WO2017144721A1 - Patina layer on galvanized product and method therefor - Google Patents
Patina layer on galvanized product and method therefor Download PDFInfo
- Publication number
- WO2017144721A1 WO2017144721A1 PCT/EP2017/054509 EP2017054509W WO2017144721A1 WO 2017144721 A1 WO2017144721 A1 WO 2017144721A1 EP 2017054509 W EP2017054509 W EP 2017054509W WO 2017144721 A1 WO2017144721 A1 WO 2017144721A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- zinc
- product
- patina layer
- artificially
- layer
- Prior art date
Links
- 241001311547 Patina Species 0.000 title claims abstract description 108
- 238000000034 method Methods 0.000 title claims description 49
- 239000011701 zinc Substances 0.000 claims abstract description 94
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims abstract description 78
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 78
- 229910052751 metal Inorganic materials 0.000 claims abstract description 44
- 239000002184 metal Substances 0.000 claims abstract description 44
- 238000000576 coating method Methods 0.000 claims abstract description 40
- 239000011248 coating agent Substances 0.000 claims abstract description 38
- 229910000010 zinc carbonate Inorganic materials 0.000 claims abstract description 24
- 239000000126 substance Substances 0.000 claims abstract description 22
- 150000001455 metallic ions Chemical class 0.000 claims abstract description 20
- FMRLDPWIRHBCCC-UHFFFAOYSA-L Zinc carbonate Chemical compound [Zn+2].[O-]C([O-])=O FMRLDPWIRHBCCC-UHFFFAOYSA-L 0.000 claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 claims abstract description 14
- UOURRHZRLGCVDA-UHFFFAOYSA-D pentazinc;dicarbonate;hexahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Zn+2].[Zn+2].[Zn+2].[Zn+2].[Zn+2].[O-]C([O-])=O.[O-]C([O-])=O UOURRHZRLGCVDA-UHFFFAOYSA-D 0.000 claims abstract description 14
- 239000011667 zinc carbonate Substances 0.000 claims abstract description 10
- 235000004416 zinc carbonate Nutrition 0.000 claims abstract description 10
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 38
- 229910001868 water Inorganic materials 0.000 claims description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 26
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 23
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 21
- 239000001569 carbon dioxide Substances 0.000 claims description 19
- 238000005246 galvanizing Methods 0.000 claims description 13
- 239000010949 copper Substances 0.000 claims description 12
- 229910052742 iron Inorganic materials 0.000 claims description 11
- 239000002243 precursor Substances 0.000 claims description 11
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 9
- 229910052802 copper Inorganic materials 0.000 claims description 9
- 239000002904 solvent Substances 0.000 claims description 9
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 8
- 238000005507 spraying Methods 0.000 claims description 8
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 6
- 230000003247 decreasing effect Effects 0.000 claims description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 5
- 238000010923 batch production Methods 0.000 claims description 5
- 229910052709 silver Inorganic materials 0.000 claims description 5
- 239000004332 silver Substances 0.000 claims description 5
- 239000010936 titanium Substances 0.000 claims description 5
- 229910052719 titanium Inorganic materials 0.000 claims description 5
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 4
- 229910052790 beryllium Inorganic materials 0.000 claims description 4
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 claims description 4
- 229910052793 cadmium Inorganic materials 0.000 claims description 4
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 4
- 238000004140 cleaning Methods 0.000 claims description 4
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 4
- 229910052737 gold Inorganic materials 0.000 claims description 4
- 239000010931 gold Substances 0.000 claims description 4
- 229910052738 indium Inorganic materials 0.000 claims description 4
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 4
- 150000002500 ions Chemical class 0.000 claims description 4
- 239000011133 lead Substances 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 4
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 239000011733 molybdenum Substances 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052763 palladium Inorganic materials 0.000 claims description 4
- 238000007747 plating Methods 0.000 claims description 4
- 229910052697 platinum Inorganic materials 0.000 claims description 4
- 229910052715 tantalum Inorganic materials 0.000 claims description 4
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims description 4
- 229910052718 tin Inorganic materials 0.000 claims description 4
- 239000011135 tin Substances 0.000 claims description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 4
- 239000010937 tungsten Substances 0.000 claims description 4
- 238000007788 roughening Methods 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 239000008367 deionised water Substances 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- 239000013535 sea water Substances 0.000 claims description 2
- 239000004094 surface-active agent Substances 0.000 claims description 2
- 239000008399 tap water Substances 0.000 claims description 2
- 235000020679 tap water Nutrition 0.000 claims description 2
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 claims 1
- -1 Smithsonite Chemical compound 0.000 abstract description 13
- ONIOAEVPMYCHKX-UHFFFAOYSA-N carbonic acid;zinc Chemical compound [Zn].OC(O)=O ONIOAEVPMYCHKX-UHFFFAOYSA-N 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 104
- 239000000047 product Substances 0.000 description 61
- 230000015572 biosynthetic process Effects 0.000 description 17
- 239000012535 impurity Substances 0.000 description 13
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 12
- 229910000831 Steel Inorganic materials 0.000 description 10
- 239000010959 steel Substances 0.000 description 10
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 7
- 229910021511 zinc hydroxide Inorganic materials 0.000 description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- 239000000428 dust Substances 0.000 description 6
- 239000004519 grease Substances 0.000 description 6
- 239000011780 sodium chloride Substances 0.000 description 6
- 235000002639 sodium chloride Nutrition 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000003921 oil Substances 0.000 description 5
- 238000010422 painting Methods 0.000 description 5
- 239000000758 substrate Substances 0.000 description 5
- UGZADUVQMDAIAO-UHFFFAOYSA-L zinc hydroxide Chemical compound [OH-].[OH-].[Zn+2] UGZADUVQMDAIAO-UHFFFAOYSA-L 0.000 description 5
- 229940007718 zinc hydroxide Drugs 0.000 description 5
- 229910001335 Galvanized steel Inorganic materials 0.000 description 4
- 238000003915 air pollution Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 230000007613 environmental effect Effects 0.000 description 4
- 239000008397 galvanized steel Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 239000003973 paint Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 239000011787 zinc oxide Substances 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 229910001297 Zn alloy Inorganic materials 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 235000010755 mineral Nutrition 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000002203 pretreatment Methods 0.000 description 3
- 239000011253 protective coating Substances 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 239000005442 atmospheric precipitation Substances 0.000 description 2
- 238000009500 colour coating Methods 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 238000005554 pickling Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- YJVLWFXZVBOFRZ-UHFFFAOYSA-N titanium zinc Chemical compound [Ti].[Zn] YJVLWFXZVBOFRZ-UHFFFAOYSA-N 0.000 description 2
- 239000011573 trace mineral Substances 0.000 description 2
- 235000013619 trace mineral Nutrition 0.000 description 2
- 229910000165 zinc phosphate Inorganic materials 0.000 description 2
- 229910000906 Bronze Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 239000005749 Copper compound Substances 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000010974 bronze Substances 0.000 description 1
- 229910001748 carbonate mineral Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 150000001880 copper compounds Chemical class 0.000 description 1
- 229910001431 copper ion Inorganic materials 0.000 description 1
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 1
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Inorganic materials [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 235000000396 iron Nutrition 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910001453 nickel ion Inorganic materials 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000001117 sulphuric acid Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 238000012384 transportation and delivery Methods 0.000 description 1
- LRXTYHSAJDENHV-UHFFFAOYSA-H zinc phosphate Chemical compound [Zn+2].[Zn+2].[Zn+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O LRXTYHSAJDENHV-UHFFFAOYSA-H 0.000 description 1
- IPCXNCATNBAPKW-UHFFFAOYSA-N zinc;hydrate Chemical compound O.[Zn] IPCXNCATNBAPKW-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/26—After-treatment
-
- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
- C23C22/53—Treatment of zinc or alloys based thereon
Definitions
- the present invention concerns a product that has a coating comprising zinc, and a patina layer.
- the product comprises iron or steel and has a coating comprising zinc, i.e. pure or high purity zinc or a zinc alloy, and a patina layer on top of the coating comprising zinc.
- the present invention also concerns a method for artificially producing a patina layer on at least one part of a product having a coating comprising zinc.
