US3615897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Black films for metal surfaces
Assignee: Diversey Wyandotte Corp
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Filing: 1969-03-19
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Granted: 1971-10-26
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Expires: 1989-03-19
Abstract
Abstract A black, smutlike film, resistant to rub off, and uniform in appearance and thickness, is deposited on a metal surface by contacting the surface with an aqueous acidic solution containing bismuth, hydrogen, nitrate, and sulfate ions. The blackened surface is rendered corrosion resistant by further treatment with a phosphating solution to deposit a phosphate conversion coating thereon.
Inventors
- 👤 Russel S Banush
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:31
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/48; C23C22/50; C23C22/78; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12681
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
12 words
from about 0.015 to 2.50 percent by weight of a nitrate ion;
Claim 2
Dependent Claim
63 words
The bath of claim 1 wherein: a. said bismuth ion is present in a weight ratio to said hydrogen ion of from 13:1 to 3.25:1; b. said sulfate ion is present in a weight ratio to said bismuth ion of at least 10:1; and c. said nitrate ion is present in a weight ratio to said bismuth ion of from 1.5:1 to 2.5:1.
Claim 3
Dependent Claim
20 words
The bath of claim 1 and further including from about 0.001 to 1.0 percent by weigHt of a stannous ion.
Claim 4
Dependent Claim
12 words
from about 0.01 to 0.20 percent by weight of a hydrogen ion;
Claim 5
Dependent Claim
12 words
from about 0.25 to 8.00 percent by weight of a sulfate ion;
Claim 6
Independent Claim
33 words
A method for producing a blackened, corrosion-resistant ferrous metal surface comprising: a. contacting said surface at about 20* to 30* C. for about 0.25 to 10 minutes with an aqueous acidic bath comprising:
Claim 7
Dependent Claim
65 words
from about 99.715 to 89.30 percent by weight of water; and wherein the minimum sulfate ion to bismuth ion weight ratio is from 7.7:1 to 15.4:1, thereby depositing a black film on said surface; b. thereafter contacting said blackened surface with a zinc phosphating solution, thereby depositing a phosphate conversion coating thereon; and c. sealing said coated surface by contacting said surface with a sealant.
Claim 8
Dependent Claim
36 words
The method of claim 4 wherein prior to said sealant being applied, said surface is passivated by contacting said surface with an aqueous acidic solution selected from the group consisting of chromic acid and chromic-phosphoric acid.
Claim 9
Dependent Claim
15 words
A blackened, corrosion-resistant ferrous metal surface prepared in accordance with the method of claim 4.
Claim 10
Dependent Claim
15 words
A blackened, corrosion-resistant ferrous metal surface prepared in accordance with the method of claim 5.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |