CA2453138A1 - Corrosion protection agent and corrosion protection method for metal surfaces - Google Patents
Corrosion protection agent and corrosion protection method for metal surfaces Download PDFInfo
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- CA2453138A1 CA2453138A1 CA002453138A CA2453138A CA2453138A1 CA 2453138 A1 CA2453138 A1 CA 2453138A1 CA 002453138 A CA002453138 A CA 002453138A CA 2453138 A CA2453138 A CA 2453138A CA 2453138 A1 CA2453138 A1 CA 2453138A1
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- treatment
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- vinylpyrrolidone
- corrosion protection
- metal surfaces
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- 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
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- 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
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- 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
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- 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
- C23C22/361—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 titanium, zirconium or hafnium compounds
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- 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
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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)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Paints Or Removers (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
Abstract
The invention relates to an agent and method for carrying out the corrosion protection treatment of a metal surface. The invention is characterized in that the metal surface is brought into contact with a homopolymer or copolymer of vinyl pyrrolidone, whereby the application solution contains: a) 0.02 to 20 g/l phosphoric acid and/or at least one fluoro acid of one or more elements of the group Zr, Ti, Hf and Si or of each of their anions, and; b) 10 to 49.9 mg/l of a homopolymer or copolymer of vinyl pyrrolidone.
Description
i .. r CA 02453138 2003-12-12 t "Anticorrosive agent and corrosion protection process for metal surfaces"
This invention relates to the field of corrosion protection treatment of metal surfaces. One aspect of the invention involves depositing an anticorrosive layer onto the bare metal surface. A second aspect of the invention involves enhancing the anticorrosive action of an anticorrosive layer already deposited onto the metal surface. A
particular feature of the invention is that no toxic heavy metals, such as chromium or nickel, have to be used.
There is extensive prior art relating to the deposition of anticorrosive layers onto bare metal surfaces and to the rinsing of already coated metal surfaces in order to increase corrosion protection. Some examples of documents which deal in particular with the chromium-free treatment of aluminum surfaces are given below. The term "conversion treatment" used in this connection indicates that components of the treatment solution react chemically with the metal surface, resulting in the formation of an anticorrosive layer into which both components of the treatment solution and metal atoms from the metal surface are incorporated.
The chromium-free conversion treatment of aluminum surfaces with fluorides of boron, silicon, titanium or zirconium, alone or in combination with organic polymers, in order to achieve a permanent corrosion protection and to produce a ' .. , CA 02453138 2003-12-12 v foundation for a subsequent coating is in principle known.
US-A-5 129 967 discloses treatment baths for a no-rinse treatment (therein referred to as "dried in place conversion coating") of aluminum, containing:
a) 10 to 16 g/1 polyacrylic acid or homopolymers thereof, b) 12 to 19 g/1 hexafluorozirconic acid, c) 0.17 to 0.3 g/1 hydrofluoric acid and d) up to 0.6 g/1 hexafluorotitanic acid.
EP-B-8 942 discloses treatment solutions, preferably for aluminum cans, containing:
a) 0.5 to 10 g/1 polyacrylic acid or an ester thereof, and b) 0.2 to 8 g/1 of at least one of the compounds H2ZrF6, HaTiFs and HzSiF6, wherein the pH of the solution is below 3.5, as well as an aqueous concentrate for replenishing the treatment solution, containing:
a) 25 to 100 g/1 polyacrylic acid or an ester thereof, b) 25 to 100 g/1 of at least one of the compounds H2ZrF6, HZTiFs and H2SiF6, and c) a source of free fluoride ions which provides 17 to 120 g/1 free fluoride.
DE-C-19 33 013 discloses treatment baths having a pH of above 3.5 which, besides complex fluorides of boron, titanium or zirconium in quantities of 0.1 to 15 g/1, based on the metals, contain in addition 0.5 to 30 g/1 oxidising agent, in particular sodium metanitrobenzenesulfonate.
DE-C-24 33 704 describes treatment baths for increasing the coating adhesion and the permanent corrosion protection on, inrP a~;a, aluminum; these baths may contain 0.1 to 5 g/1 polyacrylic acid or salts or esters thereof, as well as 0.1 .,_ , CA 02453138 2003-12-12 to 3.5 g/1 ammonium fluorozirconate, calculated as Zr02. The pH of these baths may vary over a wide range. The best results are generally obtained when the pH is from 6 to 8.
US-A-4 992 116 describes treatment baths for the conversion treatment of aluminum having a pH of between about 2.5 and 5, which contain at least three components:
a) phosphate ions within the concentration range of between 1.1 x 10'5 and 5.3 x 10'3 mol/1, corresponding to 1 to 500 mg/1, b) 1.1 x 10'5 to 1.3 x 10'' mol/1 of a fluoric acid of an element selected from Zr, Ti, Hf and Si (corresponding to 1.6 to 380 mg/1, depending on the element), and c) 0.26 to 20 g/1 of a polyphenol compound, obtainable by the reaction of poly(vinylphenol) with aldehydes and organic amines.
Here, a molar ratio of fluoric acid to phosphate of about 2.5:1 up to 1:10 is to be maintained.
DE-A-27 15 292 discloses treatment baths for the chromium-free preliminary treatment of aluminum cans. These baths contain at least 10 ppm titanium and/or zirconium, between 10 and 1000 ppm phosphate and a quantity~of fluoride sufficient for the formation of complex fluorides of the titanium and/or zirconium present, but at least 13 ppm, and have a pH of between 1.5 and 4.
WO 92/07973 discloses a chromium-free treatment process for aluminum which uses from 0.01 to about 18 wt.% H2ZrF6 and from 0.01 to about 10 wt.% of a 3-(N-Cl_,-alkyl-N-2-hydroxyethylaminomethyl)-4-hydroxystyrene polymer as essential components in acidic aqueous solution. Optional components are 0.05 to 10 wt.% dispersed Si02, 0.06 to 0.6 wt.% of a solubiliser for the polymer as well as a surfactant.
',~, , CA 02453138 2003-12-12 Notwithstanding this extensive prior art, of which only extracts are reported here, there is still a need for improved agents and processes for the corrosion protection treatment of metal surfaces.
The previously unpublished German Patent Application DE 100 05 113 is based on the finding that homo- or copolymers of vinylpyrrolidone have an excellent anticorrosive action. In a first aspect, that invention relates to a process for the corrosion protection treatment of a metal surface, which is characterised in that the metal surface is contacted with a homo- or copolymer of vinylpyrrolidone. Here, in a first embodiment of the invention, the metal surface may first of all be subjected to a conversion treatment according to prior art, for example, a phosphating using zinc or iron, a conversion treatment using fluoric acids of metals, for example, of titanium, zirconium or hafnium, or even of boron or silicon, or a treatment using a solution or suspension of an organic polymer which contains no vinylpyrrolidone units. Examples of such polymers are given in the literature cited in the introduction.
An alternative embodiment of the cited invention involves contacting the metal surface with a homo- or copolymer of vinylpyrrolidone at the same time that the metal surface is being subjected to a conversion treatment. In this case, the homo- or copolymer is therefore present in the treatment solution by means of which a conversion layer is produced on the metal surface. The treatment solution for the production of the conversion layer may contain, for example, phosphoric acid or anions thereof. Divalent cations, such as zinc and/or manganese, may also be present in the treatment solution. A particular example of such a treatment solution for the production of a conversion layer is a zinc phosphating solution, which produces a crystalline layer of zinc-containing metal phosphates on the metal surface. The treatment solution may, however, ", , CA 02453138 2003-12-12 also contain phosphoric acid and/or anions thereof, but no divalent metals. An example of this is an iron phosphating solution, which produces a substantially non-crystalline layer of metal phosphates and/or metal oxides on a metal 5 surface, in particular an iron-containing surface. The presence of homo- or copolymers of vinylpyrrolidone in such a treatment solution improves the corrosion protection achieved by the conversion layer. This also applies if the treatment solution, in addition to homo- or copolymers of vinylpyrrolidone, contains fluoric acids and/or complex fluorides of metals and semi-metals, such as boron, silicon, titanium, zirconium and/or hafnium, as components forming the conversion layer.
According to DE 100 05 113 cited above, the ready-to-use solution for treating metal surfaces preferably contains between 0.05 and 200 g/1 of a homo- or copolymer of vinylpyrrolidone. The set object of the present invention is to improve on the subject matter of DE 100 05 113 with regard to the efficiency of the chemicals used.
