US4595609A
Expired / Lapsed
US
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Corrosion resistant tantalum pentaoxide coatings
Assignee: University of Minnesota System
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Filing: 1984-11-21
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Granted: 1986-06-17
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Expires: 2004-11-21
Abstract
Abstract Substrates having free surface hydroxyl groups, such as silaceous and aluminous materials, are rendered corrosion resistant by the application thereto of an amorphous, homogeneous tantalum pentaoxide coating layer.
Inventors
- 👤 Stephen T. Wellinghoff
- 👤 Ching Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:59
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/02; C23C18/12; C23C18/1204; C23C18/1208; C23C18/1216; C23C18/1229; C23C18/1233; C23C18/1241
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
59 words
A method of imparting corrosion resistance to a substrate having free surface hydroxyl groups; said method comprising: (a) coating said surface coextensively with a partially-hydrolyzed solution of Ta[(lower)alkoxide] 5 in an organic solvent; (b) evaporating said solvent to yield a tantalum oxide-ethoxide film; and (c) curing said film to yield a uniform, amorphous tantalum pentaoxide layer on said surface.
Claim 2
Independent Claim
59 words
A method of imparting corrosion resistance to a substrate having free surface hydroxyl groups; said method comprising: (a) coating said surface coextensively with a partially-hydrolyzed solution of Ta[(lower)alkoxide] 5 in an organic solvent; (b) evaporating said solvent to yield a tantalum oxide-ethoxide film; and (c) curing said film to yield a uniform, amorphous tantalum pentaoxide layer on said surface.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein said substrate surface comprises Al--OH groups or Si--OH groups.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein said substrate surface comprises aluminum.
Claim 5
Dependent Claim
12 words
The method of claim 2 wherein said substrate surface comprises a polyimide.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein said Ta[(lower)alkoxide] 5 comprises Ta(OEt) 5 and said organic solvent comprises ethanol.
Claim 7
Dependent Claim
15 words
The method of claim 5 wherein said solution comprises about 0.1-1 vol-% Ta(OEt) 5 .
Claim 8
Dependent Claim
31 words
The method of claim 5 wherein the Ta(OEt) 5 has been partially hydrolyzed by the addition to said solution of about 0.75-5 moles of water per mole of Ta(OEt) 5 .
Claim 9
Dependent Claim
21 words
The method of claim 1 wherein said film is cured by exposure of the film to water vapor and ambient temperatures.
Claim 10
Dependent Claim
17 words
The method of claim 1 wherein said tantalum pentaoxide layer is at least about 150 Å thick.
Claim 11
Independent Claim
84 words
A method of imparting corrosion resistance to a substrate incorporating an aluminum surface comprising: (a) preparing a solution of about 0.25-0.75 vol-% Ta(OEt) 5 and water in absolute ethanol, wherein mole ratio of water:Ta(OEt) 5 is about 0.75-5; (b) coating said surface coextensively with said soution; (c) evaporating said ethanol from said solution coating to yield a prepolymer film; and (d) curing said prepolymer film in the presence of moisture to yield an amorphous, homogeneous Ta 2 O 5 layer on said aluminum surface.
Claim 12
Independent Claim
84 words
A method of imparting corrosion resistance to a substrate incorporating an aluminum surface comprising: (a) preparing a solution of about 0.25-0.75 vol-% Ta(OEt) 5 and water in absolute ethanol, wherein mole ratio of water:Ta(OEt) 5 is about 0.75-5; (b) coating said surface coextensively with said soution; (c) evaporating said ethanol from said solution coating to yield a prepolymer film; and (d) curing said prepolymer film in the presence of moisture to yield an amorphous, homogeneous Ta 2 O 5 layer on said aluminum surface.
Claim 13
Dependent Claim
17 words
The method of claim 10 wherein said Ta 2 O 5 layer is about 150-400 Å thick.
Claim 14
Dependent Claim
19 words
The method of claim 11 wherein an organic barrier coating is applied to said Ta 2 O 5 layer.
Claim 15
Dependent Claim
22 words
The method of claim 10 wherein said prepolymer film is cured by exposure of said prepolymer film to ambient temperatures and humidities.
References Cited (Backward Citations)
No citation records indexed.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |