Reversible Thermochromic Ink based on Crystal Violet Lactone/Boric Acid/Hexadecyl Alcohol for Anti-Counterfeiting Printing

Abstract

The purpose of the study is to prepare reversible thermochromic materials with good discoloration properties, which are used as fillers to prepare a new type of reversible thermochromic ink. Reversible thermochromic materials were prepared by solid phase method with crystal violet lactone as chromogenic agent, boric acid as chromogenic agent and hexadecanol as cosolvent, and reversible thermochromic ink was prepared by using thermochromic material as filler. The scanning electron microscope images of reversible thermochromic materials showed that the prepared materials were spherical and had the advantages of non-adhesion. The printability of reversible thermochromic ink was discussed by changing the parameters including content of thermochromic material, printing pressure, ink sequence and using printability tester. The test of color change performance of thermochromic ink showed that the color change temperature range was 47.5–51.1 ◦ C, the color change time was 46 s, the recolor time was 29 s, and the stability was excellent. The reversible thermochromic ink has a certain application value in anti-counterfeiting printing.

Preparation of Crystal Violet Lactone Complex and Its Effect on Discoloration of Metal Surface Coating

“…The -OH absorption peak at 3337 cm −1 of BPA in the infrared spectrum of the color-changing complex became weak, and most of them were characteristic peaks of crystalline violet lactone and BPA, which indicates that crystalline violet lactone only partially reacts with BPA to form a conjugated chromogenic system. In Figure 2 , the stretching vibration absorption peak of the lactone ring structure C=O appeared at 1740 cm −1 , the ester carbonyl C=O absorption peak appeared at 1615 cm −1 , and the -OH absorption peak of carboxyl group appeared at 3337 cm −1 , indicating that the lactone ring was broken, the conjugate system was destroyed, the structure was changed, and the color changed [ 40 , 41 , 42 ].…”

Interpol questioned documents review 2019–2022

“…Security printing as an industry hosts many international conferences to share novel techniques and components in the production of security documents, and those FDE working in this domain would typically review these resources. Given the many advanced technologies in use in the field of security documents production it is not surprising that over the past years included in this review there have been many conference presentations of interest to those FDE who specialize in security documents examination, as well as two textbooks [ 674 , 675 ], and 24 published articles [ [676] , [677] , [678] , [679] , [680] , [681] , [682] , [683] , [684] , [685] , [686] , [687] , [688] , [689] , [690] , [691] , [692] , [693] , [694] , [695] , [696] , [697] , [698] , [699] ]. In fact, there were approximately 1200 conference presentations given on topics related to security documents examination over the period of this review, however only a selection was included in this article [ [700] , [701] , [702] , [703] , [704] , [705] , [706] , [707] , [708] , [709] , [710] , [711] , [712] , [713] , [714] , [715] , [716] , [717] , [718] , [719] , [720] , [721] , [722] , [723] , [724] , [725] , [...…”

“…Liu et al studied reversible thermochromic materials as good candidates for anti-counterfeiting printing. Their study investigated reversible thermochromic materials with good discoloration properties, which were used as fillers to prepare a new type of reversible thermochromic ink [ 682 ].…”

Understanding the Role of Paper-Ink Interactions on the Lightfastness of Thermochromic Prints

“…During the last decades, thermochromic materials have received significant attention from both researchers and the industry [1]. Intelligent packaging today serves as a media for providing consumers with all the necessary information about the quality and safety of the packaging [2,3]. They are generating intense interest among artists and designers due to their interaction, responsiveness and ultimate functionality [4,5].…”