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US4172772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Printing plates
Assignee: EIDP Inc
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Filing: 1978-04-12
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Granted: 1979-10-30
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Expires: 1998-04-12
Abstract
Abstract Aluminium or aluminium alloy is electrolytically grained using alternating current and an aqueous electrolyte comprising specified amounts of hydrochloric acid and a monocarboxylic acid containing from 1 to 4 carbon atoms, preferably acetic acid. The grained aluminium or alloy may be coated with a light sensitive layer to form a light sensitive plate for use in the production of lithographic printing plates by photomechanical techniques.
Inventors
- 👤 Marshall Ould
- 👤 Geoffrey N. Stevens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:45
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/02; C25F3/04; B; B41; B41N; B41N3/00; B41N3/03; B41N3/034
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
77 words
A method of electrolytically graining aluminium or an aluminium alloy, which comprises immersing the aluminium or aluminium alloy in an aqueous electrolyte comprising a mixture of hydrochloric acid and a monocarboxylic acid containing from 1 to 4 carbon atoms and passing an alternating current through the electrolyte, the concentration of hydrochloric acid in the electrolyte being from 0.05 to 0.5 M and the concentration of mono carboxylic acid in the electrolyte being from 0.05 to 2.20 M.
Claim 2
Independent Claim
77 words
A method of electrolytically graining aluminium or an aluminium alloy, which comprises immersing the aluminium or aluminium alloy in an aqueous electrolyte comprising a mixture of hydrochloric acid and a monocarboxylic acid containing from 1 to 4 carbon atoms and passing an alternating current through the electrolyte, the concentration of hydrochloric acid in the electrolyte being from 0.05 to 0.5 M and the concentration of mono carboxylic acid in the electrolyte being from 0.05 to 2.20 M.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein the carboxylic acid is formic acid, propionic acid or butyric acid.
Claim 4
Dependent Claim
13 words
A method according to claim 1 wherein the carboxylic acid is acetic acid.
Claim 5
Dependent Claim
26 words
A method according to claim 1, 2 or 3, wherein the molar ratio of hydrochloric acid: carboxylic acid is from 2.7:1.0 to 1.0 to 7.0 respectively.
Claim 6
Dependent Claim
21 words
A method according to claim 4 as appendant to claim 3 wherein the molar ratio of hydrochloric acid:carboxylic acid is 1:2.
Claim 7
Independent Claim
109 words
A method of making a light sensitive plate suitable for use in the production of a lithographic printing plate which method comprises the steps of (i) electrolytically graining aluminium or aluminium alloy by immersing the same in an aqueous electrolyte comprising a mixture of hydrochloric acid and a monocarboxylic acid containing from 1 to 4 carbon atoms and passing an alternating current through the electrolyte, the concentration of hydrochloric acid in the electrolyte being from 0.05 M to 0.5 M and the concentration of monocarboxylic acid in the electrolyte being from 0.05 to 2.20 M, and (ii) coating the grained aluminium or aluminium alloy with a light sensitive composition.
Claim 8
Independent Claim
109 words
A method of making a light sensitive plate suitable for use in the production of a lithographic printing plate which method comprises the steps of (i) electrolytically graining aluminium or aluminium alloy by immersing the same in an aqueous electrolyte comprising a mixture of hydrochloric acid and a monocarboxylic acid containing from 1 to 4 carbon atoms and passing an alternating current through the electrolyte, the concentration of hydrochloric acid in the electrolyte being from 0.05 M to 0.5 M and the concentration of monocarboxylic acid in the electrolyte being from 0.05 to 2.20 M, and (ii) coating the grained aluminium or aluminium alloy with a light sensitive composition.
Claim 9
Dependent Claim
27 words
A method according to claim 6 and comprising the additional step of anodising the grained aluminium or aluminium alloy prior to coating with the light sensitive composition.
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) | 1982-10-29 | 1983-04-30 | 1983-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-29 | 1987-04-30 | 1987-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-29 | 1991-04-30 | 1991-10-30 | $7700.00 | Window Closed / Lapsed |