EP0111223A1 - Process for phosphatizing metallic surfaces, and solutions for use therein - Google Patents

Process for phosphatizing metallic surfaces, and solutions for use therein Download PDF

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Publication number
EP0111223A1
EP0111223A1 EP83111813A EP83111813A EP0111223A1 EP 0111223 A1 EP0111223 A1 EP 0111223A1 EP 83111813 A EP83111813 A EP 83111813A EP 83111813 A EP83111813 A EP 83111813A EP 0111223 A1 EP0111223 A1 EP 0111223A1
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Prior art keywords
baths
points
range
acid content
content
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EP83111813A
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German (de)
French (fr)
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EP0111223B1 (en
Inventor
Karl-Heinz Gottwald
Reinhard Opitz
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Gerhard Collardin GmbH
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Gerhard Collardin GmbH
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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
    • C23C22/07—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
    • C23C22/12—Orthophosphates containing zinc cations
    • 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
    • C23C22/12—Orthophosphates containing zinc cations
    • C23C22/17—Orthophosphates containing zinc cations containing also organic acids
    • 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
    • C23C22/36—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 phosphates
    • C23C22/362—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 phosphates containing also zinc cations

Definitions

  • the invention relates to a process for the phosphating of metals, in particular iron, steel and galvanized steel, with aqueous, acidic baths which contain zinc phosphate and, if desired, customary activating and / or layering-improving additives.
  • the new process is particularly suitable as a pretreatment of the metal surfaces for a subsequent cathodic electrodeposition.
  • the Laid-open European Patent Application 0056881 aims to achieve an improvement in that the temperature range of 30 - 60 ° C is carried inkphosphattreateden with chlorate Z, the O 5 - 1.5 g / 1 Zn, 0.4 - 1.3 g / 1 Ni, 10 - 26 g / l P 2 O 5 and 0.8 - 5 g / l ClO 3 , to which no nitrite is added and in which the weight ratio of Zn: Ni to a value between 1: (0.5 - 1.5), Zn: P 2 O 5 to a value between 1: (8 - 85) and free P 2 O 5 : total P 2 O 5 to a value between (0.005 (at approx.
  • the invention is based on the object of proposing acidic, aqueous zinc phosphate-containing baths within the scope of the knowledge known per se for phosphating metal surfaces, which baths work in particular with a significantly lower total acid content.
  • the production of high-quality zinc phosphate layers should be ensured, which are characterized in particular by comparatively high iron contents and are accordingly very particularly suitable for a subsequent cathodic electrocoating.
  • the invention aims to enable a type of process that can be operated effectively at very low temperatures.
  • the solution of the task according to the invention is based on the finding that the combination of certain bath parameters enables the effective reduction of the total acid content and thus the desired reduction in the chemical requirement, but that at the same time these baths at temperatures below 40 ° C effectively contain the desired iron Zinc phosphate layers can be deposited.
  • the invention relates in a first embodiment to a process for phosphating metal surfaces, in particular iron, steel and galvanized steel, by treating them with aqueous, acidic zinc phosphate baths at only moderately elevated temperatures.
  • the new method is characterized in that one works in the temperature range of 22-38 ° C with phosphating baths which correspond to the following conditions: 2-6 g / 1 zinc, 4-23 g / 1 PO 4 3- , free acid content 0.05 0.4 points and bath pH 3.0 - 4.0.
  • the method according to the invention thus uses comparatively high levels of zinc in the bath solution, in particular in comparison with the cited prior art documents, but at the same time only limited amounts of phosphate ions - and ultimately only limited amounts of total acid - are used. It is preferred to work with baths in which the ratio Zn / PO 4 3- is in the range from 1: 2 to at most 1:11, preferably at most up to 1:10.5 or 10.
  • the invention opens up the possibility of using baths in which this ratio of Zn / PO 4 3- lies clearly within the lower values of the specified maximum working range.
  • ratios Zn / PO 4 3- in the range from 1: 2 to 1: 8 and in particular in the range from 1: 2 to 1: 4 can be used.
  • This PO 4 3 content of the bath this means in absolute terms that it is possible to work with comparatively low concentrations of the PO 4 3 value.
  • This PO 4 3 content is preferably in the range from about 4 to 15 g / 1 bath solution, preferably up to a maximum of 13 g / 1 bath solution. According to the invention, it is particularly expedient to work with a PO 4 3 content in the range of about 4-8 g / 1 bath solution.
  • the zinc content in the phosphating bath is in the range of 2-4 g / l bath solution.
  • the preferred free acid content is in the range of 0.1-0.2 points.
  • the preferred pH range for these phosphating baths of the invention is in the range of about 3.5-4.0. With baths of this kind work effectively in the temperature range of 28 - 38 ° C.
  • phosphating baths whose total acid content does not exceed numerically limited values in the range of about 30 points.
  • Particularly suitable for the process according to the invention are phosphating baths with a total acid content in the range from 8 to 30 points, preferably in the range from about 9 to 15 points.
  • auxiliary components or constituents customary in baths of this type can also be used in the phosphating solutions according to the invention. It is of particular importance here, however, that the common use of manganese to this day is not necessary. This is an important advantage of the method according to the invention over other characteristic baths of the prior art, in particular over the so-called low-zinc baths which operate at a comparatively higher temperature.
  • the layer formation on the metal surfaces can be improved by adding simple and / or complex fluorides.
  • the fluoride ion content is expediently in the range of 0.01-2 g / l bath solution.
  • the complex fluoride can be, for example, the SiF 6 2- ion, concentration ranges of about 0.01-2 g / l bath solution also being preferred.
  • the solutions can also contain complexing agents known per se of organic or inorganic origin.
  • Suitable organic complexing agents are, for example, tartaric acid or tartrate, hydroxyethylene-diamino-triacetic acid or its salts, gluconic acid or its salts and / or citric acid or its salts.
  • Inorganic complexing agents are polyphosphates, for example tripolyphosphate. or hexamethaphosphate. Complexing agents of this type are usually present in the bath in quantities of 0.01-5 g / l.
  • the treatment bath can contain further metal cations, in particular divalent metal cations.
  • the co-use of nickel (I I) may - be in the phosphating.
  • the nickel content is limited in relation to the zinc and at most reaches this zinc content.
  • the Zn / Ni ratio of about 1 / 0.5 is preferably not exceeded.
  • Preferred nickel contents can be within the teaching of the invention in the range of about 0, 01-1 g / 1 B are adinate.
  • Zinc phosphate layers with a high iron content designed according to the invention are suitable for all types of application of phosphate layers known to date, but they have particular advantages for a subsequent cathodic electrocoating. They show a high resistance of the paint film against paint infiltration under corrosive stress as well as high and satisfactory values of the paint adhesion to the metallic surface.
  • the method according to the invention is therefore used in practice, for example in the phosphating of car bodies.
  • This concentrate was diluted to give a solution with 0.18% Zn, 0.002% Ni, 0.96% PO 4 , 0.17% NO 3 , 0.004% tartrate and O, 15% ClO 3 , which was a Monchure- P has unktress of 9.8.
  • the free acid was reduced to a pH in the range 3.5-4 by adding sodium hydroxide.
  • the parts were then rinsed with water, rinsed with distilled water and dried by blowing with compressed air.
  • the parts were then coated with a cathodic electrocoating material and dried by heating at 185 ° C. for 20 minutes.
  • the dry film thickness of the paint was 18 pm.
  • the parts were then provided with individual cuts and subjected to the salt spray test DIN 50021 for 240 hours.
  • the evaluation according to DIN 53167 showed an infiltration of ⁇ 0.1 mm. It follows that the proposed method of working gives a good coating despite the low treatment temperature.
  • This concentrate was diluted to give a solution with 0.48% Zn, 1.68% PO 4 , 0.19% NO 3 , 0.19% ClO 3 and 0.024% gluconate, which had a total acid score of 25, 5 has.
  • the free acid was reduced to a pH in the range 3.5-4 by adding sodium hydroxide. Then 0.1 gl NaN0 2 were added to the solution.
  • the dry film thickness of the paint was 18 ⁇ m.
  • the parts were then provided with individual cuts and subjected to the salt spray test DIN 50021 for 240 hours.
  • the evaluation according to DIN 53167 showed an infiltration of ⁇ 0.1 mm. It follows that the proposed method of working gives a good coating despite the low treatment temperature.
  • This concentrate was diluted to yield a solution having 0.34% Zn, 0.85% PO 4, 0.34% NO 3, 0.27% ClO 3, 0, 007% Si F 6 0.007% and 0.014% F
  • 3-nitrobenzenesulfonic acid which has a total acid score of 14.4.
  • the free acid was reduced to a pH in the range 3.5-4 by adding sodium hydroxide.
  • the dry film thickness of the paint was 18 ⁇ m.
  • the parts were then provided with individual cuts and subjected to the salt spray test DIN 50021 for 240 hours.
  • the evaluation according to DIN 53167 showed an infiltration of ⁇ 0.1 mm. It follows that the proposed method of working gives a good coating despite the low treatment temperature.

