GB1579307A - Method of protecting metal surfaces and structures against corrosion - Google Patents
Method of protecting metal surfaces and structures against corrosion Download PDFInfo
- Publication number
- GB1579307A GB1579307A GB21257/78A GB2125778A GB1579307A GB 1579307 A GB1579307 A GB 1579307A GB 21257/78 A GB21257/78 A GB 21257/78A GB 2125778 A GB2125778 A GB 2125778A GB 1579307 A GB1579307 A GB 1579307A
- Authority
- GB
- United Kingdom
- Prior art keywords
- calcium nitrite
- percent
- corrosion
- metal
- calcium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 229910052751 metal Inorganic materials 0.000 title claims description 33
- 239000002184 metal Substances 0.000 title claims description 33
- 230000007797 corrosion Effects 0.000 title claims description 32
- 238000005260 corrosion Methods 0.000 title claims description 32
- 238000000034 method Methods 0.000 title claims description 27
- RAFRTSDUWORDLA-UHFFFAOYSA-N phenyl 3-chloropropanoate Chemical compound ClCCC(=O)OC1=CC=CC=C1 RAFRTSDUWORDLA-UHFFFAOYSA-N 0.000 claims description 41
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- 239000007864 aqueous solution Substances 0.000 claims description 20
- 230000002401 inhibitory effect Effects 0.000 claims description 11
- 239000008199 coating composition Substances 0.000 claims description 10
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 8
- 239000012736 aqueous medium Substances 0.000 claims description 7
- 239000003921 oil Substances 0.000 claims description 7
- 239000007788 liquid Substances 0.000 claims description 5
- 239000000243 solution Substances 0.000 claims description 5
- 239000002562 thickening agent Substances 0.000 claims description 5
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical compound [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 229910001018 Cast iron Inorganic materials 0.000 claims description 2
- 239000002826 coolant Substances 0.000 claims description 2
- -1 alkali metal nitrites Chemical class 0.000 description 9
- 229910052783 alkali metal Inorganic materials 0.000 description 7
- 239000003795 chemical substances by application Substances 0.000 description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- 238000000576 coating method Methods 0.000 description 4
- 239000012071 phase Substances 0.000 description 4
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 239000011575 calcium Substances 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 239000003112 inhibitor Substances 0.000 description 3
- 230000002265 prevention Effects 0.000 description 3
- 239000013535 sea water Substances 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000008346 aqueous phase Substances 0.000 description 2
- 150000001805 chlorine compounds Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005764 inhibitory process Effects 0.000 description 2
- 239000002609 medium Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 235000010288 sodium nitrite Nutrition 0.000 description 2
- GJCOSYZMQJWQCA-UHFFFAOYSA-N 9H-xanthene Chemical compound C1=CC=C2CC3=CC=CC=C3OC2=C1 GJCOSYZMQJWQCA-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 1
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 244000007835 Cyamopsis tetragonoloba Species 0.000 description 1
- 229910001335 Galvanized steel Inorganic materials 0.000 description 1
- 239000004354 Hydroxyethyl cellulose Substances 0.000 description 1
- 229920000663 Hydroxyethyl cellulose Polymers 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 1
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical class OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- WTKZEGDFNFYCGP-UHFFFAOYSA-N Pyrazole Chemical class C=1C=NNC=1 WTKZEGDFNFYCGP-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 1
- 239000010960 cold rolled steel Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 239000008397 galvanized steel Substances 0.000 description 1
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910001504 inorganic chloride Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000008239 natural water Substances 0.000 description 1
- HLNRBHDRGMNBEG-UHFFFAOYSA-N nitrous acid Chemical compound ON=O.ON=O HLNRBHDRGMNBEG-UHFFFAOYSA-N 0.000 description 1
- 230000009972 noncorrosive effect Effects 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- DOAMZWOPDPPKJS-UHFFFAOYSA-N oxiran-2-ol Chemical class OC1CO1 DOAMZWOPDPPKJS-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
- 150000003557 thiazoles Chemical class 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000003442 weekly effect Effects 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
- 229920001285 xanthan gum Polymers 0.000 description 1
- 150000003751 zinc Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/08—Anti-corrosive paints
- C09D5/082—Anti-corrosive paints characterised by the anti-corrosive pigment
- C09D5/084—Inorganic compounds
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
- C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
- C23F11/18—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using inorganic inhibitors
- C23F11/181—Nitrogen containing compounds
Description
(54) METHOD OF PROTECTING METAL SURFACES AND
STRUCTURES AGAINST CORROSION
(71) We, W. R. GRACE & CO., a Corporation organized and existing under the Laws of the State of Connecticut, United States of
America, of: Grace Plaza, 1114 Avenue of the
Americas, New York, N.Y. 10036, United
States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-
The present invention relates to methods of inhibiting corrosion of metal surfaces and structures which are in contact with, or likely to come into contact with, an aqueous medium of a corrosive nature.
It is well known that one can inhibit the corrosion of metal surfaces in contact with corrosive aqueous media by the inclusion of various corrosion inhibiting agents therein. For example, for many years alkali metal nitrites, especially those of potassium or sodium, have been utilized in the protection of carbon steel from corrosion by introducing an alkali metal nitrite into an aqueous solution which is maintained at an alkaline pH. The utilization of alkali metal nitrites, though, leaves much to be desired. They do not exhibit a high degree of corrosion inhibiting properties against a wide variety of corrosive agents and especially against the corrosive effect of the chlorides present in seawater and other chlorides commonly found in aqueous solutions.
Various suggestions have previously been proposed to overcome the defects encountered when using the alkali metal nitrites. Such suggestions include the utilization of alkali metal chromates, alone or in combination with the alkali metal nitrite. However, chromate solutions pose the problem of being toxic to humans and having a marked staining effect on the metal material. Zinc salts have also been used but have recently been found to adversely affect the water quality of natural water bodies in which the treated water is released. Finally, various organic compounds such as phosphonates, diazoles and thiazoles have been suggested as additives. These organic constituents have the drawback of being very expensive and are, therefore, merely useful to supplement the inorganic salts.
Consequently, compositions which are both relatively inexpensive and which effectively inhibit the corrosion of metal surfaces and structures are desired for the protection of metallic equipment.
According to the present invention there is provided a method of protecting a metal surface or structure against corrosion by an aqueous medium, usually a solution, which comprises contacting the metal structure with an aqueous solution containing calcium nitrite.
Calcium nitrite has unexpectedly been found to be several times more effective as a corrosion inhibiting agent than other inorganic inhibitors, such as the alkali metal nitrites.
The present invention is effective for treating metal surfaces and metal container structures which are in contact, or liable to come into contact with, corrosive aqueous solutions.
The calcium nitrite can be added to the aqueou medium in contact with the metal or it can be applied, for example as an aqueous solution, to a metal surface which is likely to be subjected to a corrosive aqueous medium.
The major corrosive ingredients of aqueous systems are dissolved oxygen and inorganic salts such as the carbonate, bicarbonate, chloride, nitrate and sulphate of sodium, calcium and magnesium. Such salts become entrained m the aqueous media which may be present in, for example, metal containers by various means
The present invention is useful in the prevention of corrosion of metals, for example, iron, steel, galvanized steel and non-ferrous metals including copper, aluminium and their alloys which are in contact with a liquid medium which either is or contains therein an aqueous corrosive phase. It has particular utility in the prevention of the corrosion of metals used in the formation of, for example, condensers, engine blocks, cooling towers and evaporators which have water circulating through them.It is also useful in the prevention of corrosion of metal surfaces of various storage containers and especially those used in the petroleum industry. Storage containers of petroleum products are known to contain small amounts of water which almost always contain various corrosive salts. The water phase settles on the bottom of the container where it presents serious corrosion problems. This is especially true of containers which are used as oil storage tanks at refineries, domestic fuel oil tanks, oil pipe lines and cargo tanks of commercial oil tankers. Further, in the case of cargo tanks of oil tankers, it is a standard procedure to clean the inner surface of the cargo tanks with seawater. The residual seawater, with its corrosive sodium chloride, remaining in these tanks causes extensive pitting of the bottom area of the tanks where the water phase collects.
The calcium nitrite can be introduced into aqueous solutions in any known convenient method. For example in a circulating water system, that is water which is moving through various types of apparatus such as condensers, engine blocks or jackets and cooling towers, solid calcium nitrite can be conveniently added to the aqueous system. Alternatively, an aqueous solution of calcium nitrite can be injected into the system as part of the initial and/or makeup feed of the system so as to maintain a sufficient amount of the agent in the system to inhibit corrosion.
In predominantly non-aqueous systems which contain small amounts of corrosive water therein, such as is found in oil storage tanks, the calcium nitrite can conveniently be added as a concentrated aqueous solution which will eventually combine with the aqueous phase present to inhibit corrosion of the metal surfaces in contact with the treated aqueous solution.
Alternatively, solid calcium nitrite can be added.
