COMPOSITION FOR INK TO PREVENT FORGERY, INK TO PREVENT FORGERY, AND PRINTED MATTER PREVENTED FROM FORGERY

摘要

PPROBLEM TO BE SOLVED: To provide a composition which is used for ink to prevent forgery, makes reproduction, by e.g. copying, impossible, makes it possible to ascertain the genuineness of a printed matter by using near infrared rays, and is excellent in weatherbility, ink to prevent forgery, and a printed matter prevented from forgery. PSOLUTION: The composition and the ink to prevent forgery contain a near infrared absorptive material comprising at least one kind of fine particles selected from fine particles of the hexaboride of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr or Ca, fine particles of ruthenium oxide, and fine particles of rhenium oxide. A more sophisticated printed matter having a higher effect of preventing forgery can be obtained by printing with the composition or the ink which also contains a color pigment, or with the composition or the ink together with an ink comprising only a color pigment. PCOPYRIGHT: (C)2004,JPO