Inhibition of Emulsifier Breakdown in Magnetic Tape
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19
Production of chromium dioxide magnetic tape requires emulsifi- cation of the magnetic particles into a fine, evenly dispersed suspension. For this reason a dispersing agent, consisting of soybean oil and lecithin and constituting about 1% of the final formulation, is sometimes added to the media ink formulation. However, the emulsifying agent may degrade, forming a variety of volatile hydrocarbons, aldehydes and ketones. This breakdown process does not require oxygen, but does depend on the presence of chromium dioxide. A number of additives were found to substan- tially inhibit degradation of the emulsifier. The most effective inhibitors were 2,6-di-tert-butyl-alpha-dimethyl- amino-p-cresol, 1,10-phenanthroline, and 2,6-di-tert-butyl- p-cresol.