The present invention relates to an agent for treating metal surfaces, which contains phosphoric acid and/or at least one fluoric acid of one or more elements selected from Zr, Ti, Hf and Si or the respective anions thereof, as well as a homo- or copolymer of vinylpyrrolidone, characterised in that it is in the form of a ready-to-use solution for application, containing a) 0.02 to 20 g/1 phosphoric acid and/or at least one fluoric acid of one or more elements selected from Zr, Ti, Hf and Si or the respective anions thereof, as well as b) 10 to 49.9 mg/1 of a homo- or copolymer of vinylpyrrolidone.
Where phosphoric acid is present, the agent for treating metal surfaces is a phosphating solution. If this does not contain ions of divalent metals, such as zinc and/or manganese, it is a so-called "non-layer-forming"
..., , CA 02453138 2003-12-12 phosphating solution, for example, it may be in the form of an iron phosphating solution. Phosphating solutions containing zinc and/or manganese, which contain, for example, 0.3 to 2 g/1 zinc ions and, if desired, in addition to or instead of this about the same concentration of manganese ions, are referred to as so-called "layer-forming" phosphating solutions in the field of conversion treatment. The treatment solution may also contain one or more fluoric acids of one or more elements selected from Zr, Ti, Hf and Si, together with or instead of phosphoric acid. Depending on the adjusted pH of the solution, both phosphoric acid and the above-mentioned fluoric acids are present partly in the form of singly or multiply negatively charged anions. The ratio of acidic anions to undissociated acid depends on the protolysis constant of the respective acid and on the pH actually established. This phenomenon is generally known as the acid-base equilibrium. In addition to the above-mentioned essential components, the agents contain water and, if desired, other active components or auxiliary substances in order to adjust the pH, increase the anticorrosive action, improve the ease of application and possibly for other purposes.
If the agents according to the invention contain copolymers of vinylpyrrolidone, these copolymers may contain one or more other monomers in addition to vinylpyrrolidone. They may therefore be, for example, copolymers comprising 2 components or copolymers comprising 3 components (= terpolymers). Mixtures of homopolymers and two-component copolymers, of homopolymers and terpolymers or of two-component polymers and terpolymers, may also be used.
The ready-to-use agent can be obtained by diluting a concentrate; this is the subject matter of the previously unpublished German Patent Application DE 100 05 113.
Depending on the specific composition, it may be that concentrates which already contain all the active components are not sufficiently stable in storage for long ., CA 02453138 2003-12-12 periods. In these cases, it is preferable to divide the concentrates up into at least two components, each containing selected components of the ready-to-use anticorrosive agent. For example, it may be advisable that one component of the concentrate contain at least predominantly the inorganic constituents of the agent, while at least one other component of the concentrate contains the organic polymers. The two components of the concentrate may then have different pH values, thus enabling the stability of the concentrate components in storage to be enhanced. In order to prepare or to replenish the agent in its ready-to-use form, the individual components of the concentrate are diluted with water to the extent that the active components are present in the required concentration range. Here, it may be necessary to adjust the pH to within the required range by adding an acid or a lye.
Preferred concentration ranges for the active components a) and b) in the solution for application, in the case of phosphoric acid or phosphate ions, are 5 to 20 g/1, in particular 8 to 16 g/1 phosphate ions, and in the case of the fluoric acids are a quantity such that Zr, Ti, Hf and/or Si, based on these elements, are present in a concentration within the range of between 20 and 1000 mg/1, in particular 50 to 400 mg/1. The concentration of the homo- or copolymers of vinylpyrrolidone in the solution for application is preferably within the range of 20 to 45 mg/1.
Suitable homo- or copolymers of vinylpyrrolidone are, for example, the polymers listed in Table 1 or polymers of the monomers named therein.
