US3615882A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a mirror
Assignee: AGC Inc
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Filing: 1968-12-23
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Granted: 1971-10-26
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Expires: 1988-12-23
Abstract
Abstract A mirror is made by depositing silver on a glass plate by chemical reduction of silver nitrate, covering the silver film with a protective copper layer deposited from a copper sulfate solution by means of a finely divided less noble metal, and by passivating the copper coating by contact with a solution of chromic acid, a chromate, or a dichromate.
Inventors
- 👤 Kentaro Nagano
- 👤 Koji Nomaki
- 👤 Yoshihito Saoyama
- 👤 Takashi Azeyanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:58
CPC Classifications
C; C03; C03C; C03C17/00; C03C17/34; C03C17/36; C03C17/40
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
38 words
In a method as set forth in claim 1, said exposed surface being contacted with said aqueous solution after the coating of said silver film with said protective layer without intermediate rinsing of the exposed surface with water.
Claim 2
Dependent Claim
28 words
In a method as set forth in claim 2, said exposed surface being contacted with said aqueous solution while still carrying an amount of said copper sulfate solution.
Claim 3
Dependent Claim
28 words
In a method as set forth in claim 3, said aqueous solution containing an amount of chromium equivalent to not more than 20 grams per liter chromium trioxide.
Claim 4
Dependent Claim
26 words
In a method as set forth in claim 4, said aqueous solution being substantially free from acid having a strength similar to that of sulfuric acid.
Claim 5
Dependent Claim
30 words
In a method as set forth in claim 4, said aqueous solution being a solution of an alkali metal salt or of an ammonium salt of chromic or dichromic acid.
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 |