Patents by Inventor San Hoa Thang

San Hoa Thang 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: 20030149208
    Abstract: This invention concerns the preparation of polymers of low polydispersity and/or controlled molecular weight and architecture employing living free radical polymerization initiated by an alkoxyamine initiator or nitroxide plus, optionally, a free radical initiator; the polymer produced thereby; selected nitroxide and alkoxyamine initiators; and a process for making the initiators; the polymeric products being useful in protective coatings.
    Type: Application
    Filed: January 3, 2003
    Publication date: August 7, 2003
    Inventors: Albert G. Anderson, Alexei Gridnev, Graeme Moad, Ezio Rizzardo, San Hoa Thang
  • Patent number: 6512081
    Abstract: This invention relates to the synthesis of dithiocarboxylic acid esters by reaction of bis(thioacyl) disulphides, thioacetals or vinylidane bis(thioether) with free-radicals (optionally in the presence of monomers). The invention also relates to processes for the synthesis of polymers utilising these dithioesters as polymerisation regulators (chain transfer agents) or to the use of bis(thioacyl) disulphides to generate dithioester chain transfer agents in situ.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: January 28, 2003
    Assignees: E.I. DuPont Nemours and Company, Commonwealth Scientific and Industrial Research Organisation
    Inventors: Enzio Rizzardo, San Hoa Thang, Graeme Moad
  • Patent number: 6462114
    Abstract: A process for forming a microgel which comprises a crosslinked core and a multiplicity of linear polymeric arms attached to the core, wherein the process comprises (a) first forming a halogen atom terminated prepolymer with a weight average molecular weight from 1,000 to 25,000 by polymerizing monoethylenically unsaturated monomers in the presence of an organic sulfonyl halide, an organic complexing agent and a transition metal (i.e., Cu, Ru, Ni, Re, Pd, Fe, or Rh); and (b) subsequently polymerizing the prepolymer with a mixture of monoethylenically unsaturated monomers and 0.5 to 60 mole percent, based on the total moles of monomer and prepolymer, of multi-olefinic polymerizable monomers to form a microgel with a weight average molecular weight of 10,000 to 100,000,000 and crosslinked core.
    Type: Grant
    Filed: October 3, 2001
    Date of Patent: October 8, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Charles T. Berge, Michael Fryd, Jeffrey W. Johnson, Graeme Moad, Ezio Rizzardo, Christopher Scopazzi, San Hoa Thang
  • Publication number: 20020061989
    Abstract: This invention concerns the preparation of polymers of low polydispersity and/or controlled molecular weight and architecture employing living free radical polymerization initiated by an alkoxyamine initiator or nitroxide plus, optionally, a free radical initiator; the polymer produced thereby; selected nitroxide and alkoxyamine initiators; and a process for making the initiators; the polymeric products being useful in protective coatings.
    Type: Application
    Filed: May 9, 2001
    Publication date: May 23, 2002
    Inventors: Albert G. Anderson, Alexei Gridnev, Graeme Moad, Ezio Rizzardo, San Hoa Thang
  • Patent number: 6355718
    Abstract: A process for preparing microgel(s) that uses a wide range of activatable prepolymers; in the process, a polymer composition of crosslinked component A and soluble components B and C is formed from mono-olefinic and multi-olefinic monomers in the presence of catalyst and initiator; the process comprises: I) introducing mono-olefinic monomer, catalyst, and initiator into a reactor in the absence of multi-olefinic monomer and producing an activatable prepolymer, component B; II) contacting the product of I) with multi-olefinic monomer to produce components A and C, optionally in the presence of additional initiator; also optionally in the presence of additional mono-olefinic monomer and initiator; the ratio of components A/(B+C) can be controlled by varying the mole ratio of Component B/ multi-olefinic monomer from 0.05/1 up to 5/1, by decreasing the mole ratio to increase the ratio of A/(B+C), and increasing the mole ratio to decrease the ratio of A/(B+C).
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: March 12, 2002
    Assignees: E. I. du Pont de Nemours and Company, Commonwealth Scientific and Industrial Research Organization, University of Melbourne, Australia
    Inventors: Charles T. Berge, Michael Fryd, Jeffrey W. Johnson, Graeme Moad, Ezio Rizzardo, Christopher Scopazzi, San Hoa Thang
  • Publication number: 20020022683
    Abstract: A process for preparing microgel(s) that uses a wide range of activatable prepolymers; in the process, a polymer composition of crosslinked component A and soluble components B and C is formed from mono-olefinic and multi-olefinic monomers in the presence of catalyst and initiator; the process comprises:
    Type: Application
    Filed: October 3, 2001
    Publication date: February 21, 2002
    Inventors: Charles T. Berge, Michael Fryd, Jeffrey W. Johnson, Graeme Moad, Ezio Rizzardo, Christopher Scopazzi, San Hoa Thang
  • Publication number: 20020019476
    Abstract: A process for preparing microgel(s) that uses a wide range of activatable prepolymers; in the process, a polymer composition of crosslinked component A and soluble components B and C is formed from mono-olefinic and multi-olefinic monomers in the presence of catalyst and initiator; the process comprises:
    Type: Application
    Filed: October 3, 2001
    Publication date: February 14, 2002
    Inventors: Charles T. Berge, Michael Fryd, Jeffrey W. Johnson, Graeme Moad, Ezio Rizzardo, Christopher Scopazzi, San Hoa Thang
  • Publication number: 20020019475
    Abstract: A process for preparing microgel(s) that uses a wide range of activatable prepolymers; in the process, a polymer composition of crosslinked component A and soluble components B and C is formed from mono-olefinic and multi-olefinic monomers in the presence of catalyst and initiator; the process comprises:
    Type: Application
    Filed: October 3, 2001
    Publication date: February 14, 2002
    Inventors: Charles T. Berge, Michael Fryd, Jeffery W. Johnson, Graeme Moad, Ezio Rizzardo, Christopher Scopazzi, San Hoa Thang
  • Patent number: 6271340
    Abstract: This invention concerns the preparation of polymers of low polydispersity and/or controlled molecular weight and architecture employing living free radical polymerization initiated by an alkoxyamine initiator or nitroxide plus, optionally a free radical initiator, the polymer produced thereby; selected nitroxide and alkoxyamine initiators; and a process for making the initiators; the polymeric products being useful in protective coatings.
    Type: Grant
    Filed: November 5, 1999
    Date of Patent: August 7, 2001
    Assignees: E. I. du Pont de Nemours and Company, Commonwealth Scientific & Industrial Research Organization
    Inventors: Albert G. Anderson, Alexei Gridnev, Graeme Moad, Ezio Rizzardo, San Hoa Thang
  • Patent number: 6235857
    Abstract: This invention relates to a process for the production of lower molecular weight polymers by free radical-initiated polymerization of unsaturated species characterized by the use of an unsaturated compound of Formula I as a chain transfer agent: wherein R1 and R2 are the same or different and are selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted saturated or aromatic carbocyclic or heterocyclic ring, and halogen; X is selected from the group consisting of chlorine, bromine, optionally substituted alkylsulfonyl, and optionally substituted arylsulfonyl, Y is selected from the group consisting of halogen, a polymer chain, and CR3R4Z, wherein R3 and R4 are the same or different and are selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted saturated, unsaturated or aromatic carbocyclic or hetercyclic ring, and halogen; and Z is selected from the group consisting of chlorine, bromine, optionally su
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: May 22, 2001
    Assignees: Commonwealth Scientific and Industrial Research Organisation, E.I. DuPont DeNemours and Company
    Inventors: Ezio Rizzardo, San Hoa Thang, Graeme Moad, Yen Kwong Chong
  • Patent number: 6197905
    Abstract: A process for the production of polymers by free radical polymerization, characterized in that there is added to the polymerization system one or more compounds of general formula (A), where R1 is a group capable of activating the vinylic carbon towards free radical addition; Y is OR2, where R2 is an optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, or optionally substituted saturated or unsaturated carbocyclic or heterocyclic ring; X is an element other than carbon selected from the Groups, IV, V, VI or VII of the Periodic Table or a group consisting of an element selected from the Groups IV, V, or VI to which is attached one or more oxygen atoms; and n is a number from 0 to 3, such that the valency of the group X is satisfied and, when n is greater than 1, the groups represented by R2 are identical or different.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: March 6, 2001
    Assignee: Commonwealth Scientific & Industrial Resarch Organization
    Inventors: Ezio Rizzardo, Gordon Francis Meijs, San Hoa Thang
  • Patent number: 6034263
    Abstract: A process for the production of lower molecular weight polymers by free radical polymerization, characterized in that there is added to the polymerization system a compound of the general formula I ##STR1## wherein R.sup.1 is hydrogen, chlorine, an alkyl group, or a group capable of activating the vinylic carbon towards free radical addition;R.sup.2 is hydrogen or an optionally substituted alkyl, alkenyl, aryl, cycloalkenyl or cycloalkyl group or the group --COZ, where Z is R.sup.3 or OR.sup.3, where R.sup.3 is hydrogen or an optionally substituted alkyl, alkenyl or aryl group.X is a hydrogen atom, an alkyl or aryl group, or a halogen, and the two X groups may be the same or different.The invention also includes polymers or oligomers made by the process and novel compounds of the generated formula I as defined above.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: March 7, 2000
    Assignee: Commonwealth Scientific and Industrial Research Organisation
    Inventors: Ezio Rizzardo, Gordon Francis Meijs, San Hoa Thang
  • Patent number: 5977278
    Abstract: The present invention relates to polymers having the formula: ##STR1## wherein: M, Q, X, Y, Z, R.sup.3 and R.sup.4 are as defined in the text.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: November 2, 1999
    Assignees: E. I. du Pont de Nemours and Company, Commonwealth Scientific and Industrial Research Organisation
    Inventors: Ezio Rizzardo, San Hoa Thang, Graeme Moad, Charles T. Berge
  • Patent number: 5932675
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: August 3, 1999
    Assignee: Commonwealth Scientific and Industrial Research Organisation
    Inventors: Ezio Rizzardo, Gordon Francis Meijs, San Hoa Thang
  • Patent number: 5874511
    Abstract: A process for the production of polymers by free radical polymerization, characterized in that there is added to the polymerization system one or more compounds of the general formula (A). ##STR1## where R.sup.1 is hydrogen or a group capable of activating the vinylic carbon towards free radical addition;Y is OR.sup.2 or CH.sub.2 X(R.sup.2).sub.nwhere R.sup.2 is an optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, or optionally substituted saturated, unsaturated or aromatic carbocyclic or heterocyclic ring;X is an element other than carbon selected from Groups IV, V, VI or VII of the Periodic Table or a group consisting of an element selected from Groups IV, V, or VI to which is attached one or more oxygen atoms; andn is a number from 0 to 3, such that the valency of the group X is satisfied and, when n is greater than 1, the groups represented by R.sup.2 may be identical or different.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: February 23, 1999
    Assignees: E. I. du Pont de Nemours and Company, Commonwealth Scientific and Industrial Research Organisation
    Inventors: Ezio Rizzardo, Gordon Francis Meijs, San Hoa Thang
  • Patent number: 5830966
    Abstract: Compounds of general formula (I) ##STR1## characterised in that R.sup.1 and R.sup.2 are independently selected from the group consisting of COOR, CN, aryl, substituted aryl, COOH, halogen, C(O)NHR.sup.4, C(O)NR.sup.5 R.sup.6 ;X and Y are independently selected from the group consisting of H, COOH, COOR, CN, R.sup.3 CO--, C(O)NHR.sup.4, C(O)NR.sup.5 R.sup.6, P(O)(OR.sup.7).sub.2 and SO.sub.2 R.sup.8 ; with the proviso that X and Y are not both H; or X and Y together with the carbon atom to which they are attached form a carbocyclic or heterocyclic ring system which can contain oxygen, sulfur or nitrogen atoms; and R, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are various groups;and polymers and copolymers derived from such compounds.
