Heat sensitive tamper indicating markings
US9605167B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 2014 |
| Grant date | Mar 28, 2017 |
| Priority date | — |
| Expiry date | Feb 27, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24901
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to the field of heat sensitive optically variable inks and tamper indicating markings obtained thereof. The present invention relates to the field of irreversible changes in color and/or changes in structure upon a tampering attempt against articles or items comprising said tamper indicating markings through the use of temperature variation. In particular, the present invention provides optically variable ink compositions comprising a plurality of optically variable pigment particles and a plurality of thermally expandable spheres; tamper indicating marking comprising the optically variable ink compositions described herein; their uses as a proof of an illegal action as well as methods for detecting a tampering activity of a marking including the optically variable ink composition described herein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.