| (19) |
 |
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(11) |
EP 1 120 246 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
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16.08.2001 Bulletin 2001/33 |
| (43) |
Date of publication A2: |
|
01.08.2001 Bulletin 2001/31 |
| (22) |
Date of filing: 26.01.2001 |
|
| (51) |
International Patent Classification (IPC)7: B41C 1/10 |
|
| (84) |
Designated Contracting States: |
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AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
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Designated Extension States: |
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AL LT LV MK RO SI |
| (30) |
Priority: |
27.01.2000 JP 2000018379
|
| (71) |
Applicant: FUJI PHOTO FILM CO., LTD. |
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Kanagawa (JP) |
|
| (72) |
Inventors: |
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- Nakamura, Ippei
Yoshida-cho, Haibara-gun, Shizuoka (JP)
- Kunita, Kazuto
Yoshida-cho, Haibara-gun, Shizuoka (JP)
|
| (74) |
Representative: HOFFMANN - EITLE |
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Patent- und Rechtsanwälte Arabellastrasse 4
81925 München
81925 München (DE) |
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| |
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| (54) |
Planographic printing original plate and method of plate-making a planographic printing
plate |
(57) A positive type planographic printing original plate which enables direct plate-making
using a solid or semiconductor laser emitting infrared rays by recording an image
from digital data of computers, is highly sensitive to an infrared laser and has stability
to developing treatment, and a method of plate-making a positive type planographic
printing plate which is resistant to occurrence of flaw inferiors. The planographic
printing original plate includes a first layer which contains a polymer that is insoluble
in water and soluble in alkaline water, and a second layer which contains an infrared
radiation absorber and a binder, which is not penetrative into an alkali developing
solution containing an organic compound having a buffering effect and a base as principal
components, and which is increased in solubility in an alkali developing solution
by action of one of light and heat. The layers are sequentially provided on a support.