Patent US4477317A successfully refreshed from Google Patents.
US4477317A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aluminum substrates useful for lithographic printing plates
Assignee: Polychrome Corp
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Filing: 1983-10-31
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Granted: 1984-10-16
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Expires: 2003-10-31
Abstract
Abstract A method for the production of aluminum substrates useful in the production of lithographic printing plates which comprises first mechanically graining at least one surface of an aluminum sheet to obtain a pumice grained surface of the aluminum sheet, and then electrolytically etching said grained surface with alternating current.
Inventors
- 👤 Simon L. Chu
- 👤 Eugene Golda
- 👤 Jen-Chi Huang
- 👤 Alan Wilkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:10
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/02; C25F3/04; B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; B41N3/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
143 words
A method of producing a lithographic printing plate which comprises: (a) pumice graining the smooth surface of an aluminum sheet; utilizing a wet slurry containing about 5.5 percent or more pumice alone or in combination with other abrasive materials (b) cleaning the surface of the resulting pumice grained aluminum sheet; (c) electrolytically graining said aluminum surface in an aqueous electrolyte whose solute consists essentially of hydrochloric acid, nitric acid, or combinations thereof at a time period of from about 0.15 to 2 minutes per square foot of aluminum surface being treated and at an alternating current density of from 2 to 100 amps per square decimeter wherein the electrolyte is maintained at from about 20 to 80 degrees C.; (d) rinsing said aluminum sheets with water; (e) drying said aluminum sheet; and (f) coating said aluminum sheet with a lithographically suitable photosensitive composition.
Claim 2
Independent Claim
143 words
A method of producing a lithographic printing plate which comprises: (a) pumice graining the smooth surface of an aluminum sheet; utilizing a wet slurry containing about 5.5 percent or more pumice alone or in combination with other abrasive materials (b) cleaning the surface of the resulting pumice grained aluminum sheet; (c) electrolytically graining said aluminum surface in an aqueous electrolyte whose solute consists essentially of hydrochloric acid, nitric acid, or combinations thereof at a time period of from about 0.15 to 2 minutes per square foot of aluminum surface being treated and at an alternating current density of from 2 to 100 amps per square decimeter wherein the electrolyte is maintained at from about 20 to 80 degrees C.; (d) rinsing said aluminum sheets with water; (e) drying said aluminum sheet; and (f) coating said aluminum sheet with a lithographically suitable photosensitive composition.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the electrolyte is hydrochloric acid.
Claim 4
Dependent Claim
11 words
The lithographic printing plate produced by the method of claim 1.
Claim 5
Dependent Claim
11 words
The method of claim 1 wherein the electrolyte is nitric acid.
Claim 6
Dependent Claim
29 words
The method of claim 1 wherein the aluminum sheet is anodized with direct current in a sulfuric acid electrolyte prior to the application of the lithographically suitable photosensitive composition.
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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) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |