MAGNETIC POWDER FOR VALIDITY DETERMINING INK, MANUFACTURING METHOD FOR MAGNETIC POWDER FOR VALIDITY DETERMINING INK, MAGNETIC INK FOR VALIDITY DETERMINATION, PRINTING MEMBER FOR VALIDITY DETERMINATION, DETECTING DEVICE FOR PRINTING MEMBER FOR VALIDITY DETERMINATION, AND VALIDITY DETERMINATION DEVICE

摘要

The magnetic powder for validity determining ink is composed of magnetic oxide power having a Curie temperature between 50C. and 150C. and a mean powder particle diameter of 10 m or less.