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
• • 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
  • C23C22/48—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 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
  • C23C22/53—Treatment of zinc or alloys based thereon

Definitions

• chromium (VI) chromium
• chromium (III) which in the surface film which is more alkaline, inter alia, by the evolution of hydrogen is, inter alia, chromium (III) hydroxide or sparingly soluble ⁇ -oxo or ⁇ -hydroxo bridged chromium (III) complex is deposited.
• chromium (III) hydroxide or sparingly soluble ⁇ -oxo or ⁇ -hydroxo bridged chromium (III) complex is deposited.
• sparingly soluble zinc chromate (VI) is formed. Overall, a tightly closed, very well protected against the corrosion attack by electrolytes conversion layer on the zinc surface.
• chromium (VI) compounds are distinguished by their high carcinogenic potential, so that it is necessary to replace the processes associated with these compounds.
• Dyes which are also used in Cr (III) -based passivations, can in principle also be used in chromium-free conversion layers.
• a transition metal such as cobalt or iron as Co (II) or Fe (II) or Fe (III) is added to the passivation to produce in situ finely divided black pigments in the conversion layer.
• Treatment solutions for producing such black passivations are described, for example, in the document EP 1 970 470 A1 described.
• Such treatment solutions contain, in addition to Cr 3+ and Co 2+ ions, nitrate ions and at least two different carboxylic acids.
• Iron has the disadvantage that the corrosion protection of the system is significantly weakened by the incorporation of iron-containing pigments.
• the patent JP 2005-206872 describes a Cr 6+ ion-free treatment solution for producing black passivations which, in addition to Cr 3+ ions, contains at least one further ion selected from the group consisting of sulfate, chloride, ions of the oxo acids of chlorine and nitrate, and a sulfur compound.
• the black conversion layers thus produced contain chromium ions.
• the font JP 2005-187925 describes processing solutions for the preparation of colored passivation layers containing Cr 3+ ions, other metal ions and an organic sulfur compound.
• the black conversion layers thus produced contain chromium ions.
• the font JP 2005-187838 also describes aqueous treatment solutions to produce black colored passivation layers containing ions at least one of Ni and Co and a sulfur compound.
• the black conversion layers thus formed contain nickel and / or cobalt ions.
• the invention has for its object to provide reaction solutions and methods for increasing the corrosion protection and blackening zink ambiencer surfaces available, which are free of toxic metals such as chromium and cobalt.
• a method that combines the ecological and occupational medical advantage of a chromium and cobalt-free passivation with a decorative high-quality black color impression is therefore desirable.
• the invention is based on the use of sulfur-containing compounds in a chromium ion and cobalt ion-free, aqueous, acidic matrix. With such treatment solutions, black colored conversion layers can be produced on zinc and its alloys.
• the sulfur compounds of the formula (1) and (2) are added to the treatment solution of the present invention in an amount of 0.2 g / L to 500 g / L, preferably 1 g / L to 100 g / L, and most preferably 3 g / L to 20 g / l added.
• the oxo cations of the formula M'O c d + are preferably added in the form of their nitrates, sulfates and halides to the treatment solution according to the invention, from which the oxo cations form by hydrolysis in the treatment solution.
• zirconyl sulfate ZrO (SO 4 )
• ZrO 2+ zirconyl sulfate
• suitable oxo-cations are MnO +, VO 3+, VO 2+, WO 2 2+, MoO 2 2+, TiO 2+, ZrO 2+, and mixtures thereof.
• Particularly preferred oxo cations are those of titanium and zirconium.
• the oxo cations are added to the treating solution in an amount of 0.02 g / L to 50 g / L, preferably 0.05 g / L to 10 g / L, and most preferably 0.1 g / L to 5 g / L.
• halogen complex ions of the formula M "X a b - be in the form of their metal salts, preferably their alkali metal salts, more preferably their sodium and potassium salts are added, the halogen complex of the formula M are preferred."
• X a b consisting of A group comprising BF 4 - , TiF 6 2 - ZrF 6 2- , SiF 6 2- , AlF 6 3- , and mixtures thereof are selected. Particularly preferred are the halogen complex ions SiF 6 2- , TiF 6 2- and ZrF 6 2- .
• halogen complex anions of the formula M "X a b" are added to the treatment solution according to the invention in an amount of 0.02 g / l to 100 g / l, preferably 0.05 g / l to 50 g / l and most preferably 0.1 g / l to 10 g / l added.
• the treatment solution according to the invention can either contain at least one oxo cation of the formula M'O c d + with M ' equal to Mn, V, Ti, W, Mo, Zr or at least one halogen complex ion of the formula M " X a b
• the treatment solution contains a mixture of both at least one oxo cation and at least one halogen complex ion. This embodiment is preferred because it results in increased corrosion resistance of the metal layer (see Examples 3 to 7).
• the at least one oxidizing agent in the treatment solution according to the invention is selected from the group comprising hydrogen peroxide, organic peroxides, alkali metal peroxides, persulfates, perborates, nitrates and mixtures thereof.
• the most preferred oxidizing agent is hydrogen peroxide.
• the at least one oxidizing agent is added to the treating solution in an amount of 0.2 g / L to 100 g / L, preferably 1 g / L to 50 g / L, and most preferably 5 g / L to 30 g / L.
• the pH is adjusted by means of an acid or base to a value in the range from 0.5 to 5.0, preferably in the range from 1.0 to 3.0, particularly preferably in the range from 1.3 to 2.0.
• an acid or base is used as the preferred base sodium hydroxide solution.
• the application of the treatment solution according to the invention for the production of anticorrosive coatings takes place by direct treatment of the metal surfaces with the treatment solution, by immersing or pivoting the substrate to be coated in or with the treatment solution.
• Application by dipping or panning is preferably carried out at a temperature of the treating solution in the range of 20 to 100 ° C, preferably 30 to 70 ° C, more preferably 40 to 60 ° C, and most preferably about 50 ° C.
• the most suitable treatment time for the preparation of anticorrosive coatings by immersion or pivoting of the substrate to be coated in or with the treatment solution varies depending on various parameters, such.
• the treatment time is in the range of 5 to 180 s, preferably in the range of 30 to 120 s.
• the thus deposited black conversion layers already produce a good corrosion protection with respect to the formation of zinc corrosion products on zinc-containing surfaces.
• the described conversion layers can be subjected to conventional aftertreatment processes.
• This includes, for example, seals based on silicates, organofunctional silanes and nanoscale SiO 2 , and polymer dispersions.
• the sealing layers produced by the subsequent treatment improve the barrier effect of the underlying conversion layer and thus additionally improve the corrosion protection of the entire coating system.
• the pH is adjusted to pH 1.6 at 50 ° C. with NaOH.
• a sheet of low-alloy steel is, after suitable pretreatment in an alkaline galvanizing electrolyte (Protolux® 3000, a product of Atotech GmbH, containing 12 g / l zinc and 120 g / l NaOH) coated with 10 microns zinc.
• Alkaline galvanizing electrolyte Protolux® 3000, a product of Atotech GmbH, containing 12 g / l zinc and 120 g / l NaOH
• the sheet is rinsed after galvanizing and dipped directly into the above prepared treatment solution. After 60 s treatment time with slight movement the sheet is removed, rinsed and dried. It has a multicolored iridescent surface.
• a treatment solution for producing conversion layers as described in Comparative Example 1 is mixed with 10 g / l of thioglycolic acid and the pH is adjusted to pH 1.6 (50 ° C.) with NaOH.
• a sheet of low-alloy steel is coated after appropriate pretreatment in an alkaline galvanizing electrolyte (Protolux® 3000, a product of Atotech GmbH, containing 12 g / l zinc and 120 g / l NaOH) with 8-15 microns zinc.
• Alkaline galvanizing electrolyte Protolux® 3000, a product of Atotech GmbH, containing 12 g / l zinc and 120 g / l NaOH
• the sheet is rinsed after galvanizing and dipped directly into the treatment solution prepared above. After 60 s treatment time with slight movement, the sheet is removed, rinsed and dried. It has a deep black surface.
• a treatment solution for producing conversion layers as described in Comparative Example 1 is admixed with 11 g / l of 3-thiopropionic acid and the pH is adjusted to pH 1.6 (50 ° C.) with NaOH.
• a sheet of low-alloy steel is coated after suitable pretreatment in an alkaline galvanizing electrolyte (Protolux® 3000) with 10 ⁇ m zinc.
• the sheet is rinsed after galvanizing and dipped directly into the treatment solution prepared above. After 60 s treatment time with slight movement, the sheet is removed, rinsed and dried. It has a deep black surface.
• a treatment solution for producing conversion layers is admixed with 11 g / l dithiodiglycolic acid and the pH is adjusted to pH 1.6 (50 ° C.) with NaOH.
• a sheet of low-alloy steel is coated after suitable pretreatment in an alkaline galvanizing electrolyte (Protolux® 3000) with 10 ⁇ m zinc.
• the sheet is rinsed after galvanizing and dipped directly into the treatment solution prepared above. After 60 s treatment time with slight movement, the sheet is removed, rinsed and dried. It has a deep black surface.
• the sheet with the surface thus produced is dried at 80 ° C in a convection oven for 15 min and the corrosion protection in the neutral salt spray test according to ISO 9227 NSS tested.
• the sheet had a life of 48 hours until the appearance of zinc corrosion products> 5% of the area.
• a sheet with a surface produced according to Embodiment 3 is rinsed, dipped in a sealing solution consisting of a silicate-containing polyurethane dispersion (Corrosil® Plus 501, a product of Atotech GmbH) and dried at 80 ° C in a convection oven for 15 min.
• the sheet had a life of 120 h until the appearance of zinc corrosion products> 5% of the area.
• a sealing solution usually used for increasing the corrosion protection can therefore also be used on the chromium- and cobalt-free black conversion layers according to the invention.
• a treatment solution for the production of conversion layers as described in Comparative Example 1 is mixed with 13 g / l of thiolactic acid and the pH is adjusted to pH 1.6 (50 ° C.) with NaOH.
• a sheet of low-alloy steel is coated after suitable pretreatment in an alkaline galvanizing electrolyte (Protolux® 3000) with 10 ⁇ m zinc.
• the sheet is rinsed after galvanizing and dipped directly into the treatment solution prepared above. After 60 s treatment time with slight movement, the sheet is removed, rinsed and dried. It has a deep black surface.
• the sheet with the surface thus produced is dried at 80 ° C in a convection oven for 15 min and the corrosion protection in the neutral salt spray test according to ISO 9227 NSS tested.
• the sheet had a life of 48 hours until the appearance of zinc corrosion products> 5% of the area.
• the pH is adjusted to pH 1.6 at 50 ° C. with HNO 3 .
• a sheet of low-alloy steel is coated after suitable pretreatment in an alkaline galvanizing electrolyte (Protolux® 3000) with 10 ⁇ m zinc.
• the sheet is rinsed after galvanizing and dipped directly into the treatment solution prepared above. After 60 s treatment time with slight movement the sheet is removed, rinsed and dried. It has a deep black surface.
• the sheet with the surface thus produced is dried at 80 ° C in a convection oven for 15 min and the corrosion protection in the neutral salt spray test according to ISO 9227 NSS tested.
• the sheet had a life of 24 h until the appearance of zinc corrosion products> 5% of the area.
• the pH is adjusted to pH 1.6 at 50 ° C. with NaOH.
• a sheet of low-alloy steel is coated after suitable pretreatment in an alkaline galvanizing electrolyte (Protolux® 3000) with 10 ⁇ m zinc.
• the sheet is rinsed after galvanizing and dipped directly into the treatment solution prepared above. After 60 s treatment time with slight movement, the sheet is removed, rinsed and dried. It has a deep black surface.
• the sheet with the surface thus produced is dried at 80 ° C in a convection oven for 15 min and the corrosion protection in the neutral salt spray test according to ISO 9227 NSS tested.
• the sheet had a life of 24 h until the appearance of zinc corrosion products> 5% of the area.

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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)
• Inorganic Compounds Of Heavy Metals (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)

Priority Applications (9)

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• 2009
  • 2009-09-23 EP EP09171140A patent/EP2309027B1/de active Active
  • 2009-09-23 ES ES09171140T patent/ES2372146T3/es active Active
  • 2009-09-23 AT AT09171140T patent/ATE525495T1/de active
• 2010
  • 2010-09-08 JP JP2012530209A patent/JP5669848B2/ja active Active
  • 2010-09-08 BR BR112012006456-8A patent/BR112012006456B1/pt active IP Right Grant
  • 2010-09-08 KR KR1020127007303A patent/KR101692093B1/ko not_active Expired - Fee Related
  • 2010-09-08 US US13/394,362 patent/US9005373B2/en active Active
  • 2010-09-08 CN CN201080042409.XA patent/CN102575354B/zh active Active
  • 2010-09-08 WO PCT/EP2010/063178 patent/WO2011036058A1/en active Application Filing

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