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
  • C23C22/364—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
  • C23C22/07—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
  • C23C22/18—Orthophosphates containing manganese cations
  • C23C22/182—Orthophosphates containing manganese cations containing also zinc cations
  • C23C22/184—Orthophosphates containing manganese cations containing also zinc cations containing also 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

Definitions

• the invention relates to a phosphating solution and a phosphating process for phosphating metal surfaces.
• This is a layer-forming phosphating, due to the on the metal surface firmly grown crystalline metal phosphate layers are generated. This improve corrosion resistance especially related to a subsequent painting and increase the adhesion of the paint on the Metal surface.
• the present invention further develops the phosphating process described in WO 95/07370.
• This document discloses a process for phosphating metal surfaces with aqueous, acidic phosphating solutions which contain zinc, manganese and phosphate ions and as accelerators hydroxylamine or a hydroxylamine compound and / or m-nitrobenzenesulfonic acid or its water-soluble salts, characterized in that the metal surfaces are mixed with in contact with a phosphating solution which is free of nickel, cobalt, copper, nitrite and oxo anions from halogens and which 0.3 to 2 g / l Zn (II) 0.3 to 4 g / l Mn (II) 5 to 40 g / l phosphate ions 0.1 to 5 g / l hydroxylamine in free or bound form and / or 0.2 to 2 g / l M-nitrobenzenesulfonate and at most 0.5 g / l nitrate
• a phosphating process is sought in which the phosphating solution contains the lowest possible levels of accelerator and with which the in materials occurring in practice are equally reliable even with a aged phosphating solution can be phosphated.
• the concentration increases Active components.
• the accelerator levels therefore decrease during the phosphating process. Even when you leave the bath accelerator levels may decrease due to spontaneous decomposition.
• the accelerator contents can also, if no dosing is made in time fall below the actually desired minimum limits. It can even be tolerated as long as no metal surfaces with the phosphating solution get in touch.
• the phosphate ions are only too low Partly as tertiary phosphate ions, but mainly as primary and secondary Phosphate ions in connection with free phosphoric acid.
• the determination of the content is phosphoric acid and all phosphate ions treated as if they were present as tertiary phosphate ions.
• hydroxylamine lies in accordance with its acid-base balance partly as free amine, partly in protonated form. It is therefore irrelevant whether you use hydroxylamine as a free base or in the form of a Salt. If hydroxylamine is used in salt form, this is particularly so Sulfate and the primary phosphate are suitable. Hydroxylamine can also be in the form of Compounds are present at the pH values mentioned hydroxylamine secede. Examples include acetaldehyde oxime and acetoxime (WO 96/16204).
• organic N-oxide is used as the organic nitrogen compound used, this is preferably selected from the group of the following compounds from: pyrridine-N-oxide, 2-methylpyrridine-N-oxide, 4-methylpyrridine-N-oxide, morpholine-N-oxide and N-methylmorpholine-N-oxide.
• One embodiment of the phosphating solution according to the invention is characterized in that it additionally contains 0.7 to 5 g / l nitrate ions. Nitrate ions act as co-accelerators and thereby improve the layer formation. It is part of the phosphating of galvanized steel It is recommended that the chloride content of the phosphating solution is not 100 mg / l exceeds. Otherwise there is a risk of white defects (specks) forming on certain galvanized steels.
• the nitrate concentration of the Keep phosphating solution below 0.5 g / l, which also helps Chloride contents above 50 mg / l white specks can be avoided.
• the phosphating solution additionally 0.001 to 3 g / l contains free and / or complex fluoride ions, but up to a maximum of 0.8 g / l free fluoride ions.
• This improves the phosphatability of hot-dip galvanized steel and in particular aluminum and its Alloys. Higher levels of free and / or complex fluoride ions can however lead to defects.
• Free fluoride ions are those that are hydrated Form in the aqueous solution. They can be in the form of hydrofluoric acid or in the form of soluble fluorides such as sodium, potassium or Ammonium fluoride can be used.
• complex fluoride ions Anions understood where 2 or more fluorine atoms are attached to a central atom are bound. As central atoms come in particular boron, silicon, titanium and Zircon in question. Hexafluorosilicate ions are particularly preferred.
• the complex Fluoride ions can be in the form of the free acid or in the form of water-soluble salts be introduced into the phosphating solution.
