US4308079A
Expired / Lapsed
US
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Durability of adhesively bonded aluminum structures and method for inhibiting the conversion of aluminum oxide to aluminum hydroxide
Assignee: Lockheed Martin Corp
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Filing: 1980-06-16
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Granted: 1981-12-29
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Expires: 2000-06-16
Abstract
Abstract It has been found that hydration of aluminum oxide surface coatings to aluminum hydroxide may be curtailed by the presence of corrosion inhibiting amounts of amino phosphonate compounds. Effective inhibitors, such as nitrilotris (methylene) triphosphonic acid, may be applied to aluminum substrates having aluminum oxide surfaces thereupon in concentrations of less than 50% by weight in aqueous solution, and suitably from 1 to about 500 ppm.
Inventors
- 👤 John D. Venables
- 👤 Maher E. Tadros
- 👤 Brian M. Ditchek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:04
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/68; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167; C23F11/1676; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/24; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31515
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
37 words
A method for improving the bond durability of an adhesively bonded aluminum substrate which comprises treating the surface of said aluminum substrate with an aqueous solution of an amino phosphonate compound having a plurality of phosphorous atoms.
Claim 2
Independent Claim
37 words
A method for improving the bond durability of an adhesively bonded aluminum substrate which comprises treating the surface of said aluminum substrate with an aqueous solution of an amino phosphonate compound having a plurality of phosphorous atoms.
Claim 3
Dependent Claim
17 words
A method as set forth in claim 1, wherein said aluminum substrate is covered with aluminum oxide.
Claim 4
Dependent Claim
72 words
A method as set forth in claim 2, wherein said phosphonate compound is selected from the group consisting of NR 3 , NHR 2 , R'NR 2 , (CH 2 NR 2 ) 2 , and R 2 NCH 2 CH 2 NRCH 2 CH 2 NR 2 , wherein R is CH 2 PO(OH) 2 , and R' is a straight chain alkyl group having from 1 to 5 carbon atoms.
Claim 5
Dependent Claim
18 words
A method as set forth in claim 3, wherein said phosphonate compound is applied by spraying or dipping.
Claim 6
Dependent Claim
18 words
A method as set forth in claim 4, wherein the concentration of said compound is less than 50%.
Claim 7
Dependent Claim
22 words
A method as set forth in claim 5, wherein the concentration of said compound is from about 1 to about 500 ppm.
Claim 8
Dependent Claim
24 words
A method as set forth in claim 5, wherein said compound is present in a concentration of from about 10 to about 300 ppm.
Claim 9
Dependent Claim
20 words
A method as set forth in claim 7, wherein said compound is present in a concentration of about 150 ppm.
Claim 10
Dependent Claim
16 words
A method as set forth in claim 2, wherein said phosphonate is nitrilotris (methylene) triphosphonic acid.
Claim 11
Dependent Claim
20 words
A method as set forth in claim 9, wherein said phosphonate is present in a concentration of less than 50%.
Claim 12
Dependent Claim
24 words
A method as set forth in claim 10, wherein said phosphonate is present in a concentration of from about 1 to about 500 ppm.
Claim 13
Dependent Claim
24 words
A method as set forth in claim 11, wherein said phosphonate is present in a concentration of from about 10 to about 300 ppm.
Claim 14
Dependent Claim
20 words
A method as set forth in claim 12, wherein said phosphonate is present in a concentration of about 150 ppm.
Claim 15
Dependent Claim
21 words
A method as set forth in claim 10, wherein the temperature is maintained at less than 80° C. during said treatment.
Claim 16
Independent Claim
37 words
A method for preparing aluminum surfaces for adhesive bonding, said method comprising providing a micro porous aluminum oxide surface, treating said aluminum oxide surface with an amino phosphonate compound having a plurality of phosphorous atoms, and drying.
Claim 17
Independent Claim
37 words
A method for preparing aluminum surfaces for adhesive bonding, said method comprising providing a micro porous aluminum oxide surface, treating said aluminum oxide surface with an amino phosphonate compound having a plurality of phosphorous atoms, and drying.
Claim 18
Dependent Claim
34 words
A method as set forth in claim 15, wherein said micro porous aluminum oxide surface is provided by a process selected from the group consisting of Forest Product Laboratory and phosphoric acid anodization processes.
Claim 19
Dependent Claim
73 words
A method as set forth in claim 15, wherein said amino phosphonate compound is selected from the group consisting of NR 3 , NHR 2 , R'NR 2 , (CH 2 NR 2 ) 2 , and R 2 NCH 2 CH 2 NRCH 2 CH 2 NR 2 , wherein R is CH 2 PO(OH) 2 , and R' is a straight chain alkyl group having from 1 to 5 carbon atoms.
Claim 20
Dependent Claim
22 words
A method as set forth in claim 17, wherein said amino phosphonate compound is applied by dipping or spraying in aqueous solution.
Claim 21
Dependent Claim
20 words
A method as set forth in claim 18, wherein said compound is present in a concentration of less than 50%.
Claim 22
Dependent Claim
24 words
A method as set forth in claim 19, wherein said compound is present in a concentration of from about 1 to about 500 ppm.
Claim 23
Dependent Claim
24 words
A method as set forth in claim 19, wherein said compound is present in a concentration of from about 10 to about 300 ppm.
Claim 24
Dependent Claim
20 words
A method as set forth in claim 19, wherein said compound is present in a concentration of about 150 ppm.
