Patent US2044063A successfully refreshed from Google Patents.
US4657599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for improving corrosion resistance of zinc or cadmium plated metal articles
Assignee: Torcad Ltd
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Filing: 1985-10-21
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Granted: 1987-04-14
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Expires: 2005-10-21
Abstract
Abstract A process for improving corrosion resistance of a metal article plated with zinc or cadmium includes coating the plated article with a chromium solution to provide the article with a chromate coating having a yellow to olive-drab colour, and immersing the chromated article in a silicate solution for a sufficient time to cause the article to assume an acceptable white or grey colour and also increase its corrosion resistance.
Inventors
- 👤 James A. Sutherland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:05
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/82; C23C22/83
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
A process for improving corrosion resistance of a metal article plated with zinc or cadmium, comprising coating the plated articles with a chromium solution to provide the article with a chromate coating having a yellow to olive-drab colour, and contacting the chromate coating witha silicate solution and maintaining said contact for a sufficient time to cause the colour of the coating to be leached back to an acceptable white to grey colour and also increase the corrosion resistance of the article.
Claim 2
Dependent Claim
81 words
A process for improving corrosion resistance of a metal article plated with zinc or cadmium, comprising coating the plated articles with a chromium solution to provide the article with a chromate coating having a yellow to olive-drab colour, and contacting the chromate coating witha silicate solution and maintaining said contact for a sufficient time to cause the colour of the coating to be leached back to an acceptable white to grey colour and also increase the corrosion resistance of the article.
Claim 3
Dependent Claim
16 words
A process according to claim 1 wherein the silicate solution is an alkali metal silicate solution.
Claim 4
Dependent Claim
27 words
A process according to claim 2 wherein the silicate solution is a sodium silicate solution with a concentration of from about 1 to about 50% by volume.
Claim 5
Dependent Claim
23 words
A process according to claim 1 wherein the silicate solution has a temperature of from about ambient to about 200° F. (95° C.).
Claim 6
Dependent Claim
83 words
A process for improving corrosion resistance of a metal article plated with zinc or cadmium, and with the zinc or cadmium plating being coated with a chromate coating providing the article with a yellow to olive-drab colour, the process comprising contacting the chromate coating with a silicate solution and maintaining said contact for a sufficient time to cause the colour of the coating to be leached back to an acceptable while to grey colour and also increase the corrosion resistance of the article.
Claim 7
Dependent Claim
83 words
A process for improving corrosion resistance of a metal article plated with zinc or cadmium, and with the zinc or cadmium plating being coated with a chromate coating providing the article with a yellow to olive-drab colour, the process comprising contacting the chromate coating with a silicate solution and maintaining said contact for a sufficient time to cause the colour of the coating to be leached back to an acceptable while to grey colour and also increase the corrosion resistance of the article.
Claim 8
Dependent Claim
16 words
A process according to claim 5 wherein the silicate solution is an alkali metal silicate solution.
Claim 9
Dependent Claim
27 words
A process according to claim 6 wherein the silicate solution is a sodium silicate solution with a concentration of from about 1 to about 50% by volume.
Claim 10
Dependent Claim
23 words
A process according to claim 5 wherein the silicate solution has a temperature of from about ambient to about 200° F. (95° C.).
References Cited (Backward Citations)
US4462842A
Cited
US4487815A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |