Electrochemical production of dyes using graphite felt electrodes
AssigneeNoveon IP Holdings Corp.
InventorsJoseph D. Kern, Gene P. Wesseler
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Abstract
An electrochemical process for the preparation of water-soluble colorants, particularly triphenylmethane colorants and other water soluble technical dyes, is disclosed. In this process, the anode in the electrochemical cell comprises an open pore carbon material having specific void volume and surface area characteristics. A preferred electrode material is a carbon felt pad, preferably between about {fraction (1/16)} inch and ¼ inch in thickness. This process provides faster reaction rates than electrochemical processes using standard electrodes, as well as higher yields compared to processes using chemical oxidizing agents.
Claims16
An electrolytic process for the preparation of a water-soluble colorant by anodically oxidizing the corresponding leuco compound comprising the improvement wherein the anode comprises an open pore carbon material having a void volume of at least about 90% and a surface area of at least about 100 cm2/cm3.
A process for the preparation of a water-soluble triphenylmethane colorant comprising anodically oxidizing the corresponding leuco compound in an electrolysis cell divided into an anode space and a cathode space, wherein the anode in said cell comprises an open pore carbon felt pad.
Dependencies are inferred from the claim text.