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  • Engineering & Computer Science (AREA)
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  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Chemical Treatment Of Metals (AREA)
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Abstract

A process for phosphating metal surfaces, particularly iron, steel and zinc-plated steel, by treating them with aqueous, acidic zinc phosphate baths at only moderately elevated temperatures in the range of from 22 DEG to 38 DEG C. The baths used have 2 to 6 g/l of Zn; 4 to 23 g/l of PO43-; a free acid content of 0.05 to 0.4 points; and a pH-value of 3.0 to 4.0. The ratio of Zn to PO43- is preferably in the range from 1:2 to 1:11. The baths can advantageously contain nickel-(II)-ions, with a nickel content not exceeding a Zn:Ni ratio of 1:0.5. This process gives iron-containing zinc phosphate layers having an iron content of from 5 to 20% by weight and is particularly useful for pretreatment for subsequent cathodic electro-dip-lacquering.

Description

Die Erfindung betrifft ein Verfahren zur Phosphatierung von Metallen, insbesondere Eisen, Stahl und verzinktem Stahl mit wäßrigen, sauren Bädern, die Zinkphosphat und gewünschtenfalls übliche aktivierende und/oder die Schichtbildung verbessernde Zusatzstoffe enthalten. Das neue Verfahren eignet sich insbesondere als Vorbehandlung der Metalloberflächen für eine nachfolgende katodische Elektrotauchlackierung.The invention relates to a process for the phosphating of metals, in particular iron, steel and galvanized steel, with aqueous, acidic baths which contain zinc phosphate and, if desired, customary activating and / or layering-improving additives. The new process is particularly suitable as a pretreatment of the metal surfaces for a subsequent cathodic electrodeposition.

Zur Phosphatierung von Metalloberflächen sind heute eine Mehrzahl charakteristischer Badtypen und damit verbundener Verfahrensbedingungen bekannt. Die klassischen Zinkphosphatbäder arbeiten im vergleichsweise hohen Temperaturbe- reich von 50 - 60 °C und bilden auf der Metalloberfläche im wesentlichen eisenfreie-Zinkphosphatschichten aus. In einer späteren Entwicklung wird mit vergleichsweise zinkarmen und phosphatreichen Bädern - ebenfalls bei vergleichsweise höheren Temperaturen - der Einbau von Eisen in die abgeschiedenen Zinkphosphatschichten und damit die Ausbildung besonders erwünschter stabiler Zinkphosphatschichten ermöglicht. So schildert die DE-OS 22 32 067 wäßrige, saure Phosphatierlösungen mit einem Gewichtsverhältnis von Zn : PO4 = 1 : (12 - 110) zur Oberflächenbehandlung von Metallen. Die dünnen und gleichmäßigen Phosphatüberzüge sind insbesondere als Grundlage für die anschließende Elektrotauchlackierung besonders geeignet. Als Beschleuniger für solche Phosphatierungsbäder sind beispielsweise Nitritionen und/oder aromatische Nitroverbindungen bekannt - vergleiche DE-OS 30 04 927.A number of characteristic bath types and associated process conditions are known today for phosphating metal surfaces. The classic zinc phosphate baths work in the comparatively high temperature range of 5 0 - 60 ° C and form essentially iron-free zinc phosphate layers on the metal surface. In a later development, with relatively low-zinc and phosphate-rich baths - also at comparatively higher temperatures - the incorporation of iron into the deposited zinc phosphate layers and thus the formation of particularly desirable stable zinc phosphate layers is made possible. DE - O S 22 32 067 describes aqueous acidic phosphating solutions with a weight ratio of Zn: PO 4 = 1: (12-110) for the surface treatment of metals. The thin and uniform phosphate coatings are particularly suitable as a basis for the subsequent electrocoating. As an accelerator for sol che phosphating baths are known, for example, nitrite ions and / or aromatic nitro compounds - compare DE-OS 30 04 927.

Demgegenüber will die offengelegte europäische Patentanmeldung 0056881 eine Verbesserung dadurch erreichen, daß im Temperaturbereich von 30 - 60 °C mit chlorathaltigen Zinkphosphatlösungen gearbeitet wird, die O,5 - 1,5 g/1 Zn, 0,4 - 1,3 g/1 Ni, 10 - 26 g/l P2O5 und 0,8 - 5 g/l ClO3 enthalten, denen kein Nitrit zugesetzt wird und in denen das Gewichtsverhältnis von Zn : Ni auf einen Wert zwischen 1 : (0,5 - 1,5), Zn : P2O5 auf einen Wert zwischen 1 : (8 - 85) und freiem P2O5 : Gesamt-P2O5 auf einen Wert zwichen (0,005 (bei ca. 30 °C) - 0,06 (bei ca. 60 °C)) : 1 eingestellt ist. Von ausschlaggebender Bedeutung für die Qualität der nach diesem Verfahren erzeugten Phosphatschichten soll die Einhaltung des Konzentrationsverhältnisses zwischen Zn und P205 sein. Bei einem Umrechnungsfaktor P2O5 → PO4 von 1,338 liegt die Untergrenze dieses Verhältnisses (Zn/P2O5 = 1/8) bei 10,7 Gewichtsteilen PO4 je 1 Gewichtsteil Zn.In contrast, the Laid-open European Patent Application 0056881 aims to achieve an improvement in that the temperature range of 30 - 60 ° C is carried inkphosphatlösungen with chlorate Z, the O 5 - 1.5 g / 1 Zn, 0.4 - 1.3 g / 1 Ni, 10 - 26 g / l P 2 O 5 and 0.8 - 5 g / l ClO 3 , to which no nitrite is added and in which the weight ratio of Zn: Ni to a value between 1: (0.5 - 1.5), Zn: P 2 O 5 to a value between 1: (8 - 85) and free P 2 O 5 : total P 2 O 5 to a value between (0.005 (at approx. 30 ° C) - 0.06 (at approx. 60 ° C)): 1 is set. Compliance with the concentration ratio between Zn and P 2 0 5 should be of crucial importance for the quality of the phosphate layers produced by this method. With a conversion factor P 2 O 5 → PO 4 of 1.338, the lower limit of this ratio (Zn / P 2 O 5 = 1/8) is 10.7 parts by weight of PO 4 per 1 part by weight of Zn.

Alle diese Vorschläge des Standes der Technik arbeiten mit vergleichsweise hohen Gesamtsäuregehalten,oder mit anderen Worten: mit einem nicht unbeträchtlichen Chemikalienverbrauch je Volumeneinheit der wäßrigen Behandlungslösung. Eine Verringerung dieses Chemikalienbedarfes könnte die Wirtschaftlichkeit solcher Phosphatierungsverfahren ganz erheblich verbessern. So kann beispielsweise der durch Ausschleppung bedingte Stoffverlust deutlich vermindert werden. Insgesamt wird damit der Chemikalienverbrauch verringert.All of these proposals of the prior art work with comparatively high total acid contents, or in other words: with a not inconsiderable consumption of chemicals per unit volume of the aqueous treatment solution. Reducing this need for chemicals could significantly improve the profitability of such phosphating processes. For example, the loss of material due to drag-out can be significantly reduced. Overall, the chemical consumption is reduced.

Die Erfindung geht von der Aufgabe aus, im Rahmen des an sich bekannten Wissens zur Phosphatierung von Metalloberflächen saure, wäßrige Zinkphosphat enthaltende Bäder vorzuschlagen, die insbesondere mit deutlich niedrigerem Gehalt an Gesamtsäure arbeiten. Gleichzeitig soll aber die Herstellung qualitativ hochwertiger Zinkphosphatschichten sichergestellt sein, die insbesondere durch vergleichsweise hohe Eisengehalte gekennzeichnet sind und sich dementsprechend ganz besonders für eine nachfolgende katodische Elektrotauchlackierung eignen. Gleichzeitig will die Erfindung einen Verfahrenstyp ermöglichen, der bei sehr niedrigen Temperaturen wirkungsvoll gefahren werden kann.The invention is based on the object of proposing acidic, aqueous zinc phosphate-containing baths within the scope of the knowledge known per se for phosphating metal surfaces, which baths work in particular with a significantly lower total acid content. At the same time, however, the production of high-quality zinc phosphate layers should be ensured, which are characterized in particular by comparatively high iron contents and are accordingly very particularly suitable for a subsequent cathodic electrocoating. At the same time, the invention aims to enable a type of process that can be operated effectively at very low temperatures.

Die Lösung der erfindungsgemäßen Aufgabenstellung geht von der Feststellung aus, daß durch die Kombination bestimmter Badparameter die wirkungsvolle Senkung des Gehaltes an Gesamtsäure und damit die gewünschte Verringerung des Chemikalienbedarfes möglich wird, daß aber gleichzeitig mit diesen Bädern bei Temperaturen unter 40 °C wirkungsvoll die gewünschten eisenhaltigen Zinkphosphatschichten abgeschieden werden können.The solution of the task according to the invention is based on the finding that the combination of certain bath parameters enables the effective reduction of the total acid content and thus the desired reduction in the chemical requirement, but that at the same time these baths at temperatures below 40 ° C effectively contain the desired iron Zinc phosphate layers can be deposited.

Gegenstand der Erfindung ist dementsprechend in einer er- sten Ausführungsform ein Verfahren zur Phosphatierung von Metalloberflächen, insbesondere von Eisen, Stahl und verzinktem Stahl, durch deren Behandlung mit wäßrigen, sauren Zinkphosphatbädern bei nur mäßig erhöhten Temperaturen.' Accordingly, the invention relates in a first embodiment to a process for phosphating metal surfaces, in particular iron, steel and galvanized steel, by treating them with aqueous, acidic zinc phosphate baths at only moderately elevated temperatures. '

Das neue Verfahren ist dadurch gekennzeichnet, daß man im Temperaturbereich von 22 - 38 °C mit Phosphatierungsbädern arbeitet, die den folgenden Bedingungen entsprechen: 2 - 6 g/1 Zink, 4 - 23 g/1 PO4 3-, Gehalt an freier Säure 0,05 0,4 Punkte und pH-Wert des Bades 3,0 - 4,0.The new method is characterized in that one works in the temperature range of 22-38 ° C with phosphating baths which correspond to the following conditions: 2-6 g / 1 zinc, 4-23 g / 1 PO 4 3- , free acid content 0.05 0.4 points and bath pH 3.0 - 4.0.

Die Bestimmung des Gehaltes an freier Säure nach der Punktzahl ebenso wie die später noch erörterte Punktzahl zur Gesamtsäure erfolgt dabei nach den hier einschlägigen anerkannten Methoden (vergleiche beispielsweise "Die Phosphatierung von Metallen", Leuze-Verlag/Saulgau, 1974, S. 274 - 277):

  • Die Punktzahl der freien Säure entspricht dem Verbrauch an ml an n/10 NaOH bei der Titration von 10 ml-Badlösung bis zum Umschlag der ersten H3P04-Stufe (Indikator Methylorange oder Bromphenolblau).
  • Pünktzahl der Gesamtsäure entsprechend dem Verbrauch an ml von n/10 NaOH bei der Titration von 10 ml-Badlösung gegen Phenolphthalein als Indikator.
The determination of the content of free acid after the score as well as later discussed score for G esamtsäure is carried out in accordance with relevant here recognized methods (see for example "The phosphating of metals", Leuze-Verlag / Saulgau, 1974, pp 274 - 277):
  • The number of points of the free acid corresponds to the consumption of ml of N / 10 NaOH in the titration of 1 0 ml of bath solution until the color changes of the first H (Ethyl Orange indicator M or bromophenol blue) 3 P0 4 stage.
  • Point number of total acid corresponding to the consumption of ml of n / 10 NaOH when titrating 10 ml bath solution against phenolphthalein as an indicator.

Das erfindungsgenäße Verfahren setzt damit also - insbesondere gegenüber den zitierten Druckschriften des Standes der Technik - vergleichsweise hohe Gehalte an Zink in der Badlösung ein, gleichzeitig werden jedoch nur beschränkte Mengen an Phosphationen - und letztlich damit nur beschränkte Mengen an Gesamtsäure - verwendet. Bevorzugt wird mit Bädern gearbeitet, in denen das Verhältnis Zn/ PO4 3- im Bereich von 1 : 2 bis höchstens 1 : 11, vorzugsweise höchstens bis 1 : 10,5 oder 10 liegt. Die Erfindung erschließt die Möglichkeit, Bäder einzusetzen, in denen dieses Verhältnis von Zn/PO4 3- deutlich innerhalb der niedrigeren Werte des angegebenen maximalen Arbeitsbereiches liegt. So kann mit Verhältnissen Zn/PO4 3- im Bereich von 1 : 2 bis 1 : 8 und insbesondere im Bereich von 1 : 2 bis 1 : 4 gearbeitet werden.The method according to the invention thus uses comparatively high levels of zinc in the bath solution, in particular in comparison with the cited prior art documents, but at the same time only limited amounts of phosphate ions - and ultimately only limited amounts of total acid - are used. It is preferred to work with baths in which the ratio Zn / PO 4 3- is in the range from 1: 2 to at most 1:11, preferably at most up to 1:10.5 or 10. The invention opens up the possibility of using baths in which this ratio of Zn / PO 4 3- lies clearly within the lower values of the specified maximum working range. Thus, ratios Zn / PO 4 3- in the range from 1: 2 to 1: 8 and in particular in the range from 1: 2 to 1: 4 can be used.

Bezüglich des PO4 3 -Gehaltes des Bades bedeutet das absolut gesehen, daß mit vergleichsweise geringen Konzentrationen des PO4 3- -Werts gearbeitet werden kann. So liegt dieser PO4 3- -Gehalt bevorzugt im Bereich von etwa 4 - 15 g/1 Badlösung, vorzugsweise bis maximal 13 g/1 Badlösung. Besonders zweckmäßig wird erfindungsgemäß mit einem PO4 3- -Gehalt im Bereich von etwa 4 - 8 g/1 Badlösung gearbeitet.With regard to the PO 4 3 content of the bath, this means in absolute terms that it is possible to work with comparatively low concentrations of the PO 4 3 value. This PO 4 3 content is preferably in the range from about 4 to 15 g / 1 bath solution, preferably up to a maximum of 13 g / 1 bath solution. According to the invention, it is particularly expedient to work with a PO 4 3 content in the range of about 4-8 g / 1 bath solution.

Es ist weiterhin bevorzugt, innerhalb des genannten Gesamtbereiches für Zink auch wiederum den niedrigeren Bereich auszuwählen, also daß in einer besonders zweckmäßigen Ausführungsform der Erfindung der Gehalt an Zink im Phosphatierungsbad im Bereich von 2 - 4 g/l Badlösung liegt. Der bevorzugte Gehalt an freier Säure liegt im Bereich von 0,1 - 0,2 Punkten. Der bevorzugte pH-Bereich für diese Phosphatierungsbäder der Erfindung liegt im Bereich von etwa 3,5 - 4,0. Mit Bädern dieser Art

Figure imgb0001
wirkungsvoll im Temperaturbereich von 28 - 38 °C gearbeitet werden.It is further preferred to again select the lower range for zinc within the stated total range, that is to say that in a particularly expedient embodiment of the invention the zinc content in the phosphating bath is in the range of 2-4 g / l bath solution. The preferred free acid content is in the range of 0.1-0.2 points. The preferred pH range for these phosphating baths of the invention is in the range of about 3.5-4.0. With baths of this kind
Figure imgb0001
work effectively in the temperature range of 28 - 38 ° C.

Entscheidend für das erfindungsgemäße Verfahren und die damit erhaltenen Ergebnisse ist, daß durch die erfindungsgemäß bestimmt ausgewählte Parameter-Kombination die Ausbildung von Zinkphosphatschichten eines hohen Eisengehaltes möglich wird. In der bevorzugten Ausführungsform der Erfindung werden solche Zinkphosphatschichten mit Eisengehalten im Bereich von etwa 5 - 20 Gew.-% geschaffen. Damit entstehen im erfindungsgemäßen Verfahren Phosphatierungsschichten, die - vermutlich auf Grund ihres hohen Gehaltes an Phosphophyllit - beim nachfolgenden Einsatz in der katodischen Elektrotauchlackierung die erwünschte hohe Stabilität aufweisen.It is decisive for the method according to the invention and the results obtained with it that the formation of zinc phosphate layers with a high iron content is made possible by the parameter combination selected according to the invention. In the preferred embodiment of the invention, such zinc phosphate layers with iron contents in the range of about 5-20% by weight are created. This results in the phosphating layers in the process according to the invention which - presumably because of their high phosphophyllite content - have the desired high stability when subsequently used in cathodic electrocoating.

Im Rahmen der erfindungsgemäßen Zielsetzung wird bevorzugt mit Phosphatierungsbädern gearbeitet, deren Gehalt an Gesamtsäure zahlenmäßig begrenzte Werte im Bereich von etwa 30 Punkten nicht überschreitet. Geeignet sind für das erfindungsgemäße Verfahren insbesondere Phosphatierungsbäder mit einem Gehalt an Gesamtsäure im Bereich von 8 - 30 Punkten, bevorzugt im Bereich von etwa 9 - 15 Punkten.Within the scope of the objective according to the invention, preference is given to working with phosphating baths whose total acid content does not exceed numerically limited values in the range of about 30 points. Particularly suitable for the process according to the invention are phosphating baths with a total acid content in the range from 8 to 30 points, preferably in the range from about 9 to 15 points.

Im übrigen können in den erfindungsgemäßen Phosphatierungslösungen die in Bädern dieser Art üblichen Hilfskomponenten bzw. -bestandteile mit verwendet werden. Von besonderer Bedeutung ist dabei allerdings, daß die bis heute übliche Mitverwendung von Mangan nicht erforderlich ist. Hier liegt in wichtiger Vorteil des erfindungsgemäßen Verfahrens gegen andere charakteristische Bäder des Standes der Technik, insbesondere gegenüber den sogenannten Niedrig-Zink-Bädern, die bei vergleichsweise höherer Temperatur arbeiten.Otherwise, the auxiliary components or constituents customary in baths of this type can also be used in the phosphating solutions according to the invention. It is of particular importance here, however, that the common use of manganese to this day is not necessary. This is an important advantage of the method according to the invention over other characteristic baths of the prior art, in particular over the so-called low-zinc baths which operate at a comparatively higher temperature.

Übliche aktivierende Zusatzstoffe umfassen Komponenten wie Chlorat, Nitrat, Nitrit, Wasserstoffperoxid, aromatische Nitroverbindungen, einfache und/oder komplexe Fluoride und/oder organische und/oder anorganische Komplexbildner. Im einzelnen gilt hier das Folgende:

  • Die Mitverwendung von Chlorat empfiehlt sich in aller Regel. Der Chloratgehalt liegt zweckmäßig im Bereich von etwa 0,1 - 30 g/1 Badlösung, vorzugsweise im Bereich von etwa 1,5 - 10 g/1 Badlösung. Eventuell mitverwendete Nitrationen liegen zweckmäßigerweise im Konzentrationsbereich von 1 - 10 g/1 Badlösung. Sollen Nitritionen im Bad zum Einsatz kommen, so eignet sich hier besonders der Bereich von 0,01 - 1 g/1 Badlösung. Im gleichen Bereich kann Wasserstoffperoxid zum Einsatz kommen. Aromatische Nitroverbindungen, insbesondere 3-Nitrobenzolsulfonsäure oder ihre Salze, aber auch andere Vertreter dieser Stoffklasse, z. B. Nitroresorcin oder Nitrobenzoesäure sind bekannte Beschleuniger in Phosphatierungsbädern. Verbindungen dieser Art werden zweckmäßigerweise in Mengen von 0,01 - 2 g/1 Badlösung mit verwendet.
Customary activating additives include components such as chlorate, nitrate, nitrite, hydrogen peroxide, aromatic nitro compounds, simple and / or complex fluorides and / or organic and / or inorganic complexing agents. The following applies here in detail:
  • The use of chlorate is generally recommended. The chlorate is suitably in the range of about 0.1 to 30 g / 1 bath solution, preferably in the range of about 1.5 - 1 0 g / 1 B adlösung. Any nitrate ions used are expediently in the concentration range of 1 - 10 g / 1 bath solution. If nitrite ions are to be used in the bathroom, the range of 0.01 - 1 g / 1 bath solution is particularly suitable. Hydrogen peroxide can be used in the same area. Aromatic nitrover bonds, especially 3-nitrobenzenesulfonic acid or its salts, but also other representatives of this class of substances, e.g. B. N itroresorcinol or nitrobenzoic acid are known accelerators in phosphating baths. A compounds of this rt are advantageously used in amounts from 0.01 to 2 g / 1 with bath solution used.

In an sich bekannter Weise kann die Schichtbildung auf den Metalloberflächen durch Zusätze von einfachen und/oder komplexen Fluoriden verbessert werden. Der Gehalt an Fluoridionen liegt zweckmäßigerweise im Bereich von 0,01 - 2 g/1 Badlösung. Daneben oder statt dessen kann als komplexes Fluorid beispielsweise das SiF6 2- -Ion zum Einsatz kommen, wobei auch.hier Konzentrationsbereiche von etwa 0,01 - 2 g/1 Badlösung bevorzugt sind.In a manner known per se, the layer formation on the metal surfaces can be improved by adding simple and / or complex fluorides. The fluoride ion content is expediently in the range of 0.01-2 g / l bath solution. In addition or instead of this, the complex fluoride can be, for example, the SiF 6 2- ion, concentration ranges of about 0.01-2 g / l bath solution also being preferred.

Die Lösungen können weiterhin an sich bekannte Komplexbildner organischen oder anorganischen Ursprungs enthalten. Geeignete organische Komplexbildner sind beispielsweise Weinsäure oder Tartrat, Hydroxy-ethylen-diamino-triessigsäure oder deren Salze, Gluconsäure oder deren Salze und/ oder Zitronensäure bzw. ihre Salze. Anorganische Komplexbildner sind Polyphosphate, beispielsweise Tripolyphosphat. oder Hexamethaphosphat. Komplexbildner dieser Art liegen üblicherweise im Bad in Mengen von 0,01 - 5 g/l vor.The solutions can also contain complexing agents known per se of organic or inorganic origin. Suitable organic complexing agents are, for example, tartaric acid or tartrate, hydroxyethylene-diamino-triacetic acid or its salts, gluconic acid or its salts and / or citric acid or its salts. Inorganic complexing agents are polyphosphates, for example tripolyphosphate. or hexamethaphosphate. Complexing agents of this type are usually present in the bath in quantities of 0.01-5 g / l.

