DETERMINING METHOD FOR OPTIMUM CONTENT OF LUBRICANT AND MANUFACTURING METHOD FOR MAGNETIC RECORDING MEDIUM USING THE DETERMINING METHOD

摘要

PROBLEM TO BE SOLVED: To more easily determine the optimum quantity of a lubricant contained in a recording medium. SOLUTION: Relation shown by straight lines A and B is formed between the logarithmic value of the time (sec) after a magnetic recording medium is immersed in a solvent until the lubricant is extracted by 40% and the corresponding lubricant content range where the optimum lubricating effect of the magnetic recording medium can be obtained. The optimum content between the straight lines A and B can be estimated from the lines by evaluating the time (sec) until the lubricant to be contained in the magnetic recording medium is extracted by 40%.