Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/34—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
  • C23C22/361—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 titanium, zirconium or hafnium compounds
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/40—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 molybdates, tungstates or vanadates
  • C23C22/44—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 molybdates, tungstates or vanadates containing also fluorides or complex fluorides
• • 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
• • 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
  • 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

Definitions

• the invention relates to a process for the coating of metallic surfaces with an optionally colored conversion layer, in particular for the replacement of an alkali phosphating such as e.g. an iron phosphating, correspondingly coated substrates with metallic surfaces and the use of these coated substrates.
• an alkali phosphating such as e.g. an iron phosphating
• the fresh, not yet used alkali metal phosphate solutions usually have virtually no or only a very low content of aluminum, iron and zinc.
• the aqueous acidic alkali metal phosphate solutions contain, in addition to ions of at least one alkali metal or / and ammonium, also phosphate ions and, due to the staining effect of these solutions on the metallic surfaces, ion contents of the metals dissolved out of the metallic surfaces, e.g. Aluminum, iron or / and zinc as well as traces of alloy components of the recommended metallic materials.
• the phases mainly formed in the alkali phosphate layer in alkali phosphating are the corresponding phosphates, oxides or / and hydroxides of the metals from the surfaces of the base substrates to be treated.
• Alkaline phosphate solutions or coatings are also referred to as iron phosphate solutions or coatings when used on iron and steel materials.
• alkali phosphate coatings are generally also referred to as layers of the so-called “non-layer-forming phosphating". This designation is misleading since layers are also formed here, but they are significantly thinner than other phosphate layers such as the different types of zinc phosphating.
• the alkali phosphate solution always contains an increased content of at least one alkali metal such as sodium or / and ammonium.
• Alkaline phosphations can usually be carried out in a simple and inexpensive manner.
• high quality alkali phosphate coatings show only limited corrosion protection, usually a) not better than, i.e., better than, corrosion protection.
• the object was to find aqueous compositions which can be applied in a simple manner, which are composed as environmentally friendly as possible and which give a higher corrosion protection than high-quality Alkaliphos- phosphate coatings.
• the object is achieved by a method for coating metallic surfaces with an acidic aqueous conversion composition, which is a solution or dispersion characterized in that it contains:
• particulate SiO 2 having an average particle diameter ⁇ 0.3 ⁇ m, measured on a scanning electron microscope and based on the solids content
• the content of molybdate is calculated as MoO 4 2+ or / and the content of P-containing oxyanions calculated as PO 4 3+ is in each case ⁇ 0.1 g / L or approximately 0 g / L and wherein the acidic aqueous composition has a pH in the range of 2.5 to 6.5, and preferably in the range of 3.0 to 5.5.
• the ions of TiF 6 2+ , ZrF 6 2+ or / and HfF 6 2+ are largely equivalent and interchangeable in the acidic aqueous conversion composition, but in many cases the ions of ZrF 6 2+ give the best properties of the conversion coating produced herewith.
• the content of the acidic aqueous conversion composition of TiF 6 2+ , ZrF 6 2+ or / and HfF 6 2+ is 0.05 to ⁇ 1 g / L, 0.1 to 0.8 g / L, 0.15 to 0.50 g / L or 0.20 to 0.33 g / L.
• a cation content of the aqueous acidic composition only conversion of Fe 2+ ions, based on the total content of Fe 2+ - at least partially derived, Mn and Zn ions, this content from a deliberate addition.
• the ions of manganese and zinc, and to a limited extent Fe 2+, are largely equivalent and interchangeable in the acidic aqueous conversion composition, but many times the ions of manganese and / or zinc give the best properties of the conversion coating produced therewith.
• manganese and zinc are added to the acidic conversion aqueous composition, it is particularly preferable to obtain a manganese content higher than the zinc content.
• It preferably contains 0 or 0.01 to 0.3 g / L or 0.02 to 0.15 g / L of Fe 2+ ions and 0.01 to 1 g / L of Mn ions and / or 0, 01 to 1 g / L or 0.1 to 0.6 g / L of Zn ions. More preferably, it contains 0.1 to 0.6 g / L or 0.2 to 0.4 g / L of Mn ions and / or 0.1 to 0.6 g / L or 0.2 to 0.4 g / L of Zn ions.
• phosphate-free ⁇ 0.1 g / L PO 4
• completely phosphate-free about 0 or exactly 0 g / L PO 4
• a content of phosphate calculated as PO 4 3+ between 0.001 and ⁇ 0.1 g / L can not be excluded, in particular due to entrainment and impurities.
• organic polymer or / and organic copolymer can contribute to the fact that the properties of the conversion coating produced herewith can be further improved and that, if necessary, a subsequent coating can be dispensed with.
• the content of the acidic organic polymer or / and organic copolymer conversion composition is 0.01 to 3 g / L, 0.1 to 2.5 g / L, 0.2 to 2 g / L, 0.4 to 1, 5 g / L or 0.6 to 1, 2 g / L.
• the organic polymer and / or copolymer is preferably one based on (meth) acrylate / (meth) acrylic acid and / or vinyl acetate-acrylic copolymer. In the absence of a coating, it is possible to speak of passivation layer in the coating produced and of blank corrosion protection in the case of corrosion protection.
• ultrafine particulate SiO 2 (in particular ⁇ 0.3 ⁇ m), for example SiO 2 nanoparticles, can show a similar positive effect as an addition of organic polymer or / and organic copolymer, but often with the difference that the layer formation and thus the coating is even more uniform with SiO 2 .
• At least one nonionic, anionic, cationic or / and zwitterionic surfactant can be added.
• An addition of at least one nonionic surfactant is particularly preferred here.
• an addition of anions selected from the group consisting of carbonate, nitrate and sulfate often takes place via the addition of cations via water-soluble salts.
• nitrates are particularly preferred.
• carboxylate anions for example via acetic acid or / and via a manganese carboxylate
• carboxylate anions for example via acetic acid or / and via a manganese carboxylate
• carboxylic acids and their derivatives such as salts and esters, which are water-soluble, can be added are stable to the pH range, which do not have a complicated composition of matter which form anions in water which, depending on the nature and amount of the anions, do not impair the film formation and which, if appropriate, complex alkali or / and alkaline earth metal ions which do not participate in the film formation.
• aliphatic carboxylic acids and mono-, di- and / or polycarboxylic acids such as hydroxycarboxylic acids.
• carboxylate anions care must be taken to ensure that they do not impair the formation of layers, since, for example, citrate and some other complexing agents may, depending on the type and amount of anions, impair the layer formation.
• an addition of at least one sulfonic acid such as, for example, methanesulfonic acid, amidosulfonic acid or / and one of its derivatives may be advantageous in order to act as an accelerator and / or as a further counterion.
• a content of molybdate is calculated as MoO 4 of 0 or in the range of 0.01 to ⁇ 0.5 g / L, in particular from 0.02 to 0.3 or g / L, from 0.01 to ⁇ 0, 1 g / L preferred.
• An addition of molybdate has proven itself only at very low addition levels.
• P-containing oxyanions e.g. Orthophosphate, condensed phosphates and phosphonates
• P-containing oxyanions e.g. Orthophosphate, condensed phosphates and phosphonates
• P-containing oxyanions it is preferred for reasons of environmental compatibility and the avoidance of disposal that no content of P-containing oxyanions is added, and it is preferably to ensure that as far as possible no content of P-containing oxyanions is introduced ,
• the acidic aqueous composition optionally additionally contains, consists essentially of or consists of: 0.03 to 5 g / L of the sum of ions of lithium, sodium and / or potassium, 0 or 0.05 to 5 g / L of ammonium ions,
• levels of lithium, sodium, potassium or / and ammonium are usually unavoidable in order to achieve charge balance and to control not only multivalent cations, e.g. Add heavy metal ions.
• monovalent cations sodium ions are particularly preferred. They are largely equivalent and interchangeable in the acidic aqueous conversion composition and often necessary for pH regulation.
• An addition to at least one accelerator is sometimes beneficial, in particular an addition of a chlorate, nitrite or / and peroxide. In this case, however, to pay attention to the appropriate amount, for example, to a content of NO 2 of significantly less than 1 g / L.
• the layer formation can be accelerated and the properties of the coating produced thereby improved.
• an overdose of accelerator should be avoided in order not to impair the film formation as in Example B40. Addition of nitroguanidine has not proved beneficial.
• At least one vanadium compound can significantly increase the corrosion protection.
• further elemental contents of the metallic surfaces of the substrates and of the systems can be introduced into the bath by pickling of the acidic aqueous conversion composition and optionally also accumulate in the bath composition, in particular Fe 2+ ions and alloying elements or their ions.
• levels of ions and substances from other plant areas for example from a previously used purification step, may be introduced in small quantities despite rinsing with water.
• contents of alkali metals, ammonium, complexing agents, surfactants, anionic impurities of the cleaning bath or / and further impurities or of their ions can be introduced into the bath composition according to the invention.
• a separate preceding purification step is not necessarily provided, so that foreign ion input by a chemical treatment solution can be largely excluded.
• a cleaning step can be carried out with surfactant-containing water and without a scaffold (builder).
• the cleaning may be carried out before the conversion coating so that it is cleaned before contacting the substrate with the aqueous composition, in particular with an alkaline cleaning.
• the aqueous composition may also contain at least one surfactant, so that the cleaning and conversion coating takes place (also) in the same process step.
• the aqueous conversion composition preferably contains no content or only a low content, such as in each case up to 0.1 g / L of carboxylic acids, phosphates, phosphonates or / and of compounds and / or ions of calcium, chromium, chromate, cobalt, copper, Magnesium, molybdenum, nickel, vanadium or / and tin and / or of silane / silanol / siloxane / polysiloxane deliberately added.
• a low content such as in each case up to 0.1 g / L of carboxylic acids, phosphates, phosphonates or / and of compounds and / or ions of calcium, chromium, chromate, cobalt, copper, Magnesium, molybdenum, nickel, vanadium or / and tin and / or of silane / silanol / siloxane / polysiloxane deliberately added.
• Silane / silanol / siloxane / polysiloxane means silane, silanol, siloxane or / and polysiloxane, because in water and in coating, for example starting from a silane, silanols or / and siloxanes can very quickly result, which sometimes also - depending on the chemical definition - Can give polysiloxanes.
• the content of the acidic aqueous conversion composition of alkaline earth metals such as calcium or / and magnesium is preferably not higher than 0.2 g / L together to avoid precipitation in the presence of fluorides as much as possible.
• the acidic aqueous conversion composition has a pH in the range of 2.5 to 6.5 and contains, consists essentially of or consists of:
• each of Fe 2+ , Mn and / or Zn ions of which at least one kind of these ions in the content range of 0.01 to 1 g / L is contained, and optionally 0 , 01 to 2 g / L of particulate SiO 2 with a mean particle diameter diameter ⁇ 0.3 ⁇ , based on the solids content and / or
• each of Fe 2+ , Mn and / or Zn ions of which at least one kind of these ions is contained in the content range of 0.01 to 1 g / L, and 0, 01 to 2 g / L of organic polymer and / or copolymer which is stable at a pH ⁇ 6.5, based on the solids content,
• particulate SiO 2 having a mean particle diameter ⁇ 0.3 ⁇ m, based on the solids content
• a content of molybdate calculated as MoO 4 2+ or / and a content of P-containing oxyanions calculated as PO 4 3+ is in each case ⁇ 0.1 g / L or about 0 g / L.
• each of Fe 2+ , Mn and / or Zn ions of which at least one kind of these ions is contained in the content range of 0.01 to 1 g / L, and a content calculated on molybdate as MoO 4 2+ in the range of 0.01 to ⁇ 0.5 g / L and optionally 0.01 to 2 g / L of organic polymer and / or copolymer, which at a pH ⁇ 6.5 is stable, based on the solids content,
• a content of molybdate calculated as MoO 4 2+ in the range of 0.01 to ⁇ 0.5 g / L and a content of P-containing oxyanions calculated as PO 4 3+ ⁇ 0.1 g / L or about 0 g / L is.
• Mn and / or Zn ions are added, while the content of Fe 2+ ions is preferably leached out of the iron-rich metallic substrate only by a pickling effect of the acidic conversion composition. If necessary, the coating is then painted at least once.
• an acidic aqueous conversion composition that is a solution or dispersion that contains, consists essentially of or consists of:
• Type of these ions is contained in the content range of 0.01 to 1 g / L,
• particulate SiO 2 having an average particle diameter ⁇ 0.3 ⁇ m, measured on a scanning electron microscope and based on the solids content
• the content of molybdate is calculated as MoO 4 2+ or / and the content of P-containing oxyanions calculated as PO 4 3+ is in each case ⁇ 0.1 g / L or approximately 0 g / L and wherein the aqueous composition has a pH Value in the range of 2.5 to 6.5, and preferably in the range of 3.0 to 5.5.
• the acidic aqueous composition contains, consists essentially of or additionally consists of:
• the bath composition according to the invention may preferably be prepared by diluting one or two concentrates with water by a dilution factor in the range from 5: 1 to 40: 1.
• the second concentrate could, for example, contain at least one surfactant and also be aqueous.
• Fluoride can also be added as monofluoride, as bifluoride or / and in the form of the corresponding acids.
• the content of free fluoride is often in the range of 0.01 to 0.2 g / L.
• the acidic aqueous conversion composition is worked with city water having a conductance of, for example, about 200 to 600 S / cm, or with demineralized water, both for the makeup and for supplementing the liquid level in the bath, as well as for the first rinse the conversion coating.
• a demineralised water rinse with demineralized water is only required as a final rinse by default, to prevent the salt load from drying up, which can lead to inferior corrosion protection.
• HDG hot-dip galvanized sheet steel
• CRS cold rolled steel
• the properties of the coating on hot-dip galvanized steel sheets are often improved.
• a content of Fe 2+ ions often does not deteriorate the properties of the coating, but it turns out that Fe 2+ ions are gradually oxidized to Fe 3+ and settle as bath sludge. Therefore, it is preferred that the acidic aqueous conversion composition has a content of manganese and / or zinc ions.
• a surfactant-containing aqueous composition may help to further improve cleaning either after degreasing and / or pickling, or at least to dispense with degreasing prior to conversion coating so that one-pot operation can be carried out to remove and eliminate the cleaning step Frame of the conversion coating takes place.
• At least one substrate having metallic surfaces be contacted with the aqueous composition for a time in the range of 1 second to 10 minutes, more preferably 0.5 to 10 minutes in the treatment of parts.
• it is particularly preferably brought into contact for a period of time in the range from 1 to 10 minutes, in particular during dipping or, preferably, from 0.5 to 6 minutes, in particular during spraying.
• the same treatment times as in Alkaliphosphatieren can be used in these compositions, which means a switch from systems of an alkali phosphating on the inventive Conversion coating facilitates. Because alkaline phosphating often takes 3 to 5 minutes.
• composition according to the invention can also be applied to tape, if rinsing is still carried out with water after the band coating (rinse method).
• the metallic tape is preferably contacted with the aqueous composition for a time in the range of 1 second to 2 minutes.
• the substrate having metallic surfaces when in contact with the aqueous composition has a temperature in the range of 5 to 90 ° C and preferably in the range of 15 to 70 ° C or 30 to 60 ° C.
• the aqueous composition has a temperature in the range of 35 to 70 ° C or 45 to 60 ° C when contacted with the metallic surface substrate.
• the object is also achieved with a coated substrate with metallic surfaces, which has been coated according to the invention.
• the coating produced thereby has a layer thickness of 0.3 to 3 ⁇ m and / or that the sum of the coating of elementarily measured zirconium and / or titanium in the conversion coating is in the range from 1 to 300 mg / m 2 or preferably in the range of 15 to 150 mg / m 2 , measured with an X-ray fluorescence system (RFA).
• RFA X-ray fluorescence system
• the coating produced hereby is colored, iridescent or gray.
• interference colors of FIG. 1 occur. or a higher order or colors where the interference color is superimposed with the color of ions. These colours are similar or similar to an alkali phosphate coating. The colors often help to approximate the thickness and in part the uniformity and / or quality of a coating. If this is possible even with a larger viewing distance, this is particularly advantageous in a coating process.
• the conversion coating according to the invention produced therewith is subsequently rinsed with water or with an aqueous rinsing solution, in particular with a content of silane, organic polymer or / and organic copolymer, and optionally also varnished.
• aqueous rinse solutions such as with Gardolene ® D95 with a content of phenolic resin, or with Gardolene ® D6890 based on silane.
• the aqueous rinsing solution particularly preferably contains a content of at least one a) cation selected from alkaline earth metal, aluminum, titanium, yttrium and heavy metal cations, b) organic polymer or / and copolymer, c) silane, silanol, siloxane or / and Polysiloxane and / or d) complex fluoride, wherein complex fluoride is also the corresponding fluorine-containing acid.
• Particularly preferred silanes here are aminosilanes having one, two or even more amino groups and / or bis-silyl silanes.
• a coating is applied with an aqueous acidic composition according to the invention, optionally followed by rinsing with water and / or rinsing with an aqueous composition, if appropriate, and then the at least one coating produced in this way is subsequently painted at least once.
• aqueous acidic composition based on from 0.01 to 1 g / L of TiF 6 2+ , ZrF 6 2+ or / and HfF 6 2+ or only ZrF 6 2+ in Form of lo- calculated as ZrF 6 2+ and 0 or 0.01 to 1 g / L each of Fe 2+ , Mn and / or Zn ions, of which at least one kind of these ions in the content range of 0.01 to 1 g / L is contained, and optionally 0.01 to 2 g / L of particulate SiO 2 having an average particle diameter ⁇ 0.3 ⁇ , based on the solids content and / or optionally 0.01 to 10 g / L of at least one surfactant, which is essentially phosphate-free and substantially phosphonate-free, a coating is applied, if appropriate subsequently rinsed with water and / or optionally thereafter with an aqueous composition based on zirconium
• a surfactant content in the aqueous acidic composition according to the invention may optionally be dispensed with a prior purification stage.
• the conversion coating according to the invention produced herewith if it contains no organic polymer and no organic copolymer, can preferably be dried without subsequent rinsing with water or preferably with an aqueous rinsing solution, in particular containing silane, organic polymer or / and organic copolymer, and optionally also to be painted.
• the conversion coating according to the invention produced herewith may alternatively, if it contains organic polymer and / or copolymer, preferably be used without a coating with a primer, lacquer or adhesive.
• the conversion coating produced hereby according to the invention may, if appropriate after at least one rinse with water and / or with an aqueous rinsing solution, be coated at least once with a primer, lacquer or adhesive.
• the coating produced hereby can excellently provide a replacement for an alkali phosphate coating such as e.g. represent an iron phosphate coating.
• the at least one substrate with metallic surfaces which has been coated according to the invention is preferably used as an architectural element, as a container, as a construction or connection element, as a profile element, as a radiator element, as a more complicated molded part or / and as a component in construction, energy technology, vehicle construction , Appliances, Home Appliances or Mechanical Engineering.
• composition according to the invention and the process according to the invention are particularly advantageous in the chemical pretreatment of surfaces of various steel substrates used in the metalworking industry. find a turn. This can even be cleaned in one step and at the same time a coatable conversion layer can be applied, to which this three-stage treatment method from cleaning with conversion coating, flushing with city water and rinsing with fully desalinated water is completely sufficient. Especially the bath analysis is very easy to handle, since a precise determination of the anions and cations is rarely necessary, since the pH value and the conductivity provide sufficient information on the chemical bath state.
• the process according to the invention can be used to produce a colored, iridescent, gray or colorless (as in B40) passivation layer (without coating) or a colored, iridescent, gray or colorless (as in B40) conversion coating (with coating).
• a passivation layer is also a conversion-produced coating. Therefore, the term "conversion coating” in the context of this application also includes the term “passivation layer” as long as or when no coating is applied, e.g. even with the claims.
• the process according to the invention can be used as a replacement for an alkali phosphating process or even as a substitute for a zinc phosphating process.
• the products produced by the process according to the invention can be used in a variety of ways, in particular as an architectural element, as a container, as a construction or connecting element, as a profile element, as a radiator element, as a more complicated molded part or / and as a component in construction, power engineering, vehicle construction , Appliances, household appliances or mechanical engineering and, for example, as a radiator, as racks, as plates, as panels, as angles or as components in the vehicle or aircraft interior.
• Aqueous conversion compositions according to Table 1 were prepared.
• the surfactant used was a nonionic surfactant Gardobond ® Additive H7438, which provided additional cleaning of the metal surface.
• the alkaline, with potassium hydroxide stabilized SiO 2 dispersion Gardobond ® additive H 7157 Chemetall GmbH had a solids content of 20% and an average particle size of 0.2 ⁇ .
• the polymer dispersion 1 AC 2773 based on acrylate from Alberdingk had a solids content of 53%.
• the acrylate-containing copolymer dispersion 2 VA 294 VP from Alberdingk had a solids content of 47%.
• the acrylate-containing copolymer dispersion 3 AS 2084 VP from Alberdingk had a solids content of 53% solids.
• Polymer, copolymer, SiO 2 particles and / or surfactant were added to the previously prepared aqueous conversion composition separately at the end of the mixing operation. In individual experiments, ammonium molybdate was added.
• a lacquer layer on the conversion-coated panels was thereafter each applied: either an epoxy polyester powder coating Interpon ® 700 from Akzo Nobel Powder Coatings GmbH ⁇ in a layer thickness of 60 to 80, a wet paint Alexit ® monolayer on the basis of polyurethane and isocyanate of Mankiewicz in a layer thickness of 60 to 80 ⁇ or a black cathodic dip coating Cathoguard ® 350 BASF in a layer thickness of 15 to 20 ⁇ in Example B3 or in Examples B45 to B48 cathodic dip coating Cathoguard ® 800 (KTL) from BASF in one Layer thickness of 15 to 20 ⁇ and then each one layer of a car body after Daimler Benz from 25-30 ⁇ filler, 1 1 -15 ⁇ basecoat and 40-50 ⁇ clearcoat.
• Interpon ® 700 from Akzo Nobel Powder Coatings GmbH ⁇ in a layer thickness of 60 to 80
• a wet paint Alexit ® monolayer on the basis of polyurethane and is
• the paint adhesion of the painted samples was determined in the cross-hatching method in accordance with DIN EN ISO 2409 before or after 240 h of a change in climate change.
• the corrosion resistance of the painted samples was determined in the salt spray test according to DIN 50021 for 500 hours in the neutral salt spray test NSS. Unlike in the Asian and North American market, only a single layer of varnish was applied.
• Table 1 Overview of the compositions of the aqueous baths and the properties of the associated coated samples and coatings
• the aqueous conversion compositions according to the invention give excellent coatings which have excellent corrosion resistance under these conditions, excellent paint adhesion and, in most cases, a clear color. Both strongly colored and colorless coatings can be produced with these compositions.
• the corrosion resistance on steel surfaces is almost as good as that of high grade zinc phosphating and thus far superior to high corrosion alkali phosphating (e.g., B3 vs. VB1).
• the coating properties were determined only after an additional second conversion treatment-unlike the examples according to the invention.
• the paint adhesion on steel surfaces is even as good as that of a high-quality zinc phosphating and thus the paint adhesion of a high-quality alkali phosphating very clearly superior.
• the aqueous conversion compositions according to the invention are composed quite environmentally friendly, work-hygiene advantageous and phosphate-free.
• a rinse solution e.g. was used with a content of silane, organic polymer and / or organic copolymer after the conversion coating according to the invention and after at least one rinsing with water, a paint adhesion was achieved on steel surfaces, which is at least as good as that of a high-quality zinc phosphating, and was achieves corrosion resistance at least as good as zinc phosphating.
• the acidic aqueous conversion compositions according to the invention are outstandingly suitable for the replacement of alkali phosphating on various metallic substrate surfaces and not only for iron phosphating on iron and steel surfaces. This has even resulted in a multimetal ability in the treatment, so that a mix of different types of metallic surfaces in the same bath can be treated simultaneously or successively.
• Fe 2+ can be replenished from the substrate by a reaction-related pickling process from the bath of iron-containing substrate surfaces. However, this is then often oxidized by the Badumicalzung to Fe 3+ and removed from the bath as a reactive constituent. Despite the addition of Fe 2+ , a steady state Fe 2+ concentration frequently occurs in the range of 0.025 to 0.1 g / L Fe 2+ , as in Examples B41 and B42.
• the main elements and a part of the alloying elements are leached out in the acidic aqueous conversion composition and can partially accumulate in the bath composition, then it is common for a plurality of cations to be present in the bath at the same time to the cooperation composition of the coating and subordinate to their properties.
• Zn and Mn are deposited only in non-measurable quantities based on measurements with X-ray fluorescence analysis.
• Zr is the main constituent of the layer and may be present as (Zr (OH) x F y ), for example.
• Zn often acts as a fluoride scavenger in the metal-cladding interface, allowing less fluoride to be incorporated into the layer, which Applicant understands to give better results.
• Zn and Mn are only minor constituents of the layer and can therefore be detected more accurately analytically only by XPS / ESCA photoelectron spectroscopy.
• the produced properties of the coatings are often best when the Zr support is highest in comparable experiments.
• the Zr overlay is different for different steel grades and also for the same steel grade with different surface properties.

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