Black Chelate for Molecular Matrix Printing
Original Publication Date: 1984-Feb-01
Included in the Prior Art Database: 2005-Feb-02
Molecular Matrix Printing (MMP) is based on the color formation that occurs when a metal ion encounters a chelating agent, which is part of the electrolyte solution that is used to moisten the paper. The metal ion is provided by anodizing an electrode in contact with the paper. A chemical formulation for providing black printing is described. A variety of color-forming chelating agents have been found, but it is very difficult to form a black color in MMP. The chelating agent 1-pyrrolidinecarbothioic acid ammonium salt will produce a black complex with iron ions. This material is commercially available and is white, odorless, and appears to be nontoxic. The chemical formula is as follows: It can be used in MMP to produce black lettering.