Patents by Inventor Lupu Alexandru

Lupu Alexandru 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: 5274057
    Abstract: An improved process for producing resin particles by a bead suspension polymerization reaction, and a polymer formed by the process wherein the process comprises: providing a liquid reaction medium suitable for conducting the polymerization; forming a suspension agent system in the reaction medium by an in situ interaction of at least two components in the reaction medium, for example, certain water soluble metal halides and polyvinylacetate derived polymers; adding at least one polymerizable monomer compound to the resulting reaction medium having the suspension agent system dispersed therein; and effecting polymerization of the monomer in the reaction medium to form low ash content beads of the polymer.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: December 28, 1993
    Assignee: Xerox Corporation
    Inventors: Michael K. Georges, Robert D. Bayley, Lupu Alexandru
  • Patent number: 5155193
    Abstract: Process for the preparation of polymers which comprises a suspension free radical polymerization of monomers in the presence of the initiator O,O-t-amyl-O-(2-ethylhexyl)monoperoxycarbonate.
    Type: Grant
    Filed: July 2, 1990
    Date of Patent: October 13, 1992
    Assignee: Xerox Corporation
    Inventors: Michael K. Georges, Peter G. Odell, Lupu Alexandru
  • Patent number: 5122187
    Abstract: Disclosed are hot melt ink compositions suitable for ink jet printing which comprise a colorant, a binder, and a propellant selected from the group consisting of hydrazine; cyclic amines; ureas; carboxylic acids; sulfonic acids; aldehydes; ketones; hydrocarbons; esters; phenols; amides; imides; halocarbons; urethanes; ethers; sulfones; sulfamides; sulfonamides; phosphites; phosphonates; phosphates; alkyl sulfides; alkyl acetates; and sulfur dioxide.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: June 16, 1992
    Assignee: Xerox Corporation
    Inventors: William M. Schwarz, Robert H. Marchessault, Lupu Alexandru, Bernard Henrissat
  • Patent number: 5114820
    Abstract: A toner composition comprised of pigment particles and a branched polyalkyl/styrene/butadiene copolymer of the following formula ##STR1## wherein m, n and o are weight fraction numbers, p represents the number of CH.sub.2 groups, R is hydrogen or alkyl, and R' is carbonyloxy or aryl.
    Type: Grant
    Filed: October 27, 1989
    Date of Patent: May 19, 1992
    Assignee: Xerox Corporation
    Inventors: Michael K. Georges, Lupu Alexandru
  • Patent number: 5082919
    Abstract: A toner composition comprised of a crosslinked thermotropic liquid crystalline polymer, a branched liquid crystalline polymer, or mixtures thereof.
    Type: Grant
    Filed: July 30, 1990
    Date of Patent: January 21, 1992
    Assignee: Xerox Corporation
    Inventors: Guerino Sacripante, T. Brian McAneney, Stephan Drappel, Sheau Van Kao, Lupu Alexandru
  • Patent number: 5039773
    Abstract: Thermotropic liquid crystalline polymers represented by the formulas as illustrated in FIGS. 1 and 2 wherein m, n, and o represent the number of monomer segments present; and x, y, and z are independently selected from the group consisting of alkyl, substituted alkyl, alkylene, and substituted alkylene.
    Type: Grant
    Filed: October 2, 1989
    Date of Patent: August 13, 1991
    Assignee: Xerox Corporation
    Inventors: Guerino Sacripante, Lupu Alexandru
  • Patent number: 5039584
    Abstract: A process for the purification of polycarbonates or copolymers thereof containing titanium catalyst residues, which comprises mixing a polycarbonate or copolymers thereof with a solvent; adding to the formed solution mixture a complexing component; admixing the resulting mixture with water; and subsequently separating the polycarbonate or copolymer product therefrom.