Neben Zink kann das Behandlungsbad weitere Metallkationen, insbesondere zweiwertige Metallkationen, enthalten. Bevorzugt kann die Mitverwendung von Nickel (II)- im Phosphatierungsbad sein. Dabei ist jedoch in den bevorzugten Ausführungsformen der Erfindung der Nickelgehalt im Verhältnis zum Zink beschränkt und erreicht höchstens diesen Zinkgehalt Vorzugsweise wird jedoch das Verhältnis Zn/Ni von etwa 1/0,5 nicht überschritten. Bevorzugte Nickelgehalte können im Rahmen der erfindungsgemäßen Lehre im Bereich von etwa 0,01 - 1 g/1 Badlösung liegen.In addition to zinc, the treatment bath can contain further metal cations, in particular divalent metal cations. Preferably, the co-use of nickel (I I) may - be in the phosphating. In the preferred embodiments of the invention, however, the nickel content is limited in relation to the zinc and at most reaches this zinc content. However, the Zn / Ni ratio of about 1 / 0.5 is preferably not exceeded. Preferred nickel contents can be within the teaching of the invention in the range of about 0, 01-1 g / 1 B are adlösung.

Es kann zweckmäßig sein - ist aber keineswegs erforderlich - vor der Anwendung der erfindungsgemäßen Phosphatierungsbäder die zu behandelnden Metalloberflächen einer an sich bekannten Aktivierung zu unterwerfen. Geeignet sind hier beispielsweise entsprechende Aktivierungsmittel-auf Basis von Titanphosphat.It may be expedient - but is by no means necessary - to subject the metal surfaces to be treated to an activation known per se before the phosphating baths according to the invention are used. Appropriate activating agents based on titanium phosphate are suitable here, for example.

Erfindungsgemäß ausgebildete Zinkphosphatschichten mit hohem Eisengehalt eignen sich zwar für alle Anwendungsarten bis heute bekannter Phosphatschichten, sie weisen jedoch besondere Vorzüge für eine nachfolgende katodische Elektrotauchlackierung auf. Sie zeigen hier hohe Beständigkeit des Lackfilmes gegen Lackunterwanderung bei korrosiver Beansprschung sowie hohe und zufriedenstellende Werte der Lackhaftung zum metallischen Untergrund. Praktische Anwendung findet das erfindungsgemäße Verfahren damit.beispielsweise bei der Phosphatierung von Autokarosserien.Zinc phosphate layers with a high iron content designed according to the invention are suitable for all types of application of phosphate layers known to date, but they have particular advantages for a subsequent cathodic electrocoating. They show a high resistance of the paint film against paint infiltration under corrosive stress as well as high and satisfactory values of the paint adhesion to the metallic surface. The method according to the invention is therefore used in practice, for example in the phosphating of car bodies.

Bestimmte Ausführungsformen der Erfindung sind in den folgenden Beispielen geschildert.Certain embodiments of the invention are set forth in the following examples.

Beispiel 1example 1

Ein Konzentrat wurde hergestellt aus

Figure imgb0002
A concentrate was made from
Figure imgb0002

Dieses Konzentrat wurde verdünnt, um eine Lösung mit 0,18 % Zn, 0,002 % Ni, 0,96 % PO4, 0,17 % NO3, 0,004 % Tar- trat und O,15 % ClO3 zu ergeben, die eine Gesamtsäure- Punktzahl von 9,8 aufweist. Die freie Säure wurde durch Zusatz von Natriumhydroxid auf einen pH im Bereich 3,5 - 4 reduziert.This concentrate was diluted to give a solution with 0.18% Zn, 0.002% Ni, 0.96% PO 4 , 0.17% NO 3 , 0.004% tartrate and O, 15% ClO 3 , which was a Gesamtsäure- P has unktzahl of 9.8. The free acid was reduced to a pH in the range 3.5-4 by adding sodium hydroxide.

Stahlteile wurden 2 Minuten im Spritzen bei 40 °C mit einer alkalischen Reinigungslösung gereinigt und mit Wasser gespült. Die Teile wurden dann 2 Minuten im Spritzen bei 35 °C mit der oben beschriebenen Arbeitslösung phosphatiert.Steel parts were sprayed for 2 minutes at 40 ° C with an alkaline cleaning solution and rinsed with water. The parts were then phosphated for 2 minutes by spraying at 35 ° C. with the working solution described above.

Die Teile wurden anschließend mit Wasser gespült, mit destilliertem Wasser nachgespült und durch Blasen mit Druckluft getrocknet. Danach wurden die Teile mit einem katodischen Elektrotauchlack beschichtet und 20 Minuten durch Erwärmen bei 185 °C getrocknet. Die Trockenfilmdicke des Anstrichs betrug 18 pm. Die Teile wurden dann mit Einzelschnitten versehen und dem Salzsprühtest DIN 50021 für 240 Stunden unterworfen. Die Auswertung nach DIN 53167 ergab eine Unterwanderung von <0,1 mm. Daraus ergibt sich, daß die vorgeschlagene Arbeitsweise trotz der niedrigen Behandlungstemperatur einen guten Überzug ergibt.The parts were then rinsed with water, rinsed with distilled water and dried by blowing with compressed air. The parts were then coated with a cathodic electrocoating material and dried by heating at 185 ° C. for 20 minutes. The dry film thickness of the paint was 18 pm. The parts were then provided with individual cuts and subjected to the salt spray test DIN 50021 for 240 hours. The evaluation according to DIN 53167 showed an infiltration of <0.1 mm. It follows that the proposed method of working gives a good coating despite the low treatment temperature.

Beispiel 2Example 2

Ein Konzentrat wurde hergestellt aus

Figure imgb0003
A concentrate was made from
Figure imgb0003

Dieses Konzentrat wurde verdünnt, um eine Lösung mit 0,48 % Zn, 1,68 % PO4, 0,19 % NO3, 0,19 % ClO3 und 0,024 % Gluconat zu ergeben, die eine Gesamtsäure-Punktzahl von 25,5 aufweist. Die freie Säure wurde durch Zusatz von Natriumhydroxid auf einen pH im Bereich 3,5 - 4 reduziert. Anschließend wurden der Lösung 0,1 gl NaN02 zugesetzt.This concentrate was diluted to give a solution with 0.48% Zn, 1.68% PO 4 , 0.19% NO 3 , 0.19% ClO 3 and 0.024% gluconate, which had a total acid score of 25, 5 has. The free acid was reduced to a pH in the range 3.5-4 by adding sodium hydroxide. Then 0.1 gl NaN0 2 were added to the solution.