- Patina is a thin layer that naturally forms on the surface of copper, bronze and ferrous metals i.e. steels and irons, on environmental exposure to atmospheric elements such as air and precipitation, in the form of rain, snow, dew, ice, humidity, condensation, etc.
- Patinas which may comprise various chemical compounds such as oxides, carbonates, sulfides or sulfates, can provide a protective covering to materials that would otherwise be damaged by corrosion or weathering.
- Galvanization is a process of applying a protective zinc coating to a ferrous metal, i.e. iron or steel, to prevent rusting.
- the most common galvanization method is hot-dip galvanization, in which ferrous metal parts are submerged in a bath of molten zinc. Galvanizing protects the ferrous metal surface in two ways: it forms a coating of corrosion- resistant zinc which prevents corrosive substances from reaching the more delicate part of the metal, and the zinc serves as a sacrificial anode so that even if the coating is scratched, the exposed metal will still be protected by the remaining zinc.
- a patina layer forms naturally on a galvanized ferrous metal that is exposed to atmospheric elements during its use in the following stages: the zinc in the galvanized ferrous metal surface reacts with oxygen in the air to form zinc oxide, ZnO, water or moisture from atmospheric precipitation reacts with the zinc oxide to form zinc hydroxide, Zn(OH) 2 , and oxygen and carbon dioxide in the air reacts with the zinc hydroxide to form basic zinc carbonate, also known as hydrozincite, which is a white carbonate mineral consisting of Zn 5 (C0 3 )2(OH) 6 .
- hydrozincite is a white carbonate mineral consisting of Zn 5 (C0 3 )2(OH) 6 .
- the natural formation of a patina layer on a galvanized ferrous metal can take up to several years depending on environmental conditions.
- patina layer This natural formation of a patina layer is disadvantageous since it is necessary to wait until a patina layer has formed before a galvanized ferrous metal can be painted in order to ensure that the paint will properly adhere to the surface of the ferrous metal steel.
- galvanized ferrous metal is passivated to protect the relatively sensitive zinc layer from corrosion. Paint applied to a surface of a passivated galvanized ferrous metal may lose its adhesion over time since such a freshly applied passivation layer is not an optimum surface for painting.
- a naturally formed patina layer may not be uniform as regards its thickness and/or structure, and it may contain impurities, i.e.
- a naturally formed patina does provide a good substrate for painting.
- the continuous colour coating of galvanized ferrous metal usually requires several chemical pre-treatments, which may at least partly be rendered unnecessary by allowing a patina layer to form and applying paint directly on the patina layer.
- US patent no. US 3,767,478 discloses the formation of a smooth, even, corrosion resistant patina on a zinc surface by abrading or otherwise mechanically graining the surface, and thereafter forming an even zinc phosphate Zn 3 (P0 4 ) 2 coating thereon, preferably in the presence of a nickel ion.
- This solution involves the formation of a protective layer having a different chemical composition and structure than a naturally formed patina layer.
- US 6,231 ,686 concerns a method of treating a metal object having an outer layer including zinc.
- the method includes applying to the object a treating material in the form of an alkaline solution or a gas.
- the treating material reacts to form a reaction layer on the outer layer.
- the reaction layer includes a zinc reaction product.
- a protective coating such as lubricant is applied to the object, wherein the reaction layer is present in an amount effective to increase a lubricity of the object.
- the metal object includes an outer layer including zinc which may be substantially non-oxidized.
- a reaction layer comprising zinc carbonate is disposed on the outer layer.
- the reaction layer is present in an amount effective to increase a lubricity of the object during a forming process.
- a protective coating may be in contact with the reaction layer.
- the patina layer which consists of hydrozincite, is formed using a bicarbonate compound.
- US 2005/003091 relates to the production of protective coatings with a dark color by pickling rolled flat objects, made from titanium zinc, for use in construction.
- the flat objects are pickled in an aqueous pickling bath containing a mixed acid of sulphuric acid and nitric acid and passivated after rinsing by application of a protective layer.
- Rolled flat objects such as those made from a titanium zinc alloy are used.
- the alloy comprises mainly zinc of high purity with additionally a copper content of 1.0 to 2.0 wt. %, a titanium content of 0.06 to 0.2 wt. % and a maximum aluminum content of 0.015 wt. %.
- An object of the invention is to provide an improved product comprising a coating comprising zinc and a patina layer.
- a product such as a product comprising iron or steel, which has coating containing zinc, i.e. said product comprises a coating containing pure zinc, high purity zinc (i.e. at least 95% zinc), or a zinc alloy, such as zinc alloyed with aluminium or magnesium.
- the coating comprising zinc may be applied using any suitable method, such as galvanizing, hot-dip galvanizing, electro-galvanizing, spraying, thermal spray coating or mechanical plating.
- the patina layer is an artificially-formed patina layer that comprises zinc carbonate having the chemical formula ZnC0 3 , i.e.
- the artificially-formed patina layer also comprises at least one type of metallic ion of a metal that is more noble than zinc.
- the at least one type of metallic ion of a metal that is more noble than zinc constitutes part of the structure of the artificially- formed patina layer.
- the patina layer is not therefore a naturally formed patina layer, but it has been artificially- formed before it is delivered to an end user and put into use.
- a naturally formed patina layer always contains or consists of basic zinc carbonate having the chemical formula Zn 5 (C0 3 ) 2 (OH) 6 , which is also known as hydrozincite.
- a patina layer comprising zinc carbonate having the chemical formula ZnC0 3 will not form naturally during atmospheric exposure of a product having a coating comprising zinc.
- a naturally-formed patina layer does not have a needle-like structure (like artificially-formed basic zinc carbonate having the chemical formula Zn 5 (C0 3 ) 2 (OH) 6 ,) or a ball-like structure (like artificially-formed zinc carbonate having the chemical formula ZnC0 3 ) or a combination of these structures.
- a naturally-formed patina layer is a porous layer that does not have a needle-like and/or ball-like structure.
- the artificially-formed patina layer comprises basic zinc carbonate having the chemical formula (Zn 5 (C0 3 ) 2 (OH) 6 ), i.e. hydrozincite, having a needle-like structure.
- the patina layer also comprises one or more other zinc carbonate compounds.
- the artificially-formed patina layer may be produced under controlled conditions whereby impurities such as dust, dirt, oil, grease, sea salt, and/or any impurities from air pollution caused by industry or traffic for example, which are incorporated into the patina layer during its artificial formation, will be eliminated or substantially reduced compared to naturally formed patina layers.
- impurities such as dust, dirt, oil, grease, sea salt, and/or any impurities from air pollution caused by industry or traffic for example, which are incorporated into the patina layer during its artificial formation, will be eliminated or substantially reduced compared to naturally formed patina layers.
- the product according to the present invention therefore comprises a patina layer that is more uniform and of a higher quality, i.e. more pure and ideal, than a naturally formed patina layer.
- This artificially-formed patina layer is advantageously formed much more quickly than a naturally formed patina layer.
- the artificially-formed patina layer will protect the product from corrosion during the transportation, the storage and the use of the product and it serves as a good substrate for post-patination operations such as painting. Post-patination operations may be carried out, without pre-treatment or cleaning in many cases, as soon as the patina layer has been artificially-formed or as soon as the product is delivered to an end user, or as soon as the product has been mounted ready for use.
- Such an artificially-formed layer may also at least partly eliminate the need for chemical pre-treatments in post-patination operations such as continuous colour coating.
- the artificially-formed patina layer has equivalent or better chemical properties than a naturally formed patina layer but will exclude structural irregularities due to the lack of impurities such as dust, dirt, oil, grease, sea salt, and/or any impurities from air pollution. It is non-toxic, non-combustible and thereby environmentally friendly. Furthermore, zinc run-off will not take place during artificial patina formation (as it does during natural patina formation when a product having a coating comprising zinc is exposed to atmospheric elements.) This lack of run-off prolongs the useful lifetime of the product according to the invention since the product having an artificially-formed patina layer will consequently have a thicker coating comprising zinc and thereby prolonged corrosion resistance compared to a product having a natural formed patina layer.
- the artificially-formed patina layer namely has fewer OH-groups and/or less absorbed water than the naturally formed patina layer.
- the word "layer” as used in this document is intended to mean any amount of material of any uniform or non-uniform thickness that is uniformly or non-uniformly spread over an area of a substrate, i.e. over at least a part of, or the whole of a surface of a product.
- a patina layer may namely be artificially-formed on at least part of a product's coating that comprises zinc in any desired manner or pattern depending on the end use of the product, or even for aesthetic reasons.
- the coating comprising zinc may also be formed on at least part of, or the whole of any one or more surfaces of a product.
- the product according to the present invention may be of any shape, weight, or size. It may be in the form any flat, tubular or shaped product, such as strip, sheet, plate, wire or profile; it may be a hot-rolled or cold-rolled product.
- the product may be used for any suitable application, such as applications in the automotive, construction, marine, engineering or metal-producing industries.
- the product may for example constitute at least one part of a vehicle, a civil engineering construction, such as a bridge, part of a building, such as a roof, a fagade, a silo, a trailer, a monument, etc.
- the at least one type of metallic ion of a metal that is more noble than zinc is preferably an ion of at least one of the following: copper, iron, silver, palladium, platinum, gold, titanium, molybdenum, tungsten, tin, lead, tantalum, nickel, indium, cadmium or beryllium.
- the present invention also concerns a method for artificially producing a patina layer on at least part of a surface of a product having a coating comprising zinc to thereby produce a product according to any of the embodiments of the invention.
- artificially producing is intended to mean that the patina layer is not produced naturally by exposing at least part of the product having a coating comprising zinc to atmospheric elements).
- the method comprises the step of treating at least part of surface of a product having a coating comprising zinc with carbon dioxide (in any form, i.e.
- the artificial formation of a patina layer is initiated by the reduction of the metal that is more noble than zinc, such as copper (Cu 2+ to Cu), and the corresponding oxidation of the zinc in the coating comprising zinc (of Zn to Zn 2+ ).
- controlled conditions means at any place where products having a coating comprising zinc are manufactured, such as a factory or steel plant. Controlled conditions ensure that the artificially-formed patina layer that is formed will comprise zinc carbonate having the chemical formula ZnC0 3 , i.e. a mineral ore of zinc also known as Smithsonite, and/or basic zinc carbonate (Zn 5 (C0 3 ) 2 (OH) 6 ), also known as hydrozincite, and at least one type of metallic ion of a metal that is more noble than zinc.
- the artificially- formed patina layer produced using such a method comprises basic zinc carbonate having the chemical formula (Zn 5 (C0 3 ) 2 (OH) 6 ), i.e. hydrozincite, having a needle-like structure.
- the artificially-formed patina layer may also comprise one or more other zinc carbonate compounds.
- the artificially-formed patina layer does not namely contain any or very little of the following impurities: dust, dirt, oil, grease, sea salt, and/or any impurity from air pollution.
- This method is preferably performed before the product leaves the factory, i.e. before it is delivered to an end user, or before it undergoes a subsequent manufacturing or finishing step, such as painting. The method may however be performed at any suitable time during the manufacture, storage, delivery, use, repair and/or maintenance of the product.
- the step of treating at least part of a surface of a product also comprises adding a surfactant, such as ethanol, to lower surface tension between the water and the carbon dioxide and thereby improve the emulsion forming of carbon dioxide.
- a surfactant such as ethanol
- the method is performed in a continuous line manufacturing process in which the product is produced without interruption, whereby a material is substantially continuously in motion while it undergoes a coating process to form a coating comprising zinc on at least part of the product, and/or artificial patination and/or one or more chemical reactions, mechanical treatments and/or heat treatments.
- at least part of the method according to the present invention may be carried out using batch production in which one or more products are created stage by stage over a series of workstations.
- the step of treating at least part of a surface of a product involves subjecting at least part of the surface to a temperature of at least 273 K, or a temperature of 273-293 or 293-343 K, 300-340 K or 310-330 K, and/or to a pressure of 0.1 -30 MPa, or 6-30 MPa, or 0.1 -20 MPa or 0.1 -20 MPa for a predetermined exposure time.
- the predetermined exposure time is up to 60 minutes, or 5-50 minutes or 5-30 minutes or 10-30 minutes or until a patina layer having the desired properties has formed on at least part of the surface.
- an exposure time of a fraction of one second or up to 10 seconds may be sufficient.
- the method comprises the step of decreasing the pressure at a rate, such as 0.1 -30 MPa per 10 minutes or per 20 minutes or per 30 minutes or longer, after the predetermined exposure time has elapsed.
- a rate such as 0.1 -30 MPa per 10 minutes or per 20 minutes or per 30 minutes or longer. This may be done by decreasing the pressure in a pressure chamber in batch production, or by merely moving a product out of an artificial patination section of a continuous line manufacturing process at a predetermined rate.
- said coating comprising zinc is applied using one of the following methods: galvanizing, hot-dip galvanizing, electro-galvanizing, spraying, thermal spray coating or mechanical plating.
- the at least one type of metallic ion of a metal that is more noble than zinc is preferably an ion of at least one of the following: copper, iron, silver, palladium, platinum, gold, titanium, molybdenum, tungsten, tin, lead, tantalum, nickel, indium, cadmium or beryllium.
- the precursor is preferably non-soluble in water, although it can alternatively be soluble in water.
- the carbon dioxide is in at least one of the following forms: gaseous, liquid phase, solid form, supercritical, i.e. at a temperature and pressure above its critical point (304.25 K and 7.39 MPa), where distinct liquid and gas phases do not exist.
- Carbon dioxide may namely be in any form or a mixture of forms depending on the reaction time and desired structure of the patina layer.
- Supercritical carbon dioxide has the density of a liquid but the properties of a gas. At high pressure and elevated temperature the carbon dioxide (C0 2 ) becomes dissolved in water (H 2 0). The pH of this carbonated water decreases because the chemical equilibrium C0 2 + H 2 0 ⁇ H 2 C0 3 (carbonic acid) is shifted towards carbonic acid. While not wishing to be bound by theory, it appears as though carbonic acid plays an important role in dissolving metallic zinc prior to the formation of zinc carbonates. There is no carbonate formation in the absence of water or carbon dioxide. The metal that is more noble than zinc will boost the reaction since it will also cause the dissolution of metallic zinc.
- a desired morphology of the artificially-formed patina layer such as a needle-like or balllike structure, and/or a desired ratio of ZnC0 3 to other components of the artificially produced patina layer, such as (Zn 5 (C0 3 )2(OH) 6 ) and other zinc carbonate compounds can be tailored using different reaction times, temperatures, precursors and carbon dioxide pressures.
- the water is de-ionized water, tap water, sea water, lake water or any other suitable aqueous electrolyte which allows a zinc hydroxide layer to form during the artificial formation of a patina layer.
- the method preferably comprises at least one of the following steps: cleaning and/or roughening a surface of the product having a coating comprising zinc prior to artificially forming the patina layer on the coated surface. It is not however always necessary to clean and/or roughen the coated surface of the product.
- the method comprises the steps of dissolving a metal precursor comprising the at least one type of metallic ion of a metal that is more noble than zinc, which may be soluble or non-soluble in water, in a solvent, and then mixing the solvent containing the metal precursor with the water to treat the coated surface of a product.
- the solvent can be an organic solvent, such as ethanol, methanol or another alcohol or an aldehyde or a ketone. It should be noted that the expression "solvent" is intended to include a single solvent, or any mixture of solvents.
- Figure 1 shows the natural formation of a patina layer on a galvanized surface of a galvanized product that is exposed to the atmosphere
- Figure 2 shows a product according to an embodiment of the invention
- Figure 3 is a flow diagram showing the steps of a method according to an embodiment of the invention in which an artificially-formed patina is formed on at least part of a coated surface of a product.
- Figure 1 a shows a product 10, such as a galvanized product, which comprises a metal substrate 12, such as steel or iron, having a coating 14 comprising zinc.
- a product 10 such as a galvanized product, which comprises a metal substrate 12, such as steel or iron, having a coating 14 comprising zinc.
- oxygen in the air 16 illustrated as a free- flowing air flow, will react with the zinc in the galvanized surface to form zinc oxide (ZnO) 20 18.
- Figure 1 b shows that water and/or moisture from atmospheric precipitation 20 reacts with the zinc oxide 18 to form zinc hydroxide 22 (Zn(OH) 2 ).
- Figure 1 c) shows that oxygen and carbon dioxide in the air 16 reacts with the zinc hydroxide 22 to form basic zinc carbonate 23 having the chemical formula Zn 5 (C0 3 ) 2 (OH) 6 .
- a naturally formed patina 23 as illustrated in figures 1 a) to c) can take 30 years depending on the atmospheric conditions to which a galvanized product 10 is subjected during its use, transportation and/or storage. Furthermore, a naturally formed patina layer 23 may not be uniform and it may contain impurities from its surroundings, such as dust, dirt, oil, grease, sea salt and/or trace elements of contaminants present in its surroundings, since a patina layer 23 exposed to atmospheric elements is not formed 35 under controlled conditions.
- Figure 2 shows a product 10, such as a product 10 comprising iron or steel 12, i.e. an iron or steel substrate or body of any desired shape, thickness, cross-section and size having one or more surfaces that may be at least partly coated.
- the product 10 comprises a uniform or non-uniform coating 14 containing zinc and an artificially-formed patina layer 24 that is formed on top of said coating 14, i.e. on top of at least part of said coating 14 or so as to cover the entire coating 14.
- the artificially-formed patina layer 24 comprises zinc carbonate having the chemical formula ZnC0 3 , i.e. a mineral ore of zinc also known as Smithsonite, and/or basic zinc carbonate (Zn 5 (C0 3 ) 2 (OH) 6 ), also known as hydrozincite.
- the artificially-formed platina layer 24 comprises at least one type of metallic ion of a metal that is more noble than zinc, such as copper (Cu 2+ ), iron (Fe 2+ ) or silver (Ag 2+ ) which remain(s) as a consequence of the artificial patina formation.
- a metal that is more noble than zinc such as copper (Cu 2+ ), iron (Fe 2+ ) or silver (Ag 2+ ) which remain(s) as a consequence of the artificial patina formation.
- a product 10 according to the present invention such as a hot-dip galvanized iron or steel sheet, will, on the contrary, have a coated surface comprising a patina layer 24 of better quality than a naturally formed patina layer since it has been artificially-formed under controlled conditions.
- the artificially-formed patina layer 24 will not however contain avoidable impurities, such as dust, dirt, oil, grease, sea salt etc. when it is delivered to an end user.
- the steps of a method for manufacturing a product 10 comprising an artificially-formed patina layer 24 according to an embodiment of the invention are illustrated in figure 3, wherein non-essential method steps are shown in rectangles drawn with dashed lines and essential method steps are shown in rectangles drawn with continuous lines.
- the method comprises the steps of optionally cleaning and/or roughening at least part of a coated surface of a product 10 prior and artificially forming the patina layer 24 thereon in order to provide a more adhesive surface for subsequent treatments, such as painting.
- One or more impurities such as an aluminium oxide, which may be formed on top of the coated surface, after galvanization for example, may be removed from the coated surface prior to artificial patination.
- the coated surface may then be placed or moved into in a controlled environment.
- the coated surface may be placed into a pressure chamber or an artificial patination workstation during batch production or into it may be moved into an artificial patination section at a controlled feed rate during a continuous line manufacturing process.
- the coated surface is exposed to carbon dioxide in any suitable form, such as carbon dioxide having a purity of at least 99.8%, and may optionally be heated to a temperature of at least 293 K, such as 293-343 K and/or subjected to a pressure of 6-30 MPa.
- water containing a metal precursor i.e.
- any compound comprising at least one type of metal ion that is more noble than zinc may be applied and/or sprayed and/or injected onto the coated surface either separately or together with carbon dioxide, whereupon a patina layer 24 will begin to form on the coated surface.
- the metal precursor may be Cu(hfac) 2 or Ag(cod)(hfac) or Cu(N0 3 )2 or Fe(N0 3 )3-
- the precursor is non-soluble in water, such as Cu(hfac) 2 or Ag(cod)(hfac), and may firstly be dissolved in a solvent, such as an organic solvent, such as ethanol and then mixed with water before it is applied and/or sprayed and/or injected onto the coated surface.
- a solvent such as an organic solvent, such as ethanol
- the coated surface may remain in the controlled environment for a predetermined exposure time, such from a fraction of a second (which may be sufficient during a continuous line manufacturing process) up to 60 minutes. If the product 10 is being manufactured using batch production, in a pressure chamber for example, the pressure may be decreased at a predetermined rate, such as at a rate of 0.1 -30 MPa per 10 minutes or longer after the predetermined exposure time has elapsed. The rate at which the pressure is decreased will affect the structure of the artificially-formed patina layer 24.
- the patina layer 24 will continue to form during the entire method until the coated surface is removed from the pressure chamber, or from an application section of a continuous line manufacturing process, where carbon dioxide at a desired temperature and/or pressure, water and at least one metallic ion of a metal that is more noble than zinc is applied and/or injected and/or sprayed onto the coated surface.
- the artificially patinated product 10 may leave the factory where it is manufactured and be delivered to an end user or placed in storage.
- the artificially-formed patina layer 24 is not water soluble and does not wash off the coated surface.
- the at least one type of metallic ion acts as a catalyst in the formation of a patina layer 24, it speeds up the reaction time and will remain in the artificially-formed patina layer 24, which makes an artificially-formed patina layer 24 distinguishable from a naturally formed patina layer.
- the artificially-formed patina layer 24 may contain one or more copper compounds if a metal precursor containing copper ions has been used in its manufacturing method.
- the artificially-formed patina layer 24 will have superior properties as compared to a naturally formed patina layer since its structure will be more uniform (rather than randomly compact or porous) and it will adhere better to the underlying coated surface. Paint can be applied directly to the artificially-formed patina layer 24 and no adhesion problems have been encountered.
- the method according to the present invention bypasses the different stages of the natural formation of a patina layer 24 as illustrated in figures 1 a) to c) and will form a more pure and ideal and more tightly adhered layer as compared to a naturally formed patina layer.
- a naturally formed patina layer 24 may namely be non-uniform as regards its thickness and/or properties, and it may be loosely adhered to the underlying coated surface, it may be porous and contaminated with impurities.
- the method according to the present invention may comprise the step of treating a galvanized surface of a hot-dip galvanized steel sheet 10 with supercritical carbon dioxide and 0.53 m-% copper solution (including water) at a temperature of 323 K and at a pressure of 30 MPa for 30 minutes, and then decreasing the pressure at a rate of 10 MPa per 10 minutes.
Abstract
A product (10) having a coating (14) comprising zinc, and an artificially-formed patina layer (24) that comprises zinc carbonate having the chemical formula ZnCO3, i.e. Smithsonite, and/or basic zinc carbonate having the chemical formula (Zn5(CO3)2(OH)6), i.e. hydrozincite, and at least one type of metallic ion of a metal that is more noble than zinc, and a method for producing the artificially-formed patina layer (24) on at least one part of a product having a coating comprising zinc.
Description
PATINA LAYER ON GALVANIZED PRODUCT AND METHOD THEREFOR
TECHNICAL FIELD
The present invention concerns a product that has a coating comprising zinc, and a patina layer. The product comprises iron or steel and has a coating comprising zinc, i.e. pure or high purity zinc or a zinc alloy, and a patina layer on top of the coating comprising zinc. The present invention also concerns a method for artificially producing a patina layer on at least one part of a product having a coating comprising zinc.
BACKGROUND OF THE INVENTION
Patina is a thin layer that naturally forms on the surface of copper, bronze and ferrous metals i.e. steels and irons, on environmental exposure to atmospheric elements such as air and precipitation, in the form of rain, snow, dew, ice, humidity, condensation, etc. Patinas, which may comprise various chemical compounds such as oxides, carbonates, sulfides or sulfates, can provide a protective covering to materials that would otherwise be damaged by corrosion or weathering.
Galvanization is a process of applying a protective zinc coating to a ferrous metal, i.e. iron or steel, to prevent rusting. The most common galvanization method is hot-dip galvanization, in which ferrous metal parts are submerged in a bath of molten zinc. Galvanizing protects the ferrous metal surface in two ways: it forms a coating of corrosion- resistant zinc which prevents corrosive substances from reaching the more delicate part of the metal, and the zinc serves as a sacrificial anode so that even if the coating is scratched, the exposed metal will still be protected by the remaining zinc. A patina layer forms naturally on a galvanized ferrous metal that is exposed to atmospheric elements during its use in the following stages: the zinc in the galvanized ferrous metal surface reacts with oxygen in the air to form zinc oxide, ZnO, water or moisture from atmospheric precipitation reacts with the zinc oxide to form zinc hydroxide, Zn(OH)2, and oxygen and carbon dioxide in the air reacts with the zinc hydroxide to form basic zinc carbonate, also known as hydrozincite, which is a white carbonate mineral consisting of Zn5(C03)2(OH)6.
Usually, the natural formation of a patina layer on a galvanized ferrous metal can take up to several years depending on environmental conditions. This natural formation of a patina layer is disadvantageous since it is necessary to wait until a patina layer has formed before a galvanized ferrous metal can be painted in order to ensure that the paint will properly adhere to the surface of the ferrous metal steel. Normally, galvanized ferrous metal is passivated to protect the relatively sensitive zinc layer from corrosion. Paint applied to a surface of a passivated galvanized ferrous metal may lose its adhesion over time since such a freshly applied passivation layer is not an optimum surface for painting. A naturally formed patina layer may not be uniform as regards its thickness and/or structure, and it may contain impurities, i.e. contaminants picked up from its surroundings, such as dust, dirt, oil, grease and/or sea salt or trace elements from air pollution caused by industry or traffic for example. However, a naturally formed patina does provide a good substrate for painting. Furthermore, the continuous colour coating of galvanized ferrous metal usually requires several chemical pre-treatments, which may at least partly be rendered unnecessary by allowing a patina layer to form and applying paint directly on the patina layer.
US patent no. US 3,767,478 discloses the formation of a smooth, even, corrosion resistant patina on a zinc surface by abrading or otherwise mechanically graining the surface, and thereafter forming an even zinc phosphate Zn3(P04)2 coating thereon, preferably in the presence of a nickel ion. This solution involves the formation of a protective layer having a different chemical composition and structure than a naturally formed patina layer.
US 6,231 ,686 concerns a method of treating a metal object having an outer layer including zinc. The method includes applying to the object a treating material in the form of an alkaline solution or a gas. The treating material reacts to form a reaction layer on the outer layer. The reaction layer includes a zinc reaction product. A protective coating such as lubricant is applied to the object, wherein the reaction layer is present in an amount effective to increase a lubricity of the object. In another embodiment, the metal object includes an outer layer including zinc which may be substantially non-oxidized. A reaction layer comprising zinc carbonate is disposed on the outer layer. The reaction layer is present in an amount effective to increase a lubricity of the object during a forming
process. A protective coating may be in contact with the reaction layer. The patina layer, which consists of hydrozincite, is formed using a bicarbonate compound.
The article entitled "Long-term use of galvanized steel in external applications. Aspects of patina formation, zinc runoff, barrier properties of surface treatments, and coatings and environmental fate", by David Lindstrom et al., published in Environmental Monitoring and Assessment; An International Journal Devoted to Progress in the use of Monitoring Data in Assessing Environmental Risks to Man and the Environment, Vol. 173, no. 1 - 4, 7 March 2010 (2010-03-07), pages 139-153, XP019872054, ISSN: 1573-2959, DOI: 10.1007/S10661 -010-1377-8 describes the long-term run-off rates of zinc from naturally patinated galvanized steel surfaces with the main focus on hot-dipped galvanized steel exposed for up to ten years in non-sheltered urban atmospheric conditions.
US 2005/003091 relates to the production of protective coatings with a dark color by pickling rolled flat objects, made from titanium zinc, for use in construction. The flat objects are pickled in an aqueous pickling bath containing a mixed acid of sulphuric acid and nitric acid and passivated after rinsing by application of a protective layer. Rolled flat objects such as those made from a titanium zinc alloy are used. The alloy comprises mainly zinc of high purity with additionally a copper content of 1.0 to 2.0 wt. %, a titanium content of 0.06 to 0.2 wt. % and a maximum aluminum content of 0.015 wt. %.
SUMMARY OF THE INVENTION An object of the invention is to provide an improved product comprising a coating comprising zinc and a patina layer.
This object is achieved by a product, such as a product comprising iron or steel, which has coating containing zinc, i.e. said product comprises a coating containing pure zinc, high purity zinc (i.e. at least 95% zinc), or a zinc alloy, such as zinc alloyed with aluminium or magnesium. The coating comprising zinc may be applied using any suitable method, such as galvanizing, hot-dip galvanizing, electro-galvanizing, spraying, thermal spray coating or mechanical plating. The patina layer is an artificially-formed patina layer that comprises zinc carbonate having the chemical formula ZnC03, i.e. a mineral ore of zinc also known as Smithsonite, and/or basic zinc carbonate (Zn5(C03)2(OH)6), also known as
hydrozincite. The artificially-formed patina layer also comprises at least one type of metallic ion of a metal that is more noble than zinc. The at least one type of metallic ion of a metal that is more noble than zinc constitutes part of the structure of the artificially- formed patina layer.
The patina layer is not therefore a naturally formed patina layer, but it has been artificially- formed before it is delivered to an end user and put into use. A naturally formed patina layer always contains or consists of basic zinc carbonate having the chemical formula Zn5(C03)2(OH)6, which is also known as hydrozincite. A patina layer comprising zinc carbonate having the chemical formula ZnC03 will not form naturally during atmospheric exposure of a product having a coating comprising zinc. Furthermore, a naturally-formed patina layer does not have a needle-like structure (like artificially-formed basic zinc carbonate having the chemical formula Zn5(C03)2(OH)6,) or a ball-like structure (like artificially-formed zinc carbonate having the chemical formula ZnC03) or a combination of these structures. Instead, a naturally-formed patina layer is a porous layer that does not have a needle-like and/or ball-like structure. The artificially-formed patina layer comprises basic zinc carbonate having the chemical formula (Zn5(C03)2(OH)6), i.e. hydrozincite, having a needle-like structure. According to an embodiment of the invention the patina layer also comprises one or more other zinc carbonate compounds.
The artificially-formed patina layer may be produced under controlled conditions whereby impurities such as dust, dirt, oil, grease, sea salt, and/or any impurities from air pollution caused by industry or traffic for example, which are incorporated into the patina layer during its artificial formation, will be eliminated or substantially reduced compared to naturally formed patina layers.
The product according to the present invention therefore comprises a patina layer that is more uniform and of a higher quality, i.e. more pure and ideal, than a naturally formed patina layer. This artificially-formed patina layer is advantageously formed much more quickly than a naturally formed patina layer.
The artificially-formed patina layer will protect the product from corrosion during the transportation, the storage and the use of the product and it serves as a good substrate
for post-patination operations such as painting. Post-patination operations may be carried out, without pre-treatment or cleaning in many cases, as soon as the patina layer has been artificially-formed or as soon as the product is delivered to an end user, or as soon as the product has been mounted ready for use. Such an artificially-formed layer may also at least partly eliminate the need for chemical pre-treatments in post-patination operations such as continuous colour coating.
The artificially-formed patina layer has equivalent or better chemical properties than a naturally formed patina layer but will exclude structural irregularities due to the lack of impurities such as dust, dirt, oil, grease, sea salt, and/or any impurities from air pollution. It is non-toxic, non-combustible and thereby environmentally friendly. Furthermore, zinc run-off will not take place during artificial patina formation (as it does during natural patina formation when a product having a coating comprising zinc is exposed to atmospheric elements.) This lack of run-off prolongs the useful lifetime of the product according to the invention since the product having an artificially-formed patina layer will consequently have a thicker coating comprising zinc and thereby prolonged corrosion resistance compared to a product having a natural formed patina layer. The artificially-formed patina layer namely has fewer OH-groups and/or less absorbed water than the naturally formed patina layer.
The word "layer" as used in this document is intended to mean any amount of material of any uniform or non-uniform thickness that is uniformly or non-uniformly spread over an area of a substrate, i.e. over at least a part of, or the whole of a surface of a product. A patina layer may namely be artificially-formed on at least part of a product's coating that comprises zinc in any desired manner or pattern depending on the end use of the product, or even for aesthetic reasons. The coating comprising zinc may also be formed on at least part of, or the whole of any one or more surfaces of a product.
The product according to the present invention may be of any shape, weight, or size. It may be in the form any flat, tubular or shaped product, such as strip, sheet, plate, wire or profile; it may be a hot-rolled or cold-rolled product.
The product may be used for any suitable application, such as applications in the automotive, construction, marine, engineering or metal-producing industries. The product may for example constitute at least one part of a vehicle, a civil engineering construction,
such as a bridge, part of a building, such as a roof, a fagade, a silo, a trailer, a monument, etc.
According to an embodiment of the invention the at least one type of metallic ion of a metal that is more noble than zinc is preferably an ion of at least one of the following: copper, iron, silver, palladium, platinum, gold, titanium, molybdenum, tungsten, tin, lead, tantalum, nickel, indium, cadmium or beryllium.
The present invention also concerns a method for artificially producing a patina layer on at least part of a surface of a product having a coating comprising zinc to thereby produce a product according to any of the embodiments of the invention. The expression "artificially producing is intended to mean that the patina layer is not produced naturally by exposing at least part of the product having a coating comprising zinc to atmospheric elements). The method comprises the step of treating at least part of surface of a product having a coating comprising zinc with carbon dioxide (in any form, i.e. in solid, liquid, gaseous or supercritical form, or in any combination of these forms), water and at least one type of metallic ion of a metal that is more noble than zinc under controlled, for example in a controlled environment, such as under controlled temperature, pressure and time, in order to provide an artificially-formed patina layer (rather than a naturally formed patina layer) on the surface of the product having a coating comprising zinc.
The artificial formation of a patina layer is initiated by the reduction of the metal that is more noble than zinc, such as copper (Cu2+ to Cu), and the corresponding oxidation of the zinc in the coating comprising zinc (of Zn to Zn2+).
The expression "controlled conditions" means at any place where products having a coating comprising zinc are manufactured, such as a factory or steel plant. Controlled conditions ensure that the artificially-formed patina layer that is formed will comprise zinc carbonate having the chemical formula ZnC03, i.e. a mineral ore of zinc also known as Smithsonite, and/or basic zinc carbonate (Zn5(C03)2(OH)6), also known as hydrozincite, and at least one type of metallic ion of a metal that is more noble than zinc. The artificially- formed patina layer produced using such a method comprises basic zinc carbonate having the chemical formula (Zn5(C03)2(OH)6), i.e. hydrozincite, having a needle-like
structure. The artificially-formed patina layer may also comprise one or more other zinc carbonate compounds.
There will either be no impurities in the artificially-formed patina layer or much fewer impurities in the artificially-formed patina layer than in a naturally formed patina layer. The artificially-formed patina layer does not namely contain any or very little of the following impurities: dust, dirt, oil, grease, sea salt, and/or any impurity from air pollution. This method is preferably performed before the product leaves the factory, i.e. before it is delivered to an end user, or before it undergoes a subsequent manufacturing or finishing step, such as painting. The method may however be performed at any suitable time during the manufacture, storage, delivery, use, repair and/or maintenance of the product. According to an embodiment of the invention the step of treating at least part of a surface of a product also comprises adding a surfactant, such as ethanol, to lower surface tension between the water and the carbon dioxide and thereby improve the emulsion forming of carbon dioxide.
According to an embodiment of the invention, the method is performed in a continuous line manufacturing process in which the product is produced without interruption, whereby a material is substantially continuously in motion while it undergoes a coating process to form a coating comprising zinc on at least part of the product, and/or artificial patination and/or one or more chemical reactions, mechanical treatments and/or heat treatments. Alternatively, or additionally at least part of the method according to the present invention may be carried out using batch production in which one or more products are created stage by stage over a series of workstations.
According to an embodiment of the invention the step of treating at least part of a surface of a product involves subjecting at least part of the surface to a temperature of at least 273 K, or a temperature of 273-293 or 293-343 K, 300-340 K or 310-330 K, and/or to a pressure of 0.1 -30 MPa, or 6-30 MPa, or 0.1 -20 MPa or 0.1 -20 MPa for a predetermined exposure time.
According to an embodiment of the invention the predetermined exposure time is up to 60 minutes, or 5-50 minutes or 5-30 minutes or 10-30 minutes or until a patina layer having the desired properties has formed on at least part of the surface. In a continuous line
manufacturing process an exposure time of a fraction of one second or up to 10 seconds may be sufficient.
According to an embodiment of the invention the method comprises the step of decreasing the pressure at a rate, such as 0.1 -30 MPa per 10 minutes or per 20 minutes or per 30 minutes or longer, after the predetermined exposure time has elapsed. This may be done by decreasing the pressure in a pressure chamber in batch production, or by merely moving a product out of an artificial patination section of a continuous line manufacturing process at a predetermined rate.
According to an embodiment of the invention said coating comprising zinc is applied using one of the following methods: galvanizing, hot-dip galvanizing, electro-galvanizing, spraying, thermal spray coating or mechanical plating. According to an embodiment of the invention the at least one type of metallic ion of a metal that is more noble than zinc is preferably an ion of at least one of the following: copper, iron, silver, palladium, platinum, gold, titanium, molybdenum, tungsten, tin, lead, tantalum, nickel, indium, cadmium or beryllium. It is essential that at least one type of metallic ion that is more noble than zinc is used to artificially form the patina layer since a galvanic pair must be created on the coated surface, as this leads to the electrochemical dissolution of zinc during the formation of a patina. Zinc will namely corrode preferentially to metallic ion in the metal precursor that is used, i.e. the compound containing at least one type of metallic ion of a metal that is more noble than zinc. According to an embodiment of the invention, the precursor is preferably non-soluble in water, although it can alternatively be soluble in water.
According to an embodiment of the invention the carbon dioxide is in at least one of the following forms: gaseous, liquid phase, solid form, supercritical, i.e. at a temperature and pressure above its critical point (304.25 K and 7.39 MPa), where distinct liquid and gas phases do not exist. Carbon dioxide may namely be in any form or a mixture of forms depending on the reaction time and desired structure of the patina layer.
Supercritical carbon dioxide has the density of a liquid but the properties of a gas. At high pressure and elevated temperature the carbon dioxide (C02) becomes dissolved in water
(H20). The pH of this carbonated water decreases because the chemical equilibrium C02 + H20 <→ H2C03 (carbonic acid) is shifted towards carbonic acid. While not wishing to be bound by theory, it appears as though carbonic acid plays an important role in dissolving metallic zinc prior to the formation of zinc carbonates. There is no carbonate formation in the absence of water or carbon dioxide. The metal that is more noble than zinc will boost the reaction since it will also cause the dissolution of metallic zinc.
A desired morphology of the artificially-formed patina layer, such as a needle-like or balllike structure, and/or a desired ratio of ZnC03 to other components of the artificially produced patina layer, such as (Zn5(C03)2(OH)6) and other zinc carbonate compounds can be tailored using different reaction times, temperatures, precursors and carbon dioxide pressures.
According to an embodiment of the invention the water is de-ionized water, tap water, sea water, lake water or any other suitable aqueous electrolyte which allows a zinc hydroxide layer to form during the artificial formation of a patina layer.
According to an embodiment of the invention the method preferably comprises at least one of the following steps: cleaning and/or roughening a surface of the product having a coating comprising zinc prior to artificially forming the patina layer on the coated surface. It is not however always necessary to clean and/or roughen the coated surface of the product.
According to an embodiment of the invention the method comprises the steps of dissolving a metal precursor comprising the at least one type of metallic ion of a metal that is more noble than zinc, which may be soluble or non-soluble in water, in a solvent, and then mixing the solvent containing the metal precursor with the water to treat the coated surface of a product. The solvent can be an organic solvent, such as ethanol, methanol or another alcohol or an aldehyde or a ketone. It should be noted that the expression "solvent" is intended to include a single solvent, or any mixture of solvents.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be further explained by means of non-limiting examples with reference to the appended figures where;
Figure 1 shows the natural formation of a patina layer on a galvanized surface of a galvanized product that is exposed to the atmosphere,
Figure 2 shows a product according to an embodiment of the invention, and
5
Figure 3 is a flow diagram showing the steps of a method according to an embodiment of the invention in which an artificially-formed patina is formed on at least part of a coated surface of a product.
10 It should be noted that the drawings have not necessarily been drawn to scale and that the dimensions of certain features may have been exaggerated for the sake of clarity. Furthermore, any feature described in connection with the product according to the present invention may also be a feature of the method, and vice versa.
15 DETAILED DESCRIPTION OF EMBODIMENTS
Figure 1 a) shows a product 10, such as a galvanized product, which comprises a metal substrate 12, such as steel or iron, having a coating 14 comprising zinc. When the product 10 is exposed to the atmosphere during its use, oxygen in the air 16, illustrated as a free- flowing air flow, will react with the zinc in the galvanized surface to form zinc oxide (ZnO) 20 18.
Figure 1 b) shows that water and/or moisture from atmospheric precipitation 20 reacts with the zinc oxide 18 to form zinc hydroxide 22 (Zn(OH)2).
25 Figure 1 c) shows that oxygen and carbon dioxide in the air 16 reacts with the zinc hydroxide 22 to form basic zinc carbonate 23 having the chemical formula Zn5(C03)2(OH)6.
The process of naturally forming a patina 23 as illustrated in figures 1 a) to c) can take 30 years depending on the atmospheric conditions to which a galvanized product 10 is subjected during its use, transportation and/or storage. Furthermore, a naturally formed patina layer 23 may not be uniform and it may contain impurities from its surroundings, such as dust, dirt, oil, grease, sea salt and/or trace elements of contaminants present in its surroundings, since a patina layer 23 exposed to atmospheric elements is not formed 35 under controlled conditions.
Figure 2 shows a product 10, such as a product 10 comprising iron or steel 12, i.e. an iron or steel substrate or body of any desired shape, thickness, cross-section and size having one or more surfaces that may be at least partly coated. The product 10 comprises a uniform or non-uniform coating 14 containing zinc and an artificially-formed patina layer 24 that is formed on top of said coating 14, i.e. on top of at least part of said coating 14 or so as to cover the entire coating 14. The artificially-formed patina layer 24 comprises zinc carbonate having the chemical formula ZnC03, i.e. a mineral ore of zinc also known as Smithsonite, and/or basic zinc carbonate (Zn5(C03)2(OH)6), also known as hydrozincite. Additionally, the artificially-formed platina layer 24 comprises at least one type of metallic ion of a metal that is more noble than zinc, such as copper (Cu2+), iron (Fe2+) or silver (Ag2+) which remain(s) as a consequence of the artificial patina formation.
A product 10 according to the present invention, such as a hot-dip galvanized iron or steel sheet, will, on the contrary, have a coated surface comprising a patina layer 24 of better quality than a naturally formed patina layer since it has been artificially-formed under controlled conditions. The artificially-formed patina layer 24 will not however contain avoidable impurities, such as dust, dirt, oil, grease, sea salt etc. when it is delivered to an end user. The steps of a method for manufacturing a product 10 comprising an artificially-formed patina layer 24 according to an embodiment of the invention are illustrated in figure 3, wherein non-essential method steps are shown in rectangles drawn with dashed lines and essential method steps are shown in rectangles drawn with continuous lines. The method comprises the steps of optionally cleaning and/or roughening at least part of a coated surface of a product 10 prior and artificially forming the patina layer 24 thereon in order to provide a more adhesive surface for subsequent treatments, such as painting. One or more impurities, such as an aluminium oxide, which may be formed on top of the coated surface, after galvanization for example, may be removed from the coated surface prior to artificial patination.
The coated surface may then be placed or moved into in a controlled environment. For example the coated surface may be placed into a pressure chamber or an artificial patination workstation during batch production or into it may be moved into an artificial patination section at a controlled feed rate during a continuous line manufacturing process. During artificial patination, the coated surface is exposed to carbon dioxide in
any suitable form, such as carbon dioxide having a purity of at least 99.8%, and may optionally be heated to a temperature of at least 293 K, such as 293-343 K and/or subjected to a pressure of 6-30 MPa. Once the desired temperature and pressure has been reached, water containing a metal precursor, i.e. any compound comprising at least one type of metal ion that is more noble than zinc, may be applied and/or sprayed and/or injected onto the coated surface either separately or together with carbon dioxide, whereupon a patina layer 24 will begin to form on the coated surface. The metal precursor may be Cu(hfac)2 or Ag(cod)(hfac) or Cu(N03)2 or Fe(N03)3- Preferably, the precursor is non-soluble in water, such as Cu(hfac)2 or Ag(cod)(hfac), and may firstly be dissolved in a solvent, such as an organic solvent, such as ethanol and then mixed with water before it is applied and/or sprayed and/or injected onto the coated surface. This process is easily adapted to production environments and is especially suited to complex surfaces found in grooved couplings and fittings of products 10 having a coating comprising zinc.
The coated surface may remain in the controlled environment for a predetermined exposure time, such from a fraction of a second (which may be sufficient during a continuous line manufacturing process) up to 60 minutes. If the product 10 is being manufactured using batch production, in a pressure chamber for example, the pressure may be decreased at a predetermined rate, such as at a rate of 0.1 -30 MPa per 10 minutes or longer after the predetermined exposure time has elapsed. The rate at which the pressure is decreased will affect the structure of the artificially-formed patina layer 24. The patina layer 24 will continue to form during the entire method until the coated surface is removed from the pressure chamber, or from an application section of a continuous line manufacturing process, where carbon dioxide at a desired temperature and/or pressure, water and at least one metallic ion of a metal that is more noble than zinc is applied and/or injected and/or sprayed onto the coated surface. After this treatment, the artificially patinated product 10 may leave the factory where it is manufactured and be delivered to an end user or placed in storage. The artificially-formed patina layer 24 is not water soluble and does not wash off the coated surface.
The at least one type of metallic ion acts as a catalyst in the formation of a patina layer 24, it speeds up the reaction time and will remain in the artificially-formed patina layer 24,
which makes an artificially-formed patina layer 24 distinguishable from a naturally formed patina layer. For example, the artificially-formed patina layer 24 may contain one or more copper compounds if a metal precursor containing copper ions has been used in its manufacturing method. The artificially-formed patina layer 24 will have superior properties as compared to a naturally formed patina layer since its structure will be more uniform (rather than randomly compact or porous) and it will adhere better to the underlying coated surface. Paint can be applied directly to the artificially-formed patina layer 24 and no adhesion problems have been encountered. The method according to the present invention bypasses the different stages of the natural formation of a patina layer 24 as illustrated in figures 1 a) to c) and will form a more pure and ideal and more tightly adhered layer as compared to a naturally formed patina layer. A naturally formed patina layer 24 may namely be non-uniform as regards its thickness and/or properties, and it may be loosely adhered to the underlying coated surface, it may be porous and contaminated with impurities.
EXAMPLE
The method according to the present invention may comprise the step of treating a galvanized surface of a hot-dip galvanized steel sheet 10 with supercritical carbon dioxide and 0.53 m-% copper solution (including water) at a temperature of 323 K and at a pressure of 30 MPa for 30 minutes, and then decreasing the pressure at a rate of 10 MPa per 10 minutes. Further modifications of the invention within the scope of the claims would be apparent to a skilled person.
Claims
1 . A product (10) having a coating (14) comprising zinc, and a patina layer (24), characterized in that said patina layer (24) is an artificially-formed patina layer (24) and comprises zinc carbonate having the chemical formula ZnC03, i.e. Smithsonite, and/or basic zinc carbonate having the chemical formula (Zn5(C03)2(OH)6), i.e. hydrozincite, and at least one type of metallic ion of a metal that is more noble than zinc.
2. A product (10) according to claim 1 , characterized in that said basic zinc carbonate having the chemical formula (Zn5(C03)2(OH)6), i.e. hydrozincite, has a needle- like structure.
3. A product (10) according to claim 1 or 2, characterized in that said patina layer (24) also comprises one or more other zinc carbonate compounds.
4. A product (10) according to any of claims 1 -3, characterized in that said coating (14) comprising zinc is applied using one of the following methods: galvanizing, hot-dip galvanizing, electro-galvanizing, spraying, thermal spray coating, mechanical plating.
