Patents by Inventor Raymond C. Tsiang

Raymond C. Tsiang 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: 5338824
    Abstract: A process for removing alkali metal alkoxide catalyst residue from anionically polymerized hydroxy terminated conjugated diene polymer. The process comprises contacting a solution of such a polymer with an adsorbent which can be an ultrastable Y zeolite in the hydrogen form or a large pore size, low surface area cationic exchange resin.
    Type: Grant
    Filed: July 6, 1993
    Date of Patent: August 16, 1994
    Assignee: Shell Oil Company
    Inventors: Zaida Diaz, Raymond C. Tsiang
  • Patent number: 5212249
    Abstract: A method for preparing asymmetric radial polymers wherein the different polymeric arms are contacted sequentially with a nonpolymerizable coupling agent. Contacting of the final step in the process, which frequently but not necessarily always will be the second step in the process, will be carried out in the presence of a polar compound suitable for increasing the amount of vinyl content in a conjugated diolefin polymer during polymerization thereof. The method used narrows the relative arm distribution of the several asymmetric radial polymers produced and significantly increases the amount of total product having the desired ratio of polymeric arms and accomplishes this objective in relatively short reaction time.
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: May 18, 1993
    Assignee: Shell Oil Company
    Inventors: Gary W. Richie, deceased, Raymond C. Tsiang, Ronald J. Hoxmeier, Arthur R. Bean, Harvey E. Atwood
  • Patent number: 5073621
    Abstract: A process is provided for removing Group VIII metal hydrogenation catalyst residue from a polymer which comprises oxidizing the hydrogenation catalyst residue in the polymer, contacting the polymer with an aqueous solution of dicarboxylic acid and separating the hydrogenation catalyst residue from the polymer. Preferred dicarboxylic acids include adipic and azelaic acids. The amount of water contacted with the polymer cement is less than that which would form an aqueous phase. Solid particulates comprising hydrogenation catalyst metal form within minutes upon the addition of the aqueous dicarboxylic acid to the polymer cement.
    Type: Grant
    Filed: April 16, 1990
    Date of Patent: December 17, 1991
    Assignee: Shell Oil Company
    Inventor: Raymond C. Tsiang