Patents by Inventor Kathryn Hock

Kathryn Hock 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).

  • Process for recovering toluene diamine from toluene diisocyanate distillation residues
    Patent number: 6429336
    Abstract: Residues from the distillation of a toluene diamine phosgenation mixture are hydrolyzed by mixing them with water and subjecting the mixture to a temperature of 200-350 ° C. The hydrolysis is performed in the presence of a sufficient amount of a base to maintain the pressure in the reactor to no more than a predetermined operating level. The product mixture is then extracted to recover TDA, which can be recycled. This provides an efficient process whereby nearly quantitative conversion of the residues to TDA can be achieved.
    Type: Grant
    Filed: May 5, 2000
    Date of Patent: August 6, 2002
    Assignee: The Dow Chemical Company
    Inventors: Shenghong A. Dai, Duane S. Treybig, Kathryn Hock, Van A. Kent
  • Process for recovering toluene diamine from toluene diisocyanate distillation residues
    Publication number: 20020010369
    Abstract: Residues from the distillation of a toluene diamine phosgenation mixture are hydrolyzed by mixing them with water and subjecting the mixture to a temperature of 200-350° C. The hydrolysis is performed in the presence of a sufficient amount of a base to maintain the pressure in the reactor to no more than a predetermined operating level. The product mixture is then extracted to recover TDA, which can be recycled. This provides an efficient process whereby nearly quantitative conversion of the residues to TDA can be achieved.
    Type: Application
    Filed: May 5, 2000
    Publication date: January 24, 2002
    Inventors: Shenghong Dai, Duane S. Treybig, Kathryn Hock, Van A. Kent