US4421789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for treating the surfaces of aluminum heat exchangers
Assignee: Henkel Corp
•
Filing: 1982-06-28
•
Granted: 1983-12-20
•
Expires: 2002-06-28
Abstract
Abstract A method for the treatment of aluminum surfaces to provide them with a corrosion resistant, hydrophilic coating. The aluminum surfaces are first provided with a corrosion-resistant film and, thereafter, a coating of fine silica particles is applied to the corrosion resistant film. Suitable corrosion resistant films which may be used are anodized films, boehmite films, chromated films and organic resin films. The coated aluminum surfaces produced by this method are found to have particular application for aluminum heat exchangers.
Inventors
- 👤 Hideaki Kaneko
- 👤 Kazuhisa Naito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:19
CPC Classifications
B; B05; B05D; B05D7/00; B05D7/14; C; C23; C23C; C23C22/00; C23C22/82; C23C22/83; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; F; F28; F28F; F28F19/00; F28F19/02; F28F2245/00; F28F2245/02; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/252
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
85 words
A method for the treatment of aluminum surfaces to provide thereon a corrosion resistant, hydrophilic coating which comprises forming on said aluminum surface a corrosion-resistant film having a thickness which is not in excess of about 10 microns and, thereafter, applying to said corrosion resistant film a top coating of fine silica particles, having a size within the range of about 1-100 millimicrons, the amount of said silica particles applied being at least sufficient to impart the desired degree of water wetability to the surface.
Claim 2
Independent Claim
85 words
A method for the treatment of aluminum surfaces to provide thereon a corrosion resistant, hydrophilic coating which comprises forming on said aluminum surface a corrosion-resistant film having a thickness which is not in excess of about 10 microns and, thereafter, applying to said corrosion resistant film a top coating of fine silica particles, having a size within the range of about 1-100 millimicrons, the amount of said silica particles applied being at least sufficient to impart the desired degree of water wetability to the surface.
Claim 3
Independent Claim
68 words
A method for the treatment of aluminum surfaces to provide thereon a corrosion-resistant, hydrophilic coating which comprises forming on said aluminum surface a corrosion-resistant film and, thereafter, applying to said corrosion-resistant film a coating of fine anhydrous silicic acid particles in an amount at least sufficient to impart the desired degree of water wetability to the surface, said anhydrous silicic acid particles being applied as an aqueous dispersion.
Claim 4
Independent Claim
68 words
A method for the treatment of aluminum surfaces to provide thereon a corrosion-resistant, hydrophilic coating which comprises forming on said aluminum surface a corrosion-resistant film and, thereafter, applying to said corrosion-resistant film a coating of fine anhydrous silicic acid particles in an amount at least sufficient to impart the desired degree of water wetability to the surface, said anhydrous silicic acid particles being applied as an aqueous dispersion.
Claim 5
Dependent Claim
18 words
The process as claimed in claim 1 in which the silica particles are applied as an aqueous dispersion.
Claim 6
Dependent Claim
17 words
The process as claimed in claim 3 in which the silica particles are anhydrous silicic acid particles.
Claim 7
Dependent Claim
16 words
The process as claimed in claim 3 in which the silica particles are a silica sol.
Claim 8
Dependent Claim
24 words
The process as claimed in claim 1 in which the coating weight of the applied silica particles is at least 0.01 gm/m 2 .
Claim 9
Dependent Claim
27 words
The process as claimed in claim 6 in which the coating weight of the applied silica particles is from about 0.01 to about 5.0 gm/m 2 .
Claim 10
Dependent Claim
37 words
The process as claimed in claims 3, 4, 5, 6, 7, 1, or 2 in which the corrosion resistant film is selected from an anodized film, a boehmite film, a chromated film and an organic resin film.
References Cited (Backward Citations)
US2298079A
Cited
US3279316A
Cited
US3181461A
Cited
US3973510A
Cited
US4054467A
Cited
US4074010A
Cited
US4211276A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |