Patents by Inventor David Roderick Baxter

David Roderick Baxter 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 marking hydrocarbons with substituted anthraquinones
    Patent number: 7915048
    Abstract: A method for marking a liquid petroleum hydrocarbon. The method comprises adding to the liquid petroleum hydrocarbon at least one substituted anthraquinone dry having formula (I) wherein X is O or S; Y is O, NR7 or S; R1 and R2 independently are hydrogen, alkyl, aryl, aralkyl, heteroalkyl, heterocyclic or alkanoyl; R3 and R5 independently are alkyl, aryl, aralkyl, heteroalkyl or heterocyclic; R4 and R6 independently are hydrogen or alkyl; R7 is hydrogen or alkyl; and wherein the substituted anthraquinone dye(s) has an absorption maximum in the range from 600 nm to 750 nm.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: March 29, 2011
    Assignee: Rohm and Haas Company
    Inventors: David Roderick Baxter, Peter John Cranmer, Kim Sang Ho
  • Method for marking hydrocarbons with substituted anthraquinones
    Patent number: 6977177
    Abstract: A method for marking a liquid petroleum hydrocarbon. The method comprises adding to the liquid petroleum hydrocarbon at least one substituted anthraquinone dye having formula (I) wherein R1 and R2 independently are hydrogen, hydroxy, OR11, amino or NR11R12; R3 and R5 independently are alkyl, aryl, aralkyl, heteroalkyl or heterocyclic; R4 and R6 independently are hydrogen or alkyl; R7, R8, R9 and R10 independently are cyano, nitro or hydrogen, provided that at least two of R7, R8, R9 and R10 are cyano or nitro; R11 is alkyl, aryl, aralkyl, heteroalkyl, heterocyclic or alkanoyl; R12 is hydrogen or alkyl; and wherein the substituted anthraquinone dye(s) has an absorption maximum in the range from 690 nm to 1000 nm.
    Type: Grant
    Filed: May 26, 2004
    Date of Patent: December 20, 2005
    Assignee: Rohm and Haas Company
    Inventors: Kim Sang Ho, David Roderick Baxter
  • Method for marking hydrocarbons with substituted anthraquinones
    Publication number: 20040250469
    Abstract: A method for marking a liquid petroleum hydrocarbon.
    Type: Application
    Filed: May 28, 2004
    Publication date: December 16, 2004
    Inventors: David Roderick Baxter, Peter John Cranmer, Kim Sang Ho
  • Method for marking liquid hydrocarbons
    Publication number: 20040106526
    Abstract: A method for marking a liquid petroleum hydrocarbon. The method comprises adding to the liquid petroleum hydrocarbon: (i) at least one anthraquinone dye having an absorption maximum in the range from 710 nm to 850 nm selected from the group consisting of 1,4,5,8-tetrasubstituted anthraquinones and anthraquinone dimers; and (ii) at least one visible dye having an absorption maximum in the range from 500 nm to 700 nm.
    Type: Application
    Filed: November 12, 2003
    Publication date: June 3, 2004
    Inventors: David Roderick Baxter, Peter John Cranmer, Kim Sang Ho