Light-polarizing material in the form of sheets or of a web and a method for the manufacture of the material
US5004327A · kind A · utility
15Cited by
14References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1988 |
| Grant date | Apr 2, 1991 |
| Priority date | — |
| Expiry date | Nov 30, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB32B2554/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A light-polarizing element for use in a security document to permit authentication of the security document includes an intermediate layer of water-absorbing polymer material laminated between two outer layers of transparent material. The intermediate layer contains polarizing crystals that are absorbed in the intermediate layer and that are oriented in a predetermined direction through mechanical stretching. The two outer layers are sealed to one another in a liquid-tight manner along their longitudinal edges.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.