Patents by Inventor Ben Duh

Ben Duh 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: 4205157
    Abstract: A high molecular weight polyester is disclosed, having a low carboxyl content, and utilizing a low catalyst level, produced by a two-stage process; a melt process until the intrinsic viscosity of the prepolymer reaches about between 0.15 and 0.45 dl/g, and a solid state polymerization in a fluidized bed until the intrinsic viscosity of the polycondensed polymer reaches at least 0.60 dl/g. The melt process employs addition of excess initial glycol, delayed addition of excess glycol, and delayed addition of catalyst, in any combination, to achieve a low carboxyl content polyester prepolymer capable of use in the fluidized bed solid state polymerization. This prepolymer with a minimal carboxyl content achieves a maximum solid state polymerization rate in a fluidized bed. This prepolymer also permits the use of a very low catalyst level to achieve high product purity and still maintains economically satisfactory polymerization rate.
    Type: Grant
    Filed: April 2, 1979
    Date of Patent: May 27, 1980
    Assignee: The Goodyear Tire & Rubber Company
    Inventor: Ben Duh