    Type: Grant
    Filed: February 9, 1990
    Date of Patent: August 13, 1991
    Assignee: Xerox Corporation
    Inventors: Peter G. Odell, Giuseppa Baranyi, Lupu Alexandru
  • Patent number: 5034296
    Abstract: A layered photoresponsive imaging member comprised of a photogenerating layer, and in contact therewith a hole transporting layer comprised of fluorene charge transport polyesters of the following formulas: ##STR1## where A, B, Z are independently selected from a group of bifunctional groups; R is an alkyl or aryl group; Ar is an aryl or substituted aryl group; x and y are mole fractional numbers wherein x is greater than 0, and the sum of x and y is equal to 1.0; and n represents the number of repeating segments.
    Type: Grant
    Filed: April 3, 1989
    Date of Patent: July 23, 1991
    Assignee: Xerox Corporation
    Inventors: Beng S. Ong, Giuseppa Baranyi, Lupu Alexandru
  • Patent number: 5006170
    Abstract: Disclosed are hot melt ink compositions suitable for ink jet printing which comprise a colorant, a binder, and a propellant selected from the group consisting of hydrazine; cyclic amines; ureas; carboxylic acids; sulfonic acids; aldehydes; ketones; hydrocarbons; esters; phenols; amides; imides; halocarbons; urethanes; ethers; sulfones; sulfamides; sulfonamindes; phosphites; phosphonates; phosphates; alkyl sulfines; alkyl acetates; and sulfur dioxide.
    Type: Grant
    Filed: June 22, 1989
    Date of Patent: April 9, 1991
    Assignee: Xerox Corporation
    Inventors: William M. Schwarz, Robert H. Marchessault, Lupu Alexandru, Bernard Henrissat
  • Patent number: 4983482
    Abstract: A layered photoresponsive imaging member comprised of a photogenerating layer, and in contact therewith a hole transporting layer comprised of charge transport polyurethanes of the following formula, optionally doped with a charge transport compound, or optionally dispersed in an inert resinous binder: ##STR1## wherein A, B and Z are independently selected from the group of bifunctional linkages; R is an alkyl or aryl group; Ar is an aryl or substituted aryl group; x and y represent the mole fractional numbers of the polyurethane structural composition units, subject to the provision that x is greater than 0 and that the sum of x and y is equal to 1.0; and n represents the number of repeating segments.
    Type: Grant
    Filed: April 3, 1989
    Date of Patent: January 8, 1991
    Assignee: Xerox Corporation
    Inventors: Beng S. Ong, Dasarao K. Murti, Lupu Alexandru
  • Patent number: 4973539
    Abstract: A toner composition comprised of a crosslinked thermotropic liquid crystalline polymer, a branched liquid crystalline polymer, or mixtures thereof.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: November 27, 1990
    Assignee: Xerox Corporation
    Inventors: Guerino Sacripante, T. Brian McAneney, Stephan Drappel, Sheau V. Kao, Lupu Alexandru
  • Patent number: 4921940
    Abstract: A process for the purification of polycarbonates or copolymers thereof containing titanium catalyst residues, which comprises mixing a polycarbonate or copolymers thereof with a solvent; adding to the formed solution mixture a complexing component; admixing the resulting mixture with water; and subsequently separating the polycarbonate or copolymer product therefrom.
    Type: Grant
    Filed: August 15, 1988
    Date of Patent: May 1, 1990
    Assignee: Xerox Corporation
    Inventors: Peter G. Odell, Giuseppa Baranyi, Lupu Alexandru
  • Patent number: 4894309
    Abstract: A free radical suspension polymerization process for obtaining crosslinked styrene butadiene ternary copolymers which comprises the polymerization of styrene monomers, butadiene monomers, and crosslinking components in the presence of a surfactant, a stabilizer, and a first and second initiator; and wherein the aforementioned components are present in an aqueous phase; heating the resulting aqueous mixture at a temperature of from about 50.degree. C. to about 110.degree. C.; thereafter heating the mixture at a temperature of from about 110.degree. C. to about 150.degree. C.; followed by cooling and isolating the desired product.
    Type: Grant
    Filed: September 19, 1988
    Date of Patent: January 16, 1990
    Assignee: Xerox Corporation
    Inventors: Michael K. Georges, Lupu Alexandru, William J. Dale, Paul D. Szabo, Robert A. Nelson
  • Patent number: 4891293
    Abstract: Thermotropic liquid crystalline polymers represented by the formulas as illustrated in FIGS. 1 and 2 wherein m,n and o represent the number of monomer segments present; and x,y and z are independently selected form the group consisting of alkyl, substituted alkyl, alkylene, and substituted alkylene.
