US4477317A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aluminum substrates useful for lithographic printing plates
Assignee: Polychrome Corp
•
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 10:07
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.
References Cited (Backward Citations)
US308043A
Cited
US993938A
Cited
US2344510A
Cited
US3072546A
Cited
US3073765A
Cited
US3223032A
Cited
GB1113508A
Cited
GB1224226A
Cited
US3887447A
Cited
US3834998A
Cited
US3980539A
Cited
US3929591A
Cited
US4116695A
Cited
US4052275A
Cited
US4072589A
Cited
US4183788A
Cited
US4360401A
Cited
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 |