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
  • C23C22/82—After-treatment
  • C23C22/83—Chemical after-treatment
• • 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
  • C23C22/364—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 manganese cations
  • C23C22/365—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 manganese cations containing also zinc and nickel 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
  • C23C22/34—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
  • C23C22/364—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 manganese cations
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
  • C11D7/04—Water-soluble compounds
  • C11D7/10—Salts
  • C11D7/14—Silicates
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
  • C11D7/04—Water-soluble compounds
  • C11D7/10—Salts
  • C11D7/16—Phosphates including polyphosphates
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/26—Organic compounds containing oxygen
  • C11D7/265—Carboxylic acids or salts thereof
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/36—Organic compounds containing phosphorus
• • 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
  • C23C22/78—Pretreatment of the material to be coated
• • 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
  • C23C22/78—Pretreatment of the material to be coated
  • C23C22/80—Pretreatment of the material to be coated with solutions containing titanium or zirconium compounds
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
  • C23G1/16—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions using inhibitors
• • 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
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
  • C23G1/16—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions using inhibitors
  • C23G1/18—Organic inhibitors
• • C11D2111/16—
• • C11D2111/20—
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
  • C11D7/04—Water-soluble compounds
  • C11D7/10—Salts
  • C11D7/105—Nitrates; Nitrites

Definitions

• the present invention relates to a process for the essentially nickel-free phosphating of a metallic surface using a special cleaning composition and the use of this process in the automotive industry.
• Phosphate coatings on metallic surfaces are known from the prior art. Such coatings serve to protect metal surfaces from corrosion and also serve as an adhesion promoter for subsequent coats of paint.
• Such phosphate coatings are primarily used in the automotive and general industries.
• the subsequent paint layers are primarily cathodically deposited electrophoretic paints (KTL). Since a current must flow between the metallic surface and the treatment bath during the deposition of KTL, it is important to set a defined electrical conductivity of the phosphate coating in order to ensure efficient and homogeneous deposition.
• KTL cathodically deposited electrophoretic paints
• phosphate coatings are usually applied using a nickel-containing phosphating solution.
• the nickel deposited elementally or as an alloy component, e.g. Zn/Ni, ensures suitable conductivity of the coating during the subsequent electrocoating.
• nickel ions are no longer desirable as a component of treatment solutions and should therefore be avoided if possible or at least reduced in content.
• nickel-free or low-nickel phosphating solutions are known in principle. However, this is limited to certain substrates such as steel.
• a nickel-free phosphating solution is available from the DE19854431 A1 known.
• the object of the present invention was therefore to provide a method with which metallic surfaces can be phosphated essentially without nickel, while avoiding the aforementioned disadvantages of the prior art.
• an uncoated metallic surface but on the other hand, an already conversion-coated metallic surface can also be treated with the method according to the invention.
• a metallic surface it should always include a metallic surface that has already been conversion-coated. However, it is preferably an uncoated metallic surface.
• an “aqueous composition” refers to a composition which contains at least some, preferably most, i.e. more than 50% by weight, water as a solvent/dispersion medium. In addition to dissolved components, it can also include coarsely dispersed components. It can therefore be, for example, an emulsion. However, it is preferably a solution, i.e. a composition that does not contain any coarsely dispersed components.
• a silicate that has a water solubility (in demineralized water) of at least 1 mg/l at 25 °C, preferably at least 10 mg/l, more preferably at least 100 mg/l, more preferably at least 1 g/l, more preferably at least 10 g/l, more preferably at least 100 g/l, more preferably at least 200 g /l, more preferably of at least 300 g/l and particularly preferably of at least 350 g/l.
• the silicate can also be present as a colloidal solution.
• composition contains less than 0.01 g/L nickel ions, it should be considered “substantially nickel-free” for the purposes of the present invention.
• phosphate ions also means hydrogen phosphate, dihydrogen phosphate and phosphoric acid.
