Method of producing forgery-proof colored printed articles
US6013307A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1993 |
| Grant date | Jan 11, 2000 |
| Priority date | — |
| Expiry date | Nov 30, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/08
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
In order to prevent or at least render difficult the copying of colored printed security papers, for example banknotes, the printing inks used for printing are so formulated that copies made using customary color copiers produce a markedly different color impression and can therefore easily be identified as being forgeries. This is achieved by using for the formulation of the printing inks dyes (pigments) that are as different as possible from the dyes (toners) customarily used in conventional color copiers. The choice of the dyes for the formulation of the printing inks is especially such that there is the greatest possible degree of metamerism between the printing ink in question and the match of the relevant master color using the dyes of the color copier. Preferably non-amorphous or anisotropic black dyes and effect dyes, especially fluorescent effect dyes, are co-used for the formulation of the printing inks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.