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
  • C23C22/362—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 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
  • C23C22/12—Orthophosphates containing zinc cations
  • C23C22/13—Orthophosphates containing zinc cations containing also nitrate or nitrite anions
• • 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
  • 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

Definitions

• the invention relates to a method for phosphating zinc or aluminum surfaces with a phosphating solution based on zinc and nickel as cations and hydroxylamine as accelerators, which may additionally contain fluoride and / or complex-bound fluoride.
• the zinc surfaces are part of workpieces made of zinc or zinc alloys, or they are applied by hot-dip galvanizing or by electrolytic galvanizing to workpieces containing iron, in particular to workpieces made of iron and steel.
• the aluminum surfaces are part of workpieces made of aluminum or aluminum alloys. Varnishes, paints, plastic layers or oils can be applied to the phosphated zinc and aluminum surfaces, and the surfaces provided with such an application are considerably better protected against corrosion by the phosphating.
• EP-A 0 315 059 discloses a process for phosphating surfaces made of iron, which works with a phosphating solution which contains 0.5 to 50 g / l hydroxylamine and 0.2 to 2.0 g / l Zn 2+ and 3 contains up to 25 g / l phosphate.
• the phosphating solution can additionally contain iron, manganese, nickel, nitrate, fluoride and / or complex fluorides.
• the known method is suitable not only for phosphating surfaces made of iron, but also surfaces made of zinc, zinc alloys, aluminum and aluminum alloys.
• DE-A 195 38 778 discloses a method for phosphating surfaces made of steel, galvanized steel, alloy-galvanized steel and aluminum, in which the metal surface is immersed in a phosphating solution for a period of between 1 and 8 minutes which is 0.5 to Contains 2 g / l zinc ions, 2 to 25 g / l phosphate ions and 1, 2 to 5 g / l hydroxylamine in free, ionic or complex-bound form, has a free acid content between 0 and 1, 5 points and a temperature in Has a range of 32 to 93 ° C.
• This phosphating solution can additionally contain 0.2 to 1.5 g / l manganese ions, 0.2 to 1.5 g / l nickel ions and additionally fluoride in free and / or complex-bound form in amounts of up to 2.5 g / l total Contain fluoride.
• the phosphating solution should not contain more than 0.5 g / l nitrate ions. This process also works with relatively high hydroxylamine concentrations and limits the nitrate content to less than 0.5 g / l.
• DE-A 196 06 018 describes a method for phosphating metal surfaces made of steel, galvanized or alloy-galvanized steel and / or aluminum, in which the metal surfaces are sprayed or
• Phosphating solution in contact that contains 0.2 to 3 g / l zinc ions, 3 to 50 g / l
• Phosphate ions 1 to 100 mg / l nickel ions, one or more accelerators, e.g. B. 0.01 to 0.2 g / l nitrite and 0.1 to 10 g / l hydroxylamine, wherein the
• the nitrate content of this solution is ⁇ 0.5 g / l.
• the solution can additionally 0.1 to 4 g / l
• DE-A 196 21 184 discloses a method for phosphating metal surfaces made of steel, galvanized or alloy-galvanized steel, aluminum and / or aluminum-magnesium alloys, in which the Contact metal surfaces by spraying or dipping for a time between 3 seconds and 8 minutes with a zinc-containing phosphating solution containing 0.2 to 3 g / l zinc ions, 3 to 50 g / l phosphate ions, 0.001 to 4 g / l manganese ions, 0.001 up to 0.5 g / l of one or more polymers and one or more accelerators, e.g. B. 0.01 to 0.2 g / l nitrite and 0.1 to 10 g / l
• phosphating solution used in this process also has a nitrate content that does not exceed 0.5 g / l.
• a phosphating solution is known from WO 93/03 198, which is used for the phosphating of steel, zinc alloys and aluminum and which contains 5 to 25 g / l phosphate ions, 0.5 to 2 g / l zinc ions, 0.2 to 1.5 g / l
• This phosphating solution also contains a large amount of hydroxylamine and limits the nitrate content to 2 g / l.
• DE-A 196 39 596 discloses a process for phosphating steel strip or steel strip galvanized on one or both sides or alloy galvanized by spray or dip treatment for a period of time in the range from 2 to 15 seconds at a temperature of 40 to 70 ° C a phosphating solution containing 1 to 4 g / l zinc ions, 0.8 to 3.5 g / l manganese ions,
