Patents by Inventor Lai-Duien G. Fan

Lai-Duien G. Fan 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).

  • Method for inhibiting corrosion of metals using polytartaric acids
    Patent number: 5344590
    Abstract: A method for inhibiting corrosion of metals in contact with an aqueous solution comprising adding to the system a corrosion inhibiting amount of one or more polytartaric acid compounds having the generalized formula: ##STR1## wherein each R is independently selected from the group consisting of H and C.sub.1 to C.sub.4 alkyl, n is less than 4 and the average molecular weight of the mixture corresponds to an average n in the range 1.2 to 3.
    Type: Grant
    Filed: January 6, 1993
    Date of Patent: September 6, 1994
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Charles G. Carter, Lai-Duien G. Fan, Joseph C. Fan, Robert P. Kreh, Vladimir Jovancicevic
  • Method of dispersing iron
    Patent number: 5183574
    Abstract: A method of comprising iron in an aqueous system comprising adding to the system a copolymer of styrene sulfonic acid and methacrylic acid or its water soluble salt in an amount effective to disperse the iron contained therein.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: February 2, 1993
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Chih M. Hwa, John A. Kelly, Wun T. Tai, Lai-Duien G. Fan, Robert P. Kreh, Brian Greaves
  • Naphthylamine polycarboxylic acids
    Patent number: 5139702
    Abstract: A composition useful for treating aqueous systems comprising a naphthylamine polycarboxylic acid having the formula: ##STR1## wherein X is CO.sub.2 H or SO.sub.3 H, Y is H, C.sub.1 to C.sub.6 alkyl, CO.sub.2 H or SO.sub.3 H, R is H, C.sub.1 to C.sub.6 alkyl, CO.sub.2 R' or COR', R' is C.sub.1 to C.sub.6 alkyl, n is an integer from 1 to 20, and water soluble salts thereof.
    Type: Grant
    Filed: October 24, 1991
    Date of Patent: August 18, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Charles G. Carter, Robert P. Kreh, Lai-Duien G. Fan
  • Method of inhibiting scale deposits
    Patent number: 5124047
    Abstract: This invention relates to a method of inhibiting scale formation in aqueous systems wherein allylphosphonate copolymers are added to the system in an amount effective to inhibit scale formation. The allylphosphonate copolymers of this invention exhibit characteristic properties for the treatment of aqueous systems, namely strong calcium complexation, excellent iron dispersion, inhibition of calcium carbonate scale and inhibition of calcium phosphate deposition.
    Type: Grant
    Filed: November 1, 1990
    Date of Patent: June 23, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Loc Quach, Lai-Duien G. Fan