US4396468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three phase graining of aluminum substrates
Assignee: CNA Holdings LLC
•
Filing: 1981-12-21
•
Granted: 1983-08-02
•
Expires: 2001-12-21
Abstract
Abstract A method for the production of aluminum substrates useful in the production of lithographic printing plates which comprises simultaneously electrochemically graining both sides of an aluminum sheet in an electrolyte employing three phase alternating current.
Inventors
- 👤 John E. Walls
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:28
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/02; C25F3/04; B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; Y; Y10; Y10S; Y10S205/00; Y10S205/921
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
65 words
A method for simultaneously graining both sides of a metal sheet which comprises applying one phase of a three phase alternating current source to each of two electrodes disposed one on each of the opposite sides of said metal sheet and applying the third phase of said alternating current source to said metal sheet while maintaining said sheet and said electrodes in an electrolytic medium.
Claim 2
Independent Claim
65 words
A method for simultaneously graining both sides of a metal sheet which comprises applying one phase of a three phase alternating current source to each of two electrodes disposed one on each of the opposite sides of said metal sheet and applying the third phase of said alternating current source to said metal sheet while maintaining said sheet and said electrodes in an electrolytic medium.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said metal comprises aluminum or the alloys thereof.
Claim 4
Dependent Claim
41 words
The method of claim 1 wherein said medium comprises an aqueous solution containing one or more compounds selected from the group consisting of nitric acid, hydrochloric acid, aluminum salts of mineral acids, chloride ion containing compounds and phosphate ion containing compounds.
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein said electrolyte comprises nitric acid and aluminum nitrate.
Claim 6
Dependent Claim
28 words
The method of claim 3 wherein said electrolyte further comprises one or more compounds selected from the group consisting of gluconic acid, tartaric acid, boric acid and peroxides.
Claim 7
Dependent Claim
25 words
The method of claim 3 wherein the concentration of said compounds in said aqueous solution ranges from about 1% by weight to the saturation point.
Claim 8
Dependent Claim
27 words
The method of claim 1 wherein the current density applied on each side of the sheet ranges from about 30 to about 120 amperes per square decimeter.
Claim 9
Dependent Claim
19 words
The method of claim 1 further comprising the subsequent step of anodizing one or both sides of said sheet.
Claim 10
Dependent Claim
19 words
The metal sheet produced according to the method of claim 1, 2, 3, 4, 5, 6, 7 or 8.
Claim 11
Dependent Claim
31 words
A lithographic printing plate which comprises a lithographically suitable photosensitive composition applied to one or both surfaces of the sheet produced according to the method of claim 1, 2 or 8.
Claim 12
Dependent Claim
27 words
The lithographic printing plate of claim 10 wherein said photosensitive composition comprises a composition selected from the group consisting of diazonium salts, quinone diazides and photopolymerizable compositions.
Claim 13
Dependent Claim
22 words
The lithographic printing plate of claim 10 further comprising a hydrophilizing interlayer composition disposed between said sheet surface and said photosensitive composition.
Claim 14
Dependent Claim
22 words
The lithographic printing plate of claim 11 further comprising a hydrophilizing interlayer composition disposed between said sheet surface and said photosensitive composition.
Claim 15
Dependent Claim
41 words
The lithographic printing plate of claim 12 wherein said hydrophilizing composition comprises one or more compounds selected from the group consisting of alkali metal silicate, silicic acid, the Group IV-B metal fluorides, polyacrylic acid, the alkali zirconium fluorides, and hydrofluozirconic acid.
Claim 16
Dependent Claim
41 words
The lithographic printing plate of claim 13 wherein said hydrophilizing composition comprises one or more compounds selected from the group consisting of alkali metal silicate, silicic acid, the Group IV-B metal fluorides, polyacrylic acid, the alkali zirconium fluorides, and hydrofluozirconic acid.
References Cited (Backward Citations)
US2598043A
Cited
DE2305243A1
Cited
US3980539A
Cited
US3929591A
Cited
US3935080A
Cited
US3963594A
Cited
US4021836A
Cited
US4052275A
Cited
US4214961A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |