Investigation Of Photochromic Materials In Sill-Screen Printing Ink

Photochromic materials are one of well-known applicable functional materials and have been paid much attention for the inorganic, organic and material chemists. Rare earth complex is one kind of photochromic materials. The study of rare earth is very important for the fundamental and applied research. The rare earth ion is a great treasure of luminescent material since its abundant energy levels and4f transition characteristics, and the rare earth elements provide a lot of luminescent materials and laser materials with good properties for high-new technique. The luminescence complexes of europium studied in this paper related to ones that can absorb radiant energy and can produce photoluminescence.Ternary europium complexes europium-benzoic acid-1,10-phenanthroline, europium-methyl benzoate-1,10-phenanthroline, europium-methoxybenzoic acid-1,10-phenanthroline, europium-benzoylacetone-1,10-phenanthroline, europium-α-thenoy ltrifluoroacetone-1,10-phenanthroline and quaternary europium complex europium-benzoic acid-α-thenoyltrifluoroacetone-1,10-phenanthroline were synthesized in ethanol absolute with europium(Eu), benzoic acid(BA), methyl benzoate(MBA), methoxybenzoic acid(p-MBA), benzoylacetone(BZA), α-thenoyltrifluoroacetone(TTA) and1,10-phenanthroline(Phen). Under the same conditions, UV spectrum of ligand and complexes are obtained with UV-VIS spectrophotometer. The results indicated that ternary europium complexes were containing two kinds of ligand and quaternary europium complex was containing three kinds of ligand. The results also indicated that we synthesized ternary europium complexes and quaternary europium complex. The IR spectrums of europium complexes are obtained with infrared spectrometer. It indicated that the coordination is taken place between ligand and Europium ion. Excitation spectrums and emission spectrums of complexes were got with fluorospectro photometer. Fluorescence spectrum showed that europium complexes have the order of fluorescent intensity from strongest to weakest: europium-a-thenoyltrifluoroacetone-1,10-phenanthroline, europium-benzoic acid-α-thenoyltrifluoroacetone-1,10-phenanthroline, europium-methoxybenzoic acid-1,10-phenanthroline, europium-benzoylacetone-1,10-phenanthroline, europium-benzoic acid-1,10-phenanthroline, europium-methyl benzoate-1,10-phenanthroline.This paper made use of Eu(TTA)3Phen and Eu(BA)(TTA)2Phen as fluorescent pigment composed two fluorescent falsification-resistant silk-screen printing inks and their fluorescence spectrums and printability were measured. Printing test splines of silk-screen printing fluorescent ink were colorless in the visible light, and they appeared visible red silver under the ultraviolet lamp. Printability test of silk-screen printing ink was containing degree of tolerance test, fluidity test, fineness test and viscosity test. The experiments results for measuring the printability of fluorescent ink showed that they meet the requirements of fluorescent ink and have good application value. The conclusions can be used to the anti-counterfeit printing of negotiable securities, commodity packaging, and valid certificate, and it is of profound social and economic significance, and also has definite pushing effect to the innovation and development of anti-counterfeit printing.