5. A product (10) according to any of the preceding claims, characterized in that said at least one type of metallic ion of a metal is an ion of at least one of the following: copper, iron, silver, palladium, platinum, gold, titanium, molybdenum, tungsten, tin, lead, tantalum, nickel, indium, cadmium or beryllium.
6. A method for artificially producing a patina layer (24) on at least part of a surface of product (10) having a coating (14) comprising zinc, characterized in that said method comprises the step of treating at least part of a surface of a product (10) with carbon dioxide, water and at least one type of metallic ion of a metal that is more noble than zinc under controlled conditions in order to provide said artificially-formed patina layer (24) on said surface of said product (10).
7. A method according to claim 5, characterized in that said artificially-formed patina layer (24) comprises zinc carbonate having the chemical formula ZnC03, i.e. Smithsonite, and/or basic zinc carbonate (Zn5(C03)2(OH)6), i.e. hydrozincite, and at least one type of metallic ion of a metal that is more noble than zinc.
8. A method according to claim 7, characterized in that said basic zinc carbonate having the chemical formula (Zn5(C03)2(OH)6), i.e. hydrozincite, has a needle-like structure.
5 9. A method according to any of claims 6-8, characterized in that said artificially- formed patina layer (24) also comprises one or more other zinc carbonate compounds.
10. Method according to any of claims 6-9, characterized in that said step of treating at least part of a surface of a product (10) also comprises adding a surfactant to lower
10 surface tension between said water and said carbon dioxide.
1 1 . Method according to any of claims 6-10, characterized in that it is carried out in a continuous line manufacturing process, or using batch production.
15 12. A method according to any of claims 6-1 1 , characterized in that said step of treating at least part of said surface of a product (10) involves subjecting at least part of said surface to a temperature of at least 273 K and/or a pressure of 0.1 -30 MPa for a predetermined exposure time.
20 13. A method according to claim 12, characterized in that said predetermined exposure time is a fraction of a second up to 60 minutes.
14. A method according to claim 12 or 13, characterized in that it comprises the step of decreasing said pressure at a rate of 0.1 -30 MPa per 10 minutes or longer after said
25 predetermined exposure time.
15. A method according to any of claims 6-14, characterized in that said coating (14) comprising zinc is applied using one of the following methods: galvanizing, hot-dip galvanizing, electro-galvanizing, spraying, thermal spray coating, mechanical plating.
30
16. A method according to any of claims any of claims 6-15, characterized in that said at least one type of metallic ion is an ion of at least one of the following: copper, iron, silver, palladium, platinum, gold, titanium, molybdenum, tungsten, tin, lead, tantalum, nickel, indium, cadmium or beryllium.
35
17. A method according to any of claims any of claims 6-16, characterized in that said carbon dioxide is in at least one of the following forms: gaseous, liquid, solid, supercritical.
18. A method according to any of claims 6-17, characterized in that said water is at least one of the following de-ionized water, tap water, sea water, lake water.
19. Method according to any of claims 6-18, characterized in that it comprises at least one of the following steps: cleaning and/or roughening a surface of said product (10) prior to artificially forming said patina layer (24) on said surface of said product (10).
20. Method according to any of claims 6-19, characterized in that it comprises the steps of dissolving a metal precursor comprising said at least one type of metallic ion of a metal that is more noble than zinc and which is non-soluble in water in a solvent and then mixing said solvent containing said metal precursor with said water to treat said surface of a product (10).
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ES17707552T ES2853205T3 (en) | 2016-02-25 | 2017-02-27 | Patina layer on galvanized product and method for it |
| PL17707552T PL3420114T3 (en) | 2016-02-25 | 2017-02-27 | Patina layer on galvanized product and method therefor |
| DK17707552.0T DK3420114T3 (en) | 2016-02-25 | 2017-02-27 | PATINAL LAYER ON GALVANIZED PRODUCT AND PROCEDURE THEREFORE |
| EP17707552.0A EP3420114B1 (en) | 2016-02-25 | 2017-02-27 | Patina layer on galvanized product and method therefor |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP16157254.0A EP3211113A1 (en) | 2016-02-25 | 2016-02-25 | Galvanized product & method |
| EP16157254.0 | 2016-02-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2017144721A1 true WO2017144721A1 (en) | 2017-08-31 |
Family
ID=55451030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2017/054509 WO2017144721A1 (en) | 2016-02-25 | 2017-02-27 | Patina layer on galvanized product and method therefor |
Country Status (5)
| Country | Link |
|---|---|
| EP (2) | EP3211113A1 (en) |
| DK (1) | DK3420114T3 (en) |
| ES (1) | ES2853205T3 (en) |
| PL (1) | PL3420114T3 (en) |
| WO (1) | WO2017144721A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL2022279B1 (en) * | 2018-12-21 | 2020-07-15 | Aquacare Europe B V | Method for patinating zinc surfaces and system therefor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3767478A (en) | 1971-09-14 | 1973-10-23 | Ball Corp | Method for producing patina on a zinc surface and article so formed |
| US6231686B1 (en) | 1997-11-10 | 2001-05-15 | Ltv Steel Company, Inc. | Formability of metal having a zinc layer |
| US20050003091A1 (en) | 2001-11-16 | 2005-01-06 | Marianne Schoennenbeck | Method for the production of dark protective layers on flat objects made from titanium zinc |
-
2016
- 2016-02-25 EP EP16157254.0A patent/EP3211113A1/en not_active Withdrawn
-
2017
- 2017-02-27 DK DK17707552.0T patent/DK3420114T3/en active
- 2017-02-27 WO PCT/EP2017/054509 patent/WO2017144721A1/en active Application Filing
- 2017-02-27 ES ES17707552T patent/ES2853205T3/en active Active
- 2017-02-27 PL PL17707552T patent/PL3420114T3/en unknown
- 2017-02-27 EP EP17707552.0A patent/EP3420114B1/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3767478A (en) | 1971-09-14 | 1973-10-23 | Ball Corp | Method for producing patina on a zinc surface and article so formed |
| US6231686B1 (en) | 1997-11-10 | 2001-05-15 | Ltv Steel Company, Inc. | Formability of metal having a zinc layer |
| US20050003091A1 (en) | 2001-11-16 | 2005-01-06 | Marianne Schoennenbeck | Method for the production of dark protective layers on flat objects made from titanium zinc |
Non-Patent Citations (2)
| Title |
|---|
| DAVID LINDSTRÃM ET AL: "Long-term use of galvanized steel in external applications. Aspects of patina formation, zinc runoff, barrier properties of surface treatments, and coatings and environmental fate", ENVIRONMENTAL MONITORING AND ASSESSMENT ; AN INTERNATIONAL JOURNAL DEVOTED TO PROGRESS IN THE USE OF MONITORING DATA IN ASSESSINGENVIRONMENTAL RISKS TO MAN AND THE ENVIRONMENT, KLUWER ACADEMIC PUBLISHERS, DO, vol. 173, no. 1 - 4, 7 March 2010 (2010-03-07), pages 139 - 153, XP019872054, ISSN: 1573-2959, DOI: 10.1007/S10661-010-1377-8 * |
| DAVID LINDSTROM ET AL.: "Long-term use of galvanized steel in external applications. Aspects of patina formation, zinc runoff, barrier properties of surface treatments, and coatings and environmental fate", ENVIRONMENTAL MONITORING AND ASSESSMENT; AN INTERNATIONAL JOURNAL DEVOTED TO PROGRESS IN THE USE OF MONITORING DATA IN ASSESSING ENVIRONMENTAL RISKS TO MAN AND THE ENVIRONMENT, vol. 173, no. 1 - 4, 7 March 2010 (2010-03-07), pages 139 - 153 |
Also Published As
| Publication number | Publication date |
|---|---|
| EP3420114A1 (en) | 2019-01-02 |
| EP3420114B1 (en) | 2020-12-09 |
| PL3420114T3 (en) | 2021-06-28 |
| DK3420114T3 (en) | 2021-02-15 |
| ES2853205T3 (en) | 2021-09-15 |
| EP3211113A1 (en) | 2017-08-30 |
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