EP0391442B1 - Improved surface treatment for zinciferous surfaces - Google Patents
Improved surface treatment for zinciferous surfaces Download PDFInfo
- Publication number
- EP0391442B1 EP0391442B1 EP90106675A EP90106675A EP0391442B1 EP 0391442 B1 EP0391442 B1 EP 0391442B1 EP 90106675 A EP90106675 A EP 90106675A EP 90106675 A EP90106675 A EP 90106675A EP 0391442 B1 EP0391442 B1 EP 0391442B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- chromium
- group
- process according
- chromate
- silane coupling
- 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 - Lifetime
Links
- 238000004381 surface treatment Methods 0.000 title 1
- 239000011651 chromium Substances 0.000 claims abstract description 40
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 36
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 36
- 239000006087 Silane Coupling Agent Substances 0.000 claims abstract description 27
- 238000001035 drying Methods 0.000 claims abstract description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 8
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims abstract description 6
- 150000003509 tertiary alcohols Chemical class 0.000 claims abstract description 4
- 229910019142 PO4 Inorganic materials 0.000 claims abstract description 3
- 239000010452 phosphate Substances 0.000 claims abstract description 3
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 claims description 28
- 238000000034 method Methods 0.000 claims description 27
- 239000000203 mixture Substances 0.000 claims description 25
- 230000008569 process Effects 0.000 claims description 13
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 claims description 9
- 239000002253 acid Substances 0.000 claims description 9
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 claims description 8
- 239000000470 constituent Substances 0.000 claims description 7
- MSXVEPNJUHWQHW-UHFFFAOYSA-N 2-methylbutan-2-ol Chemical compound CCC(C)(C)O MSXVEPNJUHWQHW-UHFFFAOYSA-N 0.000 claims description 6
- -1 Zn+2 ions Chemical class 0.000 claims description 6
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 239000006193 liquid solution Substances 0.000 claims description 3
- 229940085991 phosphate ion Drugs 0.000 claims description 3
- 125000000217 alkyl group Chemical group 0.000 claims description 2
- 125000004432 carbon atom Chemical group C* 0.000 claims description 2
- 125000001301 ethoxy group Chemical group [H]C([H])([H])C([H])([H])O* 0.000 claims description 2
- 125000005417 glycidoxyalkyl group Chemical group 0.000 claims description 2
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 claims description 2
- 239000011368 organic material Substances 0.000 claims description 2
- 125000003396 thiol group Chemical group [H]S* 0.000 claims description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 claims description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims 1
- 239000000243 solution Substances 0.000 abstract description 28
- 238000005260 corrosion Methods 0.000 abstract description 27
- 230000007797 corrosion Effects 0.000 abstract description 27
- 239000003973 paint Substances 0.000 abstract description 18
- 239000011248 coating agent Substances 0.000 abstract description 14
- 238000000576 coating method Methods 0.000 abstract description 14
- 239000007864 aqueous solution Substances 0.000 abstract description 9
- 238000010422 painting Methods 0.000 abstract description 6
- 229910001335 Galvanized steel Inorganic materials 0.000 abstract 1
- 239000008397 galvanized steel Substances 0.000 abstract 1
- 150000002894 organic compounds Chemical class 0.000 abstract 1
- 230000003647 oxidation Effects 0.000 abstract 1
- 238000007254 oxidation reaction Methods 0.000 abstract 1
- 239000011241 protective layer Substances 0.000 abstract 1
- 239000000080 wetting agent Substances 0.000 abstract 1
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 39
- 239000003513 alkali Substances 0.000 description 27
- 229910000831 Steel Inorganic materials 0.000 description 23
- 239000010959 steel Substances 0.000 description 23
- 238000011282 treatment Methods 0.000 description 23
- 238000012360 testing method Methods 0.000 description 19
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 13
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 12
- 238000003466 welding Methods 0.000 description 10
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 8
- 238000007792 addition Methods 0.000 description 8
- 239000011701 zinc Substances 0.000 description 8
- 229910052725 zinc Inorganic materials 0.000 description 8
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 7
- 241001163841 Albugo ipomoeae-panduratae Species 0.000 description 6
- 239000000377 silicon dioxide Substances 0.000 description 6
- 229910000990 Ni alloy Inorganic materials 0.000 description 5
- 239000002585 base Substances 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 5
- ABXXWVKOBZHNNF-UHFFFAOYSA-N chromium(3+);dioxido(dioxo)chromium Chemical compound [Cr+3].[Cr+3].[O-][Cr]([O-])(=O)=O.[O-][Cr]([O-])(=O)=O.[O-][Cr]([O-])(=O)=O ABXXWVKOBZHNNF-UHFFFAOYSA-N 0.000 description 5
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 5
- QELJHCBNGDEXLD-UHFFFAOYSA-N nickel zinc Chemical compound [Ni].[Zn] QELJHCBNGDEXLD-UHFFFAOYSA-N 0.000 description 5
- 238000006722 reduction reaction Methods 0.000 description 5
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 4
- 235000011007 phosphoric acid Nutrition 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- PTFCDOFLOPIGGS-UHFFFAOYSA-N Zinc dication Chemical compound [Zn+2] PTFCDOFLOPIGGS-UHFFFAOYSA-N 0.000 description 3
- 239000002390 adhesive tape Substances 0.000 description 3
- 239000003638 chemical reducing agent Substances 0.000 description 3
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 239000010953 base metal Substances 0.000 description 2
- 238000005238 degreasing Methods 0.000 description 2
- 239000013527 degreasing agent Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 229920000620 organic polymer Polymers 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- BPSIOYPQMFLKFR-UHFFFAOYSA-N trimethoxy-[3-(oxiran-2-ylmethoxy)propyl]silane Chemical compound CO[Si](OC)(OC)CCCOCC1CO1 BPSIOYPQMFLKFR-UHFFFAOYSA-N 0.000 description 2
- 229910021511 zinc hydroxide Inorganic materials 0.000 description 2
- 239000011787 zinc oxide Substances 0.000 description 2
- UUEWCQRISZBELL-UHFFFAOYSA-N 3-trimethoxysilylpropane-1-thiol Chemical compound CO[Si](OC)(OC)CCCS UUEWCQRISZBELL-UHFFFAOYSA-N 0.000 description 1
- XDLMVUHYZWKMMD-UHFFFAOYSA-N 3-trimethoxysilylpropyl 2-methylprop-2-enoate Chemical compound CO[Si](OC)(OC)CCCOC(=O)C(C)=C XDLMVUHYZWKMMD-UHFFFAOYSA-N 0.000 description 1
- 229910003638 H2SiF6 Inorganic materials 0.000 description 1
- 229910003708 H2TiF6 Inorganic materials 0.000 description 1
- 229910003899 H2ZrF6 Inorganic materials 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 229930006000 Sucrose Natural products 0.000 description 1
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 1
- FMRLDPWIRHBCCC-UHFFFAOYSA-L Zinc carbonate Chemical compound [Zn+2].[O-]C([O-])=O FMRLDPWIRHBCCC-UHFFFAOYSA-L 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229920000180 alkyd Polymers 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000001845 chromium compounds Chemical class 0.000 description 1
- ZTXONRUJVYXVTJ-UHFFFAOYSA-N chromium copper Chemical compound [Cr][Cu][Cr] ZTXONRUJVYXVTJ-UHFFFAOYSA-N 0.000 description 1
- 229910000151 chromium(III) phosphate Inorganic materials 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 150000004696 coordination complex Chemical class 0.000 description 1
- CMMUKUYEPRGBFB-UHFFFAOYSA-L dichromic acid Chemical compound O[Cr](=O)(=O)O[Cr](O)(=O)=O CMMUKUYEPRGBFB-UHFFFAOYSA-L 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- FWDBOZPQNFPOLF-UHFFFAOYSA-N ethenyl(triethoxy)silane Chemical compound CCO[Si](OCC)(OCC)C=C FWDBOZPQNFPOLF-UHFFFAOYSA-N 0.000 description 1
- NKSJNEHGWDZZQF-UHFFFAOYSA-N ethenyl(trimethoxy)silane Chemical compound CO[Si](OC)(OC)C=C NKSJNEHGWDZZQF-UHFFFAOYSA-N 0.000 description 1
- 238000009778 extrusion testing Methods 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 229920002521 macromolecule Polymers 0.000 description 1
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 125000005372 silanol group Chemical group 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
- ZEFWRWWINDLIIV-UHFFFAOYSA-N tetrafluorosilane;dihydrofluoride Chemical compound F.F.F[Si](F)(F)F ZEFWRWWINDLIIV-UHFFFAOYSA-N 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 238000004876 x-ray fluorescence Methods 0.000 description 1
- 150000003751 zinc Chemical class 0.000 description 1
- 235000004416 zinc carbonate Nutrition 0.000 description 1
- 239000011667 zinc carbonate Substances 0.000 description 1
- 229910000010 zinc carbonate Inorganic materials 0.000 description 1
- UGZADUVQMDAIAO-UHFFFAOYSA-L zinc hydroxide Chemical compound [OH-].[OH-].[Zn+2] UGZADUVQMDAIAO-UHFFFAOYSA-L 0.000 description 1
- 229940007718 zinc hydroxide Drugs 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
- 229910000165 zinc phosphate Inorganic materials 0.000 description 1
- NDKWCCLKSWNDBG-UHFFFAOYSA-N zinc;dioxido(dioxo)chromium Chemical class [Zn+2].[O-][Cr]([O-])(=O)=O NDKWCCLKSWNDBG-UHFFFAOYSA-N 0.000 description 1
Images
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
- 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
- C23C22/34—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 containing fluorides or complex fluorides
- C23C22/37—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 containing fluorides or complex fluorides containing also hexavalent chromium compounds
- C23C22/38—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 containing fluorides or complex fluorides containing also hexavalent chromium compounds containing also phosphates
-
- 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
- C23C22/24—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 containing hexavalent chromium compounds
- C23C22/30—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 containing hexavalent chromium compounds containing also trivalent chromium
-
- 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
- C23C2222/00—Aspects relating to chemical surface treatment of metallic material by reaction of the surface with a reactive medium
- C23C2222/20—Use of solutions containing silanes
Definitions
- This invention relates to a treatment method which is capable of developing a chromium containing film that provides an excellent base for paint, by having both good paint adherence and good corrosion resistance after painting, as well as excellent corrosion resistance, alkali resistance, and ease of welding, because of relatively low electrical resistance, when left unpainted.
- Treatment according to the invention is applied to surfaces containing zinc as a predominant constituent, particularly to surfaces of electrogalvanized steel sheet, zinc-alloy electroplated steel sheet, and galvannealed steel sheet (collectively denoted as "zinc-plated steel sheet” below).
- the invention of Japanese Patent Application Laid Open [Kokai] Number 50-158535 [158,535/75] concerns a method for the formation of solution resistant chromate films on the surface of zinc-plated steel sheet.
- the chromate solution contains chromic anhydride, phosphoric acid, and water-soluble or water-dispersible polymer, and the Cr6+ in this treatment bath is at least 70 % reduced to Cr3+ by a reductant such as ethylene glycol.
- a reductant such as ethylene glycol
- the chromate bath taught in Japanese Patent Publication Number 61-58522 [58,522/86] contains specified amounts of chromic acid, reduced chromic acid, and silica sol components.
- a surface-treated steel sheet carrying the chromate film formed by the method of this invention is processed for painting, most of the hexavalent chromium in the chromate film is easily eluted by the alkali rinse prior to painting.
- the corrosion resistance of the film is then lowered due to its poor alkali resistance.
- the film contains silica because the film contains silica, its weldability, for example, its spot weldability, is poor.
- Japanese Patent Application Laid Open Numbers 58-22383 [22,383/83] and 62-83478 [83,478/87] are examples of the disclosure of the use of silane coupling agents as reductants for the hexavalent chromium in chromate treatment solutions. While the films formed by the methods of these references provide excellent paint bondability, the chromate film formed by the method of the former reference has a poor alkali resistance because it does not contain silica or organic polymer. In the latter reference, the spot weldability is unsatisfactory because colloidal silica is present.
- GB-A- 2 180 263 teaches a surface treating solution comprising hexavalent and trivalent chromium, phosphate, and fluorozirconate ions, with certain specified ratios among the ions.
- Silica is taught as a preferred optional component. With silica, the spot weldability of surfaces treated with such a solution is reduced, while without silica, the alkali resistance of the treated surface is often unsatisfactory.
- One embodiment of the present invention is a process for treating objects with a zinciferous surface, preferably sheets of zinc-plated steel, by contact between the surface of the treated object and a liquid solution composition that comprises, or preferably consists essentially of, water and the following components:
- composition of the aqueous solution used by the method of the present invention is discussed in more detail below.
- This solution uses water as its solvent, and it contains 3.0 to 50 g/L of Cr6+ and 2.0 to 40 g/L of Cr3+ as essential components.
- the formation of a satisfactorily corrosion-resistant chromium containing film becomes problematic when the Cr6+ falls below 3.0 g/L or the Cr3+ falls below 2.0 g/L.
- the Cr6+ exceeds 50 g/L or the Cr3+ exceeds 40 g/L the chromate bath will have a high viscosity and a poor stability, and it becomes difficult to control the quantity of chromium deposited in the surface coating formed.
- a crucial element of the composition is the ratio between Cr6+ and Cr3+. It is essential that the chromium ratio (Cr3+/Cr6+) fall within the range of 0.25 to 1.5. When the chromium ratio falls below 0.25, the oxidizing tendency of the Cr6+ content in the chromate bath is increased. As a result, when the silane coupling agent is added to such a bath, reduction of the Cr6+ in the chromate bath by the silane coupling agent tends to develop rather readily, and the chromate bath is heated by this. As a consequence, the rate of the Cr6+ reduction reaction by the solvent in the chromate bath and solvent volatilization are both increased, causing a decline in the quality of the chromate bath.
- the chromium ratio can be controlled by the addition as necessary of a reductant such as ethanol, methanol, oxalic acid, starch, sucrose, and the like.
- PO43 ⁇ is preferably added as orthophosphoric acid (H3PO4).
- H3PO4 orthophosphoric acid
- the corrosion resistance and alkali resistance of the surface coating formed on the zinciferous surfaces treated are reduced.
- exceeding 100 g/L promotes the rapid reduction of the Cr6+ in the solution by the silane coupling agent, and the quality of the solution is degraded as a result.
