US3920864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transparent metal film having a brown-gray appearance
Assignee: Individual
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Filing: 1973-07-30
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Granted: 1975-11-18
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Expires: 1993-07-30
Abstract
Abstract Transparent articles, each having a low-reflectance, brown-gray appearance, are produced by first applying a copper film to glass, then partially replacing the copper with silver and then briefly exposing the film to an oxidizing environment. A coppercoated glass article having a pink appearance is contacted with a silver salt, such as silver nitrate, in aqueous solution together with an alkaline buffer, such as ammonia, and an alkali metal thiosulfate, such as sodium thiosulfate. The coated glass article is then exposed to moist air, and the pink-appearing copper film is converted to a low-reflectance, brown-gray film.
Inventors
- 👤 Charles B Greenberg
- 👤 Peter P Harmon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:05
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/1851; C23C18/1855; B; B44; B44F; B44F1/00; B44F1/02; B44F1/04; C03; C03C; C03C17/00; C03C17/06; C03C17/10; C03C17/22; C03C17/23; C03C17/27; C23C18/1872; C23C18/1886; C23C18/1889; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/23; C03C2217/25; C03C2217/251; C03C2217/27; C03C2218/00; C03C2218/10; C03C2218/11; C03C2218/30; C03C2218/32; C03C2218/322
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
84 words
A METHOD OF PREPARING A COATED, TRANSPARENT ARTICLE COMPRISING THE STEPS OF: A. APPLYING A COPPER FILM TO A SURFACE OF A TRANSPARENT SUBSTRATE, B. CONTACTING SAID COPPER FILM WITH A SOLUTION CONTAINING A SILVER SALT IN THE PRESENCE OF A THIOSULFATE, AND C. MAINTAINING SAID FILM IN THE PRESENCE OF A THIOSULFATE, AND FOR A SUFFICIENT TIME FILM SAID FILM TO DEVELOP A SUBSTANTIALLY STABLE LUMINUS REFLECTANCE DIFFERENT FROM ITS LUMINOUS REFLECTANCE PRIOR TO ITS MAINTENCE IN THE PRESENCE OF OXYGEN AN WATER.
Claim 2
Independent Claim
84 words
A METHOD OF PREPARING A COATED, TRANSPARENT ARTICLE COMPRISING THE STEPS OF: A. APPLYING A COPPER FILM TO A SURFACE OF A TRANSPARENT SUBSTRATE, B. CONTACTING SAID COPPER FILM WITH A SOLUTION CONTAINING A SILVER SALT IN THE PRESENCE OF A THIOSULFATE, AND C. MAINTAINING SAID FILM IN THE PRESENCE OF A THIOSULFATE, AND FOR A SUFFICIENT TIME FILM SAID FILM TO DEVELOP A SUBSTANTIALLY STABLE LUMINUS REFLECTANCE DIFFERENT FROM ITS LUMINOUS REFLECTANCE PRIOR TO ITS MAINTENCE IN THE PRESENCE OF OXYGEN AN WATER.
Claim 3
Dependent Claim
76 words
The method according to claim 1, wherein said step of applying a copper film is accomplished by electrolessly depositing copper onto a surface of said article, wherein said copper film contacting step is accomplished with an aqueous, alkaline solution comprising water, a silver salt and an alkali metal or ammonium thiosulfate, and wherein in said step of maintaining said film in the presence of oxygen and water it is maintained in the presence of moist air.
Claim 4
Dependent Claim
32 words
The method according to claim 2 wherein said electroless deposition of copper is preceded by the step of applying a film of silver to the surface of said article to be coated.
Claim 5
Dependent Claim
105 words
The method according to claim 1 wherein said step of contacting said copper film is accomplished by contacting said copper film with an aqueous solution consisting essentially of: a. water; b. silver nitrate in an amount of from about 0.5 grams per liter to about 1.5 grams per liter; c. ammonia on a 28 percent basis in an amount of from about 0.5 cc per liter to about 1.5 cc per liter; and d. sodium thiosulfate in an amount of from about 1.0 grams per liter to about 3.0 grams per liter for a contacting time of from about 30 seconds to about 120 seconds.
Claim 6
Dependent Claim
64 words
The method according to claim 1, wherein the step of maintaining said film in the presence of oxygen and water is accomplished by directing a stream of water containing air against said film, said stream of air having a temperature within the range of from 60*F. to about 150*F. and a relative humidity within the range of from about 35 to about 90 percent.
Claim 7
Independent Claim
103 words
A METHOD OF PREPARING A COATED, TRANSPARENT GLASS SUBSTRATE HAVING A BROWN-GRAY APPEARANCE WHEN VIEWED TOWARD ITS UNCOATED SURFACE COMPRISING THE STEPS OF: A. APPLYING A COPPER FILM TO A SURFACE OF A CLEAR GLASS SUBSTRATE, B. CONTACTING SAID FILM WITH AN AQUEOUS ALKALINE SOLUTION COMPRISING WATER AND A SILVER SALT IN THE PRESENCE OF A THIOSULFATE, AND C. MAINTAINING SAID FILM IN THE PRESENCE OF OXYGEN AND WATER FOR A SUFFICIENT TIME FOR SAID FILM TO DEVELOP A BROWN-GRAY APPEARANCE AS VIEWED THROUGH SAID CLEAR GLASS SUBSTRATE AND TO DEVELOP A STABLE LUMINOUS REFLECTANCE WHEN SO VIEWED THROUGH SAID CLEAR GLASS SUBSTRATE.
Claim 8
Independent Claim
103 words
A METHOD OF PREPARING A COATED, TRANSPARENT GLASS SUBSTRATE HAVING A BROWN-GRAY APPEARANCE WHEN VIEWED TOWARD ITS UNCOATED SURFACE COMPRISING THE STEPS OF: A. APPLYING A COPPER FILM TO A SURFACE OF A CLEAR GLASS SUBSTRATE, B. CONTACTING SAID FILM WITH AN AQUEOUS ALKALINE SOLUTION COMPRISING WATER AND A SILVER SALT IN THE PRESENCE OF A THIOSULFATE, AND C. MAINTAINING SAID FILM IN THE PRESENCE OF OXYGEN AND WATER FOR A SUFFICIENT TIME FOR SAID FILM TO DEVELOP A BROWN-GRAY APPEARANCE AS VIEWED THROUGH SAID CLEAR GLASS SUBSTRATE AND TO DEVELOP A STABLE LUMINOUS REFLECTANCE WHEN SO VIEWED THROUGH SAID CLEAR GLASS SUBSTRATE.
Claim 9
Dependent Claim
12 words
A coated, transparent article prepared according to the method of claim 6.
Claim 10
Dependent Claim
144 words
The coated, transparent article according to claim 7 wherein said article comprises a clear glass substrate having a film thereon, said article having the following characteristics: a. luminous transmittance from 10 percent to 30 percent; b. dominant transmittance wavelength from 480 nanometers to 500 nanometers; c. excitation purity for transmitted light from 3 percent to 10 percent; d. luminous reflectance from the film from 30 percent to 50 percent; e. dominant reflected wavelength from the film from 500 nanometers to 620 nanometers; f. excitation purity for light reflected from the film from 0.1 percent to 10 percent; g. luminous reflectance from film side through substrate from 10 percent to 20 percent; h. dominant reflected wavelenGth from film side through substrate from 575 nanometers to 620 nanometers; and i. excitation purity for light reflected from film side through substrate from 5 percent to 25 percent.
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) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |