Fluorescent rare earth complex and security medium using the same
View Patent ↗The embodiments provide a fluorescent rare earth complex having strong emission intensity and excellent durability, and also provide a security medium using the complex. The rare earth complex according to the embodiment comprises a rare earth ion, a diphosphine dioxide ligand and a β-diketone ligand wherein two phosphorus atoms contained in the diphosphine dioxide ligand individually have substituents different from each other.
1. A rare earth complex, represented by the following formula (1):
wherein:
each Ar is independently an aryl group,
each R is independently an alkyl group having 6 to 10 carbon atoms,
each R F is independently a halogenated hydrocarbon group,
n is an integer of 3 to 5,
p is an integer of 1 or 2,
q is an integer of 1 to 3,
M is a europium (III) ion, and
X is absent when q is 3 but is an anion having a valence of 3-q when q is 1 or 2.
2. The rare earth complex of claim 1 , wherein n=4.
3. The rare earth complex of claim 1 , wherein the two R F groups have different chain lengths.
4. The rare earth complex of claim 1 , wherein p=1 and q=3.
5. The rare earth complex of claim 1 , wherein the two Ar groups are both substituted or unsubstituted phenyl groups.
6. The rare earth complex of claim 1 , wherein the R group is an alkyl group having 6 to 8 carbon atoms.
7. A light wavelength-converting medium, comprising the rare earth complex of claim 1 and a polymer.
8. A light wavelength-converting medium, comprising a substrate and the rare earth complex of claim 1 provided thereon.
9. The light wavelength-converting medium of claim 7 , wherein the polymer comprises acrylic resin, polyester resin, or a mixture thereof.
10. The light wavelength-converting medium of claim 7 , wherein the polymer is an acidic resin, and
wherein the rare earth complex is dissolved or dispersed in the polymer.
11. The light wavelength-converting medium of claim 10 , wherein the acidic resin is selected from the group consisting of an alkyd resin, a polyacrylic resin, a polystyrene sulfonic acid, and an acidic cation-exchange resin.