Tab1_e 1: Examples of homo- or copolymers of vinylpyrrolidone '... , CA 02453138 2003-12-12 Name Trade name and manufacturer Vinylpyrrolidone, homopolymer Luviskol~, BASF/
ISP
Vinylpyrrolidone/Vinyl acetate Luviskol~, BASF/
ISP
Vinylpyrrolidone/Vinylcaprolactam Luvitec~, BASF
Vinylpyrrolidone/Vinylimidazole Luvitec~, BASF
Vinylpyrrolidone/Vinylimidazolium methyl sulfateLuvitec~, BASF
Vinylpyrrolidone/Na methacrylate Luvitec~, BASF
Vinylpyrrolidonelolefins ISP~, Antaron Vinylpyrrolidone/Dimethylaminoethyl methacrylateISP~
Vinylpyrrolidone/DimethylaminopropylmethacrylamideISP~, Styleze Vinylpyrrolidone/Dimethylaminoethyl methacrylate,ISP~, Gafquat ammonium salt Vinylpyrrolidone/Vinylcaprolactam/DimethylaminoethylISP~
methacrylate VinylpyrrolidonelMethacrylamidopropyltrimethyl-ISP~, Gafquat ammonium chloride Vinylpyrrolidone/Vinylcaprolactam/DimethylaminoethylISP~, Advantage methacrylate Vinylpyrrolidone/Styrene ISP~, Antara In order to increase the corrosion protection, the agents according to the invention may contain other transition metal ions, such as ions of the elements zinc, manganese, cerium or vanadium, also hydrofluoric acid or free fluorides. The presence of chromium ions or nickel ions may in principle also have advantages. However, for reasons of industrial safety and environmental protection, the addition of chromium ions or nickel ions is preferably .. CA 02453138 2003-12-12 avoided. Consequently, in a preferred embodiment of the invention, the agent is free from nickel and chromium. This means that these metals or compounds thereof are not intentionally added to the agent. The possibility cannot be ruled out, however, that ions of nickel and/or chromium, originating from the material of the tank or from the surfaces to be treated, such as steel alloys, will enter the agent (the treatment solution) in low concentrations.
However, in practice, it is anticipated that the concentrations of nickel and/or chromium in the ready-to-use treatment solution will not be more than about 10 ppm.
The ready-to-use agent according to the invention has a pH
preferably in the range of 1 to 6 and in particular in the range of 2 to 5.5. This means that the fluoric acids of the elements Zr, Ti, Hf or Si, depending on pH and protolysis constants, are partly in the form of the free acids, but partly in the form of the acidic anions thereof. It is therefore irrelevant whether these fluoric acids are used as such or in the form of the salts. Furthermore, acid-soluble compounds of Zr, Ti, Hf or Si, as well as hydrofluoric acid or soluble fluorides may be added separately, as the fluoro anions of the above-mentioned elements can be formed from these. Depending on the method of use, the pH has to be adjusted to the desired range by addition of acid, such as the free fluoric acids of the above-mentioned elements, but even, for example, hydrofluoric acid, sulfuric acid, nitric acid or phosphoric acid or by addition of a base, such as alkali metal carbonate solution, alkali metal hydroxide solution or ammonia.
By reason of the especially good anticorrosive action of homo- or copolymers of vinylpyrrolidone which contain caprolactam groups, in a particular embodiment the agent according to the invention contains homo- or copolymers of vinylpyrrolidone containing caprolactam groups.
.- CA 02453138 2003-12-12 A further aspect of the invention is a process for treating metal surfaces, wherein the metal surfaces which, if desired, may already carry an anticorrosive layer, are 5 contacted with the above-mentioned agent. The metal surfaces may be selected, for example, from surfaces made of steel, zinc-plated steel (electroplated or hot-dip galvanised), steel coated with zinc alloy, or of aluminum or magnesium. Here, the metals aluminum and magnesium are 10 generally not in pure form, but in the form of alloys with other elements, such as lithium, zinc, copper, silicon, magnesium (in the case of aluminum alloys) or aluminum (in the case of magnesium alloys). The process is envisaged in particular for the treatment of surfaces made of those metals which are used in the construction of vehicles, in the household appliance industry, or in the field of architecture or furnishings.
