| 摘要 |
A non-reactive but highly absorbent material, such as clay, is incorporated into polyolefin/silica matrix to form a core document substrate. This material may be added to create a distinctive look of the document. Clay particles are added to the polyolefin/silica matrix in measured quantities at a known particle size distribution so that the core looks substantially the same from the front, back and side to the curious viewer. Addition of a covert component, such as a UV pigment, allows a covert characteristic and it also allows a mathematical description to be calculated describing the random distribution of a specific area on a document and then captured on it (e.g., in the bar code or magnetic stripe or digital watermark on an ID document). Each document is unique virtue of the clay's distribution within the document's core. The material is buried within the document, and the unique distribution for each document is protected by virtue of the construction for the entire length of the document's life. Since the activation and excitation of the UV pigment adhered/adsorbed onto the surface will not be disturbed by wear and tear, the signature will remain constant over the life of the card.
|
