Patents by Inventor Wilhelm Wolf

Wilhelm Wolf 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).

  • Patent number: 4092353
    Abstract: A process for purifying benzoic acid, especially benzoic acid obtained by the catalytic oxidation of toluene in the liquid phase which can be contaminated with impurities such as diphenyl, methyldiphenyl, a phenyl-benzoic acid, benzaldehyde, benzyl benzoate, succinic anhydride, phthalic anhydride, formic acid or formaldehyde, by contacting the benzoic acid with an amine of the formulaH.sub.2 N -- Rwherein R is hydrogen, a straight or branched chain alkyl radical of 1 to 4 carbon atoms or a cycloalkyl radical of 5 or 6 carbon atoms or a salt thereof and benzoic acid is distilled off or sublimed from the resultant reaction mixture. The benzoic acid so obtained can be reacted with sodium hydroxide solution and highly pure sodium benzoate can be removed by extraction with toluene or steam distillation.
    Type: Grant
    Filed: July 29, 1977
    Date of Patent: May 30, 1978
    Assignee: Bayer Aktiengesellschaft
    Inventor: Wilhelm Wolf