CH136060A - Process for the production of coatings on metals. - Google Patents
Process for the production of coatings on metals.Info
- Publication number
- CH136060A CH136060A CH136060DA CH136060A CH 136060 A CH136060 A CH 136060A CH 136060D A CH136060D A CH 136060DA CH 136060 A CH136060 A CH 136060A
- Authority
- CH
- Switzerland
- Prior art keywords
- bath
- additive
- acid
- metals
- permanganate
- Prior art date
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
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- 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
-
- 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
Description
Verfahren zur Herstellung von Überzügen auf Metallen. Den Gegenstand der Erfindung bildet ein Verfahren zur Herstellung von Überzügen auf Metallen, wie Aluminium, Magnesium und ihren Legierungen, Zink, Messing und Eisen, das dadurch gekennzeichnet ist, dass man die Metalle zweckmässig in der Kälte, in ein Bad taucht, das wasserlösliche Per manganate enthält und ausserdem einen Zu satz, der die Niederschlagung von Mangan oxyden auf den Metallen beschleunigt und das Festhaften des Niederschlages bewirkt. Als solche Zusätze können verschiedene Che mikalien benutzt werden, in erster Linie an organische oder organische Säuren.
Unter den anorganischen Säuren hat sich die Flusssäure für den vorliegenden Zweck als besonders geeignet erwiesen, unter den organischen Säuren die Essigsäure, weil diese Säuren die genannten Metalle selbst wenig oder gar nicht angreifen, besonders in der Kälte.
Man kann aber auch die Manganogyde aus vollkommen neutralen Bädern auf den Metallen niederschlagen, wenn man als Zu- satt zu den Permanganaten Wasserstoffsu peroxyd verwendet, oder wasserlösliche Chro- mate, zum Beispiel Kaliumbichromat.
Die Farbe und Art der Niederschläge, die aus diesen sauren wie neutralen Bädern erhalten werden, können in bestimmter Weise verändert werden, wenn den Bädern in ge ringen Mengen Salze von Schwermetallen beigegeben werden. Fügt man den Perman- ganat und Ohromat enthaltenden Bädern Säure zu, so arbeiten sie schneller als ohne den Säurezusatz und man erhält, zum Beispiel auf Aluminium oder Aluminiumlegierungen, Niederschläge, die offenbar aus einem Ge misch von Mangan- 'und Chromoxyden mit Aluminiumoxyd bestehen. In'ähnlicher Weise wirkt Wasserstoffsuperoxyd.
Je mehr man den Permanganatzusatz herabsetzt, desto mehr kommt die Farbe der Chromverbindungen heraus.
Der grosse Vorzug aller dieser Bäder ist, wie Versuche ergaben, dass sie schon in der Kälte in relativ kurzer Zeit einen schützen- den Überzug geben, .dessen Farbe für viele Zwecke brauchbarer ist als die natürliche Farbe des Metalls, beziehungsweise der Me tallegierungen, auf denen der Überzug ange bracht ist, und dass die oxydischen Überzüge, auch aus neutralen Lösungen entstehen kön nen, was besonders für die empfindlichen Gegenstände aus Magnesium, Zink und ihren Legierungen von Bedeutung ist.
Ein geeignetes Bad enthält zum Beispiel 5% Permanganat und 1 bis 2% Flusssäure, sowie wenn gewünscht, 0,5% eines Schwer- metallsalzes, wie Kupfersulfat, Ferrichlorid usw.
Statt der Flusssäure kann ein gleicher Prozentgehalt Essigsäure Verwendung finden oder auch 211/o Wasserstoff Superoxyd.
Will man mit Bichromat, ohne Säurezusatz, arbei ten, so empfiehlt sich die Verwendung grösserer Mengen, zum Beispiel 5 % des Chromates auf 5 % Permanganat. Bei Säurezusatz kommt man mit wesentlich geringeren Mengen Permanganat beziehungsweise Biehromat aus.
Je mehr Permanganat die Bäder enthalten, desto dunkler werden die Niederschläge. Die zunächst helleren Farbtöne gehen über braun schliesslich in ein tiefes Blauschwarz über. Je mehr Chromat verwendet wird und je weniger Permanganat, desto rötlichere Farb töne werdan erhalten.
In ein solches Bad werden zum Beispiel Gegenstände aus Aluminiumlegierungen 15 bis 30 Minuten eingetaucht, aus dem Bad herausgenommen und getrocknet.
Process for the production of coatings on metals. The subject of the invention is a process for the production of coatings on metals such as aluminum, magnesium and their alloys, zinc, brass and iron, which is characterized in that the metals are expediently immersed in the cold in a bath, the water-soluble per Manganate contains and also an additive which accelerates the precipitation of manganese oxides on the metals and causes the precipitate to stick. Various chemicals can be used as such additives, primarily organic or organic acids.
Among the inorganic acids, hydrofluoric acid has proven to be particularly suitable for the present purpose, and among the organic acids acetic acid, because these acids themselves have little or no attack on the metals mentioned, especially in the cold.
But you can also precipitate the manganogyds from completely neutral baths on the metals, if you add hydrogen peroxide to the permanganates, or water-soluble chromates, for example potassium dichromate.
The color and type of precipitates that are obtained from these acidic and neutral baths can be changed in certain ways if salts of heavy metals are added to the baths in small amounts. If acid is added to the baths containing Permanganat and Ohromat, they work faster than without the addition of acid and deposits are obtained, for example on aluminum or aluminum alloys, which apparently consist of a mixture of manganese and chromium oxides with aluminum oxide. Hydrogen peroxide works in a similar way.
The more you reduce the addition of permanganate, the more the color of the chromium compounds comes out.
The great advantage of all these baths, as tests have shown, is that they give a protective coating even in the cold in a relatively short time, the color of which is more useful for many purposes than the natural color of the metal or metal alloys to which the coating has been applied, and that the oxide coatings can also arise from neutral solutions, which is particularly important for sensitive objects made of magnesium, zinc and their alloys.
A suitable bath contains, for example, 5% permanganate and 1 to 2% hydrofluoric acid and, if desired, 0.5% of a heavy metal salt such as copper sulphate, ferric chloride, etc.
Instead of hydrofluoric acid, an equal percentage of acetic acid can be used or 211 / o hydrogen superoxide.
If you want to work with bichromate without the addition of acid, we recommend using larger amounts, for example 5% of the chromate to 5% permanganate. With the addition of acid, you can get by with much smaller amounts of permanganate or Biehromat.
The more permanganate the baths contain, the darker the precipitation. The initially lighter shades of color change over brown to a deep blue-black. The more chromate is used and the less permanganate, the more reddish color tones will be obtained.
Objects made of aluminum alloys, for example, are immersed in such a bath for 15 to 30 minutes, removed from the bath and dried.
Claims (1)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH136060T | 1928-02-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
CH136060A true CH136060A (en) | 1929-10-31 |
Family
ID=4393825
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CH136060D CH136060A (en) | 1928-02-21 | 1928-02-21 | Process for the production of coatings on metals. |
Country Status (1)
Country | Link |
---|---|
CH (1) | CH136060A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2428749A (en) * | 1944-08-19 | 1947-10-07 | Dow Chemical Co | Surface treatment of magnesium alloys |
DE19905134A1 (en) * | 1999-02-09 | 2000-09-28 | Hillebrand Walter Gmbh & Co Kg | Passivation process |
EP1612294A1 (en) * | 2004-07-02 | 2006-01-04 | Italtecno S.R.L. | Bath and associated method for the conversion coating of articles made of aluminium and alloys thereof |
-
1928
- 1928-02-21 CH CH136060D patent/CH136060A/en unknown
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2428749A (en) * | 1944-08-19 | 1947-10-07 | Dow Chemical Co | Surface treatment of magnesium alloys |
DE19905134A1 (en) * | 1999-02-09 | 2000-09-28 | Hillebrand Walter Gmbh & Co Kg | Passivation process |
EP1612294A1 (en) * | 2004-07-02 | 2006-01-04 | Italtecno S.R.L. | Bath and associated method for the conversion coating of articles made of aluminium and alloys thereof |
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