Patent US4419137A successfully refreshed from Google Patents.
US4419137A
Expired / Lapsed
US
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Corrosion inhibitors, method of producing and protective coatings containing same
Assignee: BP PLC
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Filing: 1981-07-28
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Granted: 1983-12-06
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Expires: 2001-07-28
Abstract
Abstract Corrosion inhibiting particles comprise an inorganic oxide which is silica or alumina, having corrosion inhibiting cations, particularly calcium or zinc cations, chemically bound to the particles. They may be prepared by contacting a silica or alumina containing hydroxyl groups with an alkaline solution containing the cations, at ambient temperature. The corrosion inhibiting particles may be incorporated into protective coatings, e.g. paints based on epoxy resins, alkyd resins, vinyl resins or chlorinated rubbers, in amounts up to 80% wt based on dry film weight, giving coatings with up to 7.2% wt corrosion inhibiting cations. Release of the cations is by ion exchange with other cations, e.g. the alkali metal cations of sea water, and does not, as is normal with corrosion inhibiting coatings, depend on the water solubility of the corrosion inhibitor.
Inventors
- 👤 Richard A. Cayless
- 👤 David A. Pippard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:45
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/40; C09C1/407; C09C1/28; C09C1/30; C09C1/3045; C09D; C09D5/00; C09D5/08; C09D5/082; C09D5/084; C01; C01P; C01P2004/00; C01P2004/01; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/12; C01P2006/80
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
57 words
A corrosion inhibitor comprising particles of an inorganic oxide selected from the group consisting of silica and alumina, having corrosion inhibiting metal cations chemically bound to the surface of the particles by ion exchange with protons from hydroxyl groups on said surface, whereby said cations bound to said particles can only be released by further ion exchange.
Claim 2
Dependent Claim
57 words
A corrosion inhibitor comprising particles of an inorganic oxide selected from the group consisting of silica and alumina, having corrosion inhibiting metal cations chemically bound to the surface of the particles by ion exchange with protons from hydroxyl groups on said surface, whereby said cations bound to said particles can only be released by further ion exchange.
Claim 3
Dependent Claim
32 words
A corrosion inhibitor as claimed in claim 1 characterised in that the corrosion inhibiting cations are selected from the group consisting of calcium, zinc, cobalt, lead, strontium, lithium, barium and magnesium cations.
Claim 4
Dependent Claim
30 words
A corrosion inhibitor as claimed in either of claims 1 or 2 characterised in that the silica or alumina has a BET surface area greater than 250 m 2 /g.
Claim 5
Dependent Claim
26 words
A corrosion inhibitor as claimed in claim 3 characterised in that the silica or alumina has a BET surface area greater than 500 m 2 /g.
Claim 6
Dependent Claim
22 words
A corrosion inhibitor as claimed in claim 1 characterised in that the inorganic oxide contains from 0.2 to 2.5 millimoles/g of cations.
Claim 7
Dependent Claim
20 words
A corrosion inhibitor as claimed in claim 1 characterised in that the particles are up to 40 microns in diameter.
Claim 8
Independent Claim
75 words
A method of forming corrosion inhibiting particles which particles comprise silica particles having corrosion inhibiting cations chemically bound to the surface of the particles by ion exchange, comprises contacting at ambient temperature silica particles with an alkaline solution containing corrosion inhibiting cations, the pH of the alkaline solution being sufficiently high to remove protons from hydroxyl groups effecting said exchange at the surface of the particles while not allowing the pH to rise about 10.5.
Claim 9
Independent Claim
75 words
A method of forming corrosion inhibiting particles which particles comprise silica particles having corrosion inhibiting cations chemically bound to the surface of the particles by ion exchange, comprises contacting at ambient temperature silica particles with an alkaline solution containing corrosion inhibiting cations, the pH of the alkaline solution being sufficiently high to remove protons from hydroxyl groups effecting said exchange at the surface of the particles while not allowing the pH to rise about 10.5.
Claim 10
Independent Claim
75 words
A method of forming corrosion inhibiting particles which particles comprise alumina particles having corrosion inhibiting cations chemically bound to the surface of the particles by ion exchange comprises contacting at ambient temperature alumina particles with an alkaline solution containing corrosion inhibiting cations, the pH of the alkaline solution being sufficiently high to remove protons from hydroxyl groups effecting said exchange at the surface of the particles while not allowing the pH to rise above 12.
Claim 11
Independent Claim
75 words
A method of forming corrosion inhibiting particles which particles comprise alumina particles having corrosion inhibiting cations chemically bound to the surface of the particles by ion exchange comprises contacting at ambient temperature alumina particles with an alkaline solution containing corrosion inhibiting cations, the pH of the alkaline solution being sufficiently high to remove protons from hydroxyl groups effecting said exchange at the surface of the particles while not allowing the pH to rise above 12.
Claim 12
Dependent Claim
39 words
A method as claimed in claim 7 or 8 characterised in that the inorganic oxide is contacted with an alkaline solution containing corrosion inhibiting cations in the presence of a solution of a highly soluble salt of the cation.
Claim 13
Dependent Claim
16 words
A method as claimed in claim 9 characterised in that the soluble salt is a nitrate.
Claim 14
Dependent Claim
17 words
A protective coating containing a film-forming resinous vehicle and corrosion inhibiting particles as claimed in claim 1.
Claim 15
Dependent Claim
30 words
A protective coating as claimed in claim 11 characterised in that the coating contains up to 80% wt of corrosion inhibiting particles based on the dry weight of the film.
Claim 16
Dependent Claim
31 words
A protective coating as claimed in claim 12 characterised in that the coating contains from 30 to 80% wt of corrosion inhibiting particles based on the dry weight of the film.
Claim 17
Dependent Claim
29 words
A protective coating as claimed in claim 11 characterised in that the coating is a paint based on epoxy resin, vinyl resin, alkyd resin, chlorinated rubber or cyclised rubber.
Claim 18
Dependent Claim
23 words
A protective coating containing a film forming resinous vehicle and corrosion inhibiting particles as prepared according to either claim 7 or claim 8.
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) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |