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US4869789A
Expired / Lapsed
US
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Method for the preparation of decorative coating on metals
Assignee: KSB PARTNERSHIP
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Filing: 1988-02-02
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Granted: 1989-09-26
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Expires: 2008-02-02
Abstract
Abstract The process for producing decorative coatings on metals is primarily used in the jewelry industry, in handicrafts, and in device construction according to the invention, matte, true-to-form decorative coatings with a homogenous thickness of 3 μm to 30 μm are provided means of an electrochemical and plasmachemical reaction using a pulse operation in aqueous electrolytes at voltage peaks of 250 V to 750 V, pulse times of 20 μs to 2 ms, pulse frequencies of 35 Hz to 300 Hz, pulse currents from 20 A to 120 A, electrolyte temperatures between 318 K and 360 K, and average current densities from 0.1 A cm -2 to 1 A cm -2 .
Inventors
- 👤 Peter Kurze
- 👤 Waldemar Krysmann
- 👤 Maria Berger
- 👤 Klaus Rabending
- 👤 Joachim Schreckenbach
- 👤 Thomas Schwarz
- 👤 Karl-Heinz Hartmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:41
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/024; C25D11/026
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
133 words
A method for preparing a decorative coating for a metal substrate in an aqueous electrolyte comprising subjecting a barrier-layer forming metal substrate selected from aluminum, titanium, tantalum, zirconium, niobium, and an alloy thereof to an electrochemical and plasma-chemical reaction which is determined by the pulse voltage, and which has the following characteristics: voltage peaks of 250 V to 750 V, a voltage time of 20 μs to 2 ms, a pulse frequency of 35 Hz to 300 Hz, a pulse current of 10 A to 120 A, an electrolyte temperature of 318 K to 360 K and an average current density of 0.1 A cm -2 to 1 A cm -2 , whereby a matte, true to form, decorative white coating with a homogeneous thickness of 3 μm to 30 μm is formed.
Claim 2
Independent Claim
133 words
A method for preparing a decorative coating for a metal substrate in an aqueous electrolyte comprising subjecting a barrier-layer forming metal substrate selected from aluminum, titanium, tantalum, zirconium, niobium, and an alloy thereof to an electrochemical and plasma-chemical reaction which is determined by the pulse voltage, and which has the following characteristics: voltage peaks of 250 V to 750 V, a voltage time of 20 μs to 2 ms, a pulse frequency of 35 Hz to 300 Hz, a pulse current of 10 A to 120 A, an electrolyte temperature of 318 K to 360 K and an average current density of 0.1 A cm -2 to 1 A cm -2 , whereby a matte, true to form, decorative white coating with a homogeneous thickness of 3 μm to 30 μm is formed.
Claim 3
Dependent Claim
34 words
The process according to claim 1 in which the aqueous electrolyte contains a transition metal ion in a concentration of 1% to 20% and in which a colored or black matte coating is created.
Claim 4
Dependent Claim
32 words
The process according to claim 1 in which variously colored coatings having homogeneous and heterogeneous color distributions are created by multiple electromechanical and plasma-chemical reactions using a different electrolyte for each reaction.
Claim 5
Dependent Claim
15 words
The process according to claim 1 in which the metal substrate is useful as jewelry.
Claim 6
Dependent Claim
13 words
The process according to claim 1 in which the metal substrate contains engraving.
Claim 7
Dependent Claim
18 words
The process according to claim 1 in which the substrate is an object with a large surface area.
Claim 8
Dependent Claim
14 words
A metal substrate having a decorative coating prepared by the method of claim 1.
Claim 9
Dependent Claim
17 words
A metal substrate useful as jewelry having a decorative coating prepared by the method of claim 1.
Claim 10
Dependent Claim
14 words
An engraved object having a decorative coating prepared by the method of claim 1.
References Cited (Backward Citations)
US4144142A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |