CA2428138A1 - Passivation method - Google Patents
Passivation method Download PDFInfo
- Publication number
- CA2428138A1 CA2428138A1 CA002428138A CA2428138A CA2428138A1 CA 2428138 A1 CA2428138 A1 CA 2428138A1 CA 002428138 A CA002428138 A CA 002428138A CA 2428138 A CA2428138 A CA 2428138A CA 2428138 A1 CA2428138 A1 CA 2428138A1
- Authority
- CA
- Canada
- Prior art keywords
- chrome
- passivation
- layer
- passivated layer
- zinc
- 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.)
- Abandoned
Links
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
- C23C22/48—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
-
- 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
- C23C22/46—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 oxalates
-
- 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
- C23C2222/10—Use of solutions containing trivalent chromium but free of hexavalent chromium
Landscapes
- Chemical & Material Sciences (AREA)
- Metallurgy (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
- Lubricants (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Formation Of Insulating Films (AREA)
- Chemically Coating (AREA)
Abstract
The invention relates to a method for passivating zinc, cadmium, or the alloys thereof, especially zinc-nickel alloys, with a chrome (VI)-free solution containing a weak complexing agent, preferably dicarboxylic or tricarboxylic acids, preferably a chrome (III)-oxalate complex and Co2+, the Co2+
concentration being higher than 30g/l.
concentration being higher than 30g/l.
Description
April 29, 2003 PCT/EP01/12866 44. 393 K
Welter Hillebrand GmbH 8 Co. Galvanotechnik .....~sss=s=as==smsCssasslc~aass---n-Westerfiaar 56 - 58, 58738 Wickede/Ruhr ==ssssssaas:~messss==s=:a~aa~==
"Psssivation method"
The invention refers to a method to passivate zinc and Zinc alloy layers as well as cadmium and cadmium alloy I$yen3 and claims the priority of Gem~an patent application 100 55 215.3, which is referred to for purpose of disclo..
sure.
It is known to galvanically coat metallic surfaces with metals or metal alloys in order to improve corrosion resistance. Moreover, it is known to further in-crease the anticorrosive effect of this layer both by its modification and by additional coating systems. A system with good anticornosive effect is repre-sented by a galvanically applied zinc-nickel alloy, which is subsequently chromatized and which can additionally be treated with an organic or inor-ganic coat. A good c;omosfon resistance is achieved by employing chrome(VI) for passivating the zinc-nickel layer.
Welter Hillebrand GmbH 8 Co. Galvanotechnik .....~sss=s=as==smsCssasslc~aass---n-Westerfiaar 56 - 58, 58738 Wickede/Ruhr ==ssssssaas:~messss==s=:a~aa~==
"Psssivation method"
The invention refers to a method to passivate zinc and Zinc alloy layers as well as cadmium and cadmium alloy I$yen3 and claims the priority of Gem~an patent application 100 55 215.3, which is referred to for purpose of disclo..
sure.
It is known to galvanically coat metallic surfaces with metals or metal alloys in order to improve corrosion resistance. Moreover, it is known to further in-crease the anticorrosive effect of this layer both by its modification and by additional coating systems. A system with good anticornosive effect is repre-sented by a galvanically applied zinc-nickel alloy, which is subsequently chromatized and which can additionally be treated with an organic or inor-ganic coat. A good c;omosfon resistance is achieved by employing chrome(VI) for passivating the zinc-nickel layer.
The toxicity of chrome(VI) compounds contrasts their good anticorrosive qualities. Accordingly, it has been attempted for a longer period time to es-tablish chrome(VI) free systems providing a sufficient corrosion resistance.
For this goal it is known to use chrome(ill~oontaining passivation solutions as described in the US 4 171 231, which however - due the oxidants also present in the solution -- do not lead to chrome(VI) free passivation layers, since chrome(Ili) is oxidized during the treatment.
The DE 41 35 524 C2, which is incorporated into the present description and the teaching of which is fully refer-ed to discloses a passivation method, which achieves improved anti-corrosion values by a chroive{Ill)-containing passivation solution with an oxalate complexation (Tab. II; Tab. III).
Different examples of chrome(lll) compounds for passivatlon are given in table IV of the mentioned document. The good anticorrosive effect of the passivation method described in this document is based on the use of oxalate as a cony.
plexing agent, which - in contrast to other oomplexing agents - supports the in~rporation of chrome into the passivation layer.
With this type of passivation method one can already achieve good enticor rosion results. Moreover, it is known to increase the anticorrosive protection provided by chrome(ill~based passivation methods by the use of cobalt.
