US4401690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermochromic vanadium oxide with depressed switching temperature
Assignee: PPG Industries Inc
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Filing: 1982-02-01
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Granted: 1983-08-30
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Expires: 2002-02-01
Abstract
Abstract A method is disclosed for producing a thermochromic window comprising a glass substrate and a coating containing VO 2 with a depressed switching temperature by doping the VO 2 film with a compound of a metal having an ionic radius larger than that of vanadium, such as tungsten, niobium, tantalum, iridium or molybdenum.
Inventors
- 👤 Charles B. Greenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:18
CPC Classifications
C; C03; C03C; C03C17/00; C03C17/22; C03C17/23; C03C17/27; C03C17/245; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/218; C03C2217/24; C03C2218/00; C03C2218/10; C03C2218/11; C03C2218/111; C03C2218/15; C03C2218/151; C03C2218/152; C03C2218/30; C03C2218/32; C03C2218/322
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
61 words
In a method for making a thermochromic window comprising the steps of contacting a surface of a glass substrate with a vanadium compound and heating the glass substrate to a sufficient temperature to obtain a vanadium oxide film comprising VO 2 , the improvement which comprises doping said film with a compound which depresses the switching temperature of VO 2 .
Claim 2
Dependent Claim
61 words
In a method for making a thermochromic window comprising the steps of contacting a surface of a glass substrate with a vanadium compound and heating the glass substrate to a sufficient temperature to obtain a vanadium oxide film comprising VO 2 , the improvement which comprises doping said film with a compound which depresses the switching temperature of VO 2 .
Claim 3
Dependent Claim
28 words
The method according to claim 1, wherein the dopant is a compound of a metal, the ionic radius of which is larger than the ionic radius of vanadium.
Claim 4
Dependent Claim
28 words
The method according to claim 2, wherein the compound which depresses the switching temperature of VO 2 is selected from compounds of niobium, tantalum, molybdenum, iridium and tungsten.
Claim 5
Dependent Claim
28 words
The method according to claim 1, wherein the vanadium compound is selected from the group consisting of vanadium n-propylate, vanadium ethylate, vanadium butylate, vanadium oxychloride and mixtures thereof.
Claim 6
Dependent Claim
41 words
The method according to claim 4, wherein the glass is contacted at ambient temperature with a composition comprising vanadium i-propylate and tungsten oxychloride to form a film which is subsequently heated to obtain a tungsten-doped thermochromic film comprising VO 2 .
References Cited (Backward Citations)
US3483110A
Cited
US4307942A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |