US5178916A
Expired / Lapsed
US
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Process for making corrosion-resistant articles
Assignee: Nokia Bell Labs
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Filing: 1991-09-16
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Granted: 1993-01-12
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Expires: 2011-09-16
Abstract
Abstract Transition-metal-coated metallic elements, such as electrical contacts, are protected from corrosion by a novel surface treatment. In one embodiment, the treatment involves application of a phosphonate solution, optionally preceded by application of a chromatic solution phosphonate.
Inventors
- 👤 Christopher E. D. Chidsey
- 👤 Henry H. Law
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:57
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/02; H01H1/021; C; C10; C10M; C10M105/00; C10M105/74; C23; C23C; C23C22/00; C23C22/82; C23C22/83; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167; C23F11/1676; C10M2223/00; C10M2223/06; C10M2223/065; C10N; C10N2040/00; C10N2040/14; C10N2040/16; C10N2040/17; C10N2040/175; C10N2040/18; C10N2040/185
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
220 words
A method for manufacturing a first plurality of metal-coated articles, wherein: each of said articles has a chemically modified external surface and a contact resistance associated with the external surface; associated with the coatings is a resistance to corrosion defined as the expected fraction of articles exhibiting contact resistances below a predetermined threshold after being subjected to a predetermined aging process; the method comprises the steps of: a) providing a first plurality of metal workpieces, each workpiece comprising a metal substrate and, formed on the substrate, a metal coating which has an external surface, wherein the metal coating comprises a transition metal selected from the group consisting of nickel, cobalt, titanium, chromium, and iron; and b) exposing each of said coating external surfaces to a liquid solution of a chemical compound selected from the group consisting of those phosphonic acids, and the salts thereof, which include at least 6 carbon atoms, resulting in a chemically modified coating external surface; and the exposing step is carried out such that: i) each of said modified surfaces has a contact resistance of about 50 mΩ or less; and ii) the resistance of the first plurality of articles to corrosion is increased, as compared to a second plurality of articles nominally identical to the first plurality but not exposed to such a liquid solution.
Claim 2
Independent Claim
220 words
A method for manufacturing a first plurality of metal-coated articles, wherein: each of said articles has a chemically modified external surface and a contact resistance associated with the external surface; associated with the coatings is a resistance to corrosion defined as the expected fraction of articles exhibiting contact resistances below a predetermined threshold after being subjected to a predetermined aging process; the method comprises the steps of: a) providing a first plurality of metal workpieces, each workpiece comprising a metal substrate and, formed on the substrate, a metal coating which has an external surface, wherein the metal coating comprises a transition metal selected from the group consisting of nickel, cobalt, titanium, chromium, and iron; and b) exposing each of said coating external surfaces to a liquid solution of a chemical compound selected from the group consisting of those phosphonic acids, and the salts thereof, which include at least 6 carbon atoms, resulting in a chemically modified coating external surface; and the exposing step is carried out such that: i) each of said modified surfaces has a contact resistance of about 50 mΩ or less; and ii) the resistance of the first plurality of articles to corrosion is increased, as compared to a second plurality of articles nominally identical to the first plurality but not exposed to such a liquid solution.
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein the transition metal is nickel.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein the chemical compound is at least partially fluorinated.
Claim 5
Dependent Claim
17 words
The method of claim 1, wherein the molecular structure of the chemical compound includes multiple hydrocarbon chains.
Claim 6
Dependent Claim
20 words
The method of claim 1, wherein the molecular structure of the chemical compound includes at least 6 fluorinated carbon atoms.
Claim 7
Dependent Claim
30 words
The method of claim 1, wherein the chemical compound is a partially fluorinated alkyl phosphonic acid including at least about 6, but not more than about 14, perfluorinated carbon atoms.
Claim 8
Dependent Claim
29 words
The method of claim 6, wherein the phosphonic acid has the formula C 8 F 17 SO 2 N(CH 2 CH 3 )C 2 H 4 PO(OH) 2 .
Claim 9
Dependent Claim
25 words
The method of claim 6, wherein the phosphonic acid has the formula CF 3 (CF 2 ) 11 (CH 2 ) 2 PO(OH) 2 .
Claim 10
Dependent Claim
42 words
The method of claim 1, wherein each of said metal coatings further comprises a noble metal layer overlying the transition metal coating, and each said coating external surface is the surface of the corresponding noble metal layer distal the transition metal coating.
Claim 11
Dependent Claim
16 words
The method of claim 9, wherein each of said noble metal layers is a gold layer.
Claim 12
Dependent Claim
16 words
The method of claim 10, wherein each gold layer is less than about 0.6 μm thick.
Claim 13
Dependent Claim
17 words
The method of claim 10, wherein each gold layer is no more than about 0.1 μm thick.
Claim 14
Dependent Claim
33 words
The method of claim 1, further comprising, before the chemical-compound-exposing step, the step of exposing each said coating external surface to a chromate solution such that the resistance to corrosion is further increased.
