EP0312176B1 - Process for applying conversion coatings - Google Patents

Process for applying conversion coatings Download PDF

Info

Publication number
EP0312176B1
EP0312176B1 EP88202291A EP88202291A EP0312176B1 EP 0312176 B1 EP0312176 B1 EP 0312176B1 EP 88202291 A EP88202291 A EP 88202291A EP 88202291 A EP88202291 A EP 88202291A EP 0312176 B1 EP0312176 B1 EP 0312176B1
Authority
EP
European Patent Office
Prior art keywords
tin
solution
coating
treatment
conversion
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
Application number
EP88202291A
Other languages
German (de)
French (fr)
Other versions
EP0312176A1 (en
Inventor
Yasunobu Matsushima
Shigeo Tanaka
Tomoyuki Aoki
Yohiji Ono
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nihon Parkerizing Co Ltd
Original Assignee
Nihon Parkerizing Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nihon Parkerizing Co Ltd filed Critical Nihon Parkerizing Co Ltd
Publication of EP0312176A1 publication Critical patent/EP0312176A1/en
Application granted granted Critical
Publication of EP0312176B1 publication Critical patent/EP0312176B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • C23C22/07—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 phosphates
    • C23C22/08—Orthophosphates
    • C23C22/10—Orthophosphates containing oxidants
    • 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
    • C23C22/07—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 phosphates
    • C23C22/23—Condensed phosphates
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/36—Phosphatising

Definitions

  • a disadvantage of using these known solutions is that when the treatment systems are at a standstill, the tin content in the solution drops, so that conversion coatings of inferior quality are produced when the system is restarted, unless an additional addition of tin to the treatment solution is carried out beforehand.
  • a method for cathodic deposition of a phosphate coating on stainless steels in which a phosphating solution is used which contains a chelating agent, such as condensed phosphates.
  • the object of the invention is to provide a process for applying conversion coatings on tinplate which does not have the disadvantages of the known processes and which, with small tin deposits, leads to conversion coatings with excellent corrosion resistance and precludes a decrease in the tin concentration in the treatment solution when the treatment systems are at a standstill.
  • the complexing agent content suppressed the tin precipitation from the treatment solution, but at the same time its deposition on the workpiece surface when the Conversion overlay is not prevented.
  • the complexing agent also accelerates the pickling attack on the metal surface and is responsible for a balance between the tin which dissolves (as a result of the pickling attack) and the tin which deposits as a coating component. This largely avoids fluctuations in the tin concentration in the treatment solution, which ultimately has a favorable effect on the quality, in particular the high corrosion resistance of the conversion coating.
  • the phosphate can be introduced as an alkali phosphate, such as sodium, potassium or ammonium monohydrogen phosphate or dihydrogen phosphate. It can also be formed from phosphoric acid and sodium, potassium or ammonium hydroxide. Solutions with phosphate concentrations outside the range of 1 to 50 g / l are unable to produce conversion coatings with the desired excellent properties. Concentrations within the range of 2 to 25 g / l lead to particularly high-quality conversion coatings.
  • the chlorides and / or sulfates of divalent or tetravalent tin can be used in particular as the source of tin ions.
  • Sodium stannate is also suitable.
  • the range from 0.01 to 5 g / l applies to tin II or tin IV ions, or to the sum of tin II and tin IV ions.
  • Concentrations below 0.01 g / l reduce the corrosion resistance of the conversion coatings produced.
  • concentrations above 5 g / l there is a risk that the treatment solution will become unstable. An additional improvement in the coating quality is also not achieved.
  • Complexing agents are sodium, potassium or ammonium pyrophosphate, tripolyphosphate or tetrapolyphosphate. At concentrations below 0.01 g / l, the complexing effect of the condensed phosphates is no longer sufficiently pronounced, i.e. the ability to prevent tin precipitation is waning. With concentrations above 5 g / l, an excessive pickling attack on the metal surface can be associated, in particular, the deposition of the tin in the conversion coating can be hindered.
  • phosphoric acid hydrochloric acid, sulfuric acid or sodium, potassium or ammonium hydroxide is expediently used.
  • the pH range to be set from 2 to 6 is important insofar as the corrosion resistance of the conversion coating formed becomes low at a pH value below 2 and the tendency at a pH value above 6 that tin ions precipitate out of the solution and therefore proper coating formation is no longer guaranteed.
  • the conversion coating is formed electrochemically.
  • This embodiment is particularly advantageous for the treatment of strip material made of tinplate.
  • the corrosion resistance of the conversion coating formed is particularly high.
  • the tinplate is switched as the anode against graphite, stainless steel and the like as the cathode, an electrode spacing of approximately 10 to 500 mm and a current density of approximately 0.1 A / dm 2 are set for a period of 0.5 to 60 s. Direct or alternating current can be used.
  • the conversion coating is produced in two stages, first chemically, then electrochemically. This will increase the corrosion resistance again achieved.
  • Tin-II or tin-IV and phosphate are the essential constituents forming the conversion coating.
  • the layer formation begins with the pickling attack of the acidic solution on the metal surface. It is intensified by the action of the accelerators, especially the oxo acids.
  • the complexing agent controls the tin deposition by forming a chelate complex with tin, which would otherwise easily precipitate out of the treatment solution, and provides the tin ions required for coating formation in a controlled manner.
  • Another role of the complexing agent is to bind the metal ions released from the metal surface by the pickling attack and to make them available again in a controlled manner for coating formation.
  • the complexing agent is responsible for uniform coating formation by influencing the pickling attack.
  • the coatings also have excellent properties as the basis for subsequent painting, printing and the like in terms of corrosion resistance, adhesion and gloss.
  • the treatment solution experiences practically no reduction in the tin content even after long downtimes, so that the process can then be resumed immediately and perfect conversion coatings are immediately obtained.
  • Cans made from tinplate were cleaned in a mildly alkaline cleaner with a concentration of 1% by weight in water. The coating was then sprayed for 20 s using the solutions listed below. After a water rinse, deionized water of a quality of at least 300,000 ohm ⁇ cm was sprayed for a period of 10 s and then dried in a hot air oven at 200 ° C. within 3 minutes. The conversion coating was applied in each case with a freshly prepared coating solution and one which had stood for one day for 10 cans per liter of solution.
  • H3PO4 (75% by weight) 15 g / l (PO4 11 g / l) NaClO3 6 g / l SnCl4 ⁇ 5H2O 0.6 g / l (Sn 0.2 g / l) Na4P2O7 ⁇ 10H2O 1.5 g / l (P2O7 0.6 g / l) pH 3.1 adjusted with sodium hydroxide solution
  • Tinplate cans were treated according to the procedure described in Example 1 with the following solution: H3PO4 (75% by weight) 2.8 g / l (PO4 2 g / l) NaClO3 0.3 g / l SnCl2 ⁇ 2H2O 0.04 g / l (Sn 0.02 g / l) Na4P2O7 ⁇ 10H2O 0.05 g / l (P2O7 0.02 g / l) pH 5.7 adjusted with sodium hydroxide solution Treatment temperature 70 ° C
  • tinplate cans were treated with the following solution: H3PO4 (75% by weight) 55 g / l (PO4 40 g / l) NaBrO3 17 g / l SnCl4 ⁇ 5H2O 13.2 g / l (Sn 4.5 g / l) Na5P3O10 6.5 g / l (P3O10 4.5 g / l) pH 2.2 adjusted with sodium hydroxide solution Treatment temperature 60 ° C
  • tinplate cans were treated with the following solution: H3PO4 (75% by weight) 15 g / l (PO4 11 g / l) NaClO3 6 g / l SnCl4 ⁇ 5H2O 0.6 g / l (Sn 0.2 g / l) Na4P2O7 ⁇ 10H2O 21 g / l (P2O7 8 g / l) pH 3.1 adjusted with sodium hydroxide solution Treatment temperature 60 ° C
  • the tin content was determined after the batch and after standing for one day.
  • the tinplate cans provided with conversion coatings were subjected to the corrosion test and the paint adhesion test.
  • the treated cans were immersed in tap water at 60 ° C. for 30 minutes and the rust development was assessed.
  • an epoxy / urea paint with a thickness of 5 to 7 ⁇ m was applied to the cans provided with the conversion coatings and baked at 210 ° C. (duration 10 minutes). After standing for 24 hours, the cans were immersed in a 1% by weight aqueous citric acid solution at 95 to 97 ° C and left therein for 60 minutes. It was then rinsed with water and dried.
  • the samples were provided with a cross cut reaching to the metal surface and then with cellophane adhesive tape by pressing firmly. After the adhesive tape was torn off, it was found that the paint adhesion was consistently excellent, i.e. no paint detachment was found.

Description

Die Erfindung betrifft ein Verfahren zum Aufbringen von Konversionsüberzügen auf Weißblech mit Hilfe von wäßrigen Lösungen, die

1 bis 50 g/l
Orthophosphat (ber. als PO₄)
0,01 bis 5 g/l
Zinn
0,2 bis 20 g/l
Chlorat und/oder Bromat als Beschleuniger
und einen Komplexbildner enthalten.The invention relates to a method for applying conversion coatings on tinplate with the aid of aqueous solutions
1 to 50 g / l
Orthophosphate (calc. As PO₄)
0.01 to 5 g / l
tin
0.2 to 20 g / l
Chlorate and / or bromate as accelerators
and contain a complexing agent.

Als Beispiel für die Behandlung mittels chromfreier Lösung ist es aus der GB-A-2 068 418 bekannt, Metalloberflächen, z. B. aus Eisen oder Stahl, verzinktem Stahl oder Weißblech, mit Lösungen in Kontakt zu bringen, die 1 bis 50 g/l Alkaliphosphat (berechnet als PO₄-Ion), 0,2 bis 20 g/l Chlorat und/oder Bromat und 0,01 bis 0,5 g/l Zinn-Ionen enthalten und ein Gewichtsverhältnis von Chlorid- zu Zinn-Ionen von 0,6 bis 6 aufweist. Durch diese Chlorid-Ionenkonzentration entsteht infolge der Komplexierung der Zinn-Ionen eine stabile Lösung, welche die Metalloberflächen nicht zu stark angreift. Der pH-Wert dieser Lösungen soll im Bereich von 3 bis 6 liegen. Insbesondere bei der Behandlung von aus Weißblech gefertigten Dosen wird dabei ein Konversionsüberzug mit sehr gutem Korrosionsschutz erzielt.As an example of the treatment by means of a chromium-free solution, it is known from GB-A-2 068 418 to remove metal surfaces, e.g. B. made of iron or steel, galvanized steel or tinplate, in contact with solutions containing 1 to 50 g / l alkali phosphate (calculated as PO₄ ion), 0.2 to 20 g / l chlorate and / or bromate and 0 , 01 to 0.5 g / l of tin ions and has a weight ratio of chloride to tin ions of 0.6 to 6. This chloride ion concentration creates a stable solution due to the complexation of the tin ions, which does not attack the metal surfaces too strongly. The pH of these solutions should be in the range of 3 to 6. In particular when treating cans made of tinplate, a conversion coating with very good corrosion protection is achieved.

Nachteilig bei Anwendung dieser bekannten Lösungen ist, daß bei Stillstand der Behandlungsanlagen der Zinngehalt in der Lösung absinkt, so daß bei erneuter Inbetriebnahme Konversionsüberzüge mit minderer Qualität entstehen, es sei denn, es erfolgt zuvor eine zusätzliche Ergänzung von Zinn in der Behandlungslösung.A disadvantage of using these known solutions is that when the treatment systems are at a standstill, the tin content in the solution drops, so that conversion coatings of inferior quality are produced when the system is restarted, unless an additional addition of tin to the treatment solution is carried out beforehand.

Aus der FR-A-2 262 134 ist ein Verfahren zum kathodischen Abscheiden eines Phosphatüberzugs auf rostfreien Stählen bekannt, bei dem eine Phosphatierungslösung verwendet wird, welche einen Chelatbildner, wie kondensierte Phosphate, enthält.From FR-A-2 262 134 a method for cathodic deposition of a phosphate coating on stainless steels is known, in which a phosphating solution is used which contains a chelating agent, such as condensed phosphates.

