Production of thermochromic microcapsulated inks for smart packaging and examination of printability properties

Abstract

Purpose Stimulant-sensitive materials exhibit physical or chemical reversible changes in their properties as a result of environmental variables. One of these materials is thermochromic materials. Materials with thermochromic sensitivity change their color with heat exchange. For this reason, it can be used in many different fields such as security inks. Such substances decompose rapidly by being affected by weather conditions. Furthermore, the particle sizes are larger than normal pigments, and therefore, it is difficult to stabilize thermochromic dyes. Because of all these adverse conditions, thermochromic colorants must be protected before use in the ink. This protection is planned to be provided by the microcapsulation technique. The purpose of this study is to determine the thermochromic printing inks that can be stored stably by microcapsulation technique, to protect it from environmental conditions and the determination of printability parameters. Design/methodology/approach In this study, capsules with a core material of thermochromic dyeing with polyurea formaldehyde (PUF) or poly-phenolmelamine formaldehyde (PMF) shell were synthesized at appropriate pH and temperature using the appropriate solvent and mixing speed. The chemical structure and dimensions of the obtained capsules were examined by ATR-FTIR and scanning electron microscopy, respectively. The produced thermochromic microcapsules were mixed with alkyd resin and mineral oil and screen printing ink was obtained. Printability tests such as surface morphology, color, gloss and light fastness were applied. Findings As a result, it was determined that PMF is not a suitable encapsulation technique for thermochromic dyes under suitable conditions and eliminates thermochromic property by providing heat stability. It was found that PUF microcapsulation can be used in thermochromic dyestuff encapsulation and does not lose the thermochromic property. It has also been found that PUF microcapsules increase the lightfastness and stability of thermochromic dye ink. Originality/value This study provides experimental research on the encapsulation of a thermochromic dye and its use in ink.

Stability Aspects of UV-Curable Prints on Pressure-Sensitive Labels Facestock Made from Agro-Industrial By-Products

“…Thermochromic printing inks are inks in which the process of chromism (color change) is triggered by heat [7]. Those inks can change color within a defined broad temperature range, temporarily (reversible color change) or permanently (irreversible color change).…”

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

“…According to whether the thermochromic ink can be recovered after discoloration, it can be divided into reversible thermochromic ink and irreversible thermochromic ink. In recent years, thermochromic materials have been extensively researched because of their potential applications in anti-counterfeiting signs, temperature indicators, wearable electronic devices, medical diagnostics, safety materials, aerospace and other fields [1][2][3][4][5][6][7][8]. Thermochromic material has special thermal memory function, and the color of compounds and mixtures will change significantly during heating or cooling [9][10][11][12][13].…”

Manufacturing surface active shell and bisphenol A free thermochromic acrylic microcapsules for textile applications

“…31 Arman Kandirmaz et al carried out microencapsulation of thermochromic dyes into polyurea formaldehyde (PUF) or polyphenolmelamine formaldehyde (PMF) shell in-situ polymerization technique. 32 Zhang et al produced thermochromic microcapsules with sandwich-structured through interfacial polymerization. First, the thermochromic dyes were constructed onto the docosane PCM covered with silica shell.…”

“…Polyvinyl alcohol/water‐soluble polyurethane composite was used as polymer matrix while the encapsulated PCMs were used as functional fillers 31 . Arman Kandirmaz et al carried out microencapsulation of thermochromic dyes into polyurea formaldehyde (PUF) or polyphenolmelamine formaldehyde (PMF) shell in‐situ polymerization technique 32 . Zhang et al produced thermochromic microcapsules with sandwich‐structured through interfacial polymerization.…”