Claim 15
Independent Claim
221 words
A method for manufacturing a first plurality of metal-coated articles, wherein: each of said articles has a chemically modified external surface and a contact resistance associated with the external surface; associated with the coatings is a resistance to corrosion defined as the expected fraction of articles exhibiting contact resistances below a predetermined threshold after being subjected to a predetermined aging process; the method comprises the steps of: a) providing a first plurality of metal workpieces, each workpiece comprising a metal substrate and, formed on the substrate, a metal coating which has an external surface, wherein the metal coating comprises nickel or a nickel alloy; b) exposing each of said coating external surfaces to a chromate solution; and c) then exposing each of said coating external surfaces to a liquid solution of a partially fluorinated alkyl phosphonic acid which includes at least about 6, but not more than about 14, perfluorinated carbon atoms, resulting in a chemically modified coating external surface; and the exposing steps are carried out such that: i) each of said modified surfaces has a contact resistance of about 50 mΩ or less; and ii) the resistance of the first plurality of articles to corrosion is increased, as compared to a second plurality of articles nominally identical to the first plurality but not exposed to such a liquid solution.
Claim 16
Independent Claim
221 words
A method for manufacturing a first plurality of metal-coated articles, wherein: each of said articles has a chemically modified external surface and a contact resistance associated with the external surface; associated with the coatings is a resistance to corrosion defined as the expected fraction of articles exhibiting contact resistances below a predetermined threshold after being subjected to a predetermined aging process; the method comprises the steps of: a) providing a first plurality of metal workpieces, each workpiece comprising a metal substrate and, formed on the substrate, a metal coating which has an external surface, wherein the metal coating comprises nickel or a nickel alloy; b) exposing each of said coating external surfaces to a chromate solution; and c) then exposing each of said coating external surfaces to a liquid solution of a partially fluorinated alkyl phosphonic acid which includes at least about 6, but not more than about 14, perfluorinated carbon atoms, resulting in a chemically modified coating external surface; and the exposing steps are carried out such that: i) each of said modified surfaces has a contact resistance of about 50 mΩ or less; and ii) the resistance of the first plurality of articles to corrosion is increased, as compared to a second plurality of articles nominally identical to the first plurality but not exposed to such a liquid solution.
Claim 17
Independent Claim
235 words
A method for manufacturing a first plurality of metal-coated articles, wherein: each of said articles has a chemically modified external surface and a contact resistance associated with the external surface; associated with the coatings is a resistance to corrosion defined as the expected fraction of articles exhibiting contact resistances below a predetermined threshold after being subjected to a predetermined aging process; the method comprises the steps of: a) providing a first plurality of metal workpieces, each workpiece comprising a metal substrate and, formed on the substrate, a metal coating which has an external surface, wherein the metal coating comprises a transition metal selected from the group consisting of nickel, cobalt, titanium, chromium, and iron; and b) exposing each of said coating external surfaces to a liquid solution of a monoester of phosphoric acid or of a salt of such monoester, resulting in a chemically modified coating external surface; the monoester belongs to the group which consists of the phosphatidic acids having the general formula ##STR2## wherein n is an integer in the range 10-16; and the exposing step is carried out such that: i) each of said modified surfaces has a contact resistance of about 50 mΩ or less; and ii) the resistance of the first plurality of articles to corrosion is increased, as compared to a second plurality of articles nominally identical to the first plurality but not exposed to such a liquid solution.
Claim 18
Independent Claim
235 words
A method for manufacturing a first plurality of metal-coated articles, wherein: each of said articles has a chemically modified external surface and a contact resistance associated with the external surface; associated with the coatings is a resistance to corrosion defined as the expected fraction of articles exhibiting contact resistances below a predetermined threshold after being subjected to a predetermined aging process; the method comprises the steps of: a) providing a first plurality of metal workpieces, each workpiece comprising a metal substrate and, formed on the substrate, a metal coating which has an external surface, wherein the metal coating comprises a transition metal selected from the group consisting of nickel, cobalt, titanium, chromium, and iron; and b) exposing each of said coating external surfaces to a liquid solution of a monoester of phosphoric acid or of a salt of such monoester, resulting in a chemically modified coating external surface; the monoester belongs to the group which consists of the phosphatidic acids having the general formula ##STR2## wherein n is an integer in the range 10-16; and the exposing step is carried out such that: i) each of said modified surfaces has a contact resistance of about 50 mΩ or less; and ii) the resistance of the first plurality of articles to corrosion is increased, as compared to a second plurality of articles nominally identical to the first plurality but not exposed to such a liquid solution.
Claim 19
Dependent Claim
31 words
The method of claim 15, further comprising, before the monoester-exposing step, the step of exposing each said surface to a chromate solution such that the resistance to corrosion is further increased.
Claim 20
Independent Claim
60 words
A method for lubricating a surface of a body which comprises a transition metal, transition metal alloy, or aluminum-containing alloy, the method comprising the step of applying to the surface a liquid solution which comprises a chemical compound having the formula CF.sub.3 (CF.sub.2).sub.m (CH.sub.2).sub.n PO(OH).sub.2, wherein m equals 5, 7, 9, or 11, and n equals 0, 1, or 2.
Claim 21
Independent Claim
60 words
A method for lubricating a surface of a body which comprises a transition metal, transition metal alloy, or aluminum-containing alloy, the method comprising the step of applying to the surface a liquid solution which comprises a chemical compound having the formula CF.sub.3 (CF.sub.2).sub.m (CH.sub.2).sub.n PO(OH).sub.2, wherein m equals 5, 7, 9, or 11, and n equals 0, 1, or 2.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-01-12 | 1996-07-13 | 1997-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-01-12 | 2000-07-13 | 2001-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-01-12 | 2004-07-13 | 2005-01-12 | $7700.00 | Window Closed / Lapsed |