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
  • C23C22/78—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

Definitions

• the invention relates to methods and agents for the pretreatment of metal surfaces with the aid of aqueous pre-rinse baths containing activating agents before the subsequent phosphating.
• Activation of a metal surface before phosphating means contacting this surface with an aqueous pre-rinse bath in which an activating agent is extremely finely dispersed as a solid phase.
• an activating agent is extremely finely dispersed as a solid phase.
• a number of substances have become known as activating agents.
• a pretreatment with V has or Congressbädern that finely dispersed titanium phosphate, tertiary zinc phosphate (Hopeit) and tertiary iron (II) zinc phosphate (phosphophyllite) have been found to be suitable.
• the layer formation in manganese phosphate solutions can be favorably influenced by pretreatment in an aqueous pre-rinse bath containing finely dispersed manganese phosphate or iron (II) manganese phosphate (hureaulite) (US Pat. No. 2,456,947, D E-PS 15 21 889, DE- PS 15 46 070 US-PS 2,310,239, US-PS 3,864,139, DE-OS 22 47 888 DE-OS 21 25 963).
• the effectiveness of the activation relates both to the phosphating of iron and steel and of non-ferrous metals, for example zinc, zinc alloys, metals coated with zinc and zinc alloys, aluminum, aluminum alloys and metals coated with aluminum and its alloys.
• the object of the invention is to provide a method for pretreating metal surfaces by means of a pre-rinse bath which does not have the known, in particular the aforementioned disadvantages, can be used without additional effort and remains effective over a considerably extended period of time.
• the object is achieved by designing the method of the type mentioned at the outset in accordance with the invention in such a way that the metal surfaces are brought into contact with a pre-rinse bath which additionally contains montmorillonite.
• a pre-rinse bath which additionally contains montmorillonite.
• montmorillonite can be used, products with a high proportion of montmorillonite and a high degree of distribution being particularly effective.
• bentonites have proven particularly effective.
• the montmorillonites or bentonites should be dispersed as finely as possible in the pre-rinse baths. For this reason, the highly swellable sodium bentonites are preferably used.
• the montmorillonite or bentonite content of the pre-rinse baths can be selected within wide limits. It is particularly advantageous to bring the metal surfaces into contact with pre-rinse baths which contain montmorillonite in an amount of 0.01 to 10 g / l.
• the activating agent is usually dispersed in concentrations of 3 mg / l to 5 g / l.
• alkali metal phosphates such as P yrophosphat and be co tripolyphosphate.
• Other known additives that improve effectiveness include gelatin, polyacrylates and other organic, water-soluble polymers.
• alkali orthophosphates and alkali carbonates can be added.
• the pH value of the bath is adjusted usually slightly alkaline and usually is between about 7.1 and 10.
• the pre-rinse baths can essentially be the activating agent tel, the clay mineral containing montmorillonite, in particular bentonite and others, for example the abovementioned auxiliaries, and are used as a separate treatment directly before phosphating in dipping or spraying. It is also possible to use the alkaline cleaning and degreasing bath as prewash bath, to which activating agent and bentonite as montmorillonite have been added. In the latter case, at least one water rinse step is usually switched between the combined activation and cleaning or degreasing treatment and the phosphating.
• the method according to the invention can be used universally. It can inkphosphat réelle with Vorticianbädern based on titanium phosphate or tertiary zinc phosphate in particular in the Z, isen in the manganese phosphating with manganese phosphate Vor réellebädern based or E (II) are applied -manganphosphat.
• the Vor Hughesbäder mentioned can simultaneously unification the function of R and take degreasing by giving them the necessary cleansing agents.
• the inventive method is advantageous, for example in connection with P hosphatiermaschinen to improve the L ackhaf- tung, corrosion protection, sliding, and the electric insulation can be used.
• Steel sheets were also degreased in a strongly alkaline T cleaner at 95 C and then rinsed in water.
• sheets pretreated in this way were immersed in a manganese phosphate solution at 95 ° C. for 10 minutes: and then rinsed in water and dried.
• the T abellencke clearly show that reduced by the Betonitzusatz the phosphate layer weight and the crystallinity of the phosphate layer and the effectiveness of the activation to be extended in time.
• Steel sheets were electrolytically galvanized in a sulfuric acid electrolyte and, after water rinsing with the following aqueous pre-rinse bath, were sprayed for 3 seconds at 50 ° C.:
• the mixture was then phosphated for 7 seconds at 60 ° C. while spraying with the following phosphating solution:

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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)
• Detergent Compositions (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Catalysts (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (6)

Cited By (7)

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Citations (7)

• 1983
  • 1983-03-01 DE DE19833307158 patent/DE3307158A1/de not_active Withdrawn
• 1984
  • 1984-02-27 EP EP19840200272 patent/EP0117599A1/fr not_active Withdrawn
  • 1984-02-28 DK DK121384A patent/DK121384A/da not_active Application Discontinuation
  • 1984-02-29 PT PT7816984A patent/PT78169B/pt unknown
  • 1984-03-01 JP JP3969284A patent/JPS59226181A/ja active Pending
  • 1984-03-01 ES ES530217A patent/ES8505733A1/es not_active Expired

Patent Citations (7)

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