Method for making positive working printing plates from a heat mode sensitive image element
US6083663A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Sep 28, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41C2210/262
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
According to the present invention there is provided a method for making lithographic printing plates including the following steps: PA0 a) preparing a heat mode imaging element having on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution, a compound capable of converting light to heat 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; PA0 b) exposing imagewise the heat mode imaging element to actinic light; PA0 c) developing the imagewise exposed heat mode imaging element with the 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 an organic quaternary ammonium salt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.