Patents by Inventor Raj D. Patel

Raj D. Patel 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: 7910275
    Abstract: Embodiments include a chemical toner composition having a first resin including a styrene vinyl copolymer and having a Tg of from about 46 to about 56° C., b) a second resin including a styrene vinyl copolymer having a Tg of from about 55 to about 65° C., c) a distilled wax having a heat of crystallization and a heat of enthalpy, both from about 1.0 to about 4.0 J/g for every weight percent of the wax used in the chemical toner composition, and wherein the wax has a peak melting point of from about 70 to about 99° C., and d) a colorant, wherein the chemical toner has a gloss of from about 30 to about 80 GGU.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: March 22, 2011
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, David J. Sanders, Christine Anderson, Allan K. Chen, Daryl W. Vanbesien, Patricia A. Burns
  • Patent number: 7781138
    Abstract: A process for preparing toner particles and compositions adapted for use in preparing toners that comprise a blend of a first polyester resin with a second sharp melting polyester resin. The process includes forming an emulsion resin comprising a branched polyester resin, a crystalline polyester resin, a colorant, and optionally a wax. The resin mixture is aggregated using an aggregating agent, such as a zinc acetate solution, to form an aggregate mixture. The aggregate mixture is then coalesced at a temperature of from about 5 to about 20° C. above the Tg of the emulsion resin to produce the resultant toner particles.
    Type: Grant
    Filed: October 6, 2009
    Date of Patent: August 24, 2010
    Assignee: Xerox Corporation
    Inventors: Guerino G. Sacripante, Fatima M. Mayer, Kimberly D. Nosella, Valerie M. Farrugia, Raj D. Patel, Milan Maric, Allen K. Chen, Edward G. Zwartz, T. Hwee Ng
  • Patent number: 7749670
    Abstract: Embodiments include a toner with a fractionated and/or distilled wax having from about 30 to about 64 carbon units, a degree of crystallinity as calculated by heat of melting and as measured by DSC of from about 55 to about 100, a Mw is from about 500 to about 800, and a polydispersity of from about 1 to about 1.05.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: July 6, 2010
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, David J. Sanders, T Hwee Ng, Stephan V. Drappel, Sandra J. Gardner, Sonja Hadzidedic, Louis V. Isganitis, Timothy L. Lincoln, Kevin F. Marcell
  • Patent number: 7686939
    Abstract: Embodiments include a fractionated and/or distilled wax having from about 30 to about 64 carbon units, a degree of crystallinity as calculated by heat of melting and as measured by DSC of from about 55 to about 100, a Mw is from about 500 to about 800, and a polydispersity of from about 1 to about 1.05.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: March 30, 2010
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, David J. Sanders, T Hwee Ng, Stephan V. Drappel, Sandra J. Gardner, Sonja Hadzidedic, Louis V. Isganitis, Timothy L. Lincoln, Kevin F. Marcell
  • Patent number: 7662272
    Abstract: Embodiments include a distilled wax having a crystallinity of from about 55 to about 100 percent, wherein the degree of crystallinity is calculated using the following formulas: [Heat of enthalpy (Hm) J/g/294 J/g]×100=degree of crystallinity (Xc); [Heat of recrystallization (Hrc) J/g/294 J/g]×100=degree of crystallinity (Xc); and Sc/(Sc+Sa)]×100%, wherein Sc is a diffraction peak area of a crystalline component of the wax and the Sa is a diffraction peak area of an amorphous component of the wax; and wherein the Mp, Mn and Mw of the wax are all within the range of from about 500 to about 800, and wherein the wax has a polydispersity of from about 1 to about 1.05.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: February 16, 2010
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, David J. Sanders, T Hwee Ng, Stephan V. Drappel, Sandra J. Gardner, Sonja Hadzidedic, Timothy L. Lincoln, Kevin F. Marcell, Louis V. Isganitis
  • Publication number: 20100021841
    Abstract: A process for preparing toner particles and compositions adapted for use in preparing toners that comprise a blend of a first polyester resin with a second sharp melting polyester resin. The process includes forming an emulsion resin comprising a branched polyester resin, a crystalline polyester resin, a colorant, and optionally a wax. The resin mixture is aggregated using an aggregating agent, such as a zinc acetate solution, to form an aggregate mixture. The aggregate mixture is then coalesced at a temperature of from about 5 to about 20° C. above the Tg of the emulsion resin to produce the resultant toner particles.
