Interlaminar sandwich with diffraction structure
US5104471A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1990 |
| Grant date | Apr 14, 1992 |
| Priority date | — |
| Expiry date | Nov 27, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An interlaminar sandwich comprises first and second lacquer layers, a diffraction structure embedded between the first and second lacquer layers, a heat activated adhesive layer disposed one one of the lacquer layers, and a transparent stabilization layer disposed over the other lacquer layer, the stabilization layer distributing heat evenly through the interlaminar sandwich so that when heat is applied to the stabilization layer, the adhesive layer will bond the interlaminar sandwich to a substrate. Preferably, the interlaminar sandwich also contains an intermediary layer between the stabilization layer and the first lacquer layer which bonds these layers together. At temperatures below 170.degree. C., the adhesive layer is bonded so intimately to the substrate that the interlaminar sandwich cannot be removed from the substrate without tearing it. At temperatures above 150.degree. C., the lacquer layers soften, thus destroying the diffraction structure. After being built up on a film, the interlaminar sandwich can be punched out in the form of a tag and attached to an identification document thereby protecting the document against attempts to remove the tag.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.