UV-LED磁性油墨固化时间影响因素研究

The Influencing Factor on Curing Time of UV-LED Magnetic Ink

目的应用UV-LED固化技术来降低磁性防伪油墨的固化时间。方法选用环氧丙烯酸酯和二丙二醇二丙烯酸酯,通过改变两者的质量比来配制连接料,选用TPO和819为光引发剂,改变光引发剂的质量分数,固定其他组分,配制UV-LED磁性防伪油墨,打样并使用波长为395 nm的UV-LED光源照射,测定油墨的固化时间。结果数据结果表明,当连接料中环氧丙烯酸酯和二丙二醇二丙烯酸酯的质量比为1∶0.8,光引发剂选用819(质量分数为6%)时,磁性防伪油墨固化时间最快可达0.6 s,双键转化率最高可达96%。结论 UV-LED磁性防伪油墨固化时间的主要影响因素有预聚物与单体的质量比,光引发剂的种类与质量分数。在合理的粘度范围内,预聚物与单体的质量比值越大,固化时间越短;单一光引发剂所释放的自由基越多,固化速率越高,光引发剂质量分数越高,固化时间越短。

The work aims to apply UV-LED curing technology in magnetic anti-counterfeiting ink to cut down the curing time of magnetic anti-counterfeiting ink. Epoxy acrylate and dipropylene glycol diacrylate were used to prepare the vehicle by changing the mass ratio of these two components. With TPO and 819 as photoinitiators, UV-LED magnetic anti-counterfeiting ink was prepared by changing the mass fraction of photoinitiator and fixing other components. The proof was made and the UV-LED light with wavelength of 395 nm was used to irradiate. The curing time of ink was tested. The analysis results of the research data showed that, when the mass ratio of epoxy acrylate and dipropylene glycol diacrylate in the vehicle was 1∶0.8, and the 819 photoinitiator was selected（the mass fraction was 6%）, the magnetic anti-counterfeiting ink curing time was as fast as 0.6 s and the maximum double bond conversion could be up to 96%. The main influencing factors on curing time of UV-LED magnetic anti-counterfeiting ink are the mass ratio of prepolymer and monomer, and the type and mass fraction of photoinitiator. Within a reasonable range of viscosity, the greater the mass ratio of prepolymer and monomer, the shorter the curing time; the more the free radicals released by a single photoinitiator, the higher the curing speed is; the higher the photoinitiator mass fraction, the shorter the curing time is.