    Type: Application
    Filed: October 6, 2009
    Publication date: January 28, 2010
    Applicant: Xerox Corporation
    Inventors: Guerino G. Sacripante, Fatima M. Mayer, Kimberly D. Nosella, Valerie M. Farrugia, Raj D. Patel, Milan Maric, Allan K. Chen, Edward G. Zwartz, T. Hwee Ng
  • Patent number: 7649675
    Abstract: Toner particles and a dry-powder electrophoretic display employing such particles are disclosed herein. The toner particles adapted for a dry-powder electrophoretic display comprise emulsion/aggregation particles having a negative charge. At least a portion of the toner particles include a surface coating, comprising a methacrylate polymer, disposed on the surface of the toner particles to impart a positive charge to a set of toner particles. The emulsion/aggregation toner particles have a particle size generally less than about 10 micrometers that allows for improved image quality as compared to conventional toners utilized in dry-powder electrophoretic displays.
    Type: Grant
    Filed: February 9, 2009
    Date of Patent: January 19, 2010
    Inventors: Naveen Chopra, Valerie M. Farrugia, Jurgen Daniel, Raj D. Patel, Man-Chung Tam, Meng H. Lean
  • Patent number: 7645552
    Abstract: Toner compositions include a non cross linked resin; a cross linked resin or gel; a wax; and a colorant. Processes for preparing a toner include mixing a non-cross linked resin and a cross-linked resin or gel in the presence of a wax, a colorant, and a coagulant to provide toner size aggregates; adding additional non-cross linked latex to the formed aggregates thereby providing a shell over the formed aggregates; heating the shell covered aggregates to form toner; and, optionally, isolating the toner.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: January 12, 2010
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Daryl Vanbesien, Enno E. Agur, Edward G. Zwartz, Maria N. V. McDougall, Emily L. Moore, Patricia A. Burns, Kimberly D. Nosella, Ke Zhou, Vladislav Skorokhod, Wafa F. Bashir, Shigang (Steven) Qiu
  • Patent number: 7622233
    Abstract: A toner composition includes a styrene-based polymer resin, a crystalline polyester wax, a second wax different from the crystalline polyester wax, a colorant, and a coagulant.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: November 24, 2009
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Edward G. Zwartz, T. Brian McAneney, Edward C. Hanzlik, Alan R. Kuntz
  • Patent number: 7615328
    Abstract: A process for preparing toner particles and compositions adapted for use in preparing toners that comprise a blend of a first polyester resin with a second sharp melting polyester resin. The process includes forming an emulsion resin comprising a branched polyester resin, a crystalline polyester resin, a colorant, and optionally a wax. The resin mixture is aggregated using an aggregating agent, such as a zinc acetate solution, to form an aggregate mixture. The aggregate mixture is then coalesced at a temperature of from about 5 to about 20° C. above the Tg of the emulsion resin to produce the resultant toner particles.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: November 10, 2009
    Assignee: Xerox Corporation
    Inventors: Guerino G. Sacripante, Fatima M. Mayer, Kimberly D. Nosella, Valerie M. Farrugia, Raj D. Patel, Milan Maric, Allen K. Chen, Edward G. Zwartz, T. Hwee Ng
  • Patent number: 7553596
    Abstract: Embodiments include a toner with a distilled wax having a crystallinity of from about 55 to about 100 percent, wherein the degree of crystallinity is calculated using the following formulas: [Heat of enthalpy (Hm) J/g/294 J/g]×100=degree of crystallinity (Xc); [Heat of recrystallization (Hrc) J/g/294 J/g]×100=degree of crystallinity (Xc); and Sc/(Sc+Sa)]×100%, wherein Sc is a diffraction peak area of a crystalline component of the wax and the Sa is a diffraction peak area of an amorphous component of the wax; and wherein the Mp, Mn and Mw of the wax are all within the range of from about 500 to about 800, and wherein the wax has a polydispersity of from about 1 to about 1.05.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: June 30, 2009
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, David J. Sanders, T Hwee Ng, Stephan V. Drappel, Sandra J. Gardner, Sonja Hadzidedic, Louis V. Isganitis, Timothy L. Lincoln, Kevin F. Marcell
  • Patent number: 7553595
    Abstract: A toner composition includes toner particles including a polymeric resin, a colorant, a wax, and an optional coagulant, and a coagulant applied as a surface additive to a surface of the toner particles to alter a triboelectric charge of the toner particles.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: June 30, 2009
    Assignee: Xerox Corporation
    Inventors: Valerie M. Farrugia, Raj D. Patel, Michael S. Hawkins
  • Publication number: 20090141338
    Abstract: Toner particles and a dry-powder electrophoretic display employing such particles are disclosed herein. The toner particles adapted for a dry-powder electrophoretic display comprise emulsion/aggregation particles having a negative charge. At least a portion of the toner particles include a surface coating, comprising a methacrylate polymer, disposed on the surface of the toner particles to impart a positive charge to a set of toner particles. The emulsion/aggregation toner particles have a particle size generally less than about 10 micrometers that allows for improved image quality as compared to conventional toners utilized in dry-powder electrophoretic displays.
    Type: Application
    Filed: February 9, 2009
    Publication date: June 4, 2009
    Applicant: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Naveen Chopra, Valerie M. Farrugia, Jurgen Daniel, Raj D. Patel, Man-Chung Tam, Meng H. Lean
  • Publication number: 20090061349
    Abstract: A process for preparing toner particles and compositions adapted for use in preparing toners that comprise a blend of a first polyester resin with a second sharp melting polyester resin. The process includes forming an emulsion resin comprising a branched polyester resin, a crystalline polyester resin, a colorant, and optionally a wax. The resin mixture is aggregated using an aggregating agent, such as a zinc acetate solution, to form an aggregate mixture. The aggregate mixture is then coalesced at a temperature of from about 5 to about 20° C. above the Tg of the emulsion resin to produce the resultant toner particles.
    Type: Application
    Filed: June 17, 2008
    Publication date: March 5, 2009
    Applicant: XEROX CORPORATION
    Inventors: Guerino G. Sacripante, Fatima M. Mayer, Kimberly D. Nosella, Valerie M. Farrugia, Raj D. Patel, Milan Maric, Allan K. Chen, Edward G. Zwartz, T. Hwee Ng
  • Patent number: 7499209
    Abstract: Toner particles and a dry-powder electrophoretic display employing such particles are disclosed herein. The toner particles adapted for a dry-powder electrophoretic display comprise emulsion/aggregation particles having a negative charge. At least a portion of the toner particles include a surface coating, comprising a methacrylate polymer, disposed on the surface of the toner particles to impart a positive charge to a set of toner particles. The emulsion/aggregation toner particles have a particle size generally less than about 10 micrometers that allows for improved image quality as compared to conventional toners utilized in dry-powder electrophoretic displays.
    Type: Grant
    Filed: October 26, 2004
    Date of Patent: March 3, 2009
    Assignee: Xerox Corporation
    Inventors: Naveen Chopra, Valerie M. Farrugia, Jurgen Daniel, Raj D. Patel, Man-Chung Tam, Meng H. Lean
  • Patent number: 7455943
    Abstract: The toner includes emulsion aggregation toner particles of a binder including a non-crosslinked styrene acrylate polymer, at least one colorant, at least one wax, and aluminized silica, wherein an amount of aluminum metal in the toner particles is from about 50 ppm to about 600 ppm. Such toner is able to provide a high level of gloss while maintaining a low minimum fixing temperature. The aluminized silica acts as a coagulant during the emulsion aggregation formation process of the toner.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: November 25, 2008
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Daryl W. Vanbesien, David J. Sanders, Allan K. Chen
  • Patent number: 7442740
    Abstract: A toner process that includes a first heating of a colorant dispersion, a first polyester resin free latex emulsion, a second polyester latex emulsion, and a wax dispersion in the presence of a coagulant containing a metal ion; adding a third polyester free latex; adding an organic sequestering compound or a silicate salt sequestering compound, followed by a second heating.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: October 28, 2008
    Assignee: Xerox Corporation
    Inventors: Raj D Patel, Guerino G Sacripante, Edward G Zwartz, Enno E Agur, Allan K Chen, T. Hwee Ng, Kimberly D Nosella, Cuong Vong, Karen A Moffat
  • Patent number: 7429443
    Abstract: A polyester toner includes particles of a resin, a colorant, an optional wax, and a polyion coagulant, where the toner is prepared by an emulsion aggregation process.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: September 30, 2008
    Assignee: Xerox Corporation
    Inventor: Raj D. Patel
  • Patent number: 7419753
    Abstract: A toner composition that includes a resin substantially free of cross linking, a cross linked resin, a polyester resin as a crystalline polyester resin, and a colorant.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: September 2, 2008
    Assignee: Xerox Corporation
    Inventors: Daryl W. Vanbesien, Raj D. Patel, Karen A. Moffat, Edward G. Zwartz, Cuong Vong
  • Patent number: 7413842
    Abstract: A toner process comprising aggregating or coagulating a latex emulsion comprising a resin, a colorant and wax particles using an amount of polymetal ion coagulant to provide core particles; heating the core particles to provide micron size aggregates; optionally adding a second resin emulsion; adding a sequestering or complexing component and a base to remove the polymetal ion in a controlled manner; further heating the mixture to provide toner particles; and optionally, isolating the toner particles.
    Type: Grant
    Filed: August 22, 2005
    Date of Patent: August 19, 2008
    Assignee: Xerox Corporation
    Inventors: Daryl Vanbesien, David J. Sanders, Raj D. Patel, Christine D. Anderson, Patricia Ann Burns, Nam-Suk Ro