| (19) |
 |
|
(11) |
EP 1 295 717 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
16.07.2003 Bulletin 2003/29 |
| (43) |
Date of publication A2: |
|
26.03.2003 Bulletin 2003/13 |
| (22) |
Date of filing: 05.09.2002 |
|
| (51) |
International Patent Classification (IPC)7: B41C 1/10 |
|
| (84) |
Designated Contracting States: |
|
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR |
|
Designated Extension States: |
|
AL LT LV MK RO SI |
| (30) |
Priority: |
24.09.2001 EP 01000495
|
| (71) |
Applicant: AGFA-GEVAERT |
|
2640 Mortsel (BE) |
|
| (72) |
Inventors: |
|
- Van Damme, Marc AGFA-GEVAERT
B-2640 Mortsel (BE)
- Vermeersch, Joan AGFA-GEVAERT
B-2640 Mortsel (BE)
- Deroover, Geert AGFA-GEVAERT
B-2640 Mortsel (BE)
|
| (74) |
Representative: Van Ostaeyen, Marc Albert Jozef |
|
Agfa-Gevaert Corporate IP Department, Septestraat 27
2640 Mortsel
2640 Mortsel (BE) |
|
| |
|
| (54) |
Heat-sensitive positive-working lithographic printing plate precursor |
(57) A lithographic printing plate precursor is disclosed which comprises (i) a support
having a hydrophilic surface or which is provided with a hydrophilic layer and (ii)
a coating provided thereon, the coating comprising an oleophilic layer which, upon
image-wise exposure to heat or infrared light and subsequent immersion in an aqueous
alkaline developer, dissolves in the developer at a higher dissolution rate in exposed
areas than in unexposed areas, wherein the oleophilic layer comprises a polymer that
is soluble in the developer and an organic dye in a amount sufficient to provide a
visible color to the coating, characterized in that said organic dye does not reduce
the dissolution rate of the unexposed areas in the developer.
By using non-inhibiting dyes, the sensitivity of the precursor upon image-wise exposure
is increased.