Process for thermochemical generation of squaric acid and for thermal imaging, and imaging medium for use therein
US5278031A · kind A · utility
23Cited by
35References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1992 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Oct 23, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/4989
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Certain squaric acid derivatives are useful for the thermochemical generation of acid. The squaric acid derivatives may be used in imaging media in conjunction with acid-sensitive materials which undergo a color change when contacted by the acid generated from the squaric acid derivatives. Preferably, the acid-sensitive materials undergo an irreversible color change, so that the image can be fixed by neutralizing all the acid generated with excess base, thereby preventing further color change in the image during long term storage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.