US3901773A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making microcrack chromium coatings
Assignee: Langbein Pfanhauser Werke AG
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Filing: 1973-07-30
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Granted: 1975-08-26
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Expires: 1993-07-30
Abstract
Abstract A method of forming microcrack chromium coatings in which an intervening or intermediate coating of nickel, cobalt, nickeliron, nickel-cobalt or iron-cobalt is applied to a substrate and the chromium coating is electrodeposited thereon. The intermediate coating is applied from a bath containing the metal or metals and a pyridine derivative, especially a nicotinic or isonicotinic compound.
Inventors
- 👤 Ralf Ludwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:17
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/12; C25D3/14; C25D3/18; C25D5/00; C25D5/10; C25D5/12; C25D5/60; C25D5/625
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
131 words
A METHOD OF COATING A METAL SUBSTRATE WITH MICROCRACK CHROMIUM, COMPRISING APPLYING A FIRST METALLIC LAWYER OT SAID SUBSTRATE BY ELECTROPLATING NICKEL, COBALT OR A COMBINATION OF EITHER WITH THE OTHER OR WITH IRON ONTO SAID SUBSTRATE FROM AN AQUEOUS ACIDIC ELECTROPLATING BATH CONTAINING THE RESPECTIVE METAL IONS, AMMONIUM ION AND CHLORIDE ION TOGETHER WITH A MICROCRACK-INCREASING QUANTITY OF AT LEAST ONE PYRIDINE DERIVATIVE AND THEREAFTER ELECTRODEPOSITING A CHROMIUM LAYER UPON SAID FIRST LAYER TO PRODUCE A MICROCRACK COATING, SAID PYRIDINE DERIVATIVE BEING SELECTED FROM THE GROUP WHICH CONSISTS OF NICOTINIC ACID AND ISONICOTINIC ACID, ISONICOTINIC ACID HYDRAZIDE, PYDIDINE-3-CARBINOL, PYRIDINE-4-ALDEHYDE, L-NICOTINE, 1-(3-PYRIDYL)-2-(4-PYRIDYL)-ETHYLENE, 4-PYRIDYLACRYLIC ACID AND PYRIDINE-3-ALDOXIME AND BEING PRESENT IN SAID BATH IN A CONCENTRATION BETWEEN 0.1 AND 5 G/1, SAID BATH FURTHER CONTAINING 20 TO 60 G/LITER OF PHTHALIC ACID.
Claim 2
Independent Claim
131 words
A METHOD OF COATING A METAL SUBSTRATE WITH MICROCRACK CHROMIUM, COMPRISING APPLYING A FIRST METALLIC LAWYER OT SAID SUBSTRATE BY ELECTROPLATING NICKEL, COBALT OR A COMBINATION OF EITHER WITH THE OTHER OR WITH IRON ONTO SAID SUBSTRATE FROM AN AQUEOUS ACIDIC ELECTROPLATING BATH CONTAINING THE RESPECTIVE METAL IONS, AMMONIUM ION AND CHLORIDE ION TOGETHER WITH A MICROCRACK-INCREASING QUANTITY OF AT LEAST ONE PYRIDINE DERIVATIVE AND THEREAFTER ELECTRODEPOSITING A CHROMIUM LAYER UPON SAID FIRST LAYER TO PRODUCE A MICROCRACK COATING, SAID PYRIDINE DERIVATIVE BEING SELECTED FROM THE GROUP WHICH CONSISTS OF NICOTINIC ACID AND ISONICOTINIC ACID, ISONICOTINIC ACID HYDRAZIDE, PYDIDINE-3-CARBINOL, PYRIDINE-4-ALDEHYDE, L-NICOTINE, 1-(3-PYRIDYL)-2-(4-PYRIDYL)-ETHYLENE, 4-PYRIDYLACRYLIC ACID AND PYRIDINE-3-ALDOXIME AND BEING PRESENT IN SAID BATH IN A CONCENTRATION BETWEEN 0.1 AND 5 G/1, SAID BATH FURTHER CONTAINING 20 TO 60 G/LITER OF PHTHALIC ACID.
Claim 3
Dependent Claim
50 words
The method defined in claim 1 wherein said first layer is electroplated onto said substrate at a current density of up to 30 A/dm2 for a period of 10 seconds to 10 minutes and said bath has a temperature between 20* and 70*C and a pH of 1 to 6.
Claim 4
Dependent Claim
37 words
The method defined in claim 2 wherein said pH is substantially 3 to 4, said current density is substantially 5 to 15 A/dm2, said temperature is 40* to 45*C and said period is 1 to 3 minutes.
Claim 5
Dependent Claim
17 words
The method defined in claim 3 wherein said bath contains 100 to 400 g/l of nickel chloride.
Claim 6
Dependent Claim
17 words
The method defined in claim 4 wherein said bath contains 10 to 200 g/l of ammonium chloride.
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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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |