US4604341A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the one-stage anodic oxidation of aluminum bases for offset printing plates and product thereof
Assignee: Hoechst AG
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Filing: 1984-07-26
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Granted: 1986-08-05
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Expires: 2004-07-26
Abstract
Abstract A process is disclosed for the production of bases for offset printing plates in the form of sheets, foils or webs made of roughened aluminum or one of its alloys, which is carried out in an anodic oxidation stage, i.e. in an aqueous electrolyte which contains phosphorus-containing anions. In the procedure, an electrolyte containing dissolved phosphoroxo anions, with the exception of aqueous H 3 PO 4 , is employed, and the treatment is carried out for a period of about 1 to 90 seconds, at a voltage between about 10 and 100 volts and at a temperature of about 10° to 80° C. The electrolyte is, in particular, a salt of an oxyacid of phosphorus, such as Na 3 PO 4 or K 3 PO 4 . Hydrophilization of the base can be carried out additionally after the anodic oxidation. Also disclosed is a base material produced according to the process and an offset printing plate which includes the base material.
Inventors
- 👤 Dieter Mohr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:42
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/06; C25D11/08; Y; Y10; Y10S; Y10S205/00; Y10S205/921
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
143 words
A process for producing a base for an offset printing plate comprising the steps of: subjecting a base material selected from aluminum and aluminum alloys to an electrochemical roughening treatment in an acid to produce a roughened base material, and anodically oxidizing said roughened base material in a single stage in an aqueous H 3 PO 4 -free electrolyte comprising dissolved inorganic phosphoroxo-anions of inorganic phosphoroxo compounds selected from the group consisting of metaphosphoric, pyrophosphoric or polyphosphoric acids or alkali metal or alpaline earth metal or ammonium salts of orthophosphoric, metaphosphoric, pyrophosphoric or polyphosphoric acids for a period from about 1 to about 90 seconds, at a voltage from 20 to about 100 volts and at a temperature from about 10° to about 80° C. to produce a metal oxide layer having a weight per unit of at least 0.5 g/m 2 .
Claim 2
Dependent Claim
143 words
A process for producing a base for an offset printing plate comprising the steps of: subjecting a base material selected from aluminum and aluminum alloys to an electrochemical roughening treatment in an acid to produce a roughened base material, and anodically oxidizing said roughened base material in a single stage in an aqueous H 3 PO 4 -free electrolyte comprising dissolved inorganic phosphoroxo-anions of inorganic phosphoroxo compounds selected from the group consisting of metaphosphoric, pyrophosphoric or polyphosphoric acids or alkali metal or alpaline earth metal or ammonium salts of orthophosphoric, metaphosphoric, pyrophosphoric or polyphosphoric acids for a period from about 1 to about 90 seconds, at a voltage from 20 to about 100 volts and at a temperature from about 10° to about 80° C. to produce a metal oxide layer having a weight per unit of at least 0.5 g/m 2 .
Claim 3
Dependent Claim
43 words
The process as claimed in claim 1, wherein said anodic oxidation step is carried out for a period of about 5 to 70 seconds, at a voltage between about 20 and 80 volts and at a temperature of about 15° to 60° C.
Claim 4
Dependent Claim
43 words
The process as claimed in claim 1, wherein said anodic oxidation step is carried out for a period of about 10 to 60 seconds, at a voltage between about 30 and 60 volts and at a temperature of about 25° to 60° C.
Claim 5
Dependent Claim
31 words
The process as claimed in claim 1, wherein said aqueous electrolyte comprises a salt having a cation selected from alkali metal, alkaline earth metal and ammonium cations and a phosphoroxo anion.
Claim 6
Dependent Claim
20 words
The process as claimed in claim 1, wherein said aqueous electrolyte comprises trisodium phosphate or tripotassium phosphate in de-ionized water.
Claim 7
Dependent Claim
14 words
The process as claimed in claim 4, wherein said aqueous electrolyte comprises trisodium phosphate.
Claim 8
Dependent Claim
14 words
The process as claimed in claim 4, wherein said aqueous electrolyte comprises tripotassium phosphate.
Claim 9
Dependent Claim
24 words
The process as claimed in claim 1, wherein said aqueous electrolyte comprises a phosphoroxo compound in an amount from about 20 g/l to saturation.
Claim 10
Dependent Claim
18 words
The process as claimed in claim 1, further comprising the step of hydrophilizing said anodically oxidized base material.
Claim 11
Dependent Claim
19 words
The process as claimed in claim 1, wherein said aqueous electrolyte comprises an acid having said dissolved phosphoroxo anions.
Claim 12
Dependent Claim
17 words
The process as claimed in claim 10, wherein said acid is selected from oligo- and polyphosphoric acids.
Claim 13
Dependent Claim
24 words
A base for offset printing plates in the form of a sheet, a foil or a web, produced by the process of claim 1.
Claim 14
Dependent Claim
26 words
An offset printing plate, comprising: a base material produced by the process of claim 1, and a radiation-sensitive or photosensitive coating applied to said base material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-04 | 1990-02-03 | 1990-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-04 | 1994-02-03 | 1994-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-04 | 1998-02-03 | 1998-08-05 | $7700.00 | Window Closed / Lapsed |