    Type: Grant
    Filed: January 26, 1996
    Date of Patent: November 3, 1998
    Assignees: E. I. du Pont de Nemours and Company, Commonwealth Scientific & Industrial Research Organisation
    Inventors: San Hoa Thang, Ezio Rizzardo, Graeme Moad
  • Patent number: 5773543
    Abstract: A process for the free radical initiated polymerization of unsaturated species characterized by the use of compound of Formula (I) as chain transfer agents: ##STR1## wherein: X is selected from hydrogen; CN; optionally substituted aryl; COOH; COOR; C(O)NHR.sup.6 ; C(O)NR.sup.7 R.sup.8 ; and halogen;Q is selected from COOR.sup.1 ; CN; and C(O)NR.sup.7 R.sup.8 ;Y is selected from hydrogen; C.sub.1 to C.sub.6 alkyl; C.sub.1 to C.sub.6 alkyl substituted with one or more substituents selected from hydroxy, amino, C.sub.1 to C.sub.6 alkoxy, C.sub.1 to C.sub.6 alkoxycarbonyl, halogen, CN and optionally substituted aryl; C.sub.1 to C.sub.6 alkenyl; and C.sub.1 to C.sub.6 alkynyl;Z is selected from COOR.sup.2 ; CN; and optionally substituted aryl;R.sup.3 and R.sup.4 are the same or different and are selected from hydrogen C.sub.1 to C.sub.4 alkyl and halogen; or R.sup.3 and R.sup.
    Type: Grant
    Filed: August 1, 1996
    Date of Patent: June 30, 1998
    Assignee: Commonwealth Scientific and Industrial Research Organisation
    Inventors: Ezio Rizzardo, San Hoa Thang, Graeme Moad, Charles Thomas Berge
  • Patent number: 5756605
    Abstract: A method for the solution or amulsion polymerization of ethylenically unsaturated monomers, styrene, and other free radical polymerizatable monomers in aqueous media in which a cobalt chain transfer agent is used which has both hydrolytic stability and solubility in water and in the organic phase with preferential solubility in the organic phase.
    Type: Grant
    Filed: May 5, 1997
    Date of Patent: May 26, 1998
    Assignees: E. I. du Pont de Nemours and Company, Commonwealth Scientific and Industrial
    Inventors: Graeme Moad, Catherine Louise Moad, Julia Krstina, Ezio Rizzardo, San Hoa Thang, Michael Fryd
  • Patent number: 5698648
    Abstract: A process for the production of lower molecular weight polymers by free radical polymerization, characterized in that there is added to the polymerization system a compound of the general formula I ##STR1## wherein R.sup.1 is hydrogen, chlorine, an alkyl group, or a group capable of activating the vinylic carbon towards free radical addition;R.sup.2 is hydrogen or an optionally substituted alkyl, alkenyl, aryl, cycloalkenyl or cycloalkyl group or the group --COZ, where Z is R.sup.3 or OR.sup.3, where R.sup.3 is hydrogen or an optionally substituted alkyl, alkenyl or aryl group.X is a hydrogen atom, an alkyl or aryl group, or a halogen, and the two X groups may be the same or different.The invention also includes polymers or oligomers made by the process and novel compounds of the general formula I as defined above.
    Type: Grant
    Filed: February 28, 1994
    Date of Patent: December 16, 1997
    Assignee: The Commonwealth of Australia Commonwealth Scientific and Industrial Research Organisation
    Inventors: Ezio Rizzardo, Gordon Francis Meijs, San Hoa Thang
  • Patent number: 5665839
    Abstract: Compound of the Formula 1 ##STR1## wherein: R.sup.1 and R.sup.2 are independently selected from the group comprising hydrogen, C.sub.1 to C.sub.6alkyl, C.sub.1 to C.sub.6 haloalkyl, phenyl, and substituted phenyl;X is selected from the group comprising sulfur, sulphone, disulfide;Y is selected from oxygen, carbon, N--H, N-alkyl, N-aryl, or sulfur; andZ is any linking functionality.The compounds represent a new class of ring opening monomers.
    Type: Grant
    Filed: July 20, 1995
    Date of Patent: September 9, 1997
    Assignee: Commonwealth Scientific and Industrial Research Organisation
    Inventors: Ezio Rizzardo, Richard Alexander Evans, Graeme Moad, San Hoa Thang