- a particularly important aspect of the PO43 ⁇ content is its ratio relative to the quantity of total chromium (Cr6+ + Cr3+) in the solution, and a PO43 ⁇ /total Cr ratio within the range of 0.1 to 1.2 is preferred.
- this ratio falls below 0.1, the alkali resistance and corrosion resistance of the surface film formed during a process according to the invention tend to decline.
- reduction of the Cr6+ in the chromate bath by the silane coupling agent proceeds very easily, with the result that the Cr6+ in the chromate bath is substantially or almost completely reduced to Cr3+ prior to application. As a consequence, the quality of the chromate bath is reduced, and it becomes difficult to form a coating which satisfies the object of the present invention.
- the solution used contains 3 to 50 g/L of another component which functions as a wettability improver: one compound or, if desired, a mixture of compounds selected from C4 - C8 tertiary alcohols and acetonitrile.
- a wettability improver one compound or, if desired, a mixture of compounds selected from C4 - C8 tertiary alcohols and acetonitrile.
- Each of these compounds has a relatively high stability with regard to the Cr+6 present in the chromate bath at bath temperatures below approximately 35 degrees Centigrade, while none adversely affects the quality of the treatment film formed to any significant degree.
- each can function to increase the wettability of the chromate bath on the plated surface. Accordingly, each can contribute to increasing the uniformity of chromium coating weight on the treated surface during high-speed operations.
- this organic component is added in greater amounts, the greater the total chromium concentration in the treatment solution, and the greater the application speed.
- the organic component is preferably selected from tert-butyl alcohol and/or tert-amyl alcohol.
- the alkali resistance of the treated surface can be increased by the optional addition of 0.2 to 10 g/L of zinc ions to the aqueous treatment bath.
- the improvement is vanishingly small at a zinc ion quantity below 0.2 g/L, while exceeding 10 g/L tends to precipitate the Cr3+ in the treatment bath.
- the Zn2+ ions are preferably added to the treatment bath in the form of zinc oxide, zinc carbonate, zinc phosphate, or zinc hydroxide.
- complex fluoride may optionally be added to the treatment bath, either by itself or together with zinc. It is preferably added in the range of 0.2 to 8 g/L based on F.
- Preferred examples of the complex fluoride are fluozirconic acid (H2ZrF6), fluotitanic acid (H2TiF6), fluosilicic acid (H2SiF6), and fluoboric acid (H2BF6).
- H2ZrF6 fluozirconic acid
- H2TiF6 fluotitanic acid
- H2SiF6 fluosilicic acid
- fluoboric acid H2BF6
- This zinc or other metal complex becomes a constituent component of the chromium containing film formed, and contributes to improving the film's uniformity and corrosion resistance.
- the effects of addition are difficult to note at fluoride quantities below 0.2 g/L, while exceeding 8 g/L lowers the corrosion resistance of the chromium containing film formed.
- silane coupling agent is preferably first mixed with the chromate bath at a molar ratio referred to the gram-atomic concentration of Cr6+ in the chromate bath within the range of 0.05 to 0.30.
- the silane coupling agent component is selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, gamma-mercaptopropyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropylmethyldimethoxysilane, gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropylmethyldimethoxysilane, and mixtures of any two or more of these.
- Silane coupling agents with the above general formula are preferred because they have good solubilities in the aqueous solution used to contact zinc surfaces in a process according to this invention and make a relatively large contribution to improving the corrosion resistance of the protective film formed on the zinc surface.
- the treatment bath mixed with silane coupling agent as explained above, may be coated on the zinc-plated steel sheet or other zinciferous surface by, for example, a roll coater, curtain coater, or any other convenient method that establishes contact between the solution and the surface to be treated and results in a satisfactorily uniform coating of the solution over the surface before drying.
- a film with a chromium content of 10 to 200 mg/m2 be formed by drying for 5 to 10 seconds at a temperature on the drying surface of 60 to 150 degrees Centigrade.
- the liquid treating solution itself should be maintained at no greater than 35 degrees Centigrade and preferably at no greater than 25 degrees Centigrade after addition of the silane coupling agent to the bath.
- Treatment solution according to this invention is satisfactorily stable for approximately 1 month at relatively low chromium concentrations, but use within 1 week after the addition of the silane component is strongly preferred for such solutions with high chromium concentrations.
- the corrosion resistance of the treated object with a film as formed and the corrosion resistance after painting are both unsatisfactory with less than 10 mg/m2 of chromium uptake during a treatment according to this invention.
- uptakes exceeding 200 mg/m2
- it becomes difficult to control the quantity of chromium adherence in the chromate film the improvement in corrosion resistance reaches an upper limit and further benefits cannot be expected; and paint adherence is reduced because portions of the chromate film are easily removed by external forces when it is so thick.
- pH of the aqueous chromate bath used in the present invention is not critical, values around 1.0 to 3.0 are preferable.
- the Cr6+, Cr3+, and PO43 ⁇ components in the aqueous chromate bath are believed to react with one another and/or the treated surface, at a rate speeded by the thermal energy supplied by drying.
- the constituent components of the resulting chromate film are believed to be the colorless materials respectively specified in (a) and (b) below, the green material specified in (c), and the gold colored material specified in (d) and (e).
- the aforementioned chromic chromate (e) can undergo condensation reactions as depicted by Figure 1, while at the same time, the chromic chromate is cross linked as depicted in Figure 2 by the hydrolyzate ⁇ f ⁇ deriving from the silane coupling agent. Moreover, the hexavalent chromium in the chromic chromate is reduced by the methanol. Therefore, it is thought that a companion macromolecular network structure is formed by the development of complex cross linkages between the chromic chromate and silane coupling agent hydrolyzate.
- each of the aforementioned components (a), (b), (c), and (d) may be present within the structure of the macromolecular, chromium containing coating represented by Figures 1 and 2, either in a chain-stopping position or bonded with said macromolecular chromium compound.
- the chromate film having this network molecular structure exhibits a strong alkali resistance, i.e., the chromium in the film strongly resists elution due to alkali rinsing. Moreover, it is thought that this network molecular structure contributes to increasing both the corrosion resistance and uniformity.
- this film does not contain silica or an organic macromolecular compound, the electrical resistance of the film is relatively low, so that it is relatively easy to weld surfaces treated according to this invention.
- Chromate coating bath No. A as reported in Table 1 was prepared as follows: 200 grams ("g") of chromic anhydride (Cr2O6) was first dissolved in 500 g of water, 86 g of phosphoric acid (75% aqueous solution) and 18 g of methanol were added to the aqueous solution thus obtained, and this was then heated for 1 hour at 80 to 90 degrees Centigrade to cause reduction to a Cr3+/Cr6+ weight ratio of 1.0. After cooling, 26 g of tert-butanol and sufficient water to make a total weight of 1 kg were added. This solution is denoted in the following as the aqueous base solution.
- aqueous base solution was then diluted with water to give a total chromium concentration (Cr6+ + Cr3+) of 40 g/L, along with 10 g/L tert-butanol.
- Silane coupling agent gamma-glycidoxypropyltrimethoxysilane from Toshiba Silicone Company, Limited
- Silane coupling agent was then added with stirring, in an amount to yield a concentration of 9 g/L, to give final treating bath No. A.
