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Security marking method, materials provided with security marks

  • US 4,736,425 A
  • Filed: 08/04/1986
  • Issued: 04/05/1988
  • Est. Priority Date: 08/08/1985
  • Status: Expired due to Term
First Claim
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1. A method of marking fiduciary documents and liquids requiring authentication marks by the use of the fluorescent properties of chelates comprising the steps of:

  • (a) introducing only a part of the elements forming at least one chelate into or onto the materials to be marked,(b) incorporating the missing part of the elements forming the chelate in or on the materials to be authenticated to effect the synthesis of the fluorescent chelate, and(c) adding an acid or a base into or onto the marked materials to cause the fluorescence of the identifying chelates to disappear.

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