Patents by Inventor Sheldon L. Clark

Sheldon L. Clark 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: 4602060
    Abstract: A two-stage system can provide a water-soluble releasing interface which permits a plurality of cycles of the mold between applications with such reaction-injection molding materials as reinforced urethane. The two-coat release system provides on the mold surface a base coat, including a polymer release agent with groups capable of bonding to the mold surface (e.g., a carboxy-terminated silicone) and a bonding or cross-linking agent (e.g., tetraisopropyltitanate), which reacts with and cross links the polymer and provides bonding with the mold surface and for soap-like materials, and a top coat, which is a water-soluble soap-like material (e.g., a water-soluble metallic salt of long-chain fatty acid). Such a system can be particularly adapted for use with urethane RIM materials.
    Type: Grant
    Filed: April 25, 1983
    Date of Patent: July 22, 1986
    Assignee: Frekote, Inc.
    Inventors: Sheldon L. Clark, Frank P. Pajaujis