    Type: Grant
    Filed: October 3, 1988
    Date of Patent: January 2, 1990
    Assignee: Xerox Corporation
    Inventors: Guerino Sacripante, Lupu Alexandru
  • Patent number: 4778742
    Abstract: A toner composition comprised of resin particles and polymeric dye components of the following formula: ##STR1## wherein A is selected from the group consisting of alkylene and arylene; B is selected from the group consisting of ##STR2## wherein R is selected from the group consisting of an alkylene group, an arylene group and a polyether group; and n represents a number of from 2 to about 100.
    Type: Grant
    Filed: October 7, 1987
    Date of Patent: October 18, 1988
    Assignee: Xerox Corporation
    Inventors: Beng S. Ong, Walter Mychajlowskij, Lupu Alexandru
  • Patent number: 4774160
    Abstract: Disclosed is an improved toner composition comprised of pigment particles and amorphous ternary copolycarbonate resin particles of the formula ##STR1## wherein R is an aliphatic hydrocarbon, n is a number of from about 4 to about 8, x is a number of from about 0.8 to about 0.95, y is a number of from about 0.05 to about 2, z represents the degree of polymerization, Ar.sub.1 is an aromatic substituent, and Ar.sub.2 is an aromatic substituent.
    Type: Grant
    Filed: February 24, 1987
    Date of Patent: September 27, 1988
    Assignee: Xerox Corporation
    Inventors: Hadi-Khan Mahabadi, Lupu Alexandru
  • Patent number: 4770968
    Abstract: A branched polysiloxane styrene butadiene polymer of the following formula ##STR1## wherein m is a number of from about 2 to about 10; z is the number 3,4 or 5; n is a number of from about 10 to about 1,000; k, l and o are weight fraction numbers with k being from about 0.35 to about 0.95, l being from 0.1 to about 0.2, and o is from about 0.05 to about 0.5; R is an aromatic substituent, alkyl-CR"C(O)O, and alkylene-CR"C(O)O, wherein R" is hydrogen or an alkyl substituent, and R' is an alkyl substituent or a trialkylsilylether substituent.
    Type: Grant
    Filed: July 27, 1987
    Date of Patent: September 13, 1988
    Assignee: Xerox Corporation
    Inventors: Michael K. Georges, Lupu Alexandru
  • Patent number: 4766255
    Abstract: A process for the preparation of gem-bis(hydroxyaryl)alkanes which comprises the reaction of a ketone, a hydroxyarene and an alkylhalosilane.
    Type: Grant
    Filed: June 29, 1987
    Date of Patent: August 23, 1988
    Assignee: Xerox Corporation
    Inventors: Beng S. Ong, Lupu Alexandru
  • Patent number: 4558108
    Abstract: A process for forming a copolymer of styrene and butadiene is disclosed including providing an aqueous phase comprising an aqueous mixture comprising water, styrene monomer, butadiene monomer, a suspension stabilizing agent, and a chain propogating amount of one or more free radical polymerization initiators, the ratio of the styrene monomer and the butadiene monomer being between about 80:20 and about 95:5 by weight, the weight proportion of water to the combination of styrene monomer and butadiene monomer being between about 0.8:1 and about 2:1 and a vapor phase comprising an inert gas and butadiene monomer, heating the aqueous phase and the vapor phase to a temperature between about 50.degree. C. and about 130.degree. C.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: December 10, 1985
    Assignee: Xerox Corporation
    Inventors: Lupu Alexandru, Peter G. Odell
  • Patent number: 4543313
    Abstract: Disclosed are improved toner compositions comprised of resin particles selected from the group consisting of thermotropic liquid crystalline polycarbonates, copolycarbonates, polyurethanes, polyesters, and copolyesters, and pigment particles.
    Type: Grant
    Filed: August 2, 1984
    Date of Patent: September 24, 1985
    Assignee: Xerox Corporation
    Inventors: Hadi-Khan Mahabadi, Lupu Alexandru