Printing ink for security printing

摘要

Modified iron blue pigment comprises an iron blue pigment, which is coated with an alkali and/or acid-resistant coating. Independent claims are included for: (1) a method for the preparation of modified iron blue pigment comprising coating the iron blue pigment with an alkali and/or acid- resistant coating; (2) printing inks for safety printing, comprising the modified iron blue pigment; and (3) security document with a print, where the printing takes place using the printing ink.