Patents Represented by Law Firm Sprung Horn & Woods
  • Process for the isolation of 2-naphthylamine-1,5-disulphonic acid
    Patent number: 5248812
    Abstract: When 2-naphthylamine-1,5-disulphonic acid is precipitated from the as-sulphonated reaction mixtures by dilution, a purer product is obtained, with a low level of adherent sulphuric acid, if the precipitation by dilution of the reaction mixture is carried out under precisely defined conditions.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: September 28, 1993
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Behre, Heinz-Ulrich Blank, Holger Heidenreich, Fritz Pohl, Paul Uhrhan