• This phosphating solution can additionally contain 0.8 to 3.5 g / l nickel ions and up to 0.8 g / l total fluoride. If the phosphating solution is used in the phosphating of galvanized steel, its nitrate content should not exceed 0.1 g / l.
• the nitrate concentration of the phosphating solution should generally be ⁇ 1 g / l, in particular if the phosphating solution is used for phosphating zinc surfaces, because in this case the nitrate content should even be ⁇ 0.5 g / l be, since the person skilled in the art assumes that higher nitrate contents on galvanized surfaces favor the formation of the very disadvantageous, so-called "specks".
• the person skilled in the art is aware that a significant nitrate content in the phosphating solution could certainly be advantageous, since the nitrates of zinc, nickel and manganese are readily water-soluble and can be easily obtained and handled without any problems, and
• the free acid (FS) content can optionally be easily adjusted using nitric acid.
• the invention is therefore based on the object of providing a phosphating process which is suitable for the phosphating of zinc and aluminum surfaces is suitable, which gives the workpieces to be phosphated, in particular if they are coated with lacquers, paints, plastic layers or oils after phosphating, good corrosion properties and which uses a phosphating solution which, compared to the known hydroxylamine-containing phosphating solutions, works overall more cost-effectively without the quality of the phosphate layers produced, for example by the formation of specks on zinc surfaces or by non-closed layers on aluminum surfaces.
• the object on which the invention is based is achieved by the creation of a method for phosphating zinc or aluminum surfaces by means of a phosphating solution which contains 0.5 to 2.0 g / l Zn 2+ , 0.3 to 2.0 g / l Ni 2+ , 0.1 to 0.4 g / l NH 2 OH, at least 3.0 g / l N0 3 ' and 10.0 to 20.0 g / l phosphate (calculated as P 2 O 5 ) and contains is applied to the surfaces by dipping or spraying at 35 to 75 ° C., the dipping time being 0.5 to 10 minutes and the spraying time being 3 seconds to 5 minutes.
• Phosphating solution has a high nitrate content of> 3 g / l, and that the phosphate layers produced on aluminum surfaces are completely closed, which is attributed in particular to the advantageous effect of the high nitrate content.
• the phosphate layers produced by the process according to the invention give the workpieces, in particular, which are coated with lacquers, paints, plastic layers or oils after phosphating, very good corrosion protection.
• Zinc surfaces do not cause disadvantageous speck formation and also supports the formation of a closed phosphate layer on aluminum surfaces. It also follows that nitrates and, if appropriate, nitric acid can readily be used for the production of the concentrates from which the present invention is diluted
• Phosphating solutions are prepared.
• the phosphating solution used to carry out the method according to the invention additionally contains 0.4 to 1.5 g / l Mn 2+ .
• the manganese content improves the positive corrosion protection effect of zinc phosphate layers in a known manner.
• the phosphating of zinc surfaces takes place in accordance with the method according to the invention with a phosphating solution which does not necessarily contain fluoride and complex-bound fluoride
• the phosphating of aluminum surfaces with a phosphating solution carried out which contains fluoride and / or complex-bound fluoride, wherein the complex-bound fluoride can be used for example in the form of SiF 6 2 * or BF 4 ' .
• SiF 6 2 ' is particularly suitable as a complex-bound fluoride for carrying out the process according to the invention and that a certain range must be observed with regard to the content of fluoride and complex-bound fluoride.
• the phosphating solution used to carry out the process according to the invention additionally contains 0.2 to 1.5 g / l F ' and / or 0.5 to 2.5 g / l SiF 6 2 " .
• the presence such amounts of simple and / or complex bound fluoride is in the
• Phosphating aluminum surfaces is advantageous because the aforementioned fluorides have a positive influence on the quality of the phosphate layers deposited on aluminum surfaces.
• the simple fluoride F " can be in the form of hydrofluoric acid HF or its salts.
• the zinc content is preferably 0.5 to 1.7 g / l.
• the phosphating solution used for dipping contains 1 to 2 g / l Zn 2+ and the phosphating solution used for spraying contains 0.5 to 1.5 g / l Zn 2+ .