Claim 25
Dependent Claim
16 words
A method as set forth in claim 15, wherein said compound comprises nitrilotris (methylene) triphosphonic acid.
Claim 26
Dependent Claim
24 words
A method as set forth in claim 23, wherein said nitrilotris (methylene) triphosphonic acid is present in a concentration of less than about 50%.
Claim 27
Dependent Claim
27 words
A method as set forth in claim 23, wherein said nitrilotris (methylene) triphosphonic acid is present in a concentration of from about 1 to about 500 ppm.
Claim 28
Dependent Claim
27 words
A method as set forth in claim 23, wherein said nitrilotris (methylene) triphosphonic acid is present in a concentration of from about 10 to about 300 ppm.
Claim 29
Dependent Claim
23 words
A method as set forth in claim 23, wherein said nitrilotris (methylene) triphosphonic acid is present in a concentration of about 150 ppm.
Claim 30
Dependent Claim
25 words
A method as set forth in claim 27, wherein said aluminum oxide results from pretreatment of the aluminum surface by the Forest Product Laboratory process.
Claim 31
Dependent Claim
25 words
A method as set forth in claim 27, wherein said aluminum oxide results from pretreatment of the aluminum surface by the phosphoric acid anodization method.
Claim 32
Independent Claim
81 words
A method for improving the corrosion resistance of aluminum by inhibiting the hydration of aluminum oxide by application of a corrosion inhibitor selected from the group consisting of NR 3 , NHR 2 , R'NR 2 , (CH 2 NR 2 ) 2 , and R 2 NCH 2 CH 2 NRCH 2 CH 2 NR 2 , wherein R is CH 2 PO(OH) 2 , and R is a straight chain alkyl group having from 1 to 5 carbon atoms.
Claim 33
Independent Claim
81 words
A method for improving the corrosion resistance of aluminum by inhibiting the hydration of aluminum oxide by application of a corrosion inhibitor selected from the group consisting of NR 3 , NHR 2 , R'NR 2 , (CH 2 NR 2 ) 2 , and R 2 NCH 2 CH 2 NRCH 2 CH 2 NR 2 , wherein R is CH 2 PO(OH) 2 , and R is a straight chain alkyl group having from 1 to 5 carbon atoms.
Claim 34
Dependent Claim
22 words
A method as set forth in claim 30, wherein the inhibitor is present in a concentration of less than 50% in water.
Claim 35
Dependent Claim
24 words
A method as set forth in claim 31, wherein said inhibitor is present in a concentration of from about 1 to about 500 ppm.
Claim 36
Dependent Claim
16 words
A method as set forth in claim 32, wherein said inhibitor comprises nitrilotris (methylene) triphosphonic acid.
Claim 37
Dependent Claim
30 words
A method as set forth in claim 31, wherein said inhibitor is applied to the aluminum surface by a method selected from the group consisting of dipping, spraying, and washing.
Claim 38
Dependent Claim
20 words
A method as set forth in claim 34, wherein said inhibitor is present in a concentration less than 500 ppm.
Claim 39
Dependent Claim
20 words
A method as set forth in claim 34, wherein said inhibitor is present in a concentration of about 150 ppm.
Claim 40
Dependent Claim
23 words
A bonded aluminum structure comprising one or more aluminum surfaces treated with an amino phosphonate corrosion inhibitor having a plurality of phosphorous atoms.
Claim 41
Dependent Claim
23 words
A bonded aluminum structure comprising one or more aluminum surfaces treated with an amino phosphonate corrosion inhibitor having a plurality of phosphorous atoms.
Claim 42
Dependent Claim
73 words
A bonded aluminum structure as set forth in claim 37, wherein said inhibitor is selected from the group consisting of NR 3 , NHR 2 , R'NR 2 , (CH 2 NR 2 ) 2 , and R 2 NCH 2 CH 2 NRCH 2 CH 2 NR 2 , wherein R is CH 2 PO(OH) 2 , and R' is a straight chain alkyl group having from 1 to 5 carbon atoms.
Claim 43
Dependent Claim
18 words
A bonded aluminum structure as set forth in claim 38, wherein said inhibitor comprises nitrilotris (methylene) triphosphonic acid.
Claim 44
Dependent Claim
23 words
An aluminum substrate having a monomolecular layer thereupon of a hydration inhibitor comprising an amino phosphonate compound having a plurality of phosphorous atoms.
Claim 45
Dependent Claim
23 words
An aluminum substrate having a monomolecular layer thereupon of a hydration inhibitor comprising an amino phosphonate compound having a plurality of phosphorous atoms.
Claim 46
Dependent Claim
71 words
A substrate as set forth in claim 40, wherein said inhibitor is selected from the group consisting of NR 3 , NHR 2 , R'NR 2 , (CH 2 NR 2 ) 2 , and R 2 NCH 2 CH 2 NRCH 2 CH 2 NR 2 , wherein R is CH 2 PO(OH) 2 , and R' is a straight chain alkyl group having from 1 to 5 carbon atoms.
Claim 47
Dependent Claim
17 words
An aluminum substrate as set forth in claim 40, wherein said inhibitor comprises nitrilotris (methylene) triphosphonic acid.
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) | 1984-12-28 | 1985-06-29 | 1985-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-28 | 1989-06-29 | 1989-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-28 | 1993-06-29 | 1993-12-29 | $7700.00 | Window Closed / Lapsed |