Photosensitive systems showing visible indication of exposure
US4659649A · kind A · utility
53Cited by
10References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1984 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | Apr 30, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/126
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides new compositions which change color on exposure to actinic radiation and contain a photosensitive onium, e.g. iodonium or sulphonium, salt and a dyestuff which changes color when protonated. The compositions may also include a resin, especially a resin curable by the onium salt when the latter is exposed, and preferably an epoxy resin. The compositions are useful especially as coatings, e.g. for making screen stencils or for producing lithographic printing plates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.