Patent US3720547A successfully refreshed from Google Patents.
US3720547A
Expired / Lapsed
US
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Permanganate final rinse for metal coatings
Assignee: Stauffer Chemical Co
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Filing: 1971-02-16
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Granted: 1973-03-13
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Expires: 1991-02-16
Abstract
Abstract A final rinse for conversion coated metal surfaces comprising an aqueous acidic solution of permanganate ions having a normality in the range from about 0.0001 to about 2.0 N is disclosed. The rinse of the present invention not only yields coatings having superior corrosion resistance but is also easily disposable without harmful effects on the environment.
Inventors
- 👤 D Melotik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:06
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/82; C23C22/83
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
79 words
A process for increasing the corrosion resistance of a conversion coated metal surfaces which comprises rinsing a surface which has been coated with a conversion coating selected from the group consisting of phosphates, mixed phosphate-oxides, chromates, oxalates and arsenates, with an aqueous acidic non-chromium solution of permanganate ions, said solution having a normality in the range from about 0.0001 to about 2.0 N an a pH adjusted to a value in the range from about 2 to about 6.
Claim 2
Dependent Claim
79 words
A process for increasing the corrosion resistance of a conversion coated metal surfaces which comprises rinsing a surface which has been coated with a conversion coating selected from the group consisting of phosphates, mixed phosphate-oxides, chromates, oxalates and arsenates, with an aqueous acidic non-chromium solution of permanganate ions, said solution having a normality in the range from about 0.0001 to about 2.0 N an a pH adjusted to a value in the range from about 2 to about 6.
Claim 3
Dependent Claim
14 words
The process of claim 1, wherein said permanganate ions are derived from potassium permanganate.
Claim 4
Dependent Claim
34 words
The process of claim 1, wherein said aqueous acid solution has normality in the range from about 0.00021 to about 0.00042 N and a pH in the range from about 3.0 to about 4.0.
Claim 5
Dependent Claim
13 words
The process of claim 1, wherein the pH is adjusted with phosphoric acid.
Claim 6
Dependent Claim
93 words
A process for treating metal surfaces to render them corrosion resistant which comprises: a. cleaning said metal surface; b. forming a conversion coating on said cleaned metal surface, said coating being selected from the group consisting of phosphates, mixed phosphate-oxides, oxalate, arsenate and chromate; and c. rinsing said conversion coated metal surface with an aqueous acidic non-chromium solution of permanganate ions having a normality in the range from about 0.0001 to about 2.0 N and a pH adjusted to the range from about 2.0 to about 6.0 by the addition of phosphoric acid.
Claim 7
Dependent Claim
93 words
A process for treating metal surfaces to render them corrosion resistant which comprises: a. cleaning said metal surface; b. forming a conversion coating on said cleaned metal surface, said coating being selected from the group consisting of phosphates, mixed phosphate-oxides, oxalate, arsenate and chromate; and c. rinsing said conversion coated metal surface with an aqueous acidic non-chromium solution of permanganate ions having a normality in the range from about 0.0001 to about 2.0 N and a pH adjusted to the range from about 2.0 to about 6.0 by the addition of phosphoric acid.
Claim 8
Dependent Claim
33 words
The process of claim 5 wherein said conversion coating formed on the metal surface is a phosphate coating selected from the group consisting of zinc phosphate, calcium-zinc phosphate, iron phosphate and manganese phosphate.
Claim 9
Dependent Claim
19 words
The process of claim 5 wherein said conversion coating formed on the metal surface is a zinc phosphate coating.
Claim 10
Dependent Claim
27 words
The process of claim 5 containing the additional step of water rinsing said conversion coated metal surface prior to rinsing said surface with said permanganate ion solution.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |