US4452880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for developing positive photosensitive lithographic printing plate
Assignee: Konica Minolta Inc
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Filing: 1981-09-21
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Granted: 1984-06-05
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Expires: 2001-09-21
Abstract
Abstract A developing process suitable to treat a positive photosensitive lithographic printing plate comprising a photosensitive layer containing, as the photosensitive constituent, an o-quinonediazide compound provided on an aluminium plate. A positive photo-sensitive lithographic printing plate is exposed imagewise and then developed with a developing solution containing an aqueous solution of an alkali metal silicate in which the alkali metal is essentially constituted by potassium. With the method, development treatment can be conducted stably for a long period without generating insolubes in the developing solution even when an extremely large quantity of positive photosensitive lithographic plates are treated.
Inventors
- 👤 Minoru Seino
- 👤 Atsuo Yamazaki
- 👤 Toru Aoki
- 👤 Akihiko Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:00
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32; G03F7/322
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
108 words
A process for developing a positive photosensitive lithographic printing plate comprising imagewise exposing a positive lithographic printing plate comprising a photosensitive layer containing, as a photosensitive constituent, an o-quinonediazide compound provided on an aluminum plate; and developing said imagewise exposed photosensitive lithographic printing plate with a developing solution containing an aqueous solution of an alkali metal silicate, characterized in that the alkali metal of said alkali metal silicate consists of potassium, the molar ratio of SiO 2 /K 2 O in said developing solution being within the range between 1.60 and 2,00, said developing solution containing K 2 O in an amount between 1.8% and 7.2% by weight.
Claim 2
Dependent Claim
108 words
A process for developing a positive photosensitive lithographic printing plate comprising imagewise exposing a positive lithographic printing plate comprising a photosensitive layer containing, as a photosensitive constituent, an o-quinonediazide compound provided on an aluminum plate; and developing said imagewise exposed photosensitive lithographic printing plate with a developing solution containing an aqueous solution of an alkali metal silicate, characterized in that the alkali metal of said alkali metal silicate consists of potassium, the molar ratio of SiO 2 /K 2 O in said developing solution being within the range between 1.60 and 2,00, said developing solution containing K 2 O in an amount between 1.8% and 7.2% by weight.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the aluminum plate is selected from the group consisting of a pure aluminum plate, an aluminum alloy plate, a plastic film having a layer of aluminum thereon.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein said aluminum plate is surface treated.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein said o-quinonediazide compound is an o-naphthoquinonediazide compound.
Claim 6
Dependent Claim
35 words
The process of claim 4 wherein said o-napthoquinonediazide compound is selected from o-naphthoquinonediazide sulfonates, o-naphthoquinonediazide carboxylates of an aromatic hydroxy compound, o-naphthoquinonediazide carboxylic acid amides and o-naphthoquinonediazide sulfonic acid amides of an aromatic amino compound.
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein said photosensitive layer is present in an amount of about 0.5 to 7 g/m 2 .
Claim 8
Dependent Claim
32 words
The process of claim 1 wherein said developing solution further contains at least one compound selected from the group consisting of an organic solvent, a surface active agent and an anti-foaming agent.
Claim 9
Dependent Claim
15 words
The process of claim 4 wherein said photosensitive layer further contains an alkali soluble resin.
Claim 10
Dependent Claim
16 words
The process of claim 8 wherein said alkali soluble resin is a novolak type phenolic resin.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |