US4379830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer for positive photolithographic articles
Assignee: Polychrome Corp
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Filing: 1981-10-06
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Granted: 1983-04-12
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Expires: 2001-10-06
Abstract
Abstract An improved aqueous alkaline developer for imagewise-exposed positive-acting photolithographic articles comprising a basic substance wherein the improvement comprises addition of a neutral salt of an alkali metal cation to the developer.
Inventors
- 👤 Albert S. Deutsch
- 👤 Christopher F. Lyons
- 👤 Robert Piller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:43
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32; G03F7/322
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
36 words
An improved alkaline developer for photolithographic articles comprising from 0.5 to 30% wt. sodium metasilicate, wherein the improvement comprises addition of from 2 to 5% wt. of sodium chloride, based on total weight of the developer.
Claim 2
Dependent Claim
36 words
An improved alkaline developer for photolithographic articles comprising from 0.5 to 30% wt. sodium metasilicate, wherein the improvement comprises addition of from 2 to 5% wt. of sodium chloride, based on total weight of the developer.
Claim 3
Dependent Claim
23 words
The developer according to claim 1 further comprising at least one additive selected from the group comprising organic solvents and surface active agents.
Claim 4
Dependent Claim
37 words
An improved process for developing imagewise exposed positive-acting photolithographic articles by treating same with an aqueous alkaline developer comprising sodium metasilicate to remove the exposed, non-image area, the improvement comprising addition of sodium chloride to said developer.
Claim 5
Dependent Claim
37 words
An improved process for developing imagewise exposed positive-acting photolithographic articles by treating same with an aqueous alkaline developer comprising sodium metasilicate to remove the exposed, non-image area, the improvement comprising addition of sodium chloride to said developer.
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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) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |