Patent US4492616A successfully refreshed from Google Patents.
US4492616A
Expired / Lapsed
US
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Process for treating aluminum oxide layers and use in the manufacture of offset-printing plates
Assignee: Hoechst AG
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Filing: 1983-08-19
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Granted: 1985-01-08
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Expires: 2003-08-19
Abstract
Abstract A process is disclosed for manufacturing sheets, foils, or strips which involves chemically, mechanically, and/or electrochemically roughening and anodically oxidizing aluminum or aluminum alloy surfaces, followed by two post-treatment steps. In the first step, the metal surface is treated with an aqueous alkali metal silicate solution; thereafter, the surface is treated with an aqueous solution comprising alkaline earth metal ions. The materials produced according to this process are particularly used as supports for offset-printing plates.
Inventors
- 👤 Engelbert Pliefke
- 👤 Gerhard Usbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:47
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/24; B; B41; B41N; B41N3/00; B41N3/03; B41N3/038; Y; Y10; Y10S; Y10S205/00; Y10S205/921
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
160 words
A process for using an offset printing plate comprising an aluminum or an aluminum alloy support subjected to (1) electrochemical roughening in an aqueous solution containing at least one of HCl and HNO 3 ; (2) anodic oxidation in an aqueous solution containing at least one of H 2 SO 4 and H 3 PO 4 ; (3) treatment in an aqueous alkali metal silicate solution, wherein said solution comprises from about 0.5 to 10% by weight of alkali metal silicate; and thereafter (4) treatment in an aqueous solution comprising at least one alkaline earth metal salt, wherein said solution comprises from about 0.1 to 10% by weight of alkaline earth metal salt, thereby forming a hydrophilic layer on said surface, said process comprising the steps of: (A) applying a radiation-sensitive coating to said support; (B) imagewise exposing said coating; and thereafter (C) developing said coating in an alkali developer, whereby said hydrophilic layer resists attack by said alkali developer.
Claim 2
Dependent Claim
160 words
A process for using an offset printing plate comprising an aluminum or an aluminum alloy support subjected to (1) electrochemical roughening in an aqueous solution containing at least one of HCl and HNO 3 ; (2) anodic oxidation in an aqueous solution containing at least one of H 2 SO 4 and H 3 PO 4 ; (3) treatment in an aqueous alkali metal silicate solution, wherein said solution comprises from about 0.5 to 10% by weight of alkali metal silicate; and thereafter (4) treatment in an aqueous solution comprising at least one alkaline earth metal salt, wherein said solution comprises from about 0.1 to 10% by weight of alkaline earth metal salt, thereby forming a hydrophilic layer on said surface, said process comprising the steps of: (A) applying a radiation-sensitive coating to said support; (B) imagewise exposing said coating; and thereafter (C) developing said coating in an alkali developer, whereby said hydrophilic layer resists attack by said alkali developer.
Claim 3
Dependent Claim
20 words
A process as in claim 1, wherein the alkaline earth metal salt is selected from water-soluble calcium or strontium salts.
Claim 4
Dependent Claim
15 words
A process as in claim 2, wherein the alkaline earth metal salt is a nitrate.
Claim 5
Dependent Claim
32 words
A process as in claim 1, wherein the aqueous solution of at least one alkaline earth metal salt comprises from about 0.5 to 3 percent by weight of alkaline earth metal salt.
Claim 6
Dependent Claim
45 words
A process as in claim 1, wherein said treatment (3) of said support in an aqueous metal silicate solution is carried out electrochemically at a current density of from about 0.1 to 10 A/dm 2 and/or a voltage of from about 1 to 100 V.
Claim 7
Dependent Claim
63 words
A process as in claim 1, wherein said treatment (3) of said support in an aqueous metal silicate solution and said treatment (4) of said support in an aqueous solution comprising at least one alkaline earth metal salt are both carried out for a period of from about 0.5 to 120 seconds and at a temperature of from about 15° to 80° C.
References Cited (Backward Citations)
US2714066A
Cited
US2882153A
Cited
US2882154A
Cited
FR1162653A
Cited
US2922715A
Cited
US3276868A
Cited
US3181461A
Cited
US4153461A
Cited
US3824159A
Cited
US3860426A
Cited
US3902976A
Cited
GB1523030A
Cited
US4301229A
Cited
JPS5582695A
Cited
EP0016298A1
Cited
JPS55109693A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-08 | 1988-07-09 | 1989-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-08 | 1992-07-09 | 1993-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-08 | 1996-07-09 | 1997-01-08 | $7700.00 | Window Closed / Lapsed |