US5156723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for electrochemical roughening of aluminum for printing plate supports
Assignee: Hoechst AG
•
Filing: 1991-01-22
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Granted: 1992-10-20
•
Expires: 2011-01-22
Abstract
Abstract A process for roughening aluminum or alloys thereof for printing plate supports, wherein an electrochemical roughening is performed by means of alternating current in an acidic electrolyte including sulfate ions and chloride ions, the chloride ions being in the form of aluminum chloride. In a preceding or subsequent rougheniong stage, mechanical roughening and/or electrochemical roughening by means of alternating current in an electrolyte is carried out. The electrolyte can include hydrochloric acid and aluminum ions, nitric acid and aluminum ions or sulfuric acid and chloride ions.
Inventors
- 👤 Engelbert Pliefke
- 👤 Michael Brenk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:43
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; C; C25; C25F; C25F3/00; C25F3/02; C25F3/04; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12993
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
138 words
A process for roughening an aluminum or aluminum alloy substrate for a printing plate support, comprising: a) a primary roughening stage which comprises immersing said substrate in a first electrolyte comprising sulfate ions and aluminum chloride which provides chloride ions, and applying an alternating current to said first electrolyte; and b) a secondary roughening stage which comprises performing at least one roughening step selected from the group consisting of mechanically roughening said substrate, immersing said substrate in a second electrolyte comprising hydrochloric acid and aluminum chloride which provides aluminum ions, immersing said substrate in a third electrolyte comprising nitric acid and aluminum nitrate which provides aluminum ions, and immersing said substrate in a fourth electrolyte comprising sulfuric acid and aluminum chloride which provides chloride ions, wherein an alternating current is applied to said second, third and fourth electrolytes.
Claim 2
Dependent Claim
138 words
A process for roughening an aluminum or aluminum alloy substrate for a printing plate support, comprising: a) a primary roughening stage which comprises immersing said substrate in a first electrolyte comprising sulfate ions and aluminum chloride which provides chloride ions, and applying an alternating current to said first electrolyte; and b) a secondary roughening stage which comprises performing at least one roughening step selected from the group consisting of mechanically roughening said substrate, immersing said substrate in a second electrolyte comprising hydrochloric acid and aluminum chloride which provides aluminum ions, immersing said substrate in a third electrolyte comprising nitric acid and aluminum nitrate which provides aluminum ions, and immersing said substrate in a fourth electrolyte comprising sulfuric acid and aluminum chloride which provides chloride ions, wherein an alternating current is applied to said second, third and fourth electrolytes.
Claim 3
Dependent Claim
18 words
A process according to claim 1, comprising performing said primary roughening stage prior to said secondary roughening stage.
Claim 4
Dependent Claim
18 words
A process according to claim 1, comprising performing said secondary roughening stage prior to said primary roughening stage.
Claim 5
Dependent Claim
21 words
A process according to claim 1, comprising performing said process continuously, wherein said substrate comprises an aluminum or aluminum alloy strip.
Claim 6
Dependent Claim
33 words
A process according to claim 4, comprising performing said primary roughening stage at a temperature of about 20° to 60° C. and a current density of about 3 to 180 A/dm 2 .
Claim 7
Dependent Claim
26 words
A process according to claim 4, wherein the residence time of an area of said substrate in said first electrolyte is about 10 to 300 seconds.
Claim 8
Dependent Claim
23 words
A process according to claim 4, wherein the electrolyte flow velocity on the surface of said substrate is about 5 to 100 cm/second.
Claim 9
Dependent Claim
21 words
A process according to claim 1, comprising performing said process discontinuously wherein said substrate comprises an aluminum or aluminum alloy plate.
Claim 10
Dependent Claim
24 words
A process according to claim 8, comprising performing said primary roughening stage at a current density of about 3 to 40 A/dm 2 .
Claim 11
Dependent Claim
23 words
A process according to claim 8, wherein the residence time of said plate in said first electrolyte is about 30 to 300 seconds.
Claim 12
Dependent Claim
29 words
A process according to claim 1, wherein said secondary roughening stage comprises said mechanical roughening, wherein said mechanical roughening comprises wet brushing, wire brushing, sandblasting, bead graining or embossing.
Claim 13
Dependent Claim
20 words
A process according to claim 1, wherein said first electrolyte includes sulfuric acid as the source for said sulfate ions.
Claim 14
Dependent Claim
23 words
A process according to claim 1, wherein the concentration of said sulfate ions in said first electrolyte is about 5 to 100 gl/l.
Claim 15
Dependent Claim
23 words
A process according to claim 13, wherein the concentration of said sulfate ions in said first electrolyte is about 20 to 50 g/l.
Claim 16
Dependent Claim
23 words
A process according to claim 1, wherein the concentration of said chloride ions in said first electrolyte is about 1 to 100 g/l.
Claim 17
Dependent Claim
23 words
A process according to claim 15, wherein the concentration of said chloride ions in said first electrolyte is about 10 to 70 g/l.
Claim 18
Dependent Claim
47 words
A process according to claim 1, wherein said secondary roughening stage comprises immersing said substrate in said second electrolyte, wherein said second electrolyte comprises hydrochloric acid in a concentration of about 1 to 20 g/l and aluminum ions in a concentration of about 10 to 200 g/l.
Claim 19
Dependent Claim
51 words
A process according to claim 17, wherein said secondary roughening stage comprises immersing said substrate in said second electrolyte for about 5 to 200 seconds at a temperature of about 35° to 55° C. and applying an alternating current at a current density of about 20 to 150 A/dm 2 .
Claim 20
Dependent Claim
47 words
A process according to claim 1, wherein said secondary roughening stage comprises immersing said substrate in said third electrolyte, wherein said third electrolyte comprises nitric acid in a concentration of about 20 to 35 g/l and aluminum ions in a concentration of about 30 to 50 g/l.
Claim 21
Dependent Claim
51 words
A process according to claim 19, wherein said secondary roughening stage comprises immersing said substrate in said third electrolyte for about 2 to 100 seconds at a temperature of about 22° to 50° C. and applying an alternating current at a current density of about 15 to 80 A/dm 2 .
Claim 22
Dependent Claim
15 words
A process according to claim 1, further comprising acidic or alkaline cleaning of said substrate.
Claim 23
Dependent Claim
18 words
A process according to claim 21, comprising performing said cleaning prior to said primary and secondary roughening stages.
Claim 24
Dependent Claim
17 words
A process according to claim 21, comprising performing said cleaning between said primary and secondary roughening stages.
Claim 25
Dependent Claim
18 words
A process according to claim 21, comprising performing said cleaning subsequent to said primary and secondary roughening steps.
Claim 26
Dependent Claim
37 words
A process according to claim 21, wherein said cleaning comprises immersing said substrate for about 30 to 80 seconds in an aqueous pickling solution comprised of sodium hydroxide or a mixture of sodium hydroxide and sodium carbonate.
Claim 27
Dependent Claim
30 words
A process according to claim 25, wherein said pickling solution comprises sodium hydroxide in a concentration of about 20 g/l and sodium carbonate in a concentration of about 2 g/l.
Claim 28
Dependent Claim
16 words
A process according to claim 1, wherein a sinusoidal alternating voltage at mains frequency is employed.
Claim 29
Dependent Claim
13 words
A process according to claim 1, wherein a superposed alternating voltage is employed.
Claim 30
Dependent Claim
20 words
A process according to claim 1, wherein an alternating voltage having a frequency lower than the mains frequency is employed.
Claim 31
Dependent Claim
15 words
A process according to claim 1, wherein said substrate comprises a plate, foil or strip.
Claim 32
Dependent Claim
21 words
A process according to claim 1, further comprising, subsequent to said primary and secondary roughening stages, anodic oxidation of said substrate.
Claim 33
Dependent Claim
27 words
A process according to claim 1, further comprising, subsequent to said primary and secondary roughening stages, effecting a superficial ablation of the roughened surface of said substrate.
Claim 34
Dependent Claim
28 words
A process according to claim 1, further comprising, subsequent to said primary and secondary roughening stages, treating said substrate so as to provide hydrophilic character to said substrate.
Claim 35
Dependent Claim
23 words
A process according to claim 1, further comprising, subsequent to said primary and secondary roughening stages, applying a photo-semi-conducting layer to said substrate.
Claim 36
Dependent Claim
13 words
An aluminum or aluminum alloy substrate roughened by the process of claim 1.
Claim 37
Dependent Claim
113 words
A process for roughening an aluminum or aluminum alloy substrate comprising: a) a primary roughening stage which comprises immersing said substrate in a first electrolyte comprising sulfate ions and chloride ions, and applying an alternating current to said first electrolyte; and b) a secondary roughening stage which comprises performing at least one roughening step selected from the group consisting of immersing said substrate in a second electrolyte comprising hydrochloric acid and aluminum ions, immersing said substrate in a third electrolyte comprising nitric acid and aluminum ions, and immersing said substrate in a fourth electrolyte comprising sulfuric acid and chloride ions, wherein an alternating current is applied to said second, third and fourth electrolytes.
Claim 38
Dependent Claim
113 words
A process for roughening an aluminum or aluminum alloy substrate comprising: a) a primary roughening stage which comprises immersing said substrate in a first electrolyte comprising sulfate ions and chloride ions, and applying an alternating current to said first electrolyte; and b) a secondary roughening stage which comprises performing at least one roughening step selected from the group consisting of immersing said substrate in a second electrolyte comprising hydrochloric acid and aluminum ions, immersing said substrate in a third electrolyte comprising nitric acid and aluminum ions, and immersing said substrate in a fourth electrolyte comprising sulfuric acid and chloride ions, wherein an alternating current is applied to said second, third and fourth electrolytes.
Claim 39
Dependent Claim
60 words
A process according to claim 36, wherein said first electrolyte includes aluminum chloride as the source for said chloride ions, said second electrolyte includes aluminum chloride as the source for said aluminum ions, said third electrolyte includes aluminum nitrate as the source for said aluminum ions, and said fourth electrolyte includes aluminum chloride as the source for said chloride ions.
Claim 40
Dependent Claim
19 words
A process according to claim 37, wherein said secondary roughening stage comprises immersing said substrate in said second electrolyte.
Claim 41
Dependent Claim
19 words
A process according to claim 37, wherein said secondary roughening stage comprises immersing said substrate in said third electrolyte.
Claim 42
Dependent Claim
19 words
A process according to claim 37, wherein said secondary roughening stage comprises immersing said substrate in said fourth electrolyte.
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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) | 1995-10-20 | 1996-04-20 | 1996-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-20 | 2000-04-20 | 2000-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-20 | 2004-04-20 | 2004-10-20 | $7700.00 | Window Closed / Lapsed |