Water resistant security ink composition
US5720801A · kind A · utility
7Cited by
18References
34Claims
0Family size
Inventors
Key dates
| Filing date | Nov 6, 1996 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | Nov 6, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D11/50
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A leach resistant ink composition including a diphenyl guanidine compound, an acid, and a resin. The ink composition may further include a glycol and an alcohol and can be printed on paper, such as, for example, in the word "VOID". If bleach is used to attempt to alter the document, the initially colorless ink will form a colored image in the shapes or letters printed on the paper. The ink composition is resistant to leaching upon contact with, for example, water. The presence of the acid enables the security composition to be invisible by preventing or minimizing undesirable reactions with chemically sensitive paper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.