which is hardly influenced by environmental fluctuation and long-term use and has a superior stability of a charging amount when left to stand especially under high temperature and high humidity environments. The present invention also provides a magnetic carrier characterized in that a carrier core surface is coated with a copolymer containing at least, as copolymerization components, an acrylic monomer having a specific structure and an acrylic macromonomer having a specific structure.Type: ApplicationFiled: February 26, 2009Publication date: October 28, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Yoshinobu Baba, Koh Ishigami, Naoki Okamoto, Tomoko Endo
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Publication number: 20100239975Abstract: The carrier includes a particulate core material having magnetism; and a resin layer located on the surface of the particulate core material. The resin layer is prepared by forming a layer including a copolymer, which includes a unit (A) having a specific acrylic siloxane structure, a unit (B) having a specific acrylic silicone structure having a crosslinking ability, and a unit (C) having a specific acrylic structure in a specific ratio, on the particulate core material, and then subjecting the layer to a heat treatment to crosslink the layer.Type: ApplicationFiled: March 1, 2010Publication date: September 23, 2010Inventors: Kimitoshi YAMAGUCHI, Minoru MASUDA, Yutaka TAKAHASHI, Koichi SAKATA, Hitoshi IWATSUKI, Toyoaki TANO