- the treated zinc coated steel was painted with a bakeable melamine alkyd paint (DeliconTM 700 White from Dainippon Paint Company, Limited) and then baked for 20 minutes at 140 degrees Centigrade to give a painted sheet carrying a 25 micrometer thick coating.
- a bakeable melamine alkyd paint (DeliconTM 700 White from Dainippon Paint Company, Limited) and then baked for 20 minutes at 140 degrees Centigrade to give a painted sheet carrying a 25 micrometer thick coating.
- the treated sheet was alkali rinsed using the conditions specified below, and the quantity of adhering chromium in mg/m2 was measured by X-ray fluorescence both before and after this rinse.
- the "alkali resistance" as reported in Table 2 is defined as the percentage of the chromium originally present that is removed by this rinsing. Thus, the alkali resistance increases as the percent value declines, and a zero value indicates absolutely no loss from alkali in this test, or complete resistance.
- the alkali rinse conditions were as follows: 2 minute spray at 60 degrees Centigrade using a 2% aqueous solution of a sodium silicate-based alkaline degreaser (Par-Clean® N364S from Nihon Parkerizing Company, Limited).
- test specimen 70 x 150 mm
- salt-spray test specified in Japanese Industrial Standard ("JIS") Z-2371 for 150 hours.
- JIS Japanese Industrial Standard
- the corrosion resistance was evaluated on the basis of the development of white rust by surveying the entire area of the test specimen and reported using the following symbols:
- test specimen was subjected to a composite corrosion test (50 cycles) both before and after alkali rinsing. Each cycle consisted of salt spray for 4 hours, drying at 60 degrees Centigrade for 2 hours, and wetting at 50 degrees Centigrade and a relative humidity of ⁇ 95 % for 2 hours.
- the corrosion resistance was evaluated on the basis of the development of red rust by surveying the entire area of the test specimen and reported according to the symbols below.
- the painted test specimen (with no alkali rinse) was extruded 6 mm.
- Conventional transparent adhesive tape was then applied and rapidly peeled off, and the degree of paint film peeling was inspected and reported with the same symbols as for the crosscut test.
- practice of the present invention forms a surface film which is very uniformly distributed over the surface of zinc objects, especially zinc-plated steel sheet.
- the treated sheet is well suited to welding, resistant to alkali treatment and corrosion, and very well adapted for painting, because paint adheres very well and the painted surface is corrosion resistant.
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Electroplating Methods And Accessories (AREA)
- Chemically Coating (AREA)
- Laminated Bodies (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Food Preservation Except Freezing, Refrigeration, And Drying (AREA)
- Paints Or Removers (AREA)
Abstract
Description
- This invention relates to a treatment method which is capable of developing a chromium containing film that provides an excellent base for paint, by having both good paint adherence and good corrosion resistance after painting, as well as excellent corrosion resistance, alkali resistance, and ease of welding, because of relatively low electrical resistance, when left unpainted. Treatment according to the invention is applied to surfaces containing zinc as a predominant constituent, particularly to surfaces of electrogalvanized steel sheet, zinc-alloy electroplated steel sheet, and galvannealed steel sheet (collectively denoted as "zinc-plated steel sheet" below).
- While chromate treatment solutions originally consisted essentially of aqueous solutions of chromic acid or dichromic acid, a number of methods have been proposed for the formation of films that are more resistant to the acid and alkali treatments which may be conducted after chromate film formation. This art is discussed below.
- The invention of Japanese Patent Application Laid Open [Kokai] Number 50-158535 [158,535/75] concerns a method for the formation of solution resistant chromate films on the surface of zinc-plated steel sheet. In this reference, the chromate solution contains chromic anhydride, phosphoric acid, and water-soluble or water-dispersible polymer, and the Cr⁶⁺ in this treatment bath is at least 70 % reduced to Cr³⁺ by a reductant such as ethylene glycol. However, although the film formed by the implementation of this invention is excellent in terms of low solubility, corrosion resistance, and suitability as a base for paint, it nevertheless suffers from the problem of poor weldability because it contains polymer.
- The chromate bath taught in Japanese Patent Publication Number 61-58522 [58,522/86] contains specified amounts of chromic acid, reduced chromic acid, and silica sol components. However, when a surface-treated steel sheet carrying the chromate film formed by the method of this invention is processed for painting, most of the hexavalent chromium in the chromate film is easily eluted by the alkali rinse prior to painting. Thus, the corrosion resistance of the film is then lowered due to its poor alkali resistance. Also, because the film contains silica, its weldability, for example, its spot weldability, is poor.
- Japanese Patent Application Laid Open Numbers 58-22383 [22,383/83] and 62-83478 [83,478/87] are examples of the disclosure of the use of silane coupling agents as reductants for the hexavalent chromium in chromate treatment solutions. While the films formed by the methods of these references provide excellent paint bondability, the chromate film formed by the method of the former reference has a poor alkali resistance because it does not contain silica or organic polymer. In the latter reference, the spot weldability is unsatisfactory because colloidal silica is present. When the properties of the individual components in these prior chromate treatment methods are examined, one finds that organic polymer and silica sol, while increasing the corrosion resistance, also tend to degrade the weldability. Silane coupling agents tend to make the chromate film's corrosion resistance unstable because they tend to reduce the Cr⁶⁺.
- GB-A- 2 180 263 teaches a surface treating solution comprising hexavalent and trivalent chromium, phosphate, and fluorozirconate ions, with certain specified ratios among the ions. Silica is taught as a preferred optional component. With silica, the spot weldability of surfaces treated with such a solution is reduced, while without silica, the alkali resistance of the treated surface is often unsatisfactory.
- It is an object of the present invention to solve the problems manifested by the prior art of chromate treatment methods for zinc-plated steel sheet, while retaining most or all of the benefits of these prior art methods, by a method for the formation of a chromium containing film which has an excellent corrosion resistance, alkali resistance, processability, and uniformity of application and produces a surface that is readily welded and serves as an excellent base for paint.
- One embodiment of the present invention is a process for treating objects with a zinciferous surface, preferably sheets of zinc-plated steel, by contact between the surface of the treated object and a liquid solution composition that comprises, or preferably consists essentially of, water and the following components:
- (A) from 3.0 to 50 grams per liter ("g/L") of the composition of hexavalent chromium;
- (B) from 2.0 to 40 g/L of trivalent chromium;
- (C) from 1.0 to 100 g/L of phosphate ion (PO₄³⁻);
- (D) from 3 to 50 g/L of at least one type of organic material selected from tertiary alcohols with 4 - 8 carbon atoms per molecule and acetonitrile; and
- (E) an amount of silane coupling agent such as to yield a molar ratio of 0.05 to 0.30 between the total of silane coupling agent and the hexavalent chromium concentration in the composition; and
- In a further embodiment the composition of the aqueous solution furthermore comprises
- (F) from 0.2 to 10 g/L of Zn⁺² ions; and
- (G) a component of simple and/or complex fluoride ions in an amount to give from 0.2 to 8 g/L stoichiometric equivalent of fluoride,
- The composition of the aqueous solution used by the method of the present invention is discussed in more detail below.
- This solution uses water as its solvent, and it contains 3.0 to 50 g/L of Cr⁶⁺ and 2.0 to 40 g/L of Cr³⁺ as essential components. The formation of a satisfactorily corrosion-resistant chromium containing film becomes problematic when the Cr⁶⁺ falls below 3.0 g/L or the Cr³⁺ falls below 2.0 g/L. Conversely, when the Cr⁶⁺ exceeds 50 g/L or the Cr³⁺ exceeds 40 g/L, the chromate bath will have a high viscosity and a poor stability, and it becomes difficult to control the quantity of chromium deposited in the surface coating formed.
- Furthermore, a crucial element of the composition is the ratio between Cr⁶⁺ and Cr³⁺. It is essential that the chromium ratio (Cr³⁺/Cr⁶⁺) fall within the range of 0.25 to 1.5. When the chromium ratio falls below 0.25, the oxidizing tendency of the Cr⁶⁺ content in the chromate bath is increased. As a result, when the silane coupling agent is added to such a bath, reduction of the Cr⁶⁺ in the chromate bath by the silane coupling agent tends to develop rather readily, and the chromate bath is heated by this. As a consequence, the rate of the Cr⁶⁺ reduction reaction by the solvent in the chromate bath and solvent volatilization are both increased, causing a decline in the quality of the chromate bath. When the chromium ratio exceeds 1.5, the chromate bath evidences a tendency to gel, and the corrosion resistance of the chromium containing surface film is also reduced. The chromium ratio can be controlled by the addition as necessary of a reductant such as ethanol, methanol, oxalic acid, starch, sucrose, and the like.
- Another component in the solution composition of the present invention is PO₄³⁻ at 1.0 to 100 g/L. This PO₄³⁻ is preferably added as orthophosphoric acid (H₃PO₄). When the PO₄³⁻ content falls below 1.0 g/L, the corrosion resistance and alkali resistance of the surface coating formed on the zinciferous surfaces treated are reduced. Conversely, exceeding 100 g/L promotes the rapid reduction of the Cr⁶⁺ in the solution by the silane coupling agent, and the quality of the solution is degraded as a result.
- A particularly important aspect of the PO₄³⁻ content is its ratio relative to the quantity of total chromium (Cr⁶⁺ + Cr³⁺) in the solution, and a PO₄³⁻/total Cr ratio within the range of 0.1 to 1.2 is preferred. When this ratio falls below 0.1, the alkali resistance and corrosion resistance of the surface film formed during a process according to the invention tend to decline. Conversely, at values exceeding 1.2, reduction of the Cr⁶⁺ in the chromate bath by the silane coupling agent proceeds very easily, with the result that the Cr⁶⁺ in the chromate bath is substantially or almost completely reduced to Cr³⁺ prior to application. As a consequence, the quality of the chromate bath is reduced, and it becomes difficult to form a coating which satisfies the object of the present invention.
- In order to improve the uniformity of coating achieved with the invention, the solution used contains 3 to 50 g/L of another component which functions as a wettability improver: one compound or, if desired, a mixture of compounds selected from C₄ - C₈ tertiary alcohols and acetonitrile. Each of these compounds has a relatively high stability with regard to the Cr⁺⁶ present in the chromate bath at bath temperatures below approximately 35 degrees Centigrade, while none adversely affects the quality of the treatment film formed to any significant degree. At the same time, each can function to increase the wettability of the chromate bath on the plated surface. Accordingly, each can contribute to increasing the uniformity of chromium coating weight on the treated surface during high-speed operations. The manifestation of such a beneficial effect has not been observed at a concentration below 3 g/L. An increase in effect cannot be expected from further additions in excess of 50 g/L, which are also disadvantageous from the standpoints of economics and the working environment. As a general rule, this organic component is added in greater amounts, the greater the total chromium concentration in the treatment solution, and the greater the application speed. The organic component is preferably selected from tert-butyl alcohol and/or tert-amyl alcohol.
- The alkali resistance of the treated surface can be increased by the optional addition of 0.2 to 10 g/L of zinc ions to the aqueous treatment bath. The improvement is vanishingly small at a zinc ion quantity below 0.2 g/L, while exceeding 10 g/L tends to precipitate the Cr³⁺ in the treatment bath. The Zn²⁺ ions are preferably added to the treatment bath in the form of zinc oxide, zinc carbonate, zinc phosphate, or zinc hydroxide.
- In addition, complex fluoride may optionally be added to the treatment bath, either by itself or together with zinc. It is preferably added in the range of 0.2 to 8 g/L based on F. Preferred examples of the complex fluoride are fluozirconic acid (H₂ZrF₆), fluotitanic acid (H₂TiF₆), fluosilicic acid (H₂SiF₆), and fluoboric acid (H₂BF₆). Their addition in the aforementioned quantity causes the development of etching of the zinc-plated surface by the treatment bath, and the complex fluoride complexes with the eluted metal ion or with this metal ion and any zinc ion added to the bath. This zinc or other metal complex becomes a constituent component of the chromium containing film formed, and contributes to improving the film's uniformity and corrosion resistance. The effects of addition are difficult to note at fluoride quantities below 0.2 g/L, while exceeding 8 g/L lowers the corrosion resistance of the chromium containing film formed.
- The aqueous bath as described above should be stored at a temperature of ≦ 35 degrees Centigrade and preferably at ≦ 25 degrees Centigrade after addition of the silane coupling agent, and it should be used as soon as possible after formulation. At the point of use, silane coupling agent is preferably first mixed with the chromate bath at a molar ratio referred to the gram-atomic concentration of Cr⁶⁺ in the chromate bath within the range of 0.05 to 0.30.
- While exact composition of the silane coupling agent is not crucial to the invention, silane coupling agents that conform to the following general chemical formula are preferred: YyRrSiXx, wherein R represents an alkyl group; X represents a group selected from methoxy and ethoxy groups; Y represents a group selected from a vinyl group, a mercapto group, a glycidoxyalkyl group, or a methacryloxyalkyl group; and each of r, x, and y is an integer independently selectable from 1 - 3, except that r may also be zero and the sum r+x+y = 4.
- More preferably, the silane coupling agent component is selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, gamma-mercaptopropyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropylmethyldimethoxysilane, gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropylmethyldimethoxysilane, and mixtures of any two or more of these.
- Silane coupling agents with the above general formula are preferred because they have good solubilities in the aqueous solution used to contact zinc surfaces in a process according to this invention and make a relatively large contribution to improving the corrosion resistance of the protective film formed on the zinc surface.
- When the molar ratio of silane coupling agent to Cr⁺⁶ falls below 0.05, the improvement in the chromium containing film's alkali resistance is negligible. Conversely, when a ratio of 0.3 is exceeded, the chromate bath tends to evidence a gradual decline in stability, i.e., the Cr³⁺ in the chromate bath increases and gelation is facilitated. Use of the silane coupling agent in the molar ratio to Cr⁺⁶ range of 0.1 to 0.2 is even more preferred.
- The treatment bath, mixed with silane coupling agent as explained above, may be coated on the zinc-plated steel sheet or other zinciferous surface by, for example, a roll coater, curtain coater, or any other convenient method that establishes contact between the solution and the surface to be treated and results in a satisfactorily uniform coating of the solution over the surface before drying. While the present invention does not depend critically on the drying conditions, it is preferred that a film with a chromium content of 10 to 200 mg/m² be formed by drying for 5 to 10 seconds at a temperature on the drying surface of 60 to 150 degrees Centigrade. However, the liquid treating solution itself should be maintained at no greater than 35 degrees Centigrade and preferably at no greater than 25 degrees Centigrade after addition of the silane coupling agent to the bath. Treatment solution according to this invention is satisfactorily stable for approximately 1 month at relatively low chromium concentrations, but use within 1 week after the addition of the silane component is strongly preferred for such solutions with high chromium concentrations.
- The corrosion resistance of the treated object with a film as formed and the corrosion resistance after painting are both unsatisfactory with less than 10 mg/m² of chromium uptake during a treatment according to this invention. On the other hand, with uptakes exceeding 200 mg/m², it becomes difficult to control the quantity of chromium adherence in the chromate film; the improvement in corrosion resistance reaches an upper limit and further benefits cannot be expected; and paint adherence is reduced because portions of the chromate film are easily removed by external forces when it is so thick.
- While the pH of the aqueous chromate bath used in the present invention is not critical, values around 1.0 to 3.0 are preferable.
- When the aqueous treating solution is coated on the surface of zinc-plated steel sheet, followed by drying, the Cr⁶⁺, Cr³⁺, and PO₄³⁻ components in the aqueous chromate bath are believed to react with one another and/or the treated surface, at a rate speeded by the thermal energy supplied by drying. The constituent components of the resulting chromate film are believed to be the colorless materials respectively specified in (a) and (b) below, the green material specified in (c), and the gold colored material specified in (d) and (e).
- (a) Zn(OH)₂
- (b) Cr(OH)₂
- (c) CrPO₄·4H₂O
- (d) zinc chromate compounds as represented by ZnO·3Zn(OH)₂·CrO₃; 3Zn(OH)₂·CrO₃; 2Zn(OH)₂·CrO₃
- (e) Cr(OH)₃·Cr(OH)·CrO₄ (chromic chromate)
-
- Under the influence of the thermal energy supplied after coating according to this invention, the aforementioned chromic chromate (e), for example, can undergo condensation reactions as depicted by Figure 1, while at the same time, the chromic chromate is cross linked as depicted in Figure 2 by the hydrolyzate {f} deriving from the silane coupling agent. Moreover, the hexavalent chromium in the chromic chromate is reduced by the methanol. Therefore, it is thought that a companion macromolecular network structure is formed by the development of complex cross linkages between the chromic chromate and silane coupling agent hydrolyzate. Accordingly, it is thought that each of the aforementioned components (a), (b), (c), and (d) may be present within the structure of the macromolecular, chromium containing coating represented by Figures 1 and 2, either in a chain-stopping position or bonded with said macromolecular chromium compound.
- With the additional participation of the bonding activity of the silanol group, the chromate film having this network molecular structure exhibits a strong alkali resistance, i.e., the chromium in the film strongly resists elution due to alkali rinsing. Moreover, it is thought that this network molecular structure contributes to increasing both the corrosion resistance and uniformity.
- Because this film does not contain silica or an organic macromolecular compound, the electrical resistance of the film is relatively low, so that it is relatively easy to weld surfaces treated according to this invention.
- The practice of the present invention may be further understood by consideration of the following non-limiting examples and comparison examples.
- Chromate coating bath No. A as reported in Table 1 was prepared as follows: 200 grams ("g") of chromic anhydride (Cr₂O₆) was first dissolved in 500 g of water, 86 g of phosphoric acid (75% aqueous solution) and 18 g of methanol were added to the aqueous solution thus obtained, and this was then heated for 1 hour at 80 to 90 degrees Centigrade to cause reduction to a Cr³⁺/Cr⁶⁺ weight ratio of 1.0. After cooling, 26 g of tert-butanol and sufficient water to make a total weight of 1 kg were added. This solution is denoted in the following as the aqueous base solution.
- The aqueous base solution was then diluted with water to give a total chromium concentration (Cr⁶⁺ + Cr³⁺) of 40 g/L, along with 10 g/L tert-butanol. Silane coupling agent
(gamma-glycidoxypropyltrimethoxysilane from Toshiba Silicone Company, Limited) was then added with stirring, in an amount to yield a concentration of 9 g/L, to give final treating bath No. A. - Final treating baths B through K were prepared by the same general procedure as for treating bath No. A, but with the compositions reported in Table 1.
- Using the process sequence outlined below, the treatment solutions thus formulated were applied to the surfaces of electrogalvanized steel sheets and zinc-nickel alloy electroplated steel sheets and dried to obtain products with the characteristics reported in Table 2.
steel sheet to be treated (*1) → alkali degreasing (*2) → water rinse → roll squeezing → drying (air current drying) → treating with a composition according to this invention → roll squeezing → drying (*3) → evaluation testing. - Notes on the process sequence:
- (*1) The steel sheets subjected to this treatment consisted of duplex electrogalvanized steel sheet (quantity of zinc plating = 20 g/m², 20 g/m²) and duplex zinc-nickel alloy electroplated steel sheet (plating quantity = 20 g/m², 20 g/m², containing 11 weight % nickel). The size was 200 x 300 mm, and oiled material with a sheet thickness of 0.8 mm was used.
- (*2) Alkali degreasing was carried out using a 2 % aqueous solution of a weakly alkaline degreaser (Par-Clean® 342 from Nihon Parkerizing Company, Limited, Tokyo) by spraying at 60 degrees Centigrade for 30 seconds.
- (*3) Drying was carried out at a sheet temperature of 100 degrees Centigrade for a drying time of 7 seconds.
- The treated zinc coated steel, either as such or after the alkali rinse described below in item (4)(a), was painted with a bakeable melamine alkyd paint (Delicon™ 700 White from Dainippon Paint Company, Limited) and then baked for 20 minutes at 140 degrees Centigrade to give a painted sheet carrying a 25 micrometer thick coating.
- The treated sheet was alkali rinsed using the conditions specified below, and the quantity of adhering chromium in mg/m² was measured by X-ray fluorescence both before and after this rinse. The "alkali resistance" as reported in Table 2 is defined as the percentage of the chromium originally present that is removed by this rinsing. Thus, the alkali resistance increases as the percent value declines, and a zero value indicates absolutely no loss from alkali in this test, or complete resistance. The alkali rinse conditions were as follows: 2 minute spray at 60 degrees Centigrade using a 2% aqueous solution of a sodium silicate-based alkaline degreaser (Par-Clean® N364S from Nihon Parkerizing Company, Limited).
- Each test specimen (70 x 150 mm) was evaluated before and after the alkali rinse using the salt-spray test specified in Japanese Industrial Standard ("JIS") Z-2371 for 150 hours. The corrosion resistance was evaluated on the basis of the development of white rust by surveying the entire area of the test specimen and reported using the following symbols:
- ++:
- area of white rust development = 0%
- +:
- area of white rust development < 10%
- Δ:
- area of white rust development ≧ 10%, but < 30%
- x:
- area of white rust development ≧ 30%
- The test specimen was subjected to a composite corrosion test (50 cycles) both before and after alkali rinsing. Each cycle consisted of salt spray for 4 hours, drying at 60 degrees Centigrade for 2 hours, and wetting at 50 degrees Centigrade and a relative humidity of ≧ 95 % for 2 hours. The corrosion resistance was evaluated on the basis of the development of red rust by surveying the entire area of the test specimen and reported according to the symbols below.
- ++:
- area of red rust development = 0%
- +:
- area of red rust development < 10%
- Δ:
- area of red rust development ≧ 10%, but < 30%
- x:
- area of red rust development ≧ 30%
- Using a cutter, a cut which reached to the base metal was introduced in the paint film. This was followed by salt-spray testing for 200 hours for the electrogalvanized steel sheet and 300 hours for the zinc-nickel alloy electroplated steel sheet. Conventional transparent adhesive tape was then applied over the area of the cut and then peeled off. The value reported in the Table is the maximum width in mm of peeling of paint from one side of the cut.
- Using a cutter, a checkerboard of 1 mm squares was scribed to the base metal on the painted test specimen (with no alkali rinse). Adhesive tape was applied to this and then rapidly peeled off, and the degree of peeling of the paint film was subsequently inspected. Results are reported with the same symbols as for the corrosion tests noted above, with the % of area of paint removed in peeling substituted for the area covered with red or white rust.
- Using an Erichsen extruder, the painted test specimen (with no alkali rinse) was extruded 6 mm. Conventional transparent adhesive tape was then applied and rapidly peeled off, and the degree of paint film peeling was inspected and reported with the same symbols as for the crosscut test.
- When spot welding is conducted continuously on zinc-nickel alloy electroplated steel sheet under the conditions given below, the welding tip gradually deteriorates and the weld quality becomes poor. Accordingly, the ease of welding can be judged from the number of spot welds of adequate quality that can be made with a single set of welding electrodes. Thus, several separate 30 x 100 mm test specimens were welded with 100 spots each with a single set of welding electrodes, and the number of spots for which the test specimens maintained a tensile shear strength of 400 kg was recorded. Welding conditions included an applied force of 200 kilograms, a current of 8.5 kiloamperes for 10 cycles of the current for each welding spot, and radius type electrodes of chromium-copper.
- Water-soluble organic solvent was added to bath No. G as reported in Table 1, and the uniformity of application of the chromate film by roll coating application was evaluated. This evaluation is reported in Table 3 along with the surface tension of the chromate bath. The coating uniformity of the chromate film was evaluated on the basis of the following three-level scale: + = uniform; Δ = slight cissing; x = substantial cissing.
- When the chromate film contains silane coupling agent in the amounts taught according to this invention, an excellent paint adherence is observed, as in Examples 1 to
12, while a poor paint adherence is observed in Comparison Examples 3, 5, and 8, which lack silane coupling agent, and in Comparison Examples 1, 4, and 6, in which the quantity of one or more constituents of the treating solution falls outside the scope of the claims. - As explained above, practice of the present invention forms a surface film which is very uniformly distributed over the surface of zinc objects, especially zinc-plated steel sheet. The treated sheet is well suited to welding, resistant to alkali treatment and corrosion, and very well adapted for painting, because paint adheres very well and the painted surface is corrosion resistant.
the Cr³⁺ : Cr⁶⁺ weight ratio in the solution being 0.25 to 1.5 and the weight ratio between phosphate ion and total chromium {PO₄³⁻/(Cr⁶⁺ + Cr³⁺)} in the solution being 0.1 to 1.2. After this, the treated surface is dried while some of the non-volatile constituents of the liquid composition noted above remain on the surface, to form on the surface a chromium containing film with a chromium content of 10 to 200 milligrams per square meter ("mg/m²") of surface. It is to be understood that necessary counterions to the constituents specified above in ionic form are also present in the solution composition used according to this invention.
Claims (7)
- A process for treating an object with a zinciferous surface, said process comprising steps of:(A) contacting the surface of the object to be treated with a liquid solution composition that comprises water and the following components:(1) from 3.0 to 50 g/L of hexavalent chromium;(2) from 2.0 to 40 g/L of trivalent chromium;(3) from 1.0 to 100 g/L of phosphate ion;(4) from 3 to 50 g/L of organic material selected from acetonitrile, tertiary alcohols with from 4 to 8 carbon atoms per molecule, and mixtures of any two or more of these; and(5) an amount of silane coupling agent such as to yield a ratio of 0.05 to 0.30 between the total molar concentration of silane coupling agent and the gram atomic concentration of hexavalent chromium concentration in the composition; andthe Cr³⁺ : Cr⁶⁺ weight ratio in the solution being 0.25 to 1.5 and the weight ratio between phosphate ion and total chromium being 0.1 to 1.2; and(B) drying the surface contacted in step (A) while there remains distributed over said surface non-volatile constituents derived from the liquid solution composition with which the surface is contacted in step (A), so as to form on the surface a chromium containing film with a chromium content of 10 to 200 milligrams per square meter.
- A process according to claim 1, wherein the composition comprises(6) from 0.2 to 10 g/L of Zn⁺² ions; and(7) a component selected from fluoride ions, complex fluoride ions, and mixtures of any two or more of these in an amount to give a concentration in the composition of from 0.2 to 8 g/L of stoichiometric equivalent of fluoride.
- A process according to claim 1 or 2, wherein component (4) is selected from the group consisting of 2-methyl-2-propanol, 2-methyl-2-butanol, and mixtures thereof.
- A process according to claims 1 to 3, wherein component (5) is selected from materials conforming to the general formula YyRrSiXx, wherein R represents an alkyl group; X represents a group selected from methoxy and ethoxy groups; Y represents a group selected from a vinyl group, a mercapto group, a glycidoxyalkyl group, or a methacryloxyalkyl group; and each of r, x, and y is an integer independently selectable from 1 - 3, except that r may also be zero and that the sum r+x+y = 4.
- A process according to claims 2 to 4, wherein component (6) is present and the counterions are selected from the group consisting of hydroxide, carbonate, phosphate, and mixtures thereof.
- A process according to claims 2 to 5, wherein component (7) is present and is selected from the group consisting of fluozirconic acid, fluotitanic acid, fluosilicic acid, fluoboric acid, and mixtures thereof.
- A process according to claims 1 to 6, wherein the temperature of the treated object during step (B) is between 60 and 150 degrees Centigrade and the time of drying is in the range from 5 to 10 seconds.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1089415A JPH0753911B2 (en) | 1989-04-07 | 1989-04-07 | Chromate treatment method for galvanized steel sheet |
JP89415/89 | 1989-04-07 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0391442A1 EP0391442A1 (en) | 1990-10-10 |
EP0391442B1 true EP0391442B1 (en) | 1993-10-06 |
Family
ID=13970020
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP90106675A Expired - Lifetime EP0391442B1 (en) | 1989-04-07 | 1990-04-06 | Improved surface treatment for zinciferous surfaces |
Country Status (9)
Country | Link |
---|---|
EP (1) | EP0391442B1 (en) |
JP (1) | JPH0753911B2 (en) |
KR (1) | KR930007389B1 (en) |
AT (1) | ATE95575T1 (en) |
DE (1) | DE69003716T2 (en) |
DK (1) | DK0391442T3 (en) |
ES (1) | ES2045616T3 (en) |
NZ (1) | NZ233236A (en) |
ZA (1) | ZA902660B (en) |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07100873B2 (en) * | 1989-09-27 | 1995-11-01 | 日本パーカライジング株式会社 | Chromate coating solution for zinc-based plated steel sheet |
JPH0696778B2 (en) * | 1990-10-05 | 1994-11-30 | 新日本製鐵株式会社 | Chromate treatment method for galvanized steel sheet |
JPH0753913B2 (en) * | 1990-11-14 | 1995-06-07 | 新日本製鐵株式会社 | Method for manufacturing organic composite plated steel sheet |
JP2743220B2 (en) * | 1991-04-22 | 1998-04-22 | 新日本製鐵株式会社 | Polyurethane heavy duty anti-corrosion coated steel |
BR9811239A (en) * | 1997-08-21 | 2000-08-15 | Henkel Corp | Composition for coating or touch-up or for both coating and touch-up of a metal surface, and, process for coating or touch-up or for both coating and touch-up a surface |
DE19740248A1 (en) * | 1997-09-12 | 1999-03-18 | Henkel Kgaa | Aqueous chromating or post-passivating solution |
EP1017880B1 (en) * | 1997-09-17 | 2002-05-08 | Chemetall Plc | Method and compositions for preventing corrosion of metal substrates |
JP4165943B2 (en) * | 1998-11-18 | 2008-10-15 | 日本ペイント株式会社 | Rust-proof coating agent for zinc-coated steel and uncoated steel |
US6669764B1 (en) * | 2000-10-31 | 2003-12-30 | The United States Of America As Represented By The Secretary Of The Navy | Pretreatment for aluminum and aluminum alloys |
US6663700B1 (en) * | 2000-10-31 | 2003-12-16 | The United States Of America As Represented By The Secretary Of The Navy | Post-treatment for metal coated substrates |
JP3873642B2 (en) * | 2001-03-21 | 2007-01-24 | Jfeスチール株式会社 | Tinned steel sheet |
DE10162756A1 (en) * | 2001-12-20 | 2003-07-10 | Walter Hillebrand Gmbh & Co | Schwarzpassivierungsverfahren |
RU2547374C1 (en) * | 2014-01-31 | 2015-04-10 | Закрытое акционерное общество "ФК" | Chromating composition for treating zinc-plated steel |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6256580A (en) * | 1985-09-05 | 1987-03-12 | Nippon Parkerizing Co Ltd | Chromating solution for galvanized steel sheet |
-
1989
- 1989-04-07 JP JP1089415A patent/JPH0753911B2/en not_active Expired - Fee Related
-
1990
- 1990-04-05 ZA ZA902660A patent/ZA902660B/en unknown
- 1990-04-06 EP EP90106675A patent/EP0391442B1/en not_active Expired - Lifetime
- 1990-04-06 ES ES90106675T patent/ES2045616T3/en not_active Expired - Lifetime
- 1990-04-06 DE DE90106675T patent/DE69003716T2/en not_active Expired - Fee Related
- 1990-04-06 NZ NZ233236A patent/NZ233236A/en unknown
- 1990-04-06 AT AT90106675T patent/ATE95575T1/en not_active IP Right Cessation
- 1990-04-06 DK DK90106675.3T patent/DK0391442T3/en active
- 1990-04-07 KR KR1019900004800A patent/KR930007389B1/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
ES2045616T3 (en) | 1994-01-16 |
DE69003716T2 (en) | 1994-02-17 |
JPH02267277A (en) | 1990-11-01 |
DK0391442T3 (en) | 1993-12-20 |
KR930007389B1 (en) | 1993-08-09 |
ATE95575T1 (en) | 1993-10-15 |
DE69003716D1 (en) | 1993-11-11 |
NZ233236A (en) | 1992-05-26 |
EP0391442A1 (en) | 1990-10-10 |
KR900016497A (en) | 1990-11-13 |
ZA902660B (en) | 1991-01-30 |
JPH0753911B2 (en) | 1995-06-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5141575A (en) | Surface treatment for zinciferous surfaces | |
EP0553164B1 (en) | Method for chromating treatment of zinc coated steel | |
US6773516B2 (en) | Process and solution for providing a conversion coating on a metallic surface I | |
US6361833B1 (en) | Composition and process for treating metal surfaces | |
US6193815B1 (en) | Composition and process for treating the surface of aluminiferous metals | |
EP0391442B1 (en) | Improved surface treatment for zinciferous surfaces | |
US6755917B2 (en) | Process and solution for providing a conversion coating on a metallic surface II | |
CA1183739A (en) | Multi-layer surface-treated steel plate having zinc- containing layer | |
JP5075321B2 (en) | Aqueous treatment agent for metal surface | |
US5230750A (en) | Chromating method of zinc-based plated steel sheet | |
WO2000024948A1 (en) | Composition and process for treating metal surfaces | |
US5000799A (en) | Zinc-nickel phosphate conversion coating composition and process | |
EP0545993B1 (en) | Composition and method for chromating treatment of metal | |
US20230203699A1 (en) | Treated substrates | |
JPH01225780A (en) | Highly corrosion-resistant chromated steel sheet, its production, and chromating solution | |
AU773837B2 (en) | Process and solution for providing a conversion coating on metallic surface | |
JP2003253463A (en) | Nonchromium treatment for galvanized steel sheet | |
MXPA01004311A (en) | Composition and process for treating metal surfaces |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: OGINO, TAKAO Inventor name: HONDA, TAKUMI, NIHON PARKER HIRATSUKA DORMITORY Inventor name: SAEKI, KENSHI Inventor name: YOSHITAKE, NORIAKI |
|
17P | Request for examination filed |
Effective date: 19901220 |
|
17Q | First examination report despatched |
Effective date: 19920518 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE |
|
REF | Corresponds to: |
Ref document number: 95575 Country of ref document: AT Date of ref document: 19931015 Kind code of ref document: T |
|
ITF | It: translation for a ep patent filed | ||
REF | Corresponds to: |
Ref document number: 69003716 Country of ref document: DE Date of ref document: 19931111 |
|
REG | Reference to a national code |
Ref country code: DK Ref legal event code: T3 |
|
REG | Reference to a national code |
Ref country code: GR Ref legal event code: FG4A Free format text: 3009456 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2045616 Country of ref document: ES Kind code of ref document: T3 |
|
ET | Fr: translation filed | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19940430 Ref country code: BE Effective date: 19940430 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
BERE | Be: lapsed |
Owner name: HENKEL CORP. Effective date: 19940430 |
|
EAL | Se: european patent in force in sweden |
Ref document number: 90106675.3 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GR Payment date: 19950313 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 19950323 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 19950404 Year of fee payment: 6 Ref country code: AT Payment date: 19950404 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DK Payment date: 19950427 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19950430 Year of fee payment: 6 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DK Effective date: 19960406 Ref country code: AT Effective date: 19960406 |
|
REG | Reference to a national code |
Ref country code: DK Ref legal event code: EBP |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19960408 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Effective date: 19960430 Ref country code: CH Effective date: 19960430 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GR Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY Effective date: 19961031 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19961101 |
|
REG | Reference to a national code |
Ref country code: GR Ref legal event code: MM2A Free format text: 3009456 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 19961101 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 19970319 Year of fee payment: 8 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19980407 |
|
EUG | Se: european patent has lapsed |
Ref document number: 90106675.3 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 19990503 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20010319 Year of fee payment: 12 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20010320 Year of fee payment: 12 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20010321 Year of fee payment: 12 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20020406 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20021101 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20020406 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20021231 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20050406 |