Security paper
US6159585A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 1999 |
| Grant date | Dec 12, 2000 |
| Priority date | — |
| Expiry date | Sep 23, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31993
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A security paper indicates exposure to a solvent by a solvent resistant color signal. A metal mordant dye first co-reactant and a mordant dye second co-reactant form an organic solvent-insoluble colored reaction product when the paper is washed with an organic solvent. The metal mordant dye first co-reactant and a mordant dye second co-reactant are chemically isolated from each other so as to prevent the coordinate covalent bond from forming until the paper is washed with an organic solvent. The chemical isolation can be effected by encapsulation or other physical separation of the co-reactants. The organic solvent-insoluble colored reaction product, once formed, remains entrapped in the web when the paper is washed with an organic solvent. The chemical isolation prevents the organic solvent-insoluble colored reaction product from forming upon the application of pressure alone to the paper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.