Ink with cohesive failure and identification document including same
View Patent ↗The present invention provides identification documents with security features. For example, a document may include two or more inks that are designed to cohesively fail upon a de-lamination attack. A resulting failure pattern is preferably difficult to predict. The two or more inks are applied to an identification document including a core and laminate layer. At least one of the inks is characterized such that an adhesive strength of the ink to the core and an adhesive strength of the ink to the laminate layer is each greater than the cohesive strength of the ink itself. Thus, the ink rips apart in a somewhat random-like manner upon a de-lamination attack. The ink can be arranged in interwoven or interlocking patterns or in other desired patterns and locations.
1. An identification document comprising:
a core including a front surface and a back surface;
an over-laminate including a front surface and a back surface, the back surface being adjacently positioned with said core front surface; and
two or more inks provided on at least one of front surface of the core or the back surface of the over-laminate,
the two or more inks being characterized as including substantially the same degree of adhesion to both the front surface of the core and to the back surface of the over-laminate,
the adhesion of the two or more inks to the front surface of the core and the adhesion of the two or more inks to the back surface of the over-laminate each being relatively stronger than a cohesive strength of the ink, and
the two or more inks are provided on the front surface or the back surface in a plurality of patterns, the patterns including at least a plurality of intertwined or interlocking circles or mesh structures, wherein a first ink of the two or more inks comprises patterns in a first color and a second ink of the two or more inks comprises patterns in a second, different color; and
wherein the two or more inks cohesively delaminate upon an intrusion attempt, resulting in portions of the plurality of intertwined or interlocking circles or mesh structures in the first and second colors adhering to the first surface of the core and portions of the plurality of intertwined or interlocking circles or mesh structures in the first and second colors adhering to the back surface of the over-laminate, such that tampering is evident.
2. The document of claim 1 , wherein the intrusion attempt comprises heat.
3. The document of claim 1 , wherein the two or more inks comprise a styrene-allyl alcohol copolymer.
4. The document of claim 1 , wherein the first ink comprises at least one of an optically variable ink or pearlescent ink.
5. The document of claim 1 , wherein the first ink comprises at least one of an ultraviolet pigment or infrared pigment.
6. The document of claim 1 , wherein the two or more inks comprise ultraviolet or infrared pigments.
7. The document of claim 1 , wherein the first ink is designed to unpredictably cohesively fail.
8. The document of claim 1 , wherein the back surface of the laminate comprises an adhesive.
9. A method of making a tamper-resistant identification document comprising:
providing a core including a top surface;
providing a top laminate including a top surface and bottom surface; and
providing two or more inks between the top surface of the core and the bottom surface of the top laminate,
the two or more inks being characterized as including substantially the same degree of adhesion to both the top surface of the core and to the bottom surface of the top laminate,
the adhesion of the two or more inks to the top surface of the core and the adhesion of the two or more inks to the bottom surface of the top laminate each being relatively stronger than a cohesive strength of the ink,
the two or more inks being formed in a pattern,
the pattern including at least a plurality of intertwined or interlocking circles or mesh structures, and
a first ink of the two or more inks comprises a first color and a second ink of the two or more inks comprises a second, different color and
wherein the two or more inks cohesively delaminate upon an intrusion attempt, resulting in portions of the plurality of intertwined or interlocking circles or mesh structures in the first and second colors adhering to the top surface of the core and portions of the plurality of intertwined or interlocking circles or mesh structures in the first and second colors adhering to the bottom surface of the top laminate, such that tampering is evident.
10. The method of claim 9 , wherein the two or more inks comprise a polymer-based resin.