Patents Examined by D. Hampton-Hightower
  • Process for forming end-capped polyamic acids polyimides
    Patent number: 4956450
    Abstract: This invention discloses a process where a portion of an amine terminated polyamic acid intermediate is end-capped with an aromatic monoanhydride additionally substituted with a free carboxylic acid or ester thereof. The polyamic acids of this invention are readily converted to high molecular weight polyimides which may contain a small amount of amide groups.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: September 11, 1990
    Assignee: Ethyl Corporation
    Inventors: Burnell Lee, Hsueh M. Li