Ferner war aus der US-A-2 930 723 bekannt, beim Phosphatieren eine Beschleuniger-Zinkortophosphat-Überzugslösung zu verwenden, welche Zinkdihydrogenortophosphat, Nitrat als Beschleuniger und kondensierte Phosphate enthält.It was also known from US-A-2 930 723 to use an accelerator zinc orthophosphate coating solution which contains zinc dihydrogen orthophosphate, nitrate as an accelerator and condensed phosphates in the phosphating.

Bei dem in den letzten Jahren bestehenden Trend, Weißblech mit geringerer Zinnauflage herzustellen, kommt erschwerend hinzu, daß die bekannten Behandlungsverfahren die gestellten Anforderungen an den Korrosionsschutz der erzeugten Konversionsüberzüge nicht mehr erfüllen.With the trend in recent years to produce tinplate with a smaller tin coating, it is made more difficult that the known treatment processes no longer meet the requirements placed on the corrosion protection of the conversion coatings produced.

Aufgabe der Erfindung ist es, ein Verfahren zum Aufbringen von Konversionsüberzügen auf Weißblech bereitzustellen, das die Nachteile der bekannten Verfahren nicht besitzt, und mit geringen Zinnauflagen zu Konversionsüberzügen mit hervorragendem Korrosionswiderstand führt und ein Absinken der Zinnkonzentration in der Behandlungslösung beim Stillstand von Behandlungsanlagen ausschließt.The object of the invention is to provide a process for applying conversion coatings on tinplate which does not have the disadvantages of the known processes and which, with small tin deposits, leads to conversion coatings with excellent corrosion resistance and precludes a decrease in the tin concentration in the treatment solution when the treatment systems are at a standstill.

Die Aufgabe wird gelöst, indem das Verfahren der eingangs genannten Art entsprechend der Erfindung derart ausgestaltet wird, daß die wäßrige Lösung zusätzlich

0,01 bis 5 g/l
Salze von Polyphosphorsäuren der allgemeinen Formel: Hn+2PnO3n+1,
mit n = 2,3 oder 4
als Komplexbildner enthält und einen pH-Wert von 2 bis 6 hat.The object is achieved by designing the method of the type mentioned at the outset in accordance with the invention in such a way that the aqueous solution additionally
0.01 to 5 g / l
Salts of polyphosphoric acids of the general formula: H n + 2 P n O 3n + 1 ,
with n = 2, 3 or 4
contains as a complexing agent and has a pH of 2 to 6.

Bei der Konzeption der vorliegenden Erfindung wurde festgestellt, daß durch den Komplexbildnergehalt die Zinnausfällung aus der Behandlungslösung unterdrückt wird , gleichzeitig aber dessen Abscheidung auf der Werkstückoberfläche bei der Ausbildung des Konversionsüberzuges nicht unterbunden wird. Der Komplexbildner beschleunigt darüber hinaus den Beizangriff auf die Metalloberfläche und ist für ein Gleichgewicht zwischen sich lösendem Zinn (infolge des Beizangriffes) und sich als Überzugsbestandteil abscheidendem Zinn verantwortlich. Dadurch werden Schwankungen hinsichtlich der Zinnkonzentration in der Behandlungslösung weitgehend vermieden, was sich letztlich auf die Qualität, insbesondere den hohen Korrosionswiderstand des Konversionsüberzuges, günstig auswirkt.In the conception of the present invention, it was found that the complexing agent content suppressed the tin precipitation from the treatment solution, but at the same time its deposition on the workpiece surface when the Conversion overlay is not prevented. The complexing agent also accelerates the pickling attack on the metal surface and is responsible for a balance between the tin which dissolves (as a result of the pickling attack) and the tin which deposits as a coating component. This largely avoids fluctuations in the tin concentration in the treatment solution, which ultimately has a favorable effect on the quality, in particular the high corrosion resistance of the conversion coating.

Das Phosphat kann als Alkaliphosphat, wie Natrium-, Kalium- oder Ammoniummonohydrogenphosphat oder -dihydrogenphosphat, eingebracht werden. Auch kann es aus Phosphorsäure und Natrium-, Kalium- oder Ammoniumhydroxid gebildet werden. Lösungen mit Phosphatkonzentrationen außerhalb des Bereiches von 1 bis 50 g/l sind nicht in der Lage, Konversionsüberzüge mit den erwünschten hervorragenden Eigenschaften zu erzeugen. Konzentrationen innerhalb des Bereiches von 2 bis 25 g/l führen zu besonders hochwertigen Konversionsüberzügen.The phosphate can be introduced as an alkali phosphate, such as sodium, potassium or ammonium monohydrogen phosphate or dihydrogen phosphate. It can also be formed from phosphoric acid and sodium, potassium or ammonium hydroxide. Solutions with phosphate concentrations outside the range of 1 to 50 g / l are unable to produce conversion coatings with the desired excellent properties. Concentrations within the range of 2 to 25 g / l lead to particularly high-quality conversion coatings.

Bei Beschleunigerkonzentrationen unter 0,2 g/l ist die Beschleunigungswirkung bezüglich der Ausbildung des Konversionsüberzuges unzureichend. Bei Konzentrationen über 20 g/l wird kein zusätzlicher Effekt erzielt, so daß wegen der Badüberwachung und auch bereits aus wirtschaftlichen Erwägungen heraus höhere Konzentrationen nicht sinnvoll sind.At accelerator concentrations below 0.2 g / l, the acceleration effect with regard to the formation of the conversion coating is insufficient. At concentrations above 20 g / l, no additional effect is achieved, so that higher concentrations are not sensible because of the bath monitoring and also for economic reasons.

Als Quelle für Zinnionen können insbesondere die Chloride und/oder Sulfate zwei- oder vierwertigen Zinns eingesetzt werden. Auch ist Natriumstannat geeignet. Der Bereich von 0,01 bis 5 g/l gilt für Zinn-II- bzw. Zinn-IV-Ionen, oder aber für die Summe von Zinn-II-  und Zinn-IV-Ionen. Bei Konzentrationen unter 0,01 g/l läßt der Korrosionswiderstand der erzeugten Konversionsüberzüge nach. Bei Konzentrationen über 5 g/l besteht die Gefahr, daß die Behandlungslösung instabil wird. Eine zusätzliche Verbesserung der Überzugsqualität wird zudem nicht erreicht.The chlorides and / or sulfates of divalent or tetravalent tin can be used in particular as the source of tin ions. Sodium stannate is also suitable. The range from 0.01 to 5 g / l applies to tin II or tin IV ions, or to the sum of tin II and tin IV ions. At Concentrations below 0.01 g / l reduce the corrosion resistance of the conversion coatings produced. At concentrations above 5 g / l there is a risk that the treatment solution will become unstable. An additional improvement in the coating quality is also not achieved.

Komplexbildner sind Natrium-, Kalium- oder Ammoniumpyrophosphat, -tripolyphosphat oder -tetrapolyphosphat. Bei Konzentrationen unter 0,01 g/l ist die komplexbildende Wirkung der kondensierten Phosphate nicht mehr genügend ausgeprägt, d.h. die Fähigkeit, die Zinnausfällung zu verhindern, schwindet. Mit Konzentrationen über 5 g/l kann insbesondere ein zu starker Beizangriff an der Metalloberfläche verbunden sein, auch kann die Abscheidung des Zinns im Konversionsüberzug behindert werden.Complexing agents are sodium, potassium or ammonium pyrophosphate, tripolyphosphate or tetrapolyphosphate. At concentrations below 0.01 g / l, the complexing effect of the condensed phosphates is no longer sufficiently pronounced, i.e. the ability to prevent tin precipitation is waning. With concentrations above 5 g / l, an excessive pickling attack on the metal surface can be associated, in particular, the deposition of the tin in the conversion coating can be hindered.

Zur Einstellung des pH-Wertes wird zweckmäßigerweise Phosphorsäure, Salzsäure, Schwefelsäure oder aber Natrium-, Kalium- oder Ammoniumhydroxid verwendet. Der einzustellende pH-Bereich von 2 bis 6 ist insofern von Bedeutung, als bei einem pH-Wert unter 2 der Korrosionswiderstand des gebildeten Konversionsüberzuges gering wird und bei einem pH-Wert oberhalb 6 die Tendenz besteht, daß Zinnionen aus der Lösung ausfallen und mithin eine ordnungsgemäße Überzugsbildung nicht mehr gewährleistet ist.To adjust the pH, phosphoric acid, hydrochloric acid, sulfuric acid or sodium, potassium or ammonium hydroxide is expediently used. The pH range to be set from 2 to 6 is important insofar as the corrosion resistance of the conversion coating formed becomes low at a pH value below 2 and the tendency at a pH value above 6 that tin ions precipitate out of the solution and therefore proper coating formation is no longer guaranteed.

Die Ausbildung des Konversionsüberzuges erfolgt üblicherweise nach dem Verfahrensschema

  • 1. Reinigung mit einem mildalkalischen Reiniger
  • 2. Wasserspülen
  • 3. Behandlung zur Ausbildung des Konversionsüberzuges bei Temperaturen von Raumtemperatur bis 90°C, zwecks Beschleunigung der Schichtausbildung zweckmäßigerweise bei 50 bis 60°C, im Tauchen oder Spritzen für die Dauer von 10 bis 120 s
  • 4. Wasserspülen
  • 5. Trocknen.
The conversion coating is usually designed according to the process scheme
  • 1. Cleaning with a mildly alkaline cleaner
  • 2. Rinse water
  • 3. Treatment to form the conversion coating at temperatures from room temperature to 90 ° C, in order to accelerate the layer formation, expediently at 50 to 60 ° C, in immersion or spraying for a period of 10 to 120 s
  • 4. Rinse water
  • 5. Drying.

Entsprechend einer vorteilhaften Ausführungsform der Erfindung, die mit einer Verkürzung der Behandlungsdauer verbunden ist, erfolgt die Ausbildung des Konversionsüberzuges auf elektrochemischem Wege. Diese Ausführungsform ist insbesondere für die Behandlung von Bandmaterial aus Weißblech von Vorteil. Außerdem ist der Korrosionswiderstand des gebildeten Konversionsüberzuges besonders hoch. Hierzu wird das Weißblech als Anode gegen Graphit, Edelstahl und dergleichen als Kathode geschaltet, ein Elektrodenabstand von etwa 10 bis 500 mm sowie eine Stromdichte von ca. 0,1 A/dm² für die Dauer von 0,5 bis 60 s eingestellt. Es kann Gleich- oder Wechselstrom verwendet werden.According to an advantageous embodiment of the invention, which is associated with a reduction in the duration of treatment, the conversion coating is formed electrochemically. This embodiment is particularly advantageous for the treatment of strip material made of tinplate. In addition, the corrosion resistance of the conversion coating formed is particularly high. For this purpose, the tinplate is switched as the anode against graphite, stainless steel and the like as the cathode, an electrode spacing of approximately 10 to 500 mm and a current density of approximately 0.1 A / dm 2 are set for a period of 0.5 to 60 s. Direct or alternating current can be used.

Gemäß einer besonders vorteilhaften Ausgestaltung der Erfindung wird der Konversionsüberzug in zwei Stufen, zunächst chemisch, dann elektrochemisch erzeugt. Hierdurch wird eine nochmalige Steigerung des Korrosionswiderstandes erzielt. Zinn-II bzw. Zinn-IV und Phosphat sind die wesentlichen, den Konversionsüberzug bildenden Bestandteile. Die Schichtausbildung beginnt mit dem Beizangriff der sauren Lösung auf die Metalloberfläche. Sie wird durch die Wirkung der Beschleuniger, insbesondere der Oxosäuren, intensiviert. Der Komplexbildner kontrolliert die Zinnabscheidung durch Ausbildung eines Chelatkomplexes mit Zinn, welches anderenfalls leicht aus der Behandlungslösung ausfallen würde, und stellt die zur Überzugsausbildung jeweils erforderlichen Zinnionen in kontrollierter Weise zur Verfügung. Eine andere, dem Komplexbildner zukommende Rolle besteht darin, die durch den Beizangriff aus der Metalloberfläche herausgelösten Metallionen zu binden und in kontrollierter Weise wieder zur Überzugsausbildung zur Verfügung zu stellen. Schließlich ist der Komplexbildner für eine gleichmäßige Überzugsausbildung verantwortlich, indem er auf den Beizangriff Einfluß nimmt.According to a particularly advantageous embodiment of the invention, the conversion coating is produced in two stages, first chemically, then electrochemically. This will increase the corrosion resistance again achieved. Tin-II or tin-IV and phosphate are the essential constituents forming the conversion coating. The layer formation begins with the pickling attack of the acidic solution on the metal surface. It is intensified by the action of the accelerators, especially the oxo acids. The complexing agent controls the tin deposition by forming a chelate complex with tin, which would otherwise easily precipitate out of the treatment solution, and provides the tin ions required for coating formation in a controlled manner. Another role of the complexing agent is to bind the metal ions released from the metal surface by the pickling attack and to make them available again in a controlled manner for coating formation. Finally, the complexing agent is responsible for uniform coating formation by influencing the pickling attack.

Wenn sämtliche verfahrenswesentlichen Parameter eingehalten werden, ist die Entstehung hochwertiger, insbesondere hochkorrosionsfester Konversionsüberzüge gewährleistet. Die Überzüge besitzen ferner hervorragende Eigenschaften als Basis für eine anschließende Lackierung, Bedruckung und dergleichen hinsichtlich Korrosionswiderstand, Haftung und Glanz.If all process-essential parameters are observed, the creation of high-quality, especially highly corrosion-resistant conversion coatings is guaranteed. The coatings also have excellent properties as the basis for subsequent painting, printing and the like in terms of corrosion resistance, adhesion and gloss.

Die Behandlungslösung erfährt selbst nach langen Stillstandzeiten praktisch keine Verringerung des Zinngehaltes, so daß das Verfahren danach unverzüglich wiederaufgenommen werden kann und sogleich einwandfreie Konversionsüberzüge erhalten werden.The treatment solution experiences practically no reduction in the tin content even after long downtimes, so that the process can then be resumed immediately and perfect conversion coatings are immediately obtained.

Die Erfindung wird anhand der nachfolgenden Beispiele beispielsweise und näher erläutert.The invention is illustrated by the following examples, for example and in more detail.

Beispiel 1example 1

Aus Weißblech gefertigte Dosen wurden in einem mildalkalischen Reiniger einer Konzentration von 1 Gew.-% in Wasser gereinigt. Danach erfolgte die Überzugsausbildung im Spritzen während 20 s mit den nachfolgend aufgeführten Lösungen. Nach einer Wasserspülung wurde mit vollentsalztem Wasser einer Qualität von mindestens 300.000 Ohm x cm für die Dauer von 10 s gespritzt und abschließend in einem Heißluftofen bei 200°C innerhalb von 3 min getrocknet. Die Aufbringung des Konversionsüberzuges erfolgte jeweils mit einer frisch angesetzten Überzugslösung und einer solchen, die einen Tag gestanden hatte, für jeweils 10 Dosen pro Liter Lösung.Cans made from tinplate were cleaned in a mildly alkaline cleaner with a concentration of 1% by weight in water. The coating was then sprayed for 20 s using the solutions listed below. After a water rinse, deionized water of a quality of at least 300,000 ohm × cm was sprayed for a period of 10 s and then dried in a hot air oven at 200 ° C. within 3 minutes. The conversion coating was applied in each case with a freshly prepared coating solution and one which had stood for one day for 10 cans per liter of solution.

Beschaffenheit der verwendeten Behandlungslösung: H₃PO₄ (75 Gew.-%) 15 g/l (PO₄ 11 g/l) NaClO₃ 6 g/l SnCl₄·5H₂O 0,6 g/l (Sn 0,2 g/l) Na₄P₂O₇·10H₂O 1,5 g/l (P₂O₇ 0,6 g/l) pH 3,1 mit Natronlauge eingestellt Behandlungstemperatur 60°C Condition of the treatment solution used: H₃PO₄ (75% by weight) 15 g / l (PO₄ 11 g / l) NaClO₃ 6 g / l SnCl₄ · 5H₂O 0.6 g / l (Sn 0.2 g / l) Na₄P₂O₇ · 10H₂O 1.5 g / l (P₂O₇ 0.6 g / l) pH 3.1 adjusted with sodium hydroxide solution Treatment temperature 60 ° C

Beispiel 2Example 2

Die Behandlung von Weißblechdosen erfolgte nach dem in Beispiel 1 beschriebenen Verfahrensgang mit folgender Lösung: H₃PO₄ (75 Gew.-%) 2,8 g/l (PO₄ 2 g/l) NaClO₃ 0,3 g/l SnCl₂·2H₂O 0,04 g/l (Sn 0,02 g/l) Na₄P₂O₇·10H₂O 0,05 g/l (P₂O₇ 0,02 g/l) pH 5,7 mit Natronlauge eingestellt Behandlungstemperatur 70°C Tinplate cans were treated according to the procedure described in Example 1 with the following solution: H₃PO₄ (75% by weight) 2.8 g / l (PO₄ 2 g / l) NaClO₃ 0.3 g / l SnCl₂ · 2H₂O 0.04 g / l (Sn 0.02 g / l) Na₄P₂O₇ · 10H₂O 0.05 g / l (P₂O₇ 0.02 g / l) pH 5.7 adjusted with sodium hydroxide solution Treatment temperature 70 ° C

Beispiel 3Example 3

Nach dem Verfahrensgang von Beispiel 1 wurden Weißblechdosen mit folgender Lösung behandelt: H₃PO₄ (75 Gew.-%) 55 g/l (PO₄ 40 g/l) NaBrO₃ 17 g/l SnCl₄·5H₂O 13,2 g/l (Sn 4,5 g/l) Na₅P₃O₁₀ 6,5 g/l (P₃O₁₀ 4,5 g/l) pH 2,2 mit Natronlauge eingestellt Behandlungstemperatur 60°C After the procedure of Example 1, tinplate cans were treated with the following solution: H₃PO₄ (75% by weight) 55 g / l (PO₄ 40 g / l) NaBrO₃ 17 g / l SnCl₄ · 5H₂O 13.2 g / l (Sn 4.5 g / l) Na₅P₃O₁₀ 6.5 g / l (P₃O₁₀ 4.5 g / l) pH 2.2 adjusted with sodium hydroxide solution Treatment temperature 60 ° C

Beispiel 4Example 4

Zur Behandlung gemäß Beispiel 1 diente folgende Lösung: H₃PO₄ (75 Gew.-%) 15 g/l (PO₄ 11 g/l) NaClO₃ 6 g/l SnCl₂·2H₂O 0,2 g/l (Sn 0,1 g/l) SnCl₄·5H₂O 0,3 g/l (Sn 0,1 g/l) Na₆P₄O₁₃ 0,9 g/l (P₄O₁₃ 0,6 g/l) pH 3,8 mit Natronlauge eingestellt Behandlungstemperatur 60°C The following solution was used for the treatment according to Example 1: H₃PO₄ (75% by weight) 15 g / l (PO₄ 11 g / l) NaClO₃ 6 g / l SnCl₂ · 2H₂O 0.2 g / l (Sn 0.1 g / l) SnCl₄ · 5H₂O 0.3 g / l (Sn 0.1 g / l) Na₆P₄O₁₃ 0.9 g / l (P₄O₁₃ 0.6 g / l) pH 3.8 adjusted with sodium hydroxide solution Treatment temperature 60 ° C

Vergleichsbeispiel 1Comparative Example 1

Zur Behandlung von Weißblechdosen entsprechend dem Verfahrensgang von Beispiel 1 diente folgende Lösung: H₃PO₄ (75 Gew.-%) 15 g/l (PO₄ 11 g/l) NaClO₃ 6 g/l SnCl₄·5H₂O 0,6 g/l (Sn 0,2 g/l) pH 3,8 mit Natronlauge eingestellt Behandlungstemperatur 60°C The following solution was used to treat tin cans in accordance with the procedure of Example 1: H₃PO₄ (75% by weight) 15 g / l (PO₄ 11 g / l) NaClO₃ 6 g / l SnCl₄ · 5H₂O 0.6 g / l (Sn 0.2 g / l) pH 3.8 adjusted with sodium hydroxide solution Treatment temperature 60 ° C

Vergleichsbeispiel 2Comparative Example 2

Entsprechend dem Verfahrensgang von Beispiel 1 wurden Weißblechdosen mit folgender Lösung behandelt: H₃PO₄ (75 Gew.-%) 15 g/l (PO₄ 11 g/l) NaClO₃ 6 g/l SnCl₄·5H₂O 0,6 g/l (Sn 0,2 g/l) Na₄P₂O₇·10H₂O 21 g/l (P₂O₇ 8 g/l) pH 3,1 mit Natronlauge eingestellt Behandlungstemperatur 60°C In accordance with the procedure of Example 1, tinplate cans were treated with the following solution: H₃PO₄ (75% by weight) 15 g / l (PO₄ 11 g / l) NaClO₃ 6 g / l SnCl₄ · 5H₂O 0.6 g / l (Sn 0.2 g / l) Na₄P₂O₇ · 10H₂O 21 g / l (P₂O₇ 8 g / l) pH 3.1 adjusted with sodium hydroxide solution Treatment temperature 60 ° C

In den Behandlungslösungen von Beispiel 1 bis 4 und Vergleichsbeispiel 1 und 2 wurde der Zinngehalt nach Ansatz und nach eintägigem Stehen ermittelt. Außerdem wurden die mit Konversionsüberzügen versehenen Weißblechdosen dem Korrosionstest und dem Lackhaftungstest unterworfen.In the treatment solutions of Examples 1 to 4 and Comparative Examples 1 and 2, the tin content was determined after the batch and after standing for one day. In addition, the tinplate cans provided with conversion coatings were subjected to the corrosion test and the paint adhesion test.

Zur Ermittlung des Korrosionswiderstandes wurden die behandelten Dosen in Leitungswasser von 60°C für die Dauer von 30 min eingetaucht und die Rostentwicklung bewertet.To determine the corrosion resistance, the treated cans were immersed in tap water at 60 ° C. for 30 minutes and the rust development was assessed.

Aus der nachfolgenden Tabelle ergibt sich, daß die nach dem erfindungsgemäßen Verfahren behandelten Weißblechdosen einen deutlich besseren Korrosionswiderstand aufweisen als die gemäß den Vergleichsversuchen behandelten Dosen. Tabelle Ergebnisse des Korrosionstestes frisch angesetzte Lösung nach eintägigem Stehen * Sn-Gehalt (ppm) Entwicklung v. rotem Rost (%) Sn-Gehalt (ppm) Entwicklung v. rotem Rost (%) Beispiele 1 200 0 200 0 2 20 8 20 8 3 4500 5 4500 5 4 200 0 200 0 Vergleichsbeispiele 1 200 10 0 100 2 200 20 200 20 * und Behandlung von 10 Dosen/l The table below shows that the tinplate cans treated by the process according to the invention have a significantly better corrosion resistance than the cans treated according to the comparative tests. table Results of the corrosion test freshly prepared solution after standing for one day * Sn content (ppm) Development of red rust (%) Sn content (ppm) Development of red rust (%) Examples 1 200 0 200 0 2nd 20th 8th 20th 8th 3rd 4500 5 4500 5 4th 200 0 200 0 Comparative examples 1 200 10th 0 100 2nd 200 20th 200 20th * and treatment of 10 doses / l

Zur Ermittlung der Lackhaftung wurden auf die mit den Konversionsüberzügen versehenen Dosen ein Epoxy-/Harnstofflack einer Dicke von 5 bis 7 µm aufgebracht und bei 210°C eingebrannt (Dauer 10 min). Nach 24-stündigem Stehenlassen wurden die Dosen in eine 1 Gew.-% wäßrige Zitronensäurelösung von 95 bis 97°C getaucht und 60 min darin belassen. Anschließend wurde mit Wasser gespült und getrocknet.To determine the paint adhesion, an epoxy / urea paint with a thickness of 5 to 7 μm was applied to the cans provided with the conversion coatings and baked at 210 ° C. (duration 10 minutes). After standing for 24 hours, the cans were immersed in a 1% by weight aqueous citric acid solution at 95 to 97 ° C and left therein for 60 minutes. It was then rinsed with water and dried.

Danach wurden die Proben mit einem bis auf die Metalloberfläche reichenden Gitterschnitt und dann mit Cellophan-Klebeband durch kräftiges Andrücken versehen. Nach dem Abreißen des Klebebandes zeigte sich, daß die Lackhaftung durchgängig hervorragend war, d.h. keinerlei Lackablösung festzustellen war.Thereafter, the samples were provided with a cross cut reaching to the metal surface and then with cellophane adhesive tape by pressing firmly. After the adhesive tape was torn off, it was found that the paint adhesion was consistently excellent, i.e. no paint detachment was found.

Claims (4)

  1. Method of applying conversion coatings on tinplate by use aqueous solutoins, which contain
    1 to 50 g/l   orthophosphate (calculated as PO₄)
    0,01 to 5 g/l   tin
    0,2 to 20 g/l   chlorate and/or bromate as accelerator
    and a complex forming agent, characterized in that the metal surfaces are contacted with an aqueous solution which contains
    0,01 to 5 g/l   salts of polyphosphoric acid of the general formula: Hn+2PnO3n+1,
    n = 2.3 or 4 as complex forming agent
    and having a pH value in the range of 2 to 6.
  2. Method according to claim 1, characterized in that the metal surfaces are contacted with an aqueous solution containing 2 to 25 g/l orthophosphate.
  3. Method according to claim 1 or 2, characterized in that the conversion coating is produced electrochemically.
  4. Method according to one or several of claims 1 to 3, characterized in that the conversion coating is produced in two steps, first chemically and then electrochemically.
EP88202291A 1987-10-13 1988-10-13 Process for applying conversion coatings Expired - Lifetime EP0312176B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP257678/87 1987-10-13
JP62257678A JPH01100281A (en) 1987-10-13 1987-10-13 Chemical conversion coating liquid for surface of metal

Publications (2)

Publication Number Publication Date
EP0312176A1 EP0312176A1 (en) 1989-04-19
EP0312176B1 true EP0312176B1 (en) 1992-12-16

Family

ID=17309584

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88202291A Expired - Lifetime EP0312176B1 (en) 1987-10-13 1988-10-13 Process for applying conversion coatings

Country Status (10)

Country Link
US (1) US4927472A (en)
EP (1) EP0312176B1 (en)
JP (1) JPH01100281A (en)
AU (1) AU608374B2 (en)
BR (1) BR8805286A (en)
CA (1) CA1321859C (en)
DE (2) DE3834480A1 (en)
GB (1) GB2210900B (en)
MX (1) MX169760B (en)
ZA (1) ZA887663B (en)

Families Citing this family (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5370909A (en) * 1990-06-19 1994-12-06 Henkel Corporation Liquid composition and process for treating aluminum or tin cans to impart corrosion resistance and mobility thereto
BR9106572A (en) * 1990-06-19 1993-06-01 Henkel Corp LIQUID COMPOSITION AND PROCESS FOR TREATING TIN OR ALUMINUM COATED STEEL SURFACES TO CONFER MOBILITY AND CORROSION RESISTANCE
JPH04187782A (en) * 1990-11-21 1992-07-06 Nippon Parkerizing Co Ltd Surface treating solution for di can made of tin plate
JPH05163584A (en) * 1991-12-12 1993-06-29 Nippon Parkerizing Co Ltd Surface treating liquid for di can of tin plate
JP3256009B2 (en) * 1992-12-09 2002-02-12 日本パーカライジング株式会社 Tinplate surface treatment liquid and surface treatment method
US5498300A (en) * 1992-12-09 1996-03-12 Henkel Corporation Composition and process for treating tinplate
US5603754A (en) * 1993-07-05 1997-02-18 Henkel Corporation Composition and process for treating tinplate and aluminum
US5562950A (en) * 1994-03-24 1996-10-08 Novamax Technologies, Inc. Tin coating composition and method
JP3366724B2 (en) * 1994-04-20 2003-01-14 日本ペイント株式会社 Chemical conversion aqueous solution for metal surfaces
US5965205A (en) * 1995-07-21 1999-10-12 Henkel Corporation Composition and process for treating tinned surfaces
US5711996A (en) * 1995-09-28 1998-01-27 Man-Gill Chemical Company Aqueous coating compositions and coated metal surfaces
WO1998020186A1 (en) * 1996-11-06 1998-05-14 Henkel Corporation Phosphate conversion coating composition and process
JPH11128830A (en) * 1997-10-30 1999-05-18 Nkk Corp Surface treated steel sheet excellent in corrosion resistance
CA2439135C (en) * 2001-02-26 2010-05-11 Sumitomo Metal Industries, Ltd. Surface treated steel product, method for production thereof and chemical conversion treatment solution
JP3873642B2 (en) * 2001-03-21 2007-01-24 Ｊｆｅスチール株式会社 Tinned steel sheet
DE10261014B4 (en) * 2002-12-24 2005-09-08 Chemetall Gmbh Process for coating metal surfaces with an alkali phosphating solution, aqueous concentrate and use of the metal surfaces coated in this way
CN1556246A (en) * 2004-01-08 2004-12-22 中国国际海运集装箱（集团）股份有限 Chromium less deactivation liquid
US7641744B2 (en) * 2005-04-06 2010-01-05 Rem Technologies, Inc. Superfinishing of high density carbides
DE102005023023B4 (en) * 2005-05-19 2017-02-09 Chemetall Gmbh Method of preparing metallic workpieces for cold forming, process coated workpieces and their use
US20080048178A1 (en) * 2006-08-24 2008-02-28 Bruce Gardiner Aitken Tin phosphate barrier film, method, and apparatus
JP4872602B2 (en) * 2006-10-30 2012-02-08 Ｊｆｅスチール株式会社 Method for producing tin-plated steel sheet
US20080302267A1 (en) * 2007-06-05 2008-12-11 Defalco Frank G Compositions and processes for deposition of metal ions onto surfaces of conductive substrates
US8317909B2 (en) * 2007-06-05 2012-11-27 Dfhs, Llc Compositions and processes for deposition of metal ions onto surfaces of conductive substrates
US8252734B1 (en) * 2009-12-09 2012-08-28 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Friction modifier using adherent metallic multilayered or mixed element layer conversion coatings
CN103210126B (en) * 2010-10-06 2016-09-14 塔塔钢铁艾默伊登有限责任公司 The method manufacturing ferrum tin layers on packaging steel substrate
DE102012212598A1 (en) * 2012-07-18 2014-02-20 Henkel Ag & Co. Kgaa Tinning pretreatment of galvanized steel in the presence of pyrophosphate
EP3872229A1 (en) * 2020-02-28 2021-09-01 voestalpine Stahl GmbH Method for producing hardened steel components with a conditioned zinc alloy corrosion protection layer
CN114381779A (en) * 2021-12-13 2022-04-22 首钢京唐钢铁联合有限责任公司 Tin plate with good corrosion resistance and extremely low tin content and preparation method thereof

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE974196C (en) * 1942-12-11 1960-10-13 Metallgesellschaft Ag Process for the production of smooth phosphate coatings on metallic objects
US2930723A (en) * 1954-12-07 1960-03-29 Walterisation Company Ltd Surface treatment of metals
GB872321A (en) * 1959-01-09 1961-07-05 Walterisation Company Ltd Phosphate coatings
FR1289759A (en) * 1960-05-03 1962-04-06 Amchem Prod Improvements in solutions and processes for the production of coatings by chemical conversion on zirconium and its alloys
GB1012267A (en) * 1961-08-15 1965-12-08 J N Tuttle Inc Improvements in or relating to the production of corrosion resistant coatings on ferrous metal articles
US3530012A (en) * 1965-12-23 1970-09-22 Rasa Kasei Kk Method of treating metal surfaces
US3756864A (en) * 1971-09-07 1973-09-04 Oxy Metal Finishing Corp Cyanuric acid as a scale reducing agent in coating of zinc surfaces
JPS5425500B2 (en) * 1972-11-22 1979-08-28
JPS5429979B2 (en) * 1974-02-22 1979-09-27
DE2424382A1 (en) * 1974-05-20 1975-12-04 Metallgesellschaft Ag PROCESS FOR THE PREPARATION OF METALLIC WORKPIECES FOR CHIPLESS COLD FORMING
US4045253A (en) * 1976-03-15 1977-08-30 Halliburton Company Passivating metal surfaces
JPS5562179A (en) * 1978-10-30 1980-05-10 Nippon Parkerizing Co Ltd Chemical treating solution for coating metal surface
JPS5841352B2 (en) * 1979-12-29 1983-09-12 日本パ−カライジング株式会社 Coating treatment liquid for metal surfaces
JPS60152682A (en) * 1984-01-20 1985-08-10 Nippon Parkerizing Co Ltd Phosphate treatment
DE3408577A1 (en) * 1984-03-09 1985-09-12 Metallgesellschaft Ag, 6000 Frankfurt METHOD FOR PHOSPHATING METALS

Also Published As

Publication number Publication date
GB8824016D0 (en) 1988-11-23
CA1321859C (en) 1993-09-07
AU608374B2 (en) 1991-03-28
US4927472A (en) 1990-05-22
DE3876744D1 (en) 1993-01-28
GB2210900A (en) 1989-06-21
DE3834480A1 (en) 1989-04-27
MX169760B (en) 1993-07-23
GB2210900B (en) 1991-11-20
AU2371588A (en) 1989-04-20
ZA887663B (en) 1989-06-28
BR8805286A (en) 1989-05-30
JPH0577750B2 (en) 1993-10-27
JPH01100281A (en) 1989-04-18
EP0312176A1 (en) 1989-04-19

Similar Documents

Publication Publication Date Title
EP0312176B1 (en) Process for applying conversion coatings
DE3118375C2 (en)
EP0459541B1 (en) Process for phosphating metal surfaces
EP0056881B1 (en) Method of phosphating metals
EP0213567B1 (en) Process for applying phosphate coatings
EP0045110B1 (en) Method for the production of phosphate coatings on iron and steel surfaces, and its use
EP0149720B1 (en) Process for after passivating phosphated metal surfaces using titanium and/or manganese and/or cobalt and/or nickel and/or copper cations containing solutions
EP0261704B1 (en) Process for producing phosphate coatings on metal surfaces
EP0578670B1 (en) Process for phosphatizing metallic surfaces
EP0154367B1 (en) Process for phosphatizing metals
EP0155547B1 (en) Process for the zinc-calcium phosphatizing of metal surfaces at a low treating temperature
EP0327153B1 (en) Process for applying phosphate coatings to metals
EP0656957B1 (en) Process for phosphatizing steel zinc-coated on one side only
DE3245411C2 (en)
DE2715291C3 (en) Process for the production of an amorphous, light, firmly adhering phosphate coating on ferrous metal surfaces
DE2844100A1 (en) PROCESS FOR PHOSPHATING METAL OBJECTS
EP0662164B1 (en) Process for phosphating galvanised steel surfaces
EP0264151B1 (en) Process for obtaining phosphate coatings
EP0258922A1 (en) Process for producing phosphate coatings and their use
EP1019564A1 (en) Method for phosphatizing a steel strip
WO1999045171A1 (en) Method for controlling the coating weight for strip-phosphating
EP0127204B1 (en) Phosphating process for composite metals
DE3627250A1 (en) METHOD FOR PRODUCING CONVERSION LAYERS ON STEEL AND TIN SURFACES
AT238529B (en) Aqueous, nickel-accelerated phosphate coating solution
DE2137550A1 (en) PROCESS FOR ONE-LAYER ENAMELLING

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): BE DE FR IT NL SE

17P Request for examination filed

Effective date: 19890518

17Q First examination report despatched

Effective date: 19901102

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE FR IT NL SE

ET Fr: translation filed
REF Corresponds to:

Ref document number: 3876744

Country of ref document: DE

Date of ref document: 19930128

ITF It: translation for a ep patent filed

Owner name: SOCIETA' ITALIANA BREVETTI S.P.A.

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19931018

Year of fee payment: 6

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
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19941031

EAL Se: european patent in force in sweden

Ref document number: 88202291.6

BERE Be: lapsed

Owner name: NIHON PARKERIZING CO. LTD

Effective date: 19941031

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19970918

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19970919

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19980917

Year of fee payment: 11

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: 19981014

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990501

EUG Se: european patent has lapsed

Ref document number: 88202291.6

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19990501

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19990920

Year of fee payment: 12

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: 20000630

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: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010703

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

Effective date: 20051013