• the phosphating solution additionally one or both of the contains the following cations: 0.2 to 4 g / l of manganese ions and / or 0.05 to 2.5 g / l Nickel ions. From the wastewater point of view, the presence of nickel ions undesirable. Therefore, it may be preferable that the phosphating solution is none Contains nickel ions.
• nickel ions from phosphating waste water as far to remove and even regain that legal waste water limits for Germany are far below. If such a system is available, it is preferred that the phosphating solution both Contains manganese ions as well as nickel ions.
• the phosphating solution Hydroxylamine in free, ionic or bound form in the concentration range contained from 0.05 to 0.75 g / l. This cheapens the phosphating process and facilitates waste water treatment in particular. Phosphating problems that especially by a higher concentration of the breakdown products of the Accelerators can be avoided are avoided.
• the concentrations to couple the individual accelerators to each other the higher the Concentration of an accelerator, the lower the concentration of the other accelerator can be selected.
• the organic Nitrogen compound is present in maximum concentration.
• the individual components of the phosphating solution are preferably in following concentration ranges: zinc ions 0.5 to 2 g / l, manganese ions 0.5 up to 1.5 g / l, nickel ions 0.1 to 1.5 g / l, phosphate ions 10 to 20 g / l, nitrate ions 0.7 up to 2 g / l.
• the pH is preferably set in a range from 3 to 3.4 on. Except through the concentration information of the individual components Phosphating solutions often by the parameters "free acid” and "total acid” characterized. These terms are known to the person skilled in the art.
• the free Acidity can be determined, for example, by taking a bath sample diluted from 10 ml with water to 50 ml and with 0.1N sodium hydroxide solution up to a pH value of 3.8 titrated. The consumption in ml of sodium hydroxide solution indicates the content free acid in points. The content of is determined accordingly Total acidity in points by taking the bath sample up to a pH of 8.5 titrated.
• the free acid is preferably in the range between 0.3 and 1.5 Total acidity in the range between 15 and 30 points.
• an aqueous concentrate for Prepare or supplement a phosphating solution that is diluted with Water in the weight ratio concentrate: water in the range from 1: 5 to 1:30 gives a phosphating solution as described above.
• the present invention relates to a method for Phosphating of metal surfaces selected from surfaces of steel, galvanized or alloy galvanized steel, aluminized or alloy-aluminized steel or of aluminum or aluminum alloys
• a method for Phosphating of metal surfaces selected from surfaces of steel, galvanized or alloy galvanized steel, aluminized or alloy-aluminized steel or of aluminum or aluminum alloys
• the treatment time is preferably in the range from 2 to 4 Minutes.
• the phosphating solution preferably has a temperature in the Range from 40 to 55 ° C.
• the phosphating process according to the invention is in particular for this suitable, metal surfaces selected from surfaces of aluminized or alloy-aluminized steel or of aluminum or aluminum alloys consist of at least 50 atomic percent aluminum, alone or together with surfaces of steel, galvanized or alloy galvanized steel phosphatize. Even an aged bath does not lead to phosphating problems on aluminum surfaces, as is otherwise the case at higher concentrations of organic nitro compounds caused by their degradation products can be.
• the phosphating process is therefore particularly suitable for Phosphating of vehicle bodies suitable, the components made of aluminum or aluminum alloys alone or together with steel components and / or galvanized steel.
• the phosphating time was 3 minutes.
• the sheets were then rinsed with water and dried.
• the phosphating result was assessed optically.
• the mass per unit area of the phosphate layer (“layer weight") was determined by detaching the phosphate layer and by weighing the sheets before and after detaching the layer.
• the optical evaluation gave a good and closed one for Examples 1 to 4 Layer image.
• the layer weights are in the technically desirable range.
• the Phosphating solutions according to the invention thus deliver despite a small amount Accelerator content good phosphating results.
• Example 5 Comparative Example 1 : Mixing an aged phosphating solution A with fresh phosphating solution B.
• a used solution A was used for this, in an automobile phosphating plant was in operation and because of the enriched Decomposition products of the m-nitrobenzenesulfonate was colored black.
• the visual assessment showed only a partial and therefore insufficient Phosphating of the test sheet.
• the visual assessment showed a uniform, closed Phosphate layer.

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

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Citations (5)

• 2001
  • 2001-11-13 DE DE2001155666 patent/DE10155666A1/de not_active Withdrawn
• 2002
  • 2002-10-30 JP JP2002316207A patent/JP2003183846A/ja active Pending
  • 2002-11-02 EP EP02024329A patent/EP1310578A1/fr not_active Withdrawn

Patent Citations (5)

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