Stahlteile wurden 5 Minuten im Tauchen bei 50 °C mit einer alkalischen Reinigungslösung gereinigt und dann mit Wasser gespült. Die Teile wurden dann 5 Minuten im Tauchen bei 32 °C mit der oben beschriebenen Arbeitslösung phosphatiert. Danach wurden die Teile mit Wasser gespült, mit destilliertem Wasser nachgespült und dann durch Blasen mit Druckluft getrocknet. Anschließend wurden die Teile mit einem katodischen Elektrotauchlack beschichtet und 20 Minuten durch Erwärmen bei 185 °C getrocknet.Steel parts were immersed in an alkaline cleaning solution at 50 ° C for 5 minutes and then rinsed with water. The parts were then phosphated for 5 minutes while immersing at 32 ° C. with the working solution described above. The parts were then rinsed with water, rinsed with distilled water and then dried by blowing with compressed air. The parts were then coated with a cathodic electrocoating material and dried for 20 minutes by heating at 185 ° C.

Die Trockenfilmdicke des Anstrichs betrug 18 µm. Die Teile wurden dann mit Einzelschnitten versehen und dem Salzsprühtest DIN 50021 für 240 Stunden unterworfen. Die Auswertung nach DIN 53167 ergab eine Unterwanderung von <0,1 mm. Daraus ergibt sich, daß die vorgeschlagene Arbeitsweise trotz der niedrigen Behandlungstemperatur einen guten Überzug ergibt.The dry film thickness of the paint was 18 µm. The parts were then provided with individual cuts and subjected to the salt spray test DIN 50021 for 240 hours. The evaluation according to DIN 53167 showed an infiltration of <0.1 mm. It follows that the proposed method of working gives a good coating despite the low treatment temperature.

Beispiel 3Example 3

Ein Konzentrat wurde hergestellt aus

Figure imgb0004
A concentrate was made from
Figure imgb0004

Dieses Konzentrat wurde verdünnt, um eine Lösung mit 0,34 % Zn, 0,85 % PO4, 0,34 % NO3, 0,27 % ClO3, 0,007 % Si F6, 0,007 % F und 0,014 % 3-Nitrobenzolsulfosäure zu ergeben, die eine Gesamtsäure-Punktzahl von 14,4 aufweist. Die freie Säure wurde durch Zusatz von Natriumhydroxid auf einen pH im Bereich 3,5 - 4 reduziert.This concentrate was diluted to yield a solution having 0.34% Zn, 0.85% PO 4, 0.34% NO 3, 0.27% ClO 3, 0, 007% Si F 6 0.007% and 0.014% F To give 3-nitrobenzenesulfonic acid, which has a total acid score of 14.4. The free acid was reduced to a pH in the range 3.5-4 by adding sodium hydroxide.

Stahlteile wurden 2 Minuten im Spritzen bei 40 °C mit. einer alkalischen Reinigungslösung gereinigt und dann mit Wasser gespült. Die Teile wurden dann 1 Minute im Spritzen und 2 Minuten im Tauchen bei 32 °C mit der oben beschriebenen Arbeitslösung phosphatiert. Danach wurden die Teile mit Wasser gespült, mit destilliertem Wasser nachgespült und durch Blasen mit Druckluft getrocknet. Anschließend wurden die Teile mit einem katodischen Elektrotauchlack beschichtet und 20 Minuten durch Erwärmen bei 185 °C getrocknet.Steel parts were sprayed at 40 ° C for 2 minutes. an alkaline cleaning solution and then rinsed with water. The parts were then phosphated for 1 minute by spraying and 2 minutes by immersion at 32 ° C. with the working solution described above. The parts were then rinsed with water, rinsed with distilled water and dried by blowing with compressed air. The parts were then coated with a cathodic electrocoating material and dried for 20 minutes by heating at 185 ° C.

Die Trockenfilmdicke des Anstrichs betrug 18 µm. Die Teile wurden dann mit Einzelschnitten versehen und dem Salzsprühtest DIN 50021 für 240 Stunden unterworfen. Die Auswertung nach DIN 53167 ergab eine Unterwanderung von <0,1 mm. Daraus ergibt sich, daß die vorgeschlagene Arbeitsweise trotz der niedrigen Behandlungstemperatur einen guten Überzug ergibt.The dry film thickness of the paint was 18 µm. The parts were then provided with individual cuts and subjected to the salt spray test DIN 50021 for 240 hours. The evaluation according to DIN 53167 showed an infiltration of <0.1 mm. It follows that the proposed method of working gives a good coating despite the low treatment temperature.

Claims (12)

1. Verfahren zur Phosphatierung von Metalloberflächen, insbesondere von Eisen, Stahl und verzinktem Stahl, durch deren Behandlung mit wäßrigen, sauren Zinkphosphat-Bädern bei-nur mäßig erhöhten Temperaturen, dadurch gekennzeichnet, daß man im Temperaturbereich von 22 - 38 °C mit Bädern arbeitet, die den folgenden Bedingungen entsprechen:
Figure imgb0005
Gehalt an freier Säure 0,05 - 0,4 Punkte pH 3,0 - 4,01. Process for phosphating metal surfaces, in particular iron, steel and galvanized steel, by treating them with aqueous, acidic zinc phosphate baths at only moderately elevated temperatures, characterized in that baths are used in the temperature range from 22 to 38 ° C that meet the following conditions:
Figure imgb0005
 Free acid content 0.05 - 0.4 points pH 3.0 - 4.0 -2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß man Bäder einsetzt, in denen das Verhältnis Zn/PO4 3- im Bereich von 1 : 2 bis 1 : 11, vorzugsweise im Bereich von 1 : 2 bis 1 : 4 liegt.-2. Process according to Claim 1, characterized in that baths are used in which the ratio Zn / PO 4 3 - is in the range from 1: 2 to 1:11, preferably in the range from 1: 2 to 1: 4. 3. Verfahren nach Ansprüchen 1 und 2, dadurch gekennzeichnet, daß man Bäder einsetzt, deren PO4 3-Gehalt 4 - 15 g/l, insbesondere 4 - 8 g/l beträgt.3. Process according to Claims 1 and 2, characterized in that baths are used whose PO 4 3 content is 4 - 15 g / l, in particular 4 - 8 g / l. 4. Verfahren nach Ansprüchen 1 - 3, dadurch gekennzeichnet, daß man Bäder einsetzt, die den folgenden Bedingungen entsprechen:
Figure imgb0006
bevorzugter Gehalt an freier Säure 0,1 - 0,2 Punkte pH 3,5 - 4,0.4. The method according to claims 1-3, characterized in that baths are used which meet the following conditions:
Figure imgb0006
 preferred free acid content 0.1 - 0.2 points pH 3.5 - 4.0. 5. Verfahren nach Ansprüchen 1 - 4, dadurch gekennzeichnet, daß man die Behandlung bei Temperaturen von 28- 38 C durchführt.5. Process according to Claims 1-4, characterized in that the treatment is carried out at temperatures of 28-38 ° C. 6. Verfahren nach Ansprüchen 1 - 5, dadurch gekennzeichnet, daß Bäder eingesetzt werden, die zusätzlich Nickel-(II)-Ionen enthalten, wobei bevorzugt der Nickelgehalt das Verhältnis Zn/Ni von 1/0,5 nicht überschreitet.6. The method according to claims 1-5, characterized in that baths are used which additionally contain nickel (II) ions, the nickel content preferably not exceeding the Zn / Ni ratio of 1 / 0.5. 7. Verfahren nach Ansprüchen 1 - 6, dadurch gekennzeichnet, daß eisenhaltige Zinkphosphatschichten mit einem Eisengehalt von 5 - 20 Gew.-% ausgebildet werden.7. The method according to claims 1-6, characterized in that iron-containing zinc phosphate layers are formed with an iron content of 5 - 20 wt .-%. 8. Verfahren nach Ansprüchen 1 - 7, dadurch gekennzeichnet, daß mit Bädern gearbeitet wird, deren Gehalt an Gesamtsäure im Bereich von 8 - 30 Punkten, insbesondere im Bereich von 9 - 15 Punkten, liegt.8. The method according to claims 1-7, characterized in that one works with baths, the total acid content of which is in the range of 8-30 points, in particular in the range of 9-15 points. 9. Verfahren nach Ansprüchen 1 - 8, dadurch gekennzeichnet, daß Bäder eingesetzt werden, die übliche aktivierende und/ oder die Schichtbildung verbessernde Zusatzstoffe, wie Chlorat, Nitrat, Nitrit, Wasserstoffperoxid, aromatische Nitroverbindung en, einfache und/oder komplexe Fluoride und/oder Komplexbildner enthalten.9. The method according to claims 1-8, characterized in that baths are used, the usual activating and / or layer-improving additives, such as chlorate, nitrate, nitrite, hydrogen peroxide, aromatic nitro compounds, simple and / or complex fluorides and / or Contain complexing agents. 10. Verfahren nach Ansprüchen 1 - 9, dadurch gekennzeichnet, daß es als Vorbehandlung für eine nachfolgende katodische Elektrotauchlackierung eingesetzt wird.10. The method according to claims 1-9, characterized in that it is used as a pretreatment for a subsequent cathodic electrocoating. 11. Wäßrig saures Behandlungsbad für die Phosphatierung von Metalloberflächen, insbesondere von Eisen, Stahl und verzinktem Stahl, dadurch gekennzeichnet, daß seine Zusammensetzung den folgenden Bedingungen entspricht:
Figure imgb0007
Gehalt an freier Säure 0,05 - 0,4 Punkte Gehalt an Gesamtsäure 8 - 30 Punkte Verhältnis Zn/PO4 3- 1 : 2 bis 1 : 11 pH 3,0 - 4,011. Aqueous acidic treatment bath for the phosphating of metal surfaces, in particular iron, steel and galvanized steel, characterized in that its composition corresponds to the following conditions:
Figure imgb0007
 Free acid content 0.05 - 0.4 points Total acid content 8 - 30 points ratio Zn / PO 4 3 - 1: 2 to 1:11 pH 3.0 - 4.0 12. Wäßriges Behandlungsbad nach Anspruch 11, dadurch gekennzeichnet, daß seine Zusammensetzung den folgenden Bedingungen entspricht:
Figure imgb0008
Gehalt an freier Säure 0,1 - 0,2 Punkte Gehalt an Gesamtsäure 9 - 15 Punkte Verhältnis Zn/PO4 3- 1 : 2 bis 1 : 4 pH 3,5 - 4,0
sowie zusätzlich enthaltend übliche aktivierende und/oder die Schichtbildung verbessernde Zusatzstoffe.12. Aqueous treatment bath according to claim 11, characterized in that its composition corresponds to the following conditions:
Figure imgb0008
 Free acid content 0.1 - 0.2 points Total acid content 9 - 15 points Zn / PO 4 ratio 3 - 1: 2 to 1: 4 pH 3.5 - 4.0
and additionally containing customary activating and / or layering-improving additives.
EP83111813A 1982-12-03 1983-11-25 Process for phosphatizing metallic surfaces, and solutions for use therein Expired EP0111223B1 (en)

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ZA (1) ZA839008B (en)

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US5900073A (en) * 1996-12-04 1999-05-04 Henkel Corporation Sludge reducing zinc phosphating process and composition
US6551417B1 (en) 2000-09-20 2003-04-22 Ge Betz, Inc. Tri-cation zinc phosphate conversion coating and process of making the same
JP4902841B2 (en) * 2005-09-14 2012-03-21 川崎重工業株式会社 Body frame
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RU2484041C1 (en) * 2012-02-09 2013-06-10 Юлия Алексеевна Щепочкина Mixture for making heat-insulation boards
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AU561955B2 (en) 1987-05-21
AU2192083A (en) 1984-06-07
ES8502168A1 (en) 1984-12-16
ATE27715T1 (en) 1987-06-15
ZA839008B (en) 1984-07-25
JPS59110785A (en) 1984-06-26
US4490185A (en) 1984-12-25
ES527732A0 (en) 1984-12-16
CA1205726A (en) 1986-06-10
GR81290B (en) 1984-12-11
TR23183A (en) 1989-06-06
DE3371999D1 (en) 1987-07-16
EP0111223B1 (en) 1987-06-10
DE3244715A1 (en) 1984-06-07

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