Method for making positive working printing plates from a light sensitive imaging element
US6165689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1998 |
| Grant date | Dec 26, 2000 |
| Priority date | — |
| Expiry date | Sep 28, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41C2210/262
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
According to the present invention there is provided a method for making lithographic printing plates including the following steps: PA1 a) preparing a light sensitive imaging element having on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer which top layer is unpenetrable for an alkaline developer containing SiO.sub.2 as silicate; PA1 b) exposing imagewise said light sensitive imaging element to actinic light; PA1 c) developing said imagewise exposed light sensitive imaging element with said alkaline developer so that the exposed areas of the top layer and the underlying areas of the first layer are dissolved and the unexposed areas of the first layer remain undissolved characterized in that said top layer includes a diazonium salt and for at least 20% of its weight one or more non-proteinic hydrophilic film-forming polymers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.