The imprvvemant of anticorrosive protection by the use of cobalt is described in the WO 97/40208, which is hereby incorporated.
For this goal it is known to use chrome(ill~oontaining passivation solutions as described in the US 4 171 231, which however - due the oxidants also present in the solution -- do not lead to chrome(VI) free passivation layers, since chrome(Ili) is oxidized during the treatment.
The DE 41 35 524 C2, which is incorporated into the present description and the teaching of which is fully refer-ed to discloses a passivation method, which achieves improved anti-corrosion values by a chroive{Ill)-containing passivation solution with an oxalate complexation (Tab. II; Tab. III).
Different examples of chrome(lll) compounds for passivatlon are given in table IV of the mentioned document. The good anticorrosive effect of the passivation method described in this document is based on the use of oxalate as a cony.
plexing agent, which - in contrast to other oomplexing agents - supports the in~rporation of chrome into the passivation layer.
With this type of passivation method one can already achieve good enticor rosion results. Moreover, it is known to increase the anticorrosive protection provided by chrome(ill~based passivation methods by the use of cobalt.
The imprvvemant of anticorrosive protection by the use of cobalt is described in the WO 97/40208, which is hereby incorporated.
/~s it can also be seen from this document, the experts aim to produce a conversion layer as compact as possible in order to achieve the layer's de-sired qualities with respect to resistance tv corrosion and chemicals.
The invention has the object to provide both a passivation method with fur-ther improved antioornosive protection characteristics and a respective coat-ing system.
This aim is achieved by a method and a passivation solution according to the independent daims. Favorable aspects are subject of the dependent claims.
The invention is based on the finding, that fuming away from the efforts of focussing on a compact conversion layer and thus aiming to produce a po-rous conversion layer leads to improved final products when the porosity is used for binding to at least one further layer.
The invention can be realized by using cobalt In a passivafion solution con-taining chrome(111) and a weaker complexing agent - preferably a di- or tri-carbonic acid tike oxalic acid.
By using a cobalt concentration greater than 30 gll, preferably a concentra-tion between 70 gll and 100 gll, in particular about 90 gll (concentrate -12%) already surprising cornosion protection values of 240 h until onset of primary corrosion according to DIN 50961 in the salt spray test according to OIN 50021 SS are achieved in production. Favorably the chrome-cobalt-ratio is 1,7:2,0 ~ 0,85.
The invention has the object to provide both a passivation method with fur-ther improved antioornosive protection characteristics and a respective coat-ing system.
This aim is achieved by a method and a passivation solution according to the independent daims. Favorable aspects are subject of the dependent claims.
The invention is based on the finding, that fuming away from the efforts of focussing on a compact conversion layer and thus aiming to produce a po-rous conversion layer leads to improved final products when the porosity is used for binding to at least one further layer.
The invention can be realized by using cobalt In a passivafion solution con-taining chrome(111) and a weaker complexing agent - preferably a di- or tri-carbonic acid tike oxalic acid.
By using a cobalt concentration greater than 30 gll, preferably a concentra-tion between 70 gll and 100 gll, in particular about 90 gll (concentrate -12%) already surprising cornosion protection values of 240 h until onset of primary corrosion according to DIN 50961 in the salt spray test according to OIN 50021 SS are achieved in production. Favorably the chrome-cobalt-ratio is 1,7:2,0 ~ 0,85.
The method is preferably carried out at temperatures up to 55°C and pH lev-els of 0,5 to 5,5. Preferably the passivation is Carried out .at pH 4.
Particularly good results can be achieved with a suffate free solution. This is based on the idea that the use of sulfate leads to a disturbance of the catalytic reaction and interference with the development of an anticorrosive chrome layer.
The passivated layer is re-treated with an organic or inorganic coating which penetrates into the porous conversion layer. Preferably, a coat of Aquares'~'M
(Enthone-OMI GmbH, Neuss) is applied to the passivation layer. A particu-larly good corros~n control can be achieved by a double Aquares layer. The Aquares layer surprisingly is no longer traceable in the REM in some variants of the invention.
Both the characteristics of corrosion control and resistance to chemicals can be further improved by means of a Topcoat containing a dry lubricant. Also this coat according to the invention engages in a special binding to the po-rous conversion layer. Hereby, the desired friction and flow values can achieved at the same time.
Surprising properties are displayed by a combination of the dry lubricant Molykote~ D-7t 00 (Dow Corning) and the zinc-nickel alloy passivated ac-cording to the invention. in comparison to known coating systems this sys-tem Is particularly resistant to chemicals and rim dearer. It is thus especially suitable for wheel screws. Furthermore a surprising temperature insensitivity of the combination acxording to the invention has beers stated.
