Patents by Inventor Dieter Laudien

Dieter Laudien 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 the production of polyamidocarboxylic acids
    Patent number: 3981847
    Abstract: A process for the producing a polyamidocarboxylic acid, or so-called polyamic acid, which is the prepolymer in forming a polyamide and which requires the reaction of a tetracarboxylic acid dianhydride with a diprimary diamine below about 50.degree.C. in an anhydrous, polar, aprotic organic solvent, characterized by an initial treatment of the dianhydride by only wetting with an inert organic solvent or by at least wetting this dianhydride with the polar, aprotic solvent and thereafter adding to the wetted dianhydride a solution of the diamine in the polar, aprotic solvent under thorough mixing, preferably within a very short period of time after treating the dianhydride. Stable polyamic acid solutions formed in this manner are useful intermediates in preparing films, filaments or other shaped polyimide products.
    Type: Grant
    Filed: November 7, 1974
    Date of Patent: September 21, 1976
    Assignee: Akzona Incorporated
    Inventors: Gerhard Meyer, Anton Toth, Dieter Laudien