Patent US4049504A successfully refreshed from Google Patents.
US4049504A
Expired / Lapsed
US
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Method of producing lithographic printing plates
Assignee: Polychrome Corp
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Filing: 1976-02-23
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Granted: 1977-09-20
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Expires: 1996-02-23
Abstract
Abstract In the production of lithographic printing plates, the method of anodizing the surface of an aluminum web substrate which comprises subjecting said web to an anodization treatment in an electrolyte comprised of a combination of sulfuric acid and phosphoric acid, and thereafter applying a lithographically acceptable photosensitive coating to the web to obtain a presensitized lithographic printing plate.
Inventors
- 👤 Simon L. Chu
- 👤 Eugene Golda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:40
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/06; C25D11/08; C25D11/16
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
56 words
A method of producing a lithographic printing plate which comprises applying a lithographically acceptable photosensitive coating to an aluminum sheet, at least one surface of which sheet has been anodized by treatment thereof with an electric current under anodizing conditions in an aqueous electrolyte comprised of a combination of sulfuric and phosphoric acids as the electrolyte.
Claim 2
Independent Claim
56 words
A method of producing a lithographic printing plate which comprises applying a lithographically acceptable photosensitive coating to an aluminum sheet, at least one surface of which sheet has been anodized by treatment thereof with an electric current under anodizing conditions in an aqueous electrolyte comprised of a combination of sulfuric and phosphoric acids as the electrolyte.
Claim 3
Dependent Claim
12 words
The lithographic printing plate produced according to the method of claim 1.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein the surface of said aluminum sheet has been grained prior to anodizing.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein an intermediate bonding layer is applied to the anodized surface of the aluminum sheet prior to the application of the photosensitive coating.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein the current density of said electric current is from about 10 to about 150 amps/sq.ft.
Claim 7
Independent Claim
64 words
A method of producing a lithographic printing plate which comprises applying a lithographically acceptable photosensitive coating to at least one grained surface of an aluminum sheet, which sheet has been anodized with an electric current having a current density of from about 10 to about 150 amps/sq.ft., under anodizing conditions in an aqueous electrolyte comprised of a combination of sulfuric acid and phosphoric acid.
Claim 8
Independent Claim
64 words
A method of producing a lithographic printing plate which comprises applying a lithographically acceptable photosensitive coating to at least one grained surface of an aluminum sheet, which sheet has been anodized with an electric current having a current density of from about 10 to about 150 amps/sq.ft., under anodizing conditions in an aqueous electrolyte comprised of a combination of sulfuric acid and phosphoric acid.
Claim 9
Dependent Claim
12 words
The lithographic printing plate produced according to the method of claim 6.
Claim 10
Dependent Claim
29 words
The method of claim 6 wherein an intermediate bonding layer is applied to the anodized surface of the grained aluminum sheet prior to the application of the photosensitive coating.
Claim 11
Dependent Claim
21 words
The method of claim 6 wherein the concentration of sulfuric acid in the electrolyte is from about 10% to about 30%.
Claim 12
Independent Claim
101 words
A method of producing a lithographic printing plate which comprises applying a photosensitive, lithographically acceptable coating to at least one grained surface of an aluminum sheet, said surface having been anodized for from about 0.25 to about 3.0 minutes in an aqueous electrolytic bath maintained at a temperature of from about 25 to 50° C., containing from about 5% to about 40% acid by weight wherein said acid consists essentially of from about 1 to 1.5 parts of sulfuric acid and from about 1 to 1.5 parts phosphoric acid, with a current density of from about 10 to about 150 amps/sq.ft.
Claim 13
Independent Claim
101 words
A method of producing a lithographic printing plate which comprises applying a photosensitive, lithographically acceptable coating to at least one grained surface of an aluminum sheet, said surface having been anodized for from about 0.25 to about 3.0 minutes in an aqueous electrolytic bath maintained at a temperature of from about 25 to 50° C., containing from about 5% to about 40% acid by weight wherein said acid consists essentially of from about 1 to 1.5 parts of sulfuric acid and from about 1 to 1.5 parts phosphoric acid, with a current density of from about 10 to about 150 amps/sq.ft.
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) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |