ADHESIVE LABEL FOR PREVENTION OF FORGERY AND IDENTIFYING METHOD WHETHER IT IS FORGED

摘要

PROBLEM TO BE SOLVED: To provide such an adhesive label for high-level protection of forgery that the preventing means for forgery is hardly recognized by an outsider and that the label has an identifying method whether the label is original or forged without being known to the outsider. SOLUTION: This adhesive label for prevention of forgery is produced by successively laminating an adhesive layer and a release paper on one surface of a supporting body and forming an oilsoluble layer on the back surface. The oil-soluble layer usually consists of a colorless or pale-color dye precursor and a polymer compd. Whether the adhesive label for prevention of forgery is original or forged can be identified by the following method. An electron-accepting compd. which makes the dye precursor develop a color is dissolved in an org. solvent having the solubility parameterΣ[(cal/cc)<1/2> ] which differs by <2 as an absolute value from the parameter a of the polymer compd. above described. Then the polymer compd. is dissolved in the prepared soln. to cause the color developing reaction between the dye precursor in the oil-soluble layer and the electron-accepting compd.