Patents by Inventor Susan M. Liwak

Susan M. Liwak 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).

  • Impact-strength modifiers for thermoplastic polymers
    Patent number: 5457156
    Abstract: An acrylic additive polymer containing free carboxylic acid groups is added to a core-shell impact-property modifier containing free carboxylic acid groups to produce an improved physical-property modifier for polyamide resins.
    Type: Grant
    Filed: May 3, 1994
    Date of Patent: October 10, 1995
    Assignee: Rohm and Haas Company
    Inventors: Wan-Li Liu, Susan M. Liwak
  • Impact strength modifiers for thermoplastic polymers
    Patent number: 5332782
    Abstract: An acrylic additive polymer containing free carboxylic acid groups is added to a core-shell impact-property modifier containing free carboxylic acid groups to produce an improved physical-property modifier for polyamide resins.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: July 26, 1994
    Assignee: Rohm and Haas Company
    Inventors: Wan-Li Liu, Susan M. Liwak
  • Thermal stabilizers
    Patent number: 5164434
    Abstract: The invention is directed to stabilizer compositions, to polymers containing three stabilizer compositions for use as additives in polymers, and to polymeric products which contain these additives. The stabilizer compositions comprise a compositon of: a) at least two hindered phenols and b) a sulfide. These compositions are admixed with polymers to provide polymeric additives to improve the physical and mechanical properties of polymers matrices.
    Type: Grant
    Filed: November 30, 1990
    Date of Patent: November 17, 1992
    Assignee: Rohm and Haas Company
    Inventors: Susan M. Liwak, Nazir A. Memon
  • Pigmented thermoplastic resins
    Patent number: 4617329
    Abstract: A polymer blend comprises from about 60 parts to about 99.9 parts by weight of a pigmented thermoplastic resin, which resin is a polyester or a polycarbonate or mixtures thereof, and from about 0.1 part to about 40 parts of a sequentially produced multi-stage polymer. The multi-stage polymer comprises a polymer core of at least about 10 parts, based on the weight of the multi-stage polymer. The core is polymerized from a styrenic monomer, or a mixture of styrenic monomers. The styrenic monomer of the core comprises at least about 50% by weight of said core. A second monomer may be present and a crosslinking monomer for styrene is present in said core. The second stage of the multi-stage polymer comprises a polymeric soft stage and the outer stage of the multi-stage polymer is a rigid thermoplastic.
    Type: Grant
    Filed: September 5, 1985
    Date of Patent: October 14, 1986
    Assignee: Rohm and Haas Company
    Inventors: Richard H. Weese, Evan H. Crook, Susan M. Liwak