Effection of UV-LED Illuminant on the Curation of Photolatent-amidine Mixed with Bisphenol A Epoxy Acrylate under Printing Conditions

Abstract

In order to make photocuring ink or coating cured by UV-LED illuminant, we synthesized (4-((hexahydropyrrolo[1,2-a]pyrimidin-1 (2H)-yl)methyl)phenyl)(phenyl)methanone(PL -DBN) and (4-((octahydropyrimido[1,2-a]azepin-1(2H)-yl)methyl)phenyl)(phenyl)met hanone(PL -DBU) as photoinitiators. Different mass fraction of the photoinitiators was mixed with bisphenol A epoxy acrylate, cured by different wavelengths and power of UV-LED illuminant,and investigated the curing effects of photoinitiators on bisphenol A epoxy acrylate. The results show that the conversion of C=C double bonds of bisphenol A epoxy acrylate will increase as the mass fraction of the photoinitiators or the power of UV-LED illuminant increase. In the same conditions, the curing effect of using 365nm UV-LED illuminant on bisphenol A epoxy acrylate is better than using 395nm UV-LED illuminant. PL-DBU has a better curing effect on the bisphenol A epoxy acrylate rather than PL-DBN. When using the 8W/cm2 of 365nm UV-LED illuminant to cure a mixture of 3% PL-DBU and 97% bisphenol A epoxy acrylate, it will be dry completely in 2 seconds, moreover, the conversion reach 79%.

Keywords

• (4-((hexahydropyrrolo[1,2-a]pyrimidin-1(2H)-yl)methyl)phenyl)(phenyl)methanone
• UV- LED illuminants
• (4-((octahydropyrimido[1,2-a]azepin-1(2H)-yl)methyl)phenyl)(phenyl)methanone
• photolatent-amidine
• photoinitiators