Patents by Inventor Walter Gilb

Walter Gilb 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 of the preparation of 2,5-di-phenylamino-terephthalic acid and its dialkyl esters in a high purity
    Patent number: 5347038
    Abstract: An ecologically and economically improved process for the preparation of 2,5-di-phenylamino-terephthalic acid and its di-alkyl esters of the formula (1) ##STR1## in which R is a hydrogen atom or a methyl group and R' is a hydrogen atom or a methyl or ethyl group.
    Type: Grant
    Filed: May 20, 1993
    Date of Patent: September 13, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Otto Arndt, Hermann Fuchs, Walter Gilb
  • Process for the preparation of 1,4-bis(4-fluorobenzoyl)-benzene
    Patent number: 5300693
    Abstract: Process for producing 1,4-bis-(4-fluorbenzoyl)-benzol by reacting terephthaloyl chloride with fluorbenzol in the presence of aluminium chloride or aluminium bromide, characterized in that aluminium chloride or aluminium bromide is added in metered quantities to a mixture of terephthaloyl chloride and fluorbenzol at temperatures of approximately 25.degree. C. to approximately 68.degree. C. and the mixture is allowed to react at said temperatures.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: April 5, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Gilb, Georg Grotsch, Hans Schubert
  • Process for the preparation of 2,5-di(phenylamino)-terephthalic acid and its dialkyl esters in high purity
    Patent number: 5208365
    Abstract: A process for the preparation of 2,5-di(phenylamino)terephthalic acid and its dialkyl esters of formula (I): ##STR1## in which R is a hydrogen atom or a methyl group and R' is a hydrogen atom or a methyl or ethyl group.
    Type: Grant
    Filed: June 11, 1992
    Date of Patent: May 4, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hermann Fuchs, Walter Gilb, Otto Arndt
  • Process for the continuous preparation of imidoperoxycarboxylic acids
    Patent number: 5132431
    Abstract: A process for the continuous preparation of imidoperoxycarboxylic acids of the formula ##STR1## in which A is C.sub.2 -C.sub.4 -alkylene, phenylene, naphthylene or a group of the formula ##STR2## and R is a group of the formula --COOH, --SO.sub.3 H or --Cl, and X is C.sub.1 -C.sub.19 -alkylene or arylene, in which a solution of imidocarboxylic acids of the formula ##STR3## in sulfuric acid or methanesulfonic acid and an aqueous solution of hydrogen peroxide are continuously metered into a static mixer, then the solution of the imidoperoxycarboxylic acid obtained in this way is treated with water and the precipitated product is isolated.
    Type: Grant
    Filed: February 1, 1991
    Date of Patent: July 21, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hermann Fuchs, Hanspeter Gethoffer, Walter Gilb