• pyrophosphoric acid and polyphosphoric acid and all their partially and completely deprotonated forms should be included.
• metal ion is understood to mean either a metal cation, a complex metal cation or a complex metal anion.
• the metallic surface is preferably steel, a steel alloy, hot-dip galvanizing, electrolytic galvanizing, a zinc alloy such as Zn/Fe or Zn/Mg, aluminum or an aluminum alloy. Hot-dip galvanizing and electrolytic galvanizing are particularly applied to steel. In particular, the metallic surface is at least partially galvanized.
• the method according to the invention is particularly suitable for multi-metal applications, in particular for metallic surfaces which, in addition to galvanizing on steel, preferably hot-dip galvanizing and electrolytic galvanizing, contain aluminum and/or an aluminum alloy, preferably an aluminum alloy.
• the metallic surface is first cleaned (step i), in particular degreased, in an alkaline, aqueous cleaning composition before treatment with the acidic, aqueous, essentially nickel-free phosphating composition (step ii).
• aqueous cleaning composition before treatment with the acidic, aqueous, essentially nickel-free phosphating composition (step ii).
• an acidic or neutral pickling composition can also be used for this purpose.
• the cleaning composition can be obtained from a concentrate by diluting it with a suitable solvent, preferably water, preferably by a factor between 1.5 and 1000, more preferably between 50 and 200, and if necessary adding a pH-modifying substance.
• a suitable solvent preferably water, preferably by a factor between 1.5 and 1000, more preferably between 50 and 200, and if necessary adding a pH-modifying substance.
• the at least one water-soluble silicate contained in the cleaning composition results in a better cleaning effect and reduces the pickling attack in the cleaning bath (inhibiting effect).
• the at least one water-soluble silicate comprises at least one water glass, in particular a lithium water glass, a soda water glass and/or a potassium water glass, particularly preferably a soda water glass and/or a potassium water glass, and/or at least one metasilicate such as disodium metasilicate (Na 2 SiO 3 ).
• the at least one water-soluble silicate comprises a soda water glass or a potassium water glass.
• the soda water glass is preferably one with a molar Na 2 O:SiO 2 ratio in the range from 1 to 4.
• the potassium water glass is also preferably one with a molar K 2 O:SiO 2 ratio in the range from 1 to 4.
• the at least one water-soluble silicate is present in a total concentration in the range from 0.01 to 15 g/l, preferably from 0.2 to 13 g/l and particularly preferably from 0.5 to 10 g/l.
• the cleaning composition can contain at least one cationic, nonionic and/or anionic surfactant and/or other additives, in particular complexing agents, oxidizing agents, oils and/or auxiliary substances such as solubilizers, borate and/or carbonate.
• Complexing agents contained in the cleaning composition cause a complexation of water hardness and dissolved cations, which are caused by the pickling attack go into solution or are present in the cleaning bath.
• Preferred complexing agents are, on the one hand, phosphorus-containing complexing agents.
• phosphate-based complexing agents preferably condensed phosphates such as pyrophosphates, tripolyphosphates and other polyphosphates - as well as phosphonic acids such as 1-hydroxyethane-(1,1-diphosphonic acid) (HEDP) and their salts.
• condensed phosphates such as pyrophosphates, tripolyphosphates and other polyphosphates - as well as phosphonic acids such as 1-hydroxyethane-(1,1-diphosphonic acid) (HEDP) and their salts.
• HEDP 1-hydroxyethane-(1,1-diphosphonic acid)
• the phosphorus-containing, in particular the phosphate-based, complexing agents are preferably in a total concentration in the range from 0.01 to 15 g/l, more preferably from 0.05 to 13 g/l and particularly preferably from 0.1 to 10 g/l (calculated as tetrapotassium pyrophosphate).
• preferred complexing agents are hydroxycarboxylic acids, which have at least one hydroxyl group and at least one carboxyl group, and their salts, in particular sugar acids and their salts, particularly preferably heptonate and gluconate. Gluconate is particularly preferred.
