Preparation and properties of light-resistant printing UV ink modified with nano-TiO ₂ on wood substrate

Nano-TiO ₂ was used to modify the yellow UV ink by physically blending. The modified and unmodified UV ink was respectively used for wood printing. The aging test was carried out on the printed wood and several physical, morphological, and chemical analyses were performed. The results showed that the UV ink underwent oxidation during aging, caused colour and gloss changes, surface bubbling, and polymer chain decomposition both for the unmodified and nano-TiO ₂ groups. However, on a macro level, the main structure of the UV ink was not destroyed. The aging phenomenon of nano-TiO ₂ modified group was not as severe as the unmodified one. During light aging, the primary amine, CO ₂ , and carboxylic acid were yielded, and NH radicals were generated, which promoted the formation of conjugated structure and the chromogenic enamine. Nano-TiO ₂ could inhibit these reactions. Consequently, the light-resistant polychromasia of UV ink was improved by adding of nano-TiO ₂ .