Patent US3791828A successfully refreshed from Google Patents.
US3791828A
Expired / Lapsed
US
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A developer solution for developing presensitised photolithographic printing plates
Assignee: WH Howson Ltd
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Filing: 1972-08-23
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Granted: 1974-02-12
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Expires: 1992-08-23
Abstract
Abstract This disclosure relates to developer solutions suitable for developing exposed presensitised photolithographic printing plates, which solutions comprise a solvent for the areas of presensitised layer to be removed from the printing plate and a surface active agent, the volumetric ration of solvent to surface active agent being considerably higher than conventionally used, whereby the efficacy of the developer solution is considerable enhanced.
Inventors
- 👤 B Moore
- 👤 L Watkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:17
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32; G03F7/325; B; B41; B41N; B41N3/00; B41N3/08
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
35 words
The developer solution of claim 1 wherein said solvent is selected from the group consisting of glycol ether esters, amides, alcohols, hydrocarbons, chlorinated hydrocarbons, tetrahydrofurfuryl acetate, diethylene glycol, monomethyl ether and diethylene monoethyl ether acetate.
Claim 2
Dependent Claim
49 words
The developer solution of claim 1 wherein said surface active agent is selected from the group consisting of alkyl aryl sulfonic acids, tertiary amine condensation products of fatty amines and ethylene oxide, polyoxyethylene sorbitan monopalmitate, polyoxyethylene glyceride ethers, and polyoxyethylene condensates of alcohols, higher fatty alcohols and alkyl phenols.
Claim 3
Dependent Claim
27 words
The developer solution of claim 1 wherein the volumetric ratio of said solvent to said surface active agent is in the range of from 2:1 to 5:1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |