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
  • C23C22/80—Pretreatment of the material to be coated with solutions containing titanium or zirconium compounds

Definitions

• step (3) can be omitted, the activating constituents then being introduced directly into the bath used for the step of alkaline degreasing.
• step (3) becomes essential in order to obtain a sufficiently fine and dense phosphating.
• the baths intended for covering the zinc phosphating stage can comprise, in addition to the zinc cation, other metals such as nickel, manganese, calcium or possibly iron, as widely described in the scientific literature.
• the refining agents used at the time of the activation and refining step or which can be used at the time of the alkaline degreasing step in the case of processes carried out entirely by jet are constituted by compounds of titanium, in particular colloidal titanium salts known under the name of Jernstedt salts; these salts are described in particular in US Pat. No. 2,456,947.
• Such a Jernstedt salt can be obtained by mixing 95 parts of disodium phosphate with 5 parts of potassium fluotitanate in an amount of water sufficient to dissolve the ingredients. The water is then removed from the mixture by evaporation at a temperature of 80 to 100 ° C.
• titanium can be used for the production of Jernstedt salt, such as for example titanium sulfate or titanium oxide.
• Polyphosphates can also be added to the Jernstedt salts, in particular in a proportion of 1 to 300 parts by weight of? 2 0 7 .
• Jernstedt salts are commonly found on the market and are in particular marketed by the Applicant Company under the trademark “FIXODINE 5”.
• the object of the invention is, above all, to remedy these drawbacks and to ensure that, in the phosphating methods of the genus in question, the activation and refining step can be carried out with industrial water without overflow and supply of refining salts proportional to the quantities of water added while providing a refining and stability effect comparable to that obtained with demineralized water.
• R representing an alkyl radical or a ra dical aryl optionally substituted with at least one of the substituents of the group comprising the hydroxyl radical, other phosphonic groups and the amino groups of formula in which R 2 and R 3 which may be identical or different from each other, each represent a hydrogen atom or have the meaning of R 1 .
• the salts of the acids of formula (I) and of 2-phosphono-butane-1,2,4-tricarboxylic acid which can be used are those obtained by partial or total neutralization with alkaline ions such as Na + and K + or by the NH 4 + ion .
• the bath used in the above process is also referred to as a new industrial product.
• constituents of the refining bath used in accordance with the invention may be pyrophosphates or alkali citrates.
• these baths are prepared from concentrates containing the acid of formula (1) or 2-phosphono-butane-1,2,4-tricarboxylic acid or their salt and Jernstedt salt in such proportions that mixing it with an appropriate quantity of water provides the activation and refining bath used in accordance with the invention.
• the activation and refining step according to the invention is carried out at a temperature of 20 to 50 ° C.
• the stability of the bath used is sufficient for it to be able to operate under normal conditions without regeneration, that is to say without the addition of additional amounts of concentrate other than the normal amounts to be provided by consumption of the product, for approximately 5 15 days.
• the aim is to study the influence of different activation baths on the morphology of the zinc phosphate crystals deposited in the phosphating step.
• This morphology is examined using a scanning electron microscope at a magnification of 1500.
• Two examinations are carried out, the first of which is carried out after treatment in a new bath, 10 minutes after assembly, and the second of which is carried out after treatment in the same bath, 6 days after assembly thereof.
• the activation bath comprises 2 g / l of Jernstedt salt (FIXODINE 5) in demineralized water corresponding to 20 ppm of titanium.
• FIXODINE 5 Jernstedt salt
• the other ingredients are sodium phosphates.
• the pH is 7.
• Example 2 Same composition and same pH as in Example 1, but the water consists of tap water.
• the pH 7.9.
• the bath is identical to that of Example 3, except that the phosphonic acid is present at the rate of 100 ppm.
• the bath is identical to that of Example 4, but the pH is brought to 9 with trisodium phosphate.
• the bath is identical to that of Example 6 in the except that the sodium salt of phosphonic acid is present at 200 ppm.
• the bath is identical to that of Example 7, except that the phosphonic acid is present at the rate of 100 ppm and the pH is then 7.
• test pieces thus treated are examined under the electron microscope, as indicated above.

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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)
• Manufacture And Refinement Of Metals (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

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• 1984
  • 1984-10-31 FR FR8416725A patent/FR2572422B1/fr not_active Expired - Fee Related
• 1985
  • 1985-10-30 EP EP85402096A patent/EP0180523B1/fr not_active Expired
  • 1985-10-30 DE DE8585402096T patent/DE3571050D1/de not_active Expired
  • 1985-10-30 CA CA000494250A patent/CA1260809A/en not_active Expired
  • 1985-10-30 AT AT85402096T patent/ATE44051T1/de not_active IP Right Cessation
  • 1985-10-31 US US06/793,346 patent/US4678519A/en not_active Expired - Lifetime
  • 1985-10-31 JP JP60243024A patent/JPS61124582A/ja active Granted

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