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

Definitions

• the invention relates to a method for the post-passivation of phosphated metal surfaces.
• non-layer-forming phosphating i.e. distinguish the use of alkali and / or ammonium orthophosphate solutions for the production of iron phosphate layers in which the iron ion comes from the metallic surface to be coated, and the so-called "layer-forming phosphating" in which on metal surfaces using zinc or zinc / calcium / calcium phosphate - Solutions zinc phosphate layers or zinc calcium phosphate layers are formed.
• Such phosphate layers not only improve the corrosion protection of the metal surfaces, but also increase the adhesion to the surface applying paints. In certain cases, they can also help to improve the properties of metal sheets during cold forming and when using deep-drawing processes.
• the phosphate layer on the metal surfaces is not completely closed. Rather, there remain more or less large "pores" which have to be closed in the course of a so-called “post-passivation” in order not to leave a point of attack for corrosive influences on the metal surfaces.
• the present invention now relates to a process for the post-passivation of phosphated metal surfaces, which is characterized in that these surfaces are treated with acidic to neutral, aqueous solutions in the temperature range from 20 to 120 ° C. which contain one or more divalent cations from the group manganese, Contain cobalt, nickel and copper and / or titanium (IV) ions.
• salts containing titanium (IV) and / or manganese (II) and / or cobalt (II) and / or nickel (II) and / or copper (II) can be used, which are well within the temperature range of the process Dissolve water.
• Salts of weak organic acids are particularly suitable for this. Examples are methanates (formates), ethanates (acetates), propanates (propionates), butanates (butyrates) or 2,4-pentanedionates (acetylacetonates).
• Solutions which contain only manganese cations or only cobalt cations or only nickel cations or only copper cations or only titanium cations can be used for the method according to the present invention. Solutions are preferably used which contain both nickel (II) and copper (II) cations or both manganese (II) and cobalt (II) cations or both cobalt (II) and nickel (II) also contain titanium (IV) cations or other combinations of the cations mentioned.
• Aqueous solutions which are used in the process according to the invention for the post-passivation of phosphated metal surfaces contain the titanium and / or manganese and / or cobalt and / or nickel and / or copper ions mentioned in amounts of 0.01 to 10 g each. 1-1 application solution.
• the total content of the cations used may be 10 g. Do not exceed 1 -1 application solution.
• the pH of the application solutions is in the acidic to neutral range, i.e. in the range of 3.0 to 7.0.
• the solutions are preferably adjusted, for example using ethanoic acid (acetic acid) or phosphoric acid on the one hand or sodium hydroxide solution on the other hand, in such a way that they have a pH between 4.0 and 5.0.
• the solutions containing titanium and / or manganese and / or cobalt and / or nickel and / or copper ions used according to the method of the invention can be used in the temperature range from approximately 20 to approximately 120 ° C., but are preferably used in the temperature range from 30 to 50 ° C worked. Treatment times of approximately 1 minute are sufficient to achieve excellent post-passivation of the phosphated metal surfaces even at these temperatures.
• the process according to the invention is carried out in such a way that cleaned phosphated metal surfaces are first rinsed with water and then, according to the present process, with an acidic, titanium (IV) - and / or manganese (II) - and / or cobalt (II) - and / or solution containing nickel (II) and / or copper (II) cations in the temperature range of preferably 30 to 50 ° C., which can be obtained by adding solid or liquid concentrates containing the corresponding cations in a suitable amount dissolves in water in a manner known per se.
• an acidic, titanium (IV) - and / or manganese (II) - and / or cobalt (II) - and / or solution containing nickel (II) and / or copper (II) cations in the temperature range of preferably 30 to 50 ° C.
• spray processes, dipping processes or other processes of application for the post-passivation known to the person skilled in the art are such eg splash dipping or flooding.
• the treatment time is usually 1 minute.
• the post-passivated metal surfaces are rinsed with deionized water and then dried with compressed air.
• the metal surfaces post-passivated in accordance with the method according to the invention are outstandingly suitable for subsequent coating with paints, varnishes, varnishes and the like.
• the post-passivated metal surfaces in this way offer an outstandingly suitable reason for cathodic electrocoating materials.
• the phosphated and post-passivated metal surfaces are also suitable for other post-treatment processes.
• Cu (CH 3 COO) 2 was used to prepare a post passivation solution. H20 in water to a 0.3 g. 1 -1 containing solution dissolved, corresponding to 0.1 g of Cu per liter of solution.
• Steel parts were sprayed with an alkaline cleaning solution for 2 min at 50 ° C. and then rinsed with water. They were then phosphatized with a zinc phosphate solution for 2 minutes by spraying at 50 ° C. and then rinsed with water.
• the steel parts were then coated with 0.3 g of copper (II) ethanate hydrate per liter Passivation solution at 35 ° C post-passivated for 1 min. It was then rinsed with deionized water and dried with compressed air.
• the dried parts were coated with a cathodic electrocoating material and dried at 185 ° C. for 20 minutes.
• the dry film thickness of the paint was 18 ⁇ m.
• the parts were provided with individual cuts and subjected to the salt spray test (DIN 50 021) for 480 h.
• the evaluation according to DIN 53 167 showed an infiltration of 0.4 to 0.6 mm.
• Ni (CH 3 COO) 2 was used to prepare a post-passivation solution. 4H20 g to a 0,. 7 Solution containing 1 -1 dissolved in water, corresponding to 0.17 g Ni per liter of solution. Steel parts were immersed for 10 minutes at 80 ° C with an alkaline cleaning solution and then rinsed with water. The parts were then phosphatized for 3 minutes with a zinc phosphate solution at 50 ° C. and rinsed again.
• the solution containing 0.7 g of nickel (II) ethanol tetrahydrate per liter at 35 ° C. was used for the post-passivation, the treatment time being 1 min in immersion.
• the post-passivated parts were rinsed with deionized water and dried with compressed air.
• the painted parts were then provided with individual cuts and subjected to the salt spray test (DIN 50 021) for 480 hours.
• the evaluation according to DIN 53 167 showed an infiltration of 0.4 to 0.6 mm.
• Ni (CH 3 COO) 2 was used to prepare a post-passivation solution. 4H20 and Cu (CH 3 COO) 2 . H 2 0 dissolved in water to a solution containing 0.5 g. l -1 nickel (II) ethanate tetrahydrate and 0.1 g. 1 1 copper (II) ethanate hydrate contained. This corresponds to a content of 0.12 g Ni and 0.03 g Cu per liter of solution.
• the parts were treated with the solution containing nickel and copper ions prepared as described above for 1 min at 40 ° C. in an immersion, then rinsed with deionized water and dried with compressed air.
• the parts passivated in this way were then coated with a cathodic electrocoating material and dried for 20 minutes by heating to 185.degree.
• the dry film thickness of the lacquer was 18 gm.
• the parts were provided with individual cuts and subjected to the salt spray test (DIN 50 021) for 480 h.
• the Evaluation according to DIN 53 167 showed an infiltration of 0.2 to 0.4 mm.
• the steel parts were then post-passivated with the post-passivation solutions containing the cations in the amount given in Table 1, rinsed with demineralized water and dried with compressed air.
• the dried pieces were coated with a cathodic electro-immersion l ack coated and dried 20 min at 185 ° C.
• the dry film thickness of the paint was 18 ⁇ m.
• the parts were provided with individual sections and the alternating climate test in accordance with VW standard P 12 10 30 days sub zo g s.

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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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• 1984
  • 1984-01-07 DE DE19843400339 patent/DE3400339A1/de not_active Withdrawn
  • 1984-09-17 EP EP84111060A patent/EP0149720B1/fr not_active Expired
  • 1984-09-17 DE DE8484111060T patent/DE3474839D1/de not_active Expired
  • 1984-12-14 US US06/681,769 patent/US4600447A/en not_active Expired - Fee Related
• 1985
  • 1985-01-04 ZA ZA85105A patent/ZA85105B/xx unknown
  • 1985-01-07 ES ES539387A patent/ES8703167A1/es not_active Expired
  • 1985-01-07 JP JP60001378A patent/JPS60159175A/ja active Pending

Patent Citations (6)

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