Patents by Inventor Peter A. Tasker

Peter A. Tasker 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: 5364452
    Abstract: A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal, an alkaline earth metal or ammonium chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: November 15, 1994
    Inventors: Domenico C. Cupertino, Peter A. Tasker
  • Patent number: 5342937
    Abstract: A solvent soluble heterocyclic o-hydroxy thione carrying a lipophilic group and the process for the selective extraction of gallium, and certain other related metals, especially from solutions containing excess aluminium.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: August 30, 1994
    Assignees: Zeneca, Limited, Nerco, Inc.
    Inventors: Peter W. Austin, Peter M. Quan, Peter A. Tasker, Derek Thorp
  • Patent number: 5332420
    Abstract: A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal or alkaline earth metal chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.
    Type: Grant
    Filed: February 24, 1993
    Date of Patent: July 26, 1994
    Assignee: Zeneca Limited
    Inventors: Domenico C. Cupertino, Peter A. Tasker
  • Patent number: 5213701
    Abstract: A compound is a condensate of 1,2,3-trihydroxybenzene with an aldehyde. The condensate is a macrocyclic compound such as a cyclic tetramer. The aldehyde is preferably a long-chain aldehyde such as hexanal, dodecanal or tetradecanal. The condensate can be used as an anti-wear additive in hydrocarbon liquids such as liquid paraffin or as an anti-corrosion additive. The condensate can be prepared by reacting 1,2,3-trihydroxybenzene with an equimolar quantity of an aldehyde in the presence of an acid.
    Type: Grant
    Filed: July 10, 1992
    Date of Patent: May 25, 1993
    Assignee: Imperial Chemical Industries PLC
    Inventors: Jeremy M. Holmes, Peter A. Tasker
  • Patent number: 5173210
    Abstract: A composition comprising a chelating compound which is a macrocyclic compound containing at least two coordinating centers in the ring, at least one of which is a neutral base moiety, and an organic acid containing at least one alkyl or alkenyl group containing 8 or more carbon atoms. The macrocyclic compound contains at least 10 ring atoms and especially at least 12 ring atoms. The neutral base moiety is typically a nitrogen moiety. Preferably there are at least four coordinating centers at least two of which are neutral base moities. The acid can be an alkyl or alkenyl substituted acid for example a long chain carboxylic acid. The composition can be used as an extractant system for the selective extraction of metals from an aqueous phase into an organic phase.
    Type: Grant
    Filed: July 11, 1989
    Date of Patent: December 22, 1992
    Assignee: Imperial Chemical Industries PLC
    Inventors: Leonard F. Lindoy, Darren S. Baldwin, Peter A. Tasker
  • Patent number: 5169991
    Abstract: A compound is a condensate of 1,2,3-trihydroxybenzene with an aldehyde. The condensate is a macrocyclic compound such as a cyclic tetramer. The aldehyde is preferably a long-chain aldehyde such as hexanal, dodecanal or tetradecanal. The condensate can be used as an anti-wear additive in hydrocarbon liquids such as liquid paraffin or as an anti-corrosion additive. The condensate can be prepared by reacting 1,2,3-trihydroxybenzene with an equimolar quantity of an aldehyde in the presence of an acid.
    Type: Grant
    Filed: February 28, 1990
    Date of Patent: December 8, 1992
    Assignee: Imperial Chemicals Industries PLC
    Inventors: Jeremy M. Holmes, Peter A. Tasker
  • Patent number: 5074911
    Abstract: A process for extracting metal values such as gallium and/or indium from aqueous solutions by contacting said solutions with a water immiscible organic solvent having dissolved therein a heterocyclic thione.
    Type: Grant
    Filed: June 26, 1990
    Date of Patent: December 24, 1991
    Assignees: Imperical Chemical Industries PLC, Nerco Inc.
    Inventors: Peter W. Austin, Peter M. Quan, Peter A. Tasker, Derek Thorp
  • Patent number: RE36118
    Abstract: A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal or alkaline earth metal chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: March 2, 1999
    Assignee: Zeneca Limited
    Inventors: Domenico C. Cupertino, Peter A. Tasker
  • Patent number: RE36990
    Abstract: A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal, an alkaline earth metal or ammonium chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: December 19, 2000
    Assignee: Zeneca Limited
    Inventors: Domenico C. Cupertino, Peter A. Tasker