• Such complexing agents are preferably present in a total concentration in the range from 0.01 to 6 g/l, more preferably from 0.05 to 5 g/l and particularly preferably from 0.1 to 4 g/l (calculated as sodium gluconate).
• a preferred oxidizing agent is nitrite.
• the oxidizing agents are preferably present in a total concentration in the range from 10 to 100 mg/l, particularly preferably from 20 to 50 mg/l (calculated as nitrite).
• any iron ions present in the cleaning bath come exclusively from the treated metallic one Surface.
• caustic soda potassium hydroxide
• caustic soda or caustic potash on the other hand, in particular phosphoric acid can be used.
• the pH value of the cleaning composition is in the range from 10.7 to 12.0, preferably from 11.0 to 12.0, more preferably from 11.3 to 12.0 and particularly preferably in the range from 11.5 to 12.0.
• the cleaning composition preferably has a temperature in the range from 35 to 70, more preferably from 40 to 65 and particularly preferably from 45 to 60 ° C.
• the metallic surface is treated with the cleaning composition preferably for 30 to 600, particularly preferably for 60 to 480 and very particularly preferably for 90 to 360 seconds, preferably by dipping or spraying, or a combination of both.
• the metallic surface is first sprayed with the cleaning composition for 30 to 90 seconds and then immersed in it for 100 to 300 seconds.
• At least one rinsing of the metallic surface with water advantageously takes place, with the water optionally also containing an additive dissolved in water, such as. B. a nitrite or surfactant can be added.
• the activation composition serves to deposit a large number of the finest phosphate particles as seed crystals on the metallic surface. In the subsequent process step, these help to form a particularly crystalline phosphate layer with the highest possible number of densely arranged fine phosphate crystals or a largely closed phosphate layer in contact with the phosphating composition - preferably without intermediate rinsing.
• Particularly suitable activation compositions are alkaline compositions based on titanium phosphate or zinc phosphate.
• activating agents in particular titanium phosphate or zinc phosphate, to the cleaning composition, i.e. to carry out cleaning and activation in one step.
• the acidic, aqueous, essentially nickel-free phosphating composition includes zinc ions, manganese ions and phosphate ions.
• the phosphating composition can be obtained from a concentrate by diluting it with a suitable solvent, preferably water, by a factor between 1.5 and 100, preferably between 5 and 50, and if necessary adding a pH-modifying substance.
• a suitable solvent preferably water
• the phosphating composition preferably comprises the following components in the following preferred and particularly preferred concentration ranges: Zn 0.3 to 3.0 g/l 0.5 to 2.0 g/l Mn 0.3 to 2.0 g/l 0.5 to 1.5 g/l Phosphate (calculated as P 2 O 5 ) 8 to 25 g/l 10 to 18 g/l free fluoride 30 to 250 mg/l 50 to 180 mg/l Complex fluoride (calculated e.g. as SiF 6 2- and/or BF 4 - ) 0 to 5 g/l 0.5 to 3 g/l
• the complex fluoride is preferably tetrafluoroborate (BF 4 - ) and/or hexafluorosilicate (SiF 6 2- ).
• a content of complex fluoride and simple fluoride, for example sodium fluoride, in the phosphating composition is advantageous.
• Al 3+ is a bath poison in phosphating systems and can be removed from the system by complexing with fluoride, for example as cryolite.
• fluoride for example as cryolite.
• Complex fluorides are added to the bath added as a "fluoride buffer", otherwise the fluoride content would drop quickly and no coating would take place. Fluoride supports the formation of the phosphate layer and indirectly leads to an improvement in paint adhesion and corrosion protection. Complex fluoride also helps to avoid defects such as specks on galvanized material.
• the phosphating composition contains iron(III) ions.
• the iron(III) ions are preferably added to the phosphating composition. It is preferred to add iron(III) ions in the range from 0.001 to 0.2 g/l, more preferably from 0.001 to 0.1 g/l, more preferably from 0.005 to 0.1 g/l, particularly preferably from 0.005 to 0.05 g/l and most preferably from 0.005 to 0.02 g/l.