Preferably this dry lubricant layer is applied onto a double Aquares layer.
Particularly good results can be achieved with a suffate free solution. This is based on the idea that the use of sulfate leads to a disturbance of the catalytic reaction and interference with the development of an anticorrosive chrome layer.
The passivated layer is re-treated with an organic or inorganic coating which penetrates into the porous conversion layer. Preferably, a coat of Aquares'~'M
(Enthone-OMI GmbH, Neuss) is applied to the passivation layer. A particu-larly good corros~n control can be achieved by a double Aquares layer. The Aquares layer surprisingly is no longer traceable in the REM in some variants of the invention.
Both the characteristics of corrosion control and resistance to chemicals can be further improved by means of a Topcoat containing a dry lubricant. Also this coat according to the invention engages in a special binding to the po-rous conversion layer. Hereby, the desired friction and flow values can achieved at the same time.
Surprising properties are displayed by a combination of the dry lubricant Molykote~ D-7t 00 (Dow Corning) and the zinc-nickel alloy passivated ac-cording to the invention. in comparison to known coating systems this sys-tem Is particularly resistant to chemicals and rim dearer. It is thus especially suitable for wheel screws. Furthermore a surprising temperature insensitivity of the combination acxording to the invention has beers stated.
Preferably this dry lubricant layer is applied onto a double Aquares layer.
Claims (15)
1. Method for the passivation of zinc, cadmium or their alloys, in particular of zinc-nickel alloys by means of a chrome(VI) free solution containing a weak complexing agent, preferably di- or tri-carbonic acids, preferably chrome (III)-oxalate complex and Co2+, characterized in that the Co2+
concentration is greater than 30 g/l.
concentration is greater than 30 g/l.
2. Method according to claim 1, characterized in that the Co2+ concen-tration is 70 to 110 g/l.
3. Method according to claim 1, characterized in that the Co2+ concen-tration is about 90 g/l.
4. Method according to one of the preceding claims, characterized in that the passivation is carried out at 20°C to 55°C.
5. Method according to one of the preceding claims, characterized in that the passivation is carried out at pH 0,5 to 5,5.
6. Method according to one of the preceding claims, characterized in that the passivation is carried out at pH 4.
7. Method according to one of the preceding claims, characterized in that the ratio of chrome to cobalt is 1,7: 2,0.
8. Method according to one of the preceding claims, characterized in that the solution is sulfate free.
9. Method according to one of the preceding claims, characterized in that the passivated layer is treated by an additional coating.
10. Method according to one of the preceding claims, characterized by a coating with Aquares.TM..
11. Method according to one of the preceding claims, characterized by a double coating with Aquares.TM..
12. Method according to one of the preceding claims, characterized in that the passivated layer is treated with a dry lubricant.
13. Method according to one of the preceding claims, characterized in that the passivated layer is coated with an organic Topcoat.
14. Method according to one of the preceding claims, characterized in that the passivated layer is treated with a PTFE-containing coat.
15. Method according to the preceding claim, characterized in that the passivated layer is coated with Molykote® D 7100.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10055215A DE10055215A1 (en) | 2000-11-07 | 2000-11-07 | passivation |
| DE10055215.3 | 2000-11-07 | ||
| PCT/EP2001/012866 WO2002038829A1 (en) | 2000-11-07 | 2001-11-07 | Passivation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2428138A1 true CA2428138A1 (en) | 2002-05-16 |
Family
ID=7662484
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002428138A Abandoned CA2428138A1 (en) | 2000-11-07 | 2001-11-07 | Passivation method |
Country Status (12)
| Country | Link |
|---|---|
| US (1) | US20040011431A1 (en) |
| EP (1) | EP1346081A1 (en) |
| JP (1) | JP2004513240A (en) |
| CN (1) | CN1478155A (en) |
