Heat mode sensitive imaging element for making positive working printing plates
US6447977B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1999 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Mar 2, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/165
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate 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 that is IR-sensitive and unpenetrable for an aqueous alkaline developer wherein said first layer and said top layer may be one and the same layer; characterized in that the surface of said element upon exposure and treatment with an aqueous alkaline developer is such thata) the contact angle between the unexposed areas of the imaging element and the aqueous alkaline developer changes for at most 6° during the first minute of contact with said developer;b) the contact angle between the exposed areas of the imaging element and the aqueous alkaline developer changes more than 15° during the first minute of contact with said developer;c) the difference in contact angle between on the one side the unexposed areas and on the other side the exposed areas of the imaging element with the aqueous alkaline solution at the onset of the measurement is not higher…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.