When the solid enters the aqueous phase, it readily goes into solution and has the desired corrosion inhibiting effect. It has been found that very small amounts of calcium nitrite act as effective corrosion inhibiting agents. Preferably, the calcium nitrite should be present in an amount of from 0.05 to 5 percent by weight of the aqueous solution, with amounts of up to about 2 percent by weight being found effective in most instances. Amounts in the upper end of the preferred range are most desirable when the process is used to protect petroleum storage vessels. Greater amounts of
the corrosion inhibiting agents can be used, although this has generally been found unnecessary.
The aqueous solutions into which the calcium nitrite can be incorporated may contain noncorrosive inhibiting additives. For example, the water may contain conventional anti-freezing agents, such as ethylene glycol. The calcium
nitrite has been found to be substantially unaf
fected by such additives.
Corrosion inhibition can also be achieved, unexpectedly, by coating a metallic surface of an article to be protected with a composition containing calcium nitrite. An aqueous composition can readily be formed by the inclusion of from, say, 0.05 to 5 percent calcium nitrite into any conventional water-based coating composition. The compositions may contain various conventional thickeners such as polyethylene oxides, hydroxyethylene oxides, hydroxyethyl cellulose, Xanthan or guar gums, alone or in combination with other conventional coating components. The coating can be done in any conventional manner, such as by spraying, brushing or dipping. The water based coating composition should generally be permitted to dry thoroughly prior to the utilization of the metal vessel. The calcium nitrite contained in such coatings exhibits corrosion inhibition over a sustained period of time.
Unexpectedly it has been found that even very small amounts of calcium' nitrite exhibit superior corrosion resistance of metal pieces and surfaces against substantial amounts of sodium chloride. It is believed that calcium nitrite is also an effective corrosion inhibitor of metallic surfaces and structures which are in contact with substantial amounts of various other inorganic chlorides regardless of the cation associated therewith and other corrosive salts such as sulphates.
The following Examples further illustrate the present invention. All parts and percentages are by weight unless otherwise indicated.
EXAMPLE I
Previously weighed strips about 5 cm wide by 12.5 cm long by 0.2 cm thick of cold rolled steel commonly used in forming containers were separately immersed in salt water baths (1 percent NaCl). To one bath was added 2 percent calcium nitrite, while to the other bath was added 2 percent sodium nitrite for comparative purposes. At weekly intervals each strip was removed from the bath, washed with deionized water, dried and weighed. The results are tabulated below.
Table
Total weight loss (in gm) of
Sample in 1% NaCI water bath
having
Time 2% Sodium 2% Calcium (weeks) Nitrite Nitrite
1 0.03 0.01 2 0.05 0.01 3 0.20 0.01 4 0.21 0.01 5 0.22 0.06
The above results show that calcium nitrite is an effective corrosion inhibiting agent against a corrosive aqueous solution. Further, the above results clearly show that calcium nitrite is several times more effective than the conventional inhibitor, sodium nitrite.
EXAMPLE 11 A cast iron engine block having a cooling system capacity of 18.25 11 is filled with a water solution containing 35 percent ethylene glycol and 0.1 percent (18.25 gms) calcium nitrite.
The engine is periodically run over a 16 week period. Substantially no corrosion is observed.
EXAMPLE III
The liquid media contained in an oil storage tank of a refinery is periodically injected with a sufficient amount of a concentrated aqueous solution of calcium nitrite to maintain the calcium nitrite concentration in the water phase at the bottom of the tank at about 3 percent.
Corrosion of the steel tank walls is substantially eliminated.
WHAT WE CLAIM IS:
1. A method of inhibiting corrosion of a metal surface or structure in contact with, or likely to come into contact with, an aqueous medium which comprises contacting the metal surface or structure with calcium nitrite.
2. A method according to claim 1 wherein the calcium nitrite is incorporated in the corrosive aqueous solution in contact with said metal.
3. A method according to claim 2 wherein the metal structure is a storage tank and the calcium nitrite is incorporated in the water containing liquid media therein.
4. A method according to claim 2 wherein the metal structure is an engine block and the calcium nitrite is present in the aqueous coolant contained in said engine block.
5. A method according to any one of claims 2 to 4 wherein the calcium nitrate is present in the aqueous solution in an amount from 0.05 to 5 percent by weight based on the aqueous solution.
6. A method according to claim 1 wherein the metal surface is coated with an aqueous coating composition containing calcium nitrite.
7. A method according to claim 6 wherein the calcium nitrite is present in the coating composition in an amount from 0.05 to 5 percent by weight based on the weight of the composition.
8. A method according to claim 6 or 7 wherein the coating composition comprises a thickening agent to increase the viscosity thereof.
9. A method according to claim 1 substantially as hereinbefore described.
10. A metal surface or structure whenever corrosion-inhibited by a method as claimed in any one of the preceding claims.
11. A coating composition which comprises calcium nitrite and a thickening agent.
12. A composition according to claim 11 wherein the calcium nitrite is present in an amount from 0.05 to 5 percent by weight.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (12)
1. A method of inhibiting corrosion of a metal surface or structure in contact with, or likely to come into contact with, an aqueous medium which comprises contacting the metal surface or structure with calcium nitrite.
2. A method according to claim 1 wherein the calcium nitrite is incorporated in the corrosive aqueous solution in contact with said metal.
3. A method according to claim 2 wherein the metal structure is a storage tank and the calcium nitrite is incorporated in the water containing liquid media therein.
4. A method according to claim 2 wherein the metal structure is an engine block and the calcium nitrite is present in the aqueous coolant contained in said engine block.
5. A method according to any one of claims 2 to 4 wherein the calcium nitrate is present in the aqueous solution in an amount from 0.05 to 5 percent by weight based on the aqueous solution.
6. A method according to claim 1 wherein the metal surface is coated with an aqueous coating composition containing calcium nitrite.
7. A method according to claim 6 wherein the calcium nitrite is present in the coating composition in an amount from 0.05 to 5 percent by weight based on the weight of the composition.
8. A method according to claim 6 or 7 wherein the coating composition comprises a thickening agent to increase the viscosity thereof.
9. A method according to claim 1 substantially as hereinbefore described.
10. A metal surface or structure whenever corrosion-inhibited by a method as claimed in any one of the preceding claims.
11. A coating composition which comprises calcium nitrite and a thickening agent.
12. A composition according to claim 11 wherein the calcium nitrite is present in an amount from 0.05 to 5 percent by weight.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86682378A | 1978-01-04 | 1978-01-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1579307A true GB1579307A (en) | 1980-11-19 |
Family
ID=25348498
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB21257/78A Expired GB1579307A (en) | 1978-01-04 | 1978-05-22 | Method of protecting metal surfaces and structures against corrosion |
Country Status (5)
| Country | Link |
|---|---|
| DE (1) | DE2856839A1 (en) |
| FR (1) | FR2414080A1 (en) |
| GB (1) | GB1579307A (en) |
| IT (1) | IT1109903B (en) |
| SE (1) | SE7900029L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1989008728A1 (en) * | 1988-03-17 | 1989-09-21 | Comalco Aluminium Limited | Metallic surface protection |
| WO2000071265A1 (en) * | 1999-05-21 | 2000-11-30 | Henkel Corporation | Autodeposition post-bath rinse process |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19524316C2 (en) * | 1995-07-04 | 2000-08-31 | Sotralentz Sa | Steel mesh mat |
| DE29520395U1 (en) * | 1995-12-22 | 1996-03-21 | Wako Wachs Und Korrosionsschut | Anticorrosive |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1968722A (en) * | 1932-08-29 | 1934-07-31 | Stone Irwin | Method of inhibiting the corrosive action of alkaline aqueous solutions, etc. |
| SU456786A1 (en) * | 1973-01-03 | 1975-01-15 | Предприятие П/Я А-3732 | Method for producing calcium chloride inhibited by calcium nitrite-nitrate |
-
1978
- 1978-05-22 GB GB21257/78A patent/GB1579307A/en not_active Expired
- 1978-12-18 FR FR7835594A patent/FR2414080A1/en active Granted
- 1978-12-30 DE DE19782856839 patent/DE2856839A1/en not_active Withdrawn
-
1979
- 1979-01-02 SE SE7900029A patent/SE7900029L/en unknown
- 1979-01-02 IT IT19021/79A patent/IT1109903B/en active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1989008728A1 (en) * | 1988-03-17 | 1989-09-21 | Comalco Aluminium Limited | Metallic surface protection |
| WO2000071265A1 (en) * | 1999-05-21 | 2000-11-30 | Henkel Corporation | Autodeposition post-bath rinse process |
| US6410092B1 (en) | 1999-05-21 | 2002-06-25 | Henkel Corporation | Autodeposition post-bath rinse process |
Also Published As
| Publication number | Publication date |
|---|---|
| IT7919021A0 (en) | 1979-01-02 |
| FR2414080B1 (en) | 1983-02-18 |
| IT1109903B (en) | 1985-12-23 |
| DE2856839A1 (en) | 1979-07-12 |
| FR2414080A1 (en) | 1979-08-03 |
| SE7900029L (en) | 1979-07-05 |
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| Date | Code | Title | Description |
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| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |