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).

  • Publication number: 20020186450
    Abstract: Disclosed is a display comprising an arrangement of a plurality of optically anisotropic rotatable elements, each of the rotatable elements having a surface in contact with an enabling fluid, the rotatable elements being electrically dipolar in the presence of the enabling fluid and thus being subject to rotation upon application of an electric field, the rotatable elements being free to rotate in place but not free to translate substantially so as to disrupt the arrangement of rotatable elements, wherein a first portion of the surface contains a mixture of a chelating agent and a spiropyran material of the formula 1
    Type: Application
    Filed: May 24, 2001
    Publication date: December 12, 2002
    Applicant: Xerox Corporation
    Inventors: Daniel A. Foucher, Raj D. Patel, Naveen Chopra, Peter M. Kazmaier, Erwin Buncel, James Wojtyk
  • Publication number: 20020187414
    Abstract: Disclosed are marking particles comprising a resin, a chelating agent, and a spiropyran material which is of the formula 1
    Type: Application
    Filed: January 11, 2002
    Publication date: December 12, 2002
    Applicant: Xerox Corporation
    Inventors: Daniel A. Foucher, Raj D. Patel, Naveen Chopra, Peter M. Kazmaier
  • Publication number: 20020187416
    Abstract: A toner process including, for example, mixing a latex with a colorant wherein the latex contains resin and an ionic surfactant, and the colorant contains a surfactant and a colorant; adding a polyaluminum chloride; affecting aggregation by heating; adding a chelating component and a base wherein the base increases the pH of the formed aggregates; heating the resulting mixture to accomplish coalescence; and isolating the toner.
    Type: Application
    Filed: June 5, 2002
    Publication date: December 12, 2002
    Applicant: Xerox Corporation
    Inventors: Lu Jiang, Nan-Xing Hu, Raj D. Patel, Walter Mychajlowskij, Michael A. Hopper
  • Patent number: 6458165
    Abstract: Disclosed are marking particles comprising a first polymer a second polymer, a chelating agent, and a spiropyran material of the formula wherein n is an integer representing the number of repeat —CH2— units and R is —H or —CH═CH2. The marking particles comprise a core containing the first polymer in which is dispersed the chelating agent and the spiropyran and encapsulated within a shell of the second polymer formulated by an interfacial polymerization.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: October 1, 2002
    Assignee: Xerox Corporation
    Inventors: Daniel A. Foucher, Raj D. Patel, Naveen Chopra, Peter M. Kazmaier, James Wojtyk, Erwin Buncel
  • Patent number: 6432601
    Abstract: A toner composition containing colorant and an alkali sulfonated polyester-amine resin composition generated, for example, from the reaction of an organic diol, an organic diacid, an alkali sulfonated diacid and an amino-organic diacid.
    Type: Grant
    Filed: April 19, 2001
    Date of Patent: August 13, 2002
    Assignee: Xerox Corporation
    Inventors: Daniel A. Foucher, Walter Mychajlowskij, Raj D. Patel, Guerino G. Sacripante
  • Patent number: 6416920
    Abstract: A process for the preparation of toner by, for example, mixing a colorant, a latex, optionally a wax and a water solubilized silica with an alumina coating or an aluminized silica as a coagulant.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: July 9, 2002
    Assignee: Xerox Corporation
    Inventors: Michael A. Hopper, Raj D. Patel, Daryl Vanbesien
  • Patent number: 6365312
    Abstract: Disclosed are marking particles comprising a first polymer, a second polymer, a chelating agent, and a spiropyran material of the formula wherein n is an integer representing the number of repeat —CH2— units and R is —H or —CH═CH2. The marking particles comprise a core containing the first polymer in which is dispersed the chelating agent and the spiropyran and encapsulated within a shell of the second polymer formulated by an interfacial polymerization.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: April 2, 2002
    Assignee: Xerox Corporation
    Inventors: Daniel A. Foucher, Raj D. Patel, Naveen Chopra, Peter M. Kazmaier, James Wojtyk, Erwin Buncel
  • Patent number: 6358655
    Abstract: Disclosed are marking particles comprising a resin, a chelating agent, and a spiropyran material which is of the formula The marking particles are prepared by an emulsion aggregation process.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: March 19, 2002
    Assignee: Xerox Corporation
    Inventors: Daniel A. Foucher, Raj D. Patel, Naveen Chopra, Peter M. Kazmaier
  • Patent number: 6348561
    Abstract: An alkali sulfonated polyester-amine resin generated from the reaction of an organic diol, and a mixture of an organic diacid, an alkali sulfonated diacid and an amino-organic diacid.
    Type: Grant
    Filed: April 19, 2001
    Date of Patent: February 19, 2002
    Assignee: Xerox Corporation
    Inventors: Walter Mychajlowskij, Daniel A. Foucher, Raj D. Patel, Guerino G. Sacripante
  • Patent number: 6268102
    Abstract: A process for the preparation of toner comprising mixing a colorant, a latex, optionally a wax and a polyaluminum sulfosilicate.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: July 31, 2001
    Assignee: Xerox Corporation
    Inventors: Michael A. Hopper, Raj D. Patel, Tanya J. Martin
  • Patent number: 6268103
    Abstract: A toner process comprising mixing a functionalized wax with a colorant and a resin latex emulsion; adding an inorganic cationic coagulant; heating below the latex resin Tg; adjusting the pH to basic; and heating above the latex resin Tg.
    Type: Grant
    Filed: August 24, 2000
    Date of Patent: July 31, 2001
    Assignee: Xerox Corporation
    Inventors: Michael A. Hopper, Raj D. Patel
  • Patent number: 6210853
    Abstract: A process for the preparation of toner including (i) gerating by emulsion polymerization in the presence of an initiator a first resin latex emulsion; (ii) generating by polycondensation a second resin latex optionally in the presence of a catalyst; (iib) dispersing the resin of (ii) in water; (iii) mixing (iib) with a colorant thereby providing a colorant dispersion; (iiib) mixing the resin latex emulsion of (i) with the resin/colorant mixture of (iii) to provide a blend of a resin and colorant; (iv) adding an aqueous inorganic cationic coagulant solution of a polymeric metal salt and optionally an organic cationic coagulant to the resin/colorant blend of (iiib); (v) heating at a temperature of from about 5 to about 10 degrees Centigrade below the resin Tg of (i), to thereby form aggregate particles and which particles are optionally at a pH of from about 2 to about 3.5; (vi) adjusting the pH of (v) to about 6.
    Type: Grant
    Filed: September 7, 2000
    Date of Patent: April 3, 2001
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Michael A. Hopper, Emily L. Moore, Guerino G. Sacripante
  • Patent number: 6190820
    Abstract: A process for the preparation of toner by, for example (i) generating by emulsion polymerization in the presence of an initiator a first resin latex emulsion; (ii) generating in the presence of an oil soluble initiator by solution polymerization a second resin latex; (iii) mixing (ii) with a colorant; (iiib) mixing the resin latex emulsion of (i) with the resin/colorant mixture of (iii) to provide a blend of a resin and colorant; (iv) adding an aqueous inorganic cationic coagulant solution of a metal salt and optionally an organic cationic coagulant to the resin/colorant blend of (iiib); (v) heating at a temperature of from about 5° C. to about 10° C. below the resin Tg of (i), to form aggregate particles; (vi) adjusting the pH of (v) by the addition of a base; (vii) heating the aggregate particles of (v) at temperatures of from about 5° C. to about 50° C. above the Tg of the resin of (i), followed by the addition of an acid.
    Type: Grant
    Filed: September 7, 2000
    Date of Patent: February 20, 2001
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Michael A. Hopper, Walter Mychajlowskij
  • Patent number: 6132924
    Abstract: A process for the preparation of toner comprising mixing a colorant, a latex, and two coagulants, followed by aggregation and coalescence.
    Type: Grant
    Filed: October 15, 1998
    Date of Patent: October 17, 2000
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Michael A. Hopper, Richard P. N. Veregin
  • Patent number: 6130021
    Abstract: A process involving the mixing of a latex emulsion containing resin and a surfactant with a colorant dispersion containing a nonionic surfactant, and a polymeric additive and adjusting the resulting mixture pH to less than about 4 by the addition of an acid and thereafter heating at a temperature below about, or equal to about the glass transition temperature (Tg) of the latex resin, subsequently heating at a temperature above about, or about equal to the Tg of the latex resin, cooling to about room temperature, and isolating the toner product.
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: October 10, 2000
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Michael A. Hopper
  • Patent number: 6120967
    Abstract: A process for the preparation of a toner composition includes (i) forming a resin latex dispersion of a resin in an aqueous ionic surfactant solution from a latex utilizing an ionic surfactant and optionally a nonionic surfactant; (ii) preparing a pigment dispersion in water of a pigment dispersed in water and a nonionic dispersant, and optionally an ionic surfactant of the same polarity as that employed in preparing the resin latex dispersion of step (i); (iii) blending at least a portion of the resin latex dispersion with the pigment dispersion, and optionally a wax dispersion, to form a resin-pigment blend; (iv) adding a portion of a counterionic coagulant in an aqueous solution to the resin-pigment blend, while continuously subjecting the mixture to high shear, to induce a homogeneous gel of the resin-pigment blend, wherein the amount of the counterionic coagulant added is 25 to 90% by weight of a total amount of counterionic coagulant to be added during the process; (v) heating the sheared gel at tempera
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: September 19, 2000
    Assignee: Xerox Corporation
    Inventors: Michael A. Hopper, Raj D. Patel, Lori Ann Rettinger, Tanya Jane Martin
  • Patent number: 6110636
    Abstract: A surfactant free process for the preparation of toner comprising heating a mixture of an emulsion latex, a colorant, and a polyelectrolyte.
    Type: Grant
    Filed: October 29, 1998
    Date of Patent: August 29, 2000
    Assignee: Xerox Corporation
    Inventors: Daniel A. Foucher, Walter Mychajlowskij, Guerino G. Sacripante, Raj D. Patel
  • Patent number: 6020101
    Abstract: A toner comprised of a core comprised a first resin and colorant, and thereover a shell comprised of a second resin and wherein said first resin is an ion complexed sulfonated polyester resin, and said second resin is a transition metal ion complex sulfonated polyester resin.
    Type: Grant
    Filed: April 21, 1999
    Date of Patent: February 1, 2000
    Assignee: Xerox Corporation
    Inventors: Guerino G. Sacripante, Raj D. Patel, Walter Mychajlowskij, Daniel A. Foucher
  • Patent number: 5994020
    Abstract: A toner process which comprises mixing(i) a colorant dispersion, and a(ii) a nonionic surfactant, an ionic surfactant or mixtures thereof, with(iii) a latex comprised of resin and a mixture of anionic surfactant and a nonionic surfactant;(iv) heating the resulting blend of (iii) about equal to, or below about the glass transition temperature (Tg) of the resin; and(v) optionally adding additional anionic surfactant to the resulting aggregated suspension of (iv);(vi) heating the resulting mixture of (v) about equal to, or above about the Tg of the resin and(vii) isolating the toner.
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: November 30, 1999
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Michael A. Hopper, Paul F. Smith, Beng S. Ong, Allan K. Chen
  • Patent number: 5981651
    Abstract: A process comprising (1) polymerizing an organic phase of monomer in the presence of a carboxylic acid, an oil soluble chain transfer agent, and a partially water soluble chain transfer agent; and which polymerizing is accomplished in the presence of (2) an aqueous phase containing a nonionic surfactant, and an anionic surfactant, and wherein there is added to the aqueous phase an aqueous initiator solution of an inorganic persulfate, and wherein the resulting latex contains particles of polymer with carboxylic acid; aggregating said latex particles with colorant; thereafter adding an effective amount of anionic surfactant and heating the mixture resulting about equal to, or about above the polymer Tg resulting from said monomer, or said monomers.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: November 9, 1999
    Assignee: Xerox Corporation
    Inventors: Raj D. Patel, Grazyna E. Kmiecik-Lawrynowicz, Michael A. Hopper, Walter Mychajlowskij