• the phosphating composition preferably contains at least one accelerator selected from the group consisting of the following compounds in the following preferred and particularly preferred concentration ranges: Nitroguanidine 0.2 to 3.0 g/l 0.2 to 1.55 g/l H2O2 _ 10 to 100 mg/l 15 to 50 mg/l Nitroguanidine / H2O2 0.2 to 2.0 g/l / 10 to 50 mg/l 0.2 to 1.5 g/l / 15 to 30 mg/l nitrite 30 to 300 mg/l 90 to 150 mg/l Hydroxylamine 0.1 to 5 g/l 0.4 to 3 g/l
• nitroguanidine a concentration in the range of 0.1 to 3.0 g/l has already proven to be advantageous, and with regard to H 2 O 2 a concentration in the range of 5 to 200 mg/l has proven to be advantageous.
• the at least one accelerator is H 2 O 2 .
• the phosphating composition preferably contains less than 1 g/l, more preferably less than 0.5 g/l, particularly preferably less than 0.2 g/l and most preferably less than 0.1 g/l nitrate.
• the nitrate in the phosphating composition causes an additional acceleration Layer formation reaction, which leads to lower layer weights but above all reduces the incorporation of manganese into the crystal.
• the manganese content of the phosphate coating is too low, this will affect its alkali resistance.
• Alkaline resistance in turn plays a crucial role in subsequent cathodic electrocoating. This results in an electrolytic splitting of water on the substrate surface: hydroxide ions are formed. This causes the pH value at the interface of the substrate to increase. Only in this way can the electrophoretic paint be agglomerated and deposited. However, the increased pH can also damage the crystalline phosphate layer.
• the phosphating composition preferably has a temperature in the range from 30 to 55°C.
• the phosphating composition can be characterized by the following preferred and particularly preferred parameter ranges: FS 0.3 to 2.0 0.7 to 1.6 FS (dil.) 0.5 to 8 1 to 6 GSF 12 to 28 22 to 26 G.S 12 to 45 18 to 35 S value 0.01 to 0.2 0.03 to 0.15 temperature 30 to 50°C 35 to 45°C
• FS stands for free acid
• FS (diluted) for free acid (diluted)
• GSF for total acid according to Fischer
• GS for total acid
• S-value for acid value
• a suitable vessel for example a 300 ml Erlenmeyer flask. If the phosphating composition contains complex fluorides, 2-3 g of potassium chloride are added to the sample. Then titrate to a pH of 3.6 using a pH meter and an electrode with 0.1 M NaOH. The amount of 0.1 M NaOH in ml used per 10 ml of the phosphating composition gives the value of the free acid (FS) in points.
• the diluted phosphating composition is titrated to a pH of 8.9 using a pH meter and an electrode with 0.1 M NaOH after adding potassium oxalate solution.
• the consumption of 0.1 M NaOH in ml per 10 ml of the diluted phosphating composition gives the total acid according to Fischer (GSF) in points. If this value is multiplied by 0.71, the total phosphate ion content is calculated as P 2 O 5 .
• the total acid (GS) is the sum of the divalent cations contained as well as free and bound phosphoric acids (the latter are phosphates). It is determined by the consumption of 0.1 M NaOH using a pH meter and an electrode. To do this, 10 ml of the phosphating composition are pipetted into a suitable vessel, for example a 300 ml Erlenmeyer flask, and diluted with 25 ml of demineralized water. The mixture is then titrated with 0.1 M NaOH to a pH of 9. The consumption in ml per 10 ml of the diluted phosphating composition corresponds to the total acid score (GS). Acid value (S value): (Please refer W. Rausch "The phosphating of metals", Eugen G. Leuze Verlag, 3rd edition, 2005, chapter 8.4, p. 338 )
• S value stands for the ratio FS: GSF and is obtained by dividing the value of the free acid (FS) by the value of the total acid according to Fischer (GSF).
