改性UV油墨对印刷薄木耐光变色性能的影响

利用纳米二氧化钛和纳米氧化锌作为改性剂改性红色紫外光固化（UV）油墨和黄色UV油墨，并使用改性后的UV油墨印刷杨木薄木，采用激光粒度仪、紫外可见分光光度计和色彩分析仪表征了改性UV油墨的物理性能和老化前后印刷薄木的颜色变化。结果表明:改性后的UV油墨粒径变化较小；纳米二氧化钛和纳米氧化锌均能提高UV油墨在紫外区的吸光度，随着添加量的增加而增强；采用适量的纳米二氧化钛或纳米氧化锌改性UV油墨能够改善印刷薄木的耐光变色性能，但纳米氧化锌改性UV油墨印刷薄木的耐光变色性能优于纳米二氧化钛。纳米氧化锌在红色UV油墨中添加的较优质量分数为1.5%，印刷薄木的色差（ΔE*）为0.41，比未改性红色UV油墨印刷薄木降低了78.1%；纳米氧化锌在黄色UV油墨中添加的较优质量分数为0.5%，印刷薄木的ΔE*为3.12，比未改性黄色UV油墨印刷薄木降低了66.9%。

Effect of modified UV-curing ink on the light-induced discoloration of printed veneer

To reduce the light-induced discoloration of printed veneer, nano-TiO₂ and nano-ZnO were chosen to modify red UV ink and yellow UV ink. Relative ink quality of 0.5%, 1.0%, 1.5% and 2.0% of modifier was added to UV ink by stirring. Then the modified UV ink was printed on the surface of poplar veneer. Using a laser particle sizer, UV-Vis spectrophotometer, and colorimeter, physical properties of the modified ink and color differences printed on poplar veneer were studied. Results showed that the average particle size of the UV inks modified by nano-TiO₂ decreased a little while the UV inks modified by nano-ZnO had no change. Absorbance of UV ink in the ultraviolet region was increased with the addition of nano-TiO₂ or nano-ZnO. Both of nano-TiO₂ and nano-ZnO could prevent light-induced discoloration of printed veneer. But when UV ink modified by nano-ZnO was printed on a veneer surface, the color difference was lower than those modified by nano-TiO₂. The optimum amount of nano-ZnO in red UV ink was 1.5%, and the ΔE* of the printed veneer was 0.41. Compared with the veneer printed by unmodified red UV ink, ΔE* decreased 78.1%. The optimum amount in yellow UV ink was 0.5%, and the ΔE* of the printed veneer was 3.12. Compared with veneer printed by unmodified yellow UV ink, ΔE* decreased 66.9%.