Photoreaction quenchers in on-press developable lithographic printing plates
US5599650A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1995 |
| Grant date | Feb 4, 1997 |
| Priority date | — |
| Expiry date | Apr 28, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/002
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a lithographic printing plate comprising a substrate and a photocurable polymeric photoresist, such as those based on free-radical initiated photocuring mechanisms. To constrain detrimental and undesired activity of excess free radicals, an embodiment of the printing plate is further provided with a free-radical regulating system. In a particular embodiment, the free-radical regulating system is provided as an overcoat, the overcoat being a light-transmissive overcoat and comprising a polymer having a pendant free-radical trapping group. A particular polymer for the overcoat has the formula ##STR1## wherein, m is from approximately 20% by weight to approximately 95% by weight, and n is from approximately 0% by weight to approximately 75% by weight. Capable of deactivating free-radicals actinically generated in the photoresist subsequent to exposure, the polymer is soluble in fountain or ink solution and incompatible with the photoresist.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.