发明名称 |
Method for identifying articles and process for maintaining security |
摘要 |
<p>The invention is directed to a method by exposing at least a portion of a luminescent coating disposed on a surface of an article to ultraviolet light at one or more preselected wavelengths causing said luminescent coating to exhibit a luminescence spectrum, the luminescence spectrum exhibiting a plurality of intensity peaks that have been priorly determined to create a standard; determining the intensity of at least two peaks in the luminescence spectrum of the coating; determining a peak intensity ratio of the at least two peaks; comparing the peak intensity ratio determined with the standard; and, classifying the article according to whether or not the peak intensity ratio does or does not match the standard; wherein the luminescent coating comprises a particulate luminescent composition comprising a rare earth doped fluoride represented by the formula
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ RE x A 1-x F 2+x-2y O y
wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002 ‰ x ‰ 0.20, and 0 ‰ y ‰ x.</p> |
申请公布号 |
EP1887066(A2) |
申请公布日期 |
2008.02.13 |
申请号 |
EP20070010049 |
申请日期 |
2007.05.21 |
申请人 |
E.I. DU PONT DE NEMOURS AND COMPANY |
发明人 |
CRAWFORD, MICHAEL CARL;MIKESKA, KURT RICHARD |
分类号 |
C09K11/02;B42D15/00;C09D11/00;C09K11/77;D21H21/48;G06K7/12;G07D7/12 |
主分类号 |
C09K11/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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