| AU (1) | AU2002221819A1 (en) |
| BR (1) | BR0115161A (en) |
| CA (1) | CA2428138A1 (en) |
| CZ (1) | CZ20031237A3 (en) |
| DE (1) | DE10055215A1 (en) |
| MX (1) | MXPA03004019A (en) |
| SK (1) | SK5442003A3 (en) |
| WO (1) | WO2002038829A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3332373B1 (en) † | 2001-11-30 | 2002-10-07 | ディップソール株式会社 | A treatment solution for forming a hexavalent chromium-free rust preventive film on zinc and zinc alloy plating, a hexavalent chromium-free rust preventive film, and a method for forming the same. |
| CN1307323C (en) * | 2004-06-14 | 2007-03-28 | 广州市集胜化工有限公司 | Trivalent chromic rainbow color passivating agent for galvanizing and its production |
| EP1677371A1 (en) * | 2004-12-30 | 2006-07-05 | STMicroelectronics S.r.l. | Dual resistance heater for phase change devices and manufacturing method thereof |
| US7276424B2 (en) * | 2005-06-29 | 2007-10-02 | Hewlett-Packard Development Company, L.P. | Fabrication of aligned nanowire lattices |
| JP4993959B2 (en) * | 2006-07-10 | 2012-08-08 | 日本化学工業株式会社 | Chromium (III) organic acid aqueous solution and method for producing the same |
| DE102016005656A1 (en) | 2016-05-11 | 2017-11-16 | Surtec International Gmbh | Conversion layers for metallic surfaces |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4359348A (en) * | 1981-06-17 | 1982-11-16 | Occidental Chemical Corporation | Stabilized trivalent chromium passivate composition and process |
| US4359347A (en) * | 1981-04-16 | 1982-11-16 | Occidental Chemical Corporation | Chromium-free passivate solution and process |
| US4359346A (en) * | 1981-04-16 | 1982-11-16 | Occidental Chemical Corporation | Trivalent chromium passivate solution and process for yellow passivate film |
| US4359345A (en) * | 1981-04-16 | 1982-11-16 | Occidental Chemical Corporation | Trivalent chromium passivate solution and process |
| US4349392A (en) * | 1981-05-20 | 1982-09-14 | Occidental Chemical Corporation | Trivalent chromium passivate solution and process |
| US4384902A (en) * | 1981-06-15 | 1983-05-24 | Occidental Chemical Corporation | Trivalent chromium passivate composition and process |
| US4367099A (en) * | 1981-06-15 | 1983-01-04 | Occidental Chemical Corporation | Trivalent chromium passivate process |
| CA1228000A (en) * | 1981-04-16 | 1987-10-13 | David E. Crotty | Chromium appearance passivate solution and process |
| FR2600072B1 (en) * | 1986-06-13 | 1988-10-21 | Dacral Sa | ANTICORROSION COATING COMPOSITION WITH IMPROVED STABILITY, AND COATED SUBSTRATE |
| US4971635A (en) * | 1987-02-06 | 1990-11-20 | Guhde Donald J | Low-cure coating composition |
| US5368655A (en) * | 1992-10-23 | 1994-11-29 | Alchem Corp. | Process for chromating surfaces of zinc, cadmium and alloys thereof |
| DE19905134A1 (en) * | 1999-02-09 | 2000-09-28 | Hillebrand Walter Gmbh & Co Kg | Passivation process |
-
2000
- 2000-11-07 DE DE10055215A patent/DE10055215A1/en not_active Withdrawn
-
2001
- 2001-11-07 EP EP01993716A patent/EP1346081A1/en not_active Withdrawn
- 2001-11-07 JP JP2002541141A patent/JP2004513240A/en not_active Withdrawn
- 2001-11-07 CN CNA018197477A patent/CN1478155A/en active Pending
- 2001-11-07 US US10/416,087 patent/US20040011431A1/en not_active Abandoned
- 2001-11-07 MX MXPA03004019A patent/MXPA03004019A/en unknown
- 2001-11-07 CZ CZ20031237A patent/CZ20031237A3/en unknown
- 2001-11-07 WO PCT/EP2001/012866 patent/WO2002038829A1/en not_active Application Discontinuation
- 2001-11-07 CA CA002428138A patent/CA2428138A1/en not_active Abandoned
- 2001-11-07 BR BR0115161-4A patent/BR0115161A/en not_active Application Discontinuation
- 2001-11-07 AU AU2002221819A patent/AU2002221819A1/en not_active Abandoned
- 2001-11-07 SK SK544-2003A patent/SK5442003A3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE10055215A1 (en) | 2002-05-08 |
| BR0115161A (en) | 2003-10-21 |
| SK5442003A3 (en) | 2003-10-07 |
| JP2004513240A (en) | 2004-04-30 |
| US20040011431A1 (en) | 2004-01-22 |
| CN1478155A (en) | 2004-02-25 |
| WO2002038829A1 (en) | 2002-05-16 |
| MXPA03004019A (en) | 2004-02-12 |
| AU2002221819A1 (en) | 2002-05-21 |
| EP1346081A1 (en) | 2003-09-24 |
| CZ20031237A3 (en) | 2003-10-15 |
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| FZDE | Dead |