Negative-working dry planographic printing plate
US6045963A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1998 |
| Grant date | Apr 4, 2000 |
| Priority date | — |
| Expiry date | Mar 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/0752
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A negative waterless plate contains a sheet substrate; a radiation sensitive imaging layer composed of a diazido naphthaquinone ester or amide compound, such as diazido naphthaquinone sulfonate of a phenolic resin, and a polyurethane prepared by reacting a di-isocyanate and a diol; and a silicone layer. The planographic printing plate is imagewise exposed to actinic radiation through a negative original to form exposed areas of the imaged layer which are soluble or dispersible in a developer liquid. After imaging exposure, the developer liquid is applied which penetrates the silicone layer and dissolves the areas exposed to the radiation. The coating areas not exposed by the radiation remain intact. During this development procedure, areas of the silicone layer overlying the exposed areas are removed along with the underlying soluble areas to produce an imaged planographic printing plate having uncovered ink receptive areas and complimentary ink repellent areas of the silicone layer. In use, the developed plate is mounted on a dry planographic printing press containing only a lithographic ink; and used to print a positive image on conventional print stock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.