US4474607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of inhibiting corrosion using cations
Assignee: BP PLC
•
Filing: 1983-03-10
•
Granted: 1984-10-02
•
Expires: 2003-03-10
Abstract
Abstract A corrosion inhibitor comprises particles of an inorganic oxide having cations of yttrium or cations of one or more metals of the lanthanide group chemically bound to the particles by ion-exchange. The cations are released by ion-exchange with other cations and not by the water solubility of the corrosion inhibitor. The corrosion inhibiting particles may be prepared by contacting particles of the inorganic oxide with an aqueous solution containing the required cations. Alternatively, the particles of the inorganic oxide may be contacted with an aqueous solution of an alkali metal so that alkali metal ions are exchanged onto the surface of the oxide and then contacting the alkali metal exchanged oxide with a solution of the required cations so that the required cations replace the alkali metal cations. 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 the dry film weight of the coating.
Inventors
- 👤 Brian P. F. Goldie
- 👤 John J. McCarroll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:04
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/22; C09C1/24; C09C1/28; C09C1/30; C09C1/3045; C09C1/40; C09C1/42; C09C3/00; C09C3/06; C09D; C09D5/00; C09D5/08; C09D5/082; C09D5/084; C23; C23F; C23F11/00; C23F11/08; C23F11/18; C01; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/80; C01P2004/82; C01P2004/84; C01P2006/00; C01P2006/12; C01P2006/80
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
73 words
A corrosion inhibitor comprising particles of an inorganic oxide having cations chemically bound to the surface of the particles by ion-exchange with protons from hydroxyl groups on the said surface, the cations bound to the particles being releasable by further ion-exchange characterised in that the cations are cations of yttrium or cations of one or more metals of the Lanthanide group which group comprises metals having atomic numbers from 57 to 71 inclusive.
Claim 2
Dependent Claim
73 words
A corrosion inhibitor comprising particles of an inorganic oxide having cations chemically bound to the surface of the particles by ion-exchange with protons from hydroxyl groups on the said surface, the cations bound to the particles being releasable by further ion-exchange characterised in that the cations are cations of yttrium or cations of one or more metals of the Lanthanide group which group comprises metals having atomic numbers from 57 to 71 inclusive.
Claim 3
Dependent Claim
15 words
A corrosion inhibitor as claimed in claim 1 in which the inorganic oxide is silica.
Claim 4
Dependent Claim
25 words
A corrosion inhibitor as claimed in claim 1 in which the BET surface area of the inorganic oxide is greater than 100 m 2 /g.
Claim 5
Dependent Claim
25 words
A corrosion inhibitor as claimed in claim 3 in which the BET surface area of the inorganic oxide is greater than 250 m 2 /g.
Claim 6
Dependent Claim
25 words
A corrosion inhibitor as claimed in claim 4 in which the BET surface area of the inorganic oxide is greater than 500 m 2 /g.
Claim 7
Dependent Claim
21 words
A corrosion inhibitor as claimed in claim 1 in which the inorganic oxide contains from 0.01 to 0.5 millimoles/g of cations.
Claim 8
Dependent Claim
21 words
A corrosion inhibitor as claimed in claim 6 in which the inorganic oxide contains from 0.05 to 0.5 millimoles/g of cations.
Claim 9
Dependent Claim
23 words
A corrosion inhibitor as claimed in claim 1 in which the particles of the inorganic oxide are less than 25 microns in diameter.
Claim 10
Independent Claim
113 words
A method of forming corrosion inhibiting particles comprising contacting an inorganic oxide having surface hydroxyl groups with an aqueous solution containing cations of yttrium or cations of one or more metals of the lanthanide group at an initial pH in the range 3.5 to 7 which pH is sufficiently high for the protons of the hydroxyl groups to be replaced by the cations of yttrium or the lanthanide metal or metals, but which is not so high as to cause precipitation of the cation hydroxide or hydrous oxide and thereafter maintaining the pH within the range 3.5 to 7, the pH being controlled by the addition to the solution of a basic salt.
Claim 11
Independent Claim
113 words
A method of forming corrosion inhibiting particles comprising contacting an inorganic oxide having surface hydroxyl groups with an aqueous solution containing cations of yttrium or cations of one or more metals of the lanthanide group at an initial pH in the range 3.5 to 7 which pH is sufficiently high for the protons of the hydroxyl groups to be replaced by the cations of yttrium or the lanthanide metal or metals, but which is not so high as to cause precipitation of the cation hydroxide or hydrous oxide and thereafter maintaining the pH within the range 3.5 to 7, the pH being controlled by the addition to the solution of a basic salt.
Claim 12
Dependent Claim
28 words
A method as claimed in claim 9 in which the solution is a solution of a nitrate of yttrium or one or more metals of the lanthanide group.
Claim 13
Independent Claim
95 words
A method of forming corrosion inhibiting particles comprising contacting particles of an inorganic oxide having surface hydroxyl groups with an aqueous solution of an alkali metal salt at a pH sufficiently above 7 for the protons of the hydroxyl groups to be replaced by alkali metal cations and thereafter contacting the particles of the alkali metal exchanged inorganic oxide with a solution containing yttrium cations or cations of one or more metals of the lanthanide group so that the alkali metal cations are replaced by the cations of yttrium or the lanthanide metal or metals.
Claim 14
Independent Claim
95 words
A method of forming corrosion inhibiting particles comprising contacting particles of an inorganic oxide having surface hydroxyl groups with an aqueous solution of an alkali metal salt at a pH sufficiently above 7 for the protons of the hydroxyl groups to be replaced by alkali metal cations and thereafter contacting the particles of the alkali metal exchanged inorganic oxide with a solution containing yttrium cations or cations of one or more metals of the lanthanide group so that the alkali metal cations are replaced by the cations of yttrium or the lanthanide metal or metals.
Claim 15
Dependent Claim
17 words
A method as claimed in claim 11 in which the alkali metal salt is a sodium salt.
Claim 16
Dependent Claim
12 words
A protective coating containing corrosion inhibiting particles as claimed in claim 1.
Claim 17
Dependent Claim
20 words
A protective coating containing corrosion inhibiting particles prepared by a method as claimed in either claim 9 or claim 11.
Claim 18
Dependent Claim
30 words
A protective coating as claimed in claim 13 in which the coating contains up to 80% by weight of corrosion inhibiting particles based on the dry weight of the film.
Claim 19
Dependent Claim
31 words
A protective coating as claimed in claim 15 in which the coating contains from 30 to 80% by weight of corrosion inhibiting particles based on the dry weight of the film.
Claim 20
Dependent Claim
28 words
A protective coating as claimed in claim 13 in which the coating is a paint based on epoxy resin, vinyl resin, alkyd resin, chlorinated rubber or cyclised rubber.
References Cited (Backward Citations)
US2913419A
Cited
US3899624A
Cited
GB1503153A
Cited
US4210575A
Cited
GB2071070A
Cited
EP0046057A1
Cited
US4419137A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |