Luminescent compositions, methods for making luminescent compositions and inks incorporating the same
First Claim
Patent Images
1. A secure document, comprising:
- a document; and
a security taggant comprising a powder batch comprising a luminescent composition that, when excited by electromagnetic radiation at a first frequency, emits electromagnetic radiation at a second frequency equal to or within 1500 cm−
1 of the first frequency, wherein particles of said luminescent composition are substantially spherical.
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Abstract
A particulate luminescent composition is disclosed that, when excited by electromagnetic radiation at a first frequency, emits electromagnetic radiation at a second frequency equal to or within 1500 cm−1 of the first frequency. The luminescent composition comprises substantially spherical particles having a weight average particle size of less than about 10 μm and a particle size distribution such that at least about 90 weight percent of the particles are not larger than twice the average particle size.
25 Citations
30 Claims
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1. A secure document, comprising:
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a document; and a security taggant comprising a powder batch comprising a luminescent composition that, when excited by electromagnetic radiation at a first frequency, emits electromagnetic radiation at a second frequency equal to or within 1500 cm−
1 of the first frequency, wherein particles of said luminescent composition are substantially spherical. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A luminescent ink, comprising:
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(a) a liquid vehicle phase; and (b) a functional phase dispersed throughout the liquid phase, the functional phase comprising a powder batch comprising a luminescent composition that, when excited by electromagnetic radiation at a first frequency, emits electromagnetic radiation at a second frequency equal to or within 1500 cm−
1 of the first frequency, wherein particles of said luminescent composition are substantially spherical. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification