Patents by Inventor Siusun K. Leung

Siusun K. Leung 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: 5395860
    Abstract: It has been discovered that particular flexible polyurethane foam formulations having a chlorinated alkane incorporated therein have the advantage of improved combustion resistance, but also unexpectedly the additional advantages of improved durability (dynamic fatigue), and better processing in terms of a delayed onset of gel. These results were surprisingly achieved with the use of a chlorinated alkane as the sole component to improve combustion resistance. Incorporation of as much as 34 parts of chlorinated alkane per hundred parts of polyol have been accomplished.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: March 7, 1995
    Assignee: Arco Chemical Technology, L.P.
    Inventors: Siusun K. Leung, Frank E. Critchfield, Paul M. Westfall
  • Patent number: 5124368
    Abstract: It has been discovered that a particular polyurethane formulation may be used to prepare "pour-in-place" (PIP) polyurethane foam articles where the formulation is injected into a mold bearing an exterior covering such as a fabric without the foaming liquid striking through the layer. The formulation employs a hydrophilic polyhydric compound to help the reactivity balance that minimizes penetration of the exterior covering while also stabilizing the rising foam against shear collapse without excessively tightening the foam. Contrary to the conventional expectation that the hydrophilic polyhydric compound would cause strike through problems since it delays the initial reaction time, it has been found to have the noted stabilizing effect. A preferred hydrophilic polyhydric compound is glycerine. A preferred isocyanate for the formulation is tolylene diisocyanate (TDI), in contrast to diphenylmethane diisocyanate (MDI) heretofore used in PIP foams.
    Type: Grant
    Filed: July 29, 1991
    Date of Patent: June 23, 1992
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: William A. Gill, Siusun K. Leung
  • Patent number: 4997857
    Abstract: A stabilizer for polymer/polyols characterized by four key features: (1) prepared from a starting polyol having a functionality greater than 4; (2) having at least 60% retained unsaturation; (3) having a viscosity greater than 2000 cSt; and (4) prepared where the starting polyol is capped with alkylene oxide and/or the adduct formed between the starting polyol and the reactive unsaturated compound is capped with ethylene oxide.
    Type: Grant
    Filed: September 30, 1986
    Date of Patent: March 5, 1991
    Assignee: Arco Chemical Technology, Inc.
    Inventors: John F. Timberlake, Siusun K. Leung, Edgar G. Shook, Donald W. Simroth, Richard C. Myerly