US4144142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing colored anodic film on aluminum-based material
Assignee: Riken Keikinzoku Kogyo KK
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Filing: 1977-12-05
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Granted: 1979-03-13
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Expires: 1997-12-05
Abstract
Abstract A method for inexpensively producing a colored anodized film on aluminum or aluminum alloy material by electrolyzing the aluminum material in a sulphuric acid bath in the presence of a resistivity agent selected from trivalent aluminum ions and oxalic acid, by applying thereto a pulsating electric current having a peak voltage of 25 to 45 volts and a pulse duration of 5 to 70 milliseconds (m.sec.) and a ratio of pulse frequency to pulse duration of between 2 and 7.
Inventors
- 👤 Toshiro Takahashi
- 👤 Masashi Ikegaya
- 👤 Masamichi Ozaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:01
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/14
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
118 words
A method for producing a coloured anodic film on the surface of an aluminum material which comprises: electroloyzing the aluminum material in a sulphuric acid electrolyte bath containing a resistivity control agent comprising from 3 to less than 5 grams per liter of water soluble, trivalent aluminum ions, by applying to the aluminum material a pulsating electric current characterized by having a current density between 2 and 8 A/ dm2, a peak voltage of 25 to 45 volts, a pulse duration of 5 to 70 m.sec., and a ratio of pulse frequency to pulse duration of between 2 and 7, wherein the aluminum material includes zinc and magnesium, the ratio of zinc to magnesium being less than 5.
Claim 2
Independent Claim
118 words
A method for producing a coloured anodic film on the surface of an aluminum material which comprises: electroloyzing the aluminum material in a sulphuric acid electrolyte bath containing a resistivity control agent comprising from 3 to less than 5 grams per liter of water soluble, trivalent aluminum ions, by applying to the aluminum material a pulsating electric current characterized by having a current density between 2 and 8 A/ dm2, a peak voltage of 25 to 45 volts, a pulse duration of 5 to 70 m.sec., and a ratio of pulse frequency to pulse duration of between 2 and 7, wherein the aluminum material includes zinc and magnesium, the ratio of zinc to magnesium being less than 5.
Claim 3
Dependent Claim
30 words
A method according to claim 1 wherein the pulse duration is from 10 to 45 m.sec., and the ratio of pulse frequency to pulse duration is between 3 and 5.
References Cited (Backward Citations)
GB1090840A
Cited
US3836439A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-12 | 1982-09-11 | 1983-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-12 | 1986-09-11 | 1987-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-12 | 1990-09-11 | 1991-03-13 | $7700.00 | Window Closed / Lapsed |