Patents by Inventor Gotthilf Wenner

Gotthilf Wenner 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).

  • Manufacture of 4,4'-diphenylmethane diisocyanate and a mixture of diisocyanates and polyisocyanates
    Patent number: 4014914
    Abstract: Production of 4,4'-diphenylmethane diisocyanate and a mixture of diisocyanates and polyisocyanates by the phosgenation of pure 4,4'-diaminodiphenylmethane and a mixture of diamines and polyamines. 4,4'-Diaminodiphenylmethane is obtained by distillation of the mixture of products obtained from the reaction of aniline with formaldehyde and crystallization of the distillate from a solvent. The combined distillation residue and mother liquor from the crystallization form the mixture for reaction with phosgene to produce a mixture of diisocyanates and polyiisocyanates. This process produces a highly pure 4,4'-diphenylmethane diisocyanate which is particularly suitable for the production of polyurethanes serving as intermediates in the manufacture of rigid foams or as glue.
    Type: Grant
    Filed: October 25, 1974
    Date of Patent: March 29, 1977
    Assignee: Badische Anilin- & Soda-Fabrik Aktiengesellschaft
    Inventors: Hans Joachim Pistor, Herwig Hoffmann, Hans-Ingo Joschek, Gotthilf Wenner