• a temperature of the phosphating composition of less than 45 ° C, preferably in the range between 35 and 45 ° C, leads to further improved corrosion and paint adhesion values.
• the metallic surface is treated with the phosphating composition preferably for 30 to 480, particularly preferably for 60 to 300 and very particularly preferably for 90 to 240 seconds, preferably by dipping or spraying.
• the following preferred and particularly preferred zinc phosphate layer weights are applied to the surface, depending on the surface being treated metallic surface (determined using X-ray fluorescence analysis (XRF)): Treated surface Zinc phosphate layer weight (g/m 2 ) steel 0.5 to 6 1 to 5 Hot-dip galvanizing 1.0 to 6 1.5 to 5 electrolytic galvanizing 1.0 to 6 1.5 to 5 aluminum 0.5 to 6 1 to 5
• XRF X-ray fluorescence analysis
• the metallic surface is preferably rinsed with the phosphating composition, more preferably rinsed with deionized water or city water.
• the metallic surface that has already been treated with the phosphating composition i.e. phosphate-coated, is further treated with an aqueous rinsing composition.
• the metallic surface is optionally dried before treatment with the rinsing composition.
• the rinse composition can be obtained from a concentrate by diluting it with a suitable solvent, preferably water, by a factor between 1.5 and 1000, preferably between 5 and 700, and if necessary adding a pH-modifying substance.
• a suitable solvent preferably water
• the electrical conductivity of the phosphate-coated metal surface can be specifically adjusted by creating defined pores in the phosphate layer.
• the conductivity can be either greater than, equal to or less than that of a corresponding metal surface provided with a nickel-containing phosphate coating.
• the set electrical conductivity of the phosphate-coated metal surface can be influenced by varying the concentration of a given metal ion or polymer in the rinsing composition.
• the rinse composition contains at least one type of metal ion selected from the group consisting of the ions of the following metals in the following preferred, particularly preferred and very particularly preferred concentration ranges (all calculated as the corresponding metal): Mo 1 to 500 mg/l 10 to 250 mg/l 20 to 150 mg/l Cu 1 to 1000 mg/l 100 to 500 mg/l 150 to 225 mg/l Ag 1 to 500 mg/l 5 to 300 mg/l 20 to 150 mg/l Ow 1 to 500 mg/l 10 to 300 mg/l 20 to 200 mg/l Pd 1 to 200 mg/l 5 to 100 mg/l 15 to 60 mg/l Sn 1 to 500 mg/l 2 to 200 mg/l 3 to 100 mg/l Sb 1 to 500 mg/l 2 to 200 mg/l 3 to 100 mg/l Ti 20 to 500 mg/l 50 to 300 mg/l 50 to 150 mg/l Zr 20 to 500 mg/l 50 to 300 mg/l 50 to 150 mg/l Hf 20 to 500 mg/l 50 to 300 mg/l 50 to 150 mg/l Hf 20 to 500
• the metal ions contained in the rinsing composition separate either in the form of a salt, which contains the corresponding metal cation (e.g. molybdenum or tin) preferably in at least two oxidation states - in particular in the form of an oxide hydroxide, a hydroxide, a spinel or a defect spinel - or elementally on the surface to be treated (e.g. copper, silver, gold or palladium).
• a salt which contains the corresponding metal cation (e.g. molybdenum or tin) preferably in at least two oxidation states - in particular in the form of an oxide hydroxide, a hydroxide, a spinel or a defect spinel - or elementally on the surface to be treated (e.g. copper, silver, gold or palladium).
• the metal ions are molybdenum ions. These are preferably added to the rinsing composition as molybdate, more preferably as ammonium heptamolybdate and particularly preferably as ammonium heptamolybdate x 7 H 2 O.
• the molybdenum ions can also be added as sodium molybdate.
• Molybdenum ions can, for example, also be added to the rinsing composition in the form of at least one salt containing molybdenum cations, such as molybdenum chloride, and then oxidized to molybdate by a suitable oxidizing agent, for example by the accelerators described above.
• a suitable oxidizing agent for example by the accelerators described above.
• the rinse composition itself contains a corresponding oxidizing agent.
• the invention contains molybdenum ions in combination with zirconium ions and optionally a polymer or copolymer, in particular selected from Group consisting of the polymer classes of polyamines, polyethyleneamines, polyanilines, polyimines, polyethyleneimines, polythiophenes and polypryrols as well as their mixtures and copolymers and polyacrylic acid, the content of molybdenum ions and zirconium ions each being in the range from 10 to 500 mg/l (calculated as metal). .
• a polymer or copolymer in particular selected from Group consisting of the polymer classes of polyamines, polyethyleneamines, polyanilines, polyimines, polyethyleneimines, polythiophenes and polypryrols as well as their mixtures and copolymers and polyacrylic acid, the content of molybdenum ions and zirconium ions each being in the range from 10 to 500 mg/l (calculated as metal). .
• the molybdenum ion content is preferably in the range from 20 to 150 mg/l, particularly preferably from 25 to 100 mg/l and very particularly preferably from 30 to 75 mg/l and the zirconium ion content is in the range from 50 to 300 mg/l. l, particularly preferably from 50 to 150 mg/l.
• Copper ions are preferably also present in the rinsing solution.
• the rinse solution then preferably contains this in a concentration of 100 to 500 mg/l, more preferably 150 to 225 mg/l.
• the rinse composition according to the invention contains at least one polymer selected from the group consisting of the polymer classes of polyamines, polyethyleneamines, polyanilines, polyimines, polyethyleneimines, polythiophenes and polypyroles as well as mixtures and copolymers thereof.
• the at least one polymer is preferably in a concentration in the range from 0.1 to 5 g/l, more preferably from 0.1 to 3 g/l, more preferably from 0.3 to 2 g/l and particularly preferably in the range from 0.5 to 1.5 g/l (calculated as pure polymer).
• Cationic polymers in particular polyamines, polyethyleneamines, polyimines and/or polyethyleneimines, are preferably used as polymers.
• the rinse composition according to the invention contains at least one type of metal ion selected from the group consisting of the ions of molybdenum, copper, silver, gold, palladium, tin, antimony, titanium, zirconium and hafnium and at least one polymer selected from the Group consisting of the polymer classes of polyamines, polyethyleneamines, polyanilines, polyimines, polyethyleneimines, polythiophenes and polypryrols and their Mixtures and copolymers, each in the following preferred, particularly preferred and very particularly preferred concentration ranges (polymer calculated as pure polymer and metal ions calculated as the corresponding metal).
• metal ion selected from the group consisting of the ions of molybdenum, copper, silver, gold, palladium, tin, antimony, titanium, zirconium and hafnium
• the at least one polymer is a cationic polymer, in particular a polyamine and/or polyimine, and the metal ions are copper ions, molybdenum ions and/or zirconium ions, each in the following preferred, particularly preferred and very particularly preferred concentration ranges ( Polymer calculated as pure polymer and metal ions calculated as corresponding metal).
• Mo 1 to 500 mg/l 10 to 250 mg/l 20 to 150 mg/l Cu 1 to 1000 mg/l 100 to 500 mg/l 150 to 225 mg/l Zr 20 to 500 mg/l 50 to 300 mg/l 50 to 150 mg/l cat.
• the rinsing composition comprises - particularly if the metallic surface is aluminum or an aluminum alloy - preferably additionally 20 to 500 mg/l, more preferably 50 to 300 mg/l and particularly preferably 50 to 150 mg/l Ti, Zr and /or Hf in complexed form (calculated as metal). These are preferably fluoro complexes.
• the rinse composition preferably comprises 10 to 500 mg/l, more preferably 15 to 100 mg/l and particularly preferably 15 to 50 mg/l of free fluoride.
• the rinse composition particularly preferably contains Zr in complexed form (calculated as metal) and at least one type of metal ion selected from the group consisting of the ions of molybdenum, copper, silver, gold, palladium, tin and antimony, preferably molybdenum.
• the pH of the rinse composition is preferably in the acidic range, more preferably in the range from 3 to 5, particularly preferably in the range from 3.5 to 5. Surprisingly, it was found that lowering the pH causes the deposition of molybdenum ions on the phosphate-coated metallic surface promotes. In the case of a rinsing solution containing molybdenum ions, the pH value is therefore preferably 3.5 to 4.5 and particularly preferably 3.5 to 4.0.
• the rinse composition is essentially nickel-free. It preferably contains less than 0.1 g/l and particularly preferably less than 0.01 g/l nickel ions.
• the rinsing composition preferably has a temperature in the range from 15 to 40 ° C.
• the metallic surface is treated with the rinsing composition preferably for 10 to 180, particularly preferably for 20 to 150 and very particularly preferably for 30 to 120 seconds, preferably by dipping or spraying.
• An electrophoretic paint can then be deposited cathodically and a paint structure can be applied to the phosphate-coated metallic surface - as well as the metal surface that may have been treated with the rinsing composition.
• the metallic surface is first rinsed, preferably with deionized water, and optionally dried.
• the present disclosure further relates to the alkaline, aqueous, but unclaimed, cleaning composition described above, which contains at least one water-soluble silicate, as well as to the concentrate described at the relevant point from which this cleaning composition is available.
• the disclosure also relates to an unclaimed phosphate-coated metallic surface, which is obtainable using the method according to the invention.
• the invention also relates to the use of the method in the automotive sector, automotive suppliers or general industry.
• the cleaning bath F and the cleaning bath G were also prepared.
• the cleaning bath F was identical to the cleaning bath B with the exception of the pH value of 10.5, while the cleaning bath G was identical to the cleaning bath E with the exception of the pH value of 10.5.
• the pH value for both cleaning baths F and G was adjusted with phosphoric acid.
• the following rinsing bath was prepared by mixing H 2 ZrF 6 and ammonium heptamolybdate in demineralised water and adjusting the pH with dilute ammonia solution: component Contents (mg/l) Zr 130 Mo 50 PH value 4
• test sheets ii) Treatment of test sheets:
• Test sheets made of hot-dip galvanized steel (EA), electrolytically galvanized steel (G) and the aluminum alloy AA 6014 (AI) were immersed in one of the cleaning baths A to D for 300 seconds at 60 °C and then in an activation bath at 25 °C for 30 seconds , which contained 0.6 g/l zinc phosphate.
• the test panels were then immersed in one of the phosphating baths A' to C' for 180 seconds at 45 °C and then in the rinsing bath described above for 30 seconds at 25 °C. After thoroughly rinsing with demineralized water, the test panels were coated with a cathodic electrophoretic paint and a standard automotive paint composition (filler, base coat, clear coat).
• test panels pretreated and painted in this way were then subjected to a cross-cut test in accordance with DIN EN ISO 2409. Three sheets were tested before and after exposure to condensation for 240 hours (DIN EN ISO 6270-2 CH).
• test panels made of electrolytically and hot-dip galvanized steel were subjected to a VDA test (VDA 621-415; 10 rounds), whereby the paint infiltration (U) was determined in mm as well as the paint detachment after stone chipping (DIN EN ISO 20567-1, Author C) was determined.
• U paint infiltration
• DIN EN ISO 20567-1, Author C paint detachment after stone chipping
• a result of 0 is the best
• a result of 5 is the worst value after a rockfall.
• a value of up to 1.5 is considered a good value.
• the results (average values from three sheets) are also summarized in Table 2 . ⁇ b>Table 2 ⁇ /b> (cf.-) Ex. Subst. Clean. Phosph.

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• 2018
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