• the method according to the invention produces particularly good results when the phosphating solution contains 3 to 15 g / l NO 3 " .
• a phosphating solution which, in addition to the components already mentioned, preferably 0.5 to 1.3 g / l Ni 2+ , 12 to 16 g / l phosphate (calculated as P 2 O 5 ), 5 to 1.3 g / l Mn 2+ and 0.2 to 1.0 g / l F " and / or 0.8 to 2.0 g / l SiF 6 2 ' contains.
• Hydroxylamine can be used as a free base, as a hydroxylamine complex or in the form of hydroxylammonium salts. If free hydroxylamine is added to the phosphating solution or the concentrate of this solution, it becomes are largely present as hydroxylammonium ion due to the acidic nature of these solutions. When using hydroxylammonium salts, the sulfates and phosphates are particularly suitable.
• the hydroxylamine content is preferably up to 0.3 g / l.
• the nitrate can be added to the phosphating solution as HN0 3 or as nitrate of zinc, manganese and / or nickel.
• Zinc, manganese and nickel can also be used in the form of their oxides and / or carbonates for the preparation of the phosphating solution.
• the phosphate is used as phosphoric acid or in the form of soluble phosphates.
• SiF 6 2 " is used, for example, as H 2 SiF 6 for the preparation of the phosphating solution.
• Cations of zinc, nickel and manganese can contain the phosphating solution alkali metal and / or ammonium cations in order to adjust the free acid (FS) content, which is in the range of 0.5 to 3.5 points in the process according to the invention.
• free acid is generally used in the field of phosphating.
• the free acid score is the number of ml that results when 10 ml of phosphating solution, which has been diluted to 50 ml with deionized water, are titrated with 0.1 normal sodium hydroxide solution to a pH of 4.2. whereby KCI is added to the sample to be titrated until saturation is present in the sample when complex-bound fluoride is present in order to largely avoid its dissociation.
• Table 1 shows the composition of the phosphating solutions used and those used in the
• Examples 1 to 4 are comparative examples, while Examples 5 and 6 were carried out in accordance with the method according to the invention.
• the phosphating results show the following:
• Comparative Examples 1 and 3 which - as recommended by the prior art - have a low nitrate content, are, as expected, free of specks, while Example 5 according to the invention is surprisingly free of specks.
• Example 2 the problem of speck formation is not relevant, since specks are not formed on Al surfaces anyway.
• Comparative Examples 2 and 4 although they were carried out according to the prior art - have a non-closed and thus an unusable phosphate layer, since the layer only covers 20% of the Al surface; consequently the layer weight could not be determined either.
• Example 6 according to the invention has a closed phosphate layer with an advantageous layer weight, although the phosphating solution had only a low hydroxylamine content and a high nitrate content.
• Comparative Example 1 since it used a high hydroxylamine content and a low nitrate content in a known manner - has a closed phosphate layer with an advantageous layer weight.
• the phosphate layer has a relatively dark color. This is disadvantageous if after the phosphating bright single-layer paints on the
• Comparative Example 3 has a closed phosphate layer, but the layer weight is too high, although the phosphating solution had both a low hydroxylamine content and a low nitrate content. In addition, the phosphate layer has an undesirable dark gray color.
• Example 5 according to the invention has a closed phosphate layer with an advantageous layer weight and is colored light gray in the desired manner.

Applications Claiming Priority (3)

Publications (2)

Family

ID=7897026

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (11)

• 1999
  • 1999-02-10 DE DE19905479A patent/DE19905479A1/de not_active Withdrawn
• 2000
  • 2000-02-03 CA CA002362556A patent/CA2362556A1/fr not_active Abandoned
  • 2000-02-03 DE DE50004321T patent/DE50004321D1/de not_active Expired - Fee Related
  • 2000-02-03 AU AU26694/00A patent/AU2669400A/en not_active Abandoned
  • 2000-02-03 AT AT00905014T patent/ATE253651T1/de not_active IP Right Cessation
  • 2000-02-03 WO PCT/EP2000/000865 patent/WO2000047799A1/fr active IP Right Grant
  • 2000-02-03 EP EP00905014A patent/EP1155163B1/fr not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events