Patents by Inventor Janis C. Stevenson

Janis C. Stevenson 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 making encapsulated micro-agglomerated core/shell additives for PVC blends
    Patent number: 5442012
    Abstract: Core/shell additives, useful in modifying the processing and/or physical properties of poly(vinyl chloride) and other thermoplastic matrix polymers, are prepared separately at small particle sizes by emulsion polymerization, co-agglomerated, further encapsulated by a final shell, and isolated by spray-drying or coagulation. The isolated powders are readily re-dispersed to their original particle sizes in the matrix polymer.
    Type: Grant
    Filed: October 26, 1993
    Date of Patent: August 15, 1995
    Assignee: Rohm and Haas Company
    Inventors: James S. Kempner, Hsing-Yeh Parker, Janis C. Stevenson, Morris C. Wills, Judith L. Allison
  • Encapsulated micro-agglomerated core/shell additives in poly(vinyl chloride) blends
    Patent number: 5276092
    Abstract: Core/shell additives, useful in modifying the processing and/or physical properties of poly(vinyl chloride) and other thermoplastic matrix polymers, are prepared separately at small particle sizes by emulsion polymerization, co-agglomerated, further encapsulated by a final shell, and isolated by spray-drying or coagulation. The isolated powders are readily re-dispersed to their original particle sizes in the matrix polymer.
    Type: Grant
    Filed: March 25, 1993
    Date of Patent: January 4, 1994
    Assignee: Rohm and Haas Company
    Inventors: James S. Kempner, Hsing-Yeh Parker, Janis C. Stevenson, Morris C. Wills, Judith L. Allison
  • Co-microagglomeration of emulsion polymers (encapsulated core/shell additives for PVC)
    Patent number: 5221713
    Abstract: Core/shell additives, useful in modifying the processing and/or physical properties of poly(vinyl chloride) and other thermoplastic matrix polymers, are prepared separately at small particle sizes by emulsion polymerization, co-agglomerated, further encapsulated by a final shell, and isolated by spray-drying or coagulation. The isolated powders are readily re-dispersed to their original particle sizes in the matrix polymer.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: June 22, 1993
    Assignee: Rohm and Haas Company
    Inventors: James S. Kempner, Hsing-Yeh Parker, Janis C. Stevenson, Morris C. Wills, Judith L. Allison
  • Poly(vinyl chloride) blends and additives therefor
    Patent number: 5194498
    Abstract: This invention relates to poly(vinyl chloride) injection molding compositions which contain novel additive polymers which modify the rheology characteristics of the composition, and to the novel additive polymers themselves.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: March 16, 1993
    Assignee: Rohm and Haas Company
    Inventors: Janis C. Stevenson, Hsing-Yeh Parker