US4072589A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for electrolytic graining of aluminum sheet
Assignee: Polychrome Corp
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Filing: 1977-04-13
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Granted: 1978-02-07
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Expires: 1997-04-13
Abstract
Abstract A method for electrolytically graining the surface of aluminum sheets useful in the production of lithographic printing plates which comprises subjecting said aluminum sheets to the action of alternating electric current in an aqueous electrolytic solution containing, in combination, small but effective amounts of both hydrochloric and nitric acids.
Inventors
- 👤 Eugene Golda
- 👤 Jen-Chi Huang
- 👤 Ken-ichi Shimazu
- 👤 Simon L. Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:08
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/02; C25F3/04; B; B41; B41N; B41N3/00; B41N3/03; B41N3/034
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
68 words
A method for electrolytically graining aluminum which comprises immersing the aluminum in an aqueous electrolytic solution containing in combination, one part by weight of hydrochloric acid and from four to six parts by weight of nitric acid as electrolytes, applying thereto an alternating electric current of from 150 to 300 amp. minutes per square foot and maintaining the electrolytic solution at a temperature of 40° C. or above.
Claim 2
Independent Claim
68 words
A method for electrolytically graining aluminum which comprises immersing the aluminum in an aqueous electrolytic solution containing in combination, one part by weight of hydrochloric acid and from four to six parts by weight of nitric acid as electrolytes, applying thereto an alternating electric current of from 150 to 300 amp. minutes per square foot and maintaining the electrolytic solution at a temperature of 40° C. or above.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the nitric acid is present in a concentration of from 0.8% to 6.0% by weight.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein the hydrochloric acid is present in a concentration of from 0.2% to 1.0% by weight.
Claim 5
Dependent Claim
49 words
The method of claim 1 wherein the hydrochloric acid is present in a concentration of from 0.2% to 0.7% by weight; the nitric acid is present in a concentration of from 0.8% to 4.3% by weight; and the current is from 180 to 220 amp. minutes per square foot.
Claim 6
Dependent Claim
24 words
The method of claim 1, wherein the temperature of the electrolytic solution is maintained at a temperature of from 40° C. to 60° C.
Claim 7
Dependent Claim
23 words
The method of claim 1, wherein 1 part by weight of hydrochloric acid is combined with 5 parts by weight of nitric acid.
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) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |