高性能水性上转换荧光油墨的制备及包装防伪应用

将一步合成法制备的氨基修饰类沸石咪唑酯骨架晶体原位引入水性聚氨酯(WPU)基体中,结合酮肼交联改性,制备室温自交联WPU分散液.以水热法合成的稀土掺杂NaYF4上转换晶体为颜料、改性WPU分散液为连接料,制备水性上转换荧光油墨,并探讨其在包装防伪中的应用.结果表明:综合改性WPU涂膜的抗水性能和热稳定性明显提高,三基色油墨具备良好的印刷适性和稳定性;印制的防伪标签,自然光下不可见,在980 nm激光照射下呈现出精细的多色荧光团花图案.基于高性能水性上转换荧光油墨,结合印刷工艺防伪技术实现综合防伪,为绿色高端包装防伪提供了新的思路.

Preparation of High-Performance Waterborne Up-Conversion Fluorescent Inks for Packaging Anti-Counterfeiting Application

The amino-modified zeolitic imidazolate framework crystals, synthesized by the one-step synthesis method, were introduced into the waterborne polyurethane (WPU) matrix in situ for preparing self-crosslinking WPU dispersion combined with modification of ketone-hydrazine crosslinking. Water-based gravure printing inks were formulated with hydrothermal synthesized rare-earth-doped NaYF4 up-conversion crystals as the pigments and the obtained WPU dispersion as the binder, and their applications in anti-counterfeiting packaging were discussed. The results showed that the water resistance and thermal stability of the WPU coating film with composite modification were improved obviously, and trichromatic inks also presented satisfactory printability and stability. In addition, the obtained anti-counterfeiting labels were invisible in natural light and could produce a fine guilloche with multicolor fluorescence under the 980 nm excitation. Therefore, the comprehensive anti-counterfeiting technology was achieved by combining high-performance waterborne up-conversion fluorescent inks with the anti-counterfeiting printing processes, providing new ideas for the eco-friendly and high-end packaging anti-counterfeiting.