Removal of brown stain on magnetic head by a chelating agent on magnetic tapes

We found that a chelating agent on magnetic tape can drastically suppress the loss of signal amplitude caused by brown stains. After a streaming-mode test using MP tape on which a chelating agent was coated, we found no brown stain on the magnetic head. A chelating agent on magnetic tape is able to prevent from formation of brown stains. In addition, we found that a chelating agent on magnetic tapes can remove brown stain, already on the magnetic head. It is suggested that a chelating agent reacts with the iron oxide of brown stains to make metal complexes, and that the complexes can be removed easily by chemical lapping.