In this connection, those metal surfaces which as yet have no anticorrosive layer may be treated. The treatment process according to the invention then produces an anticorrosive coating, which at the same time improves the adhesion of an organic coating, such as a lacquer, optionally to be applied subsequently. However, those metal surfaces which already have a previously formed anticorrosive layer may also be treated by the process according to the invention. In this case, the anticorrosive action of this previously applied anticorrosive layer is further improved. For example, the process according to the invention is suitable for the aftertreatment of metal surfaces which have an X-ray-amorphous or crystalline coating, such as are produced, for example, by a non-layer-forming or a layer-forming phosphating, for instance, a layer-forming zinc phosphating. The treatment according to the invention of such pretreated metal surfaces results in the closure of the pores remaining in the initial anticorrosive layer after the pretreatment.
' CA 02453138 2003-12-12 ZZ
In the treatment process according to the invention, the metal surfaces may be contacted with the treatment solution, for example, by spraying or dipping. In this case, it is preferable to arrange that the treatment solution be rinsed off with water after a contact time, which may range, for example, from 30 seconds to 5 minutes.
Alternatively, the treatment solution may be contacted with the metal surface in the so-called no-rinse process. Here, the treatment solution is either sprayed onto the metal surface or transferred onto the surface by spreading rollers. After a contact time, which may range, for example, from 2 to 20 seconds, the treatment solution is then dried without further intermediate rinsing. This may take place, for example, in a heated furnace.
For the treatment process according to the invention, the treatment solution has a pH preferably in the range of 1 to 6. However, narrower pH ranges may be preferred, depending on the substrate and method of application and the contact time. For example, the pH is adjusted preferably to within the range of 2 to 6 for the treatment of bare metal surfaces; in particular to within the range of 2 to 4 for the treatment of aluminum surfaces and in particular to within the range of 3 to 5 for the treatment of steel, zinc or zinc-plated steel. Already pretreated metal surfaces having, for example, a phosphate layer, are preferably contacted with a treatment solution having a pH in the range of 3.5 to 5. The temperature of the treatment solution in the course of the process according to the invention may generally be between the freezing point and the boiling point of the treatment solution, temperatures in the region of room temperature or above being preferred for practical reasons. For example, the temperature of the treatment solution may be within the range of 15~C to 60~C
and in particular from 20~C to 45~C.
The treatment process according to the invention is one step in an otherwise conventional sequence of steps in the field concerned. For example, the metal surfaces to be treated are usually cleaned using a conventional cleaning solution prior to the treatment according to the invention.
However, the cleaning step may be omitted if, immediately before the treatment according to the invention, the metal surfaces to be treated are coated, for example, zinc-plated, or are subjected to a conversion treatment, for example, a phosphating. After the treatment step according to the invention, the metal surfaces are conventionally coated with an organic coating, for instance, a lacquer.
This may be a powder coating, for example, or an electrolytically, especially cathodically, precipitable electrophoretic coating.
A particularly preferred procedure in carrying out the process according to the invention involves treating the metal surface with an aqueous solution of an acid prior to its being contacted with the above-mentioned agent in order to produce a conversion layer, i.e. during a conversion treatment. The inserted processing step, involving the treatment of the metal surface with an aqueous solution of an acid prior to the conversion treatment, is also referred to in the industry as "acid pickling" or "pickle passivation'. Acids which are conventionally used for acid pickling or pickle passivation can be employed for this purpose in the procedure according to the invention. An example of these is phosphoric acid.
Examples: Use as a conversion treatment Conversion process with previous pickle passivation Substrates: Hot-dip galvanised steel (HDG), electrolytically galvanised steel (EG), aluminum (AC120), cold-rolled steel (CRS) Order of procedure (spray application):
1. Cleaning: Ridolinem 1570, 3%; 82 seconds, 55~C
Ridosol~ 1270, 0.3% (commercial metal cleaner manufactured by the Applicant) 2. Rinse deionised water 3. Pickle passivation: phosphoric acid, 0.23%, 82 seconds 4. Rinse deionised water 5. Conversion treatment: 108 seconds; 30~C, using an aqueous solution containing H2ZrF6 acid (45%; 1.38 g/1) vinylpyrrolidone/vinylcaprolactam polymer (37 mg/1 solids content) 6. Rinse deionised water 7. Drying: compressed air 8. Coating: lead-free cathodic electrophoretic coating (BASF CG 310) Thickness of coating: 20-23 ~.m ~~-xamOrder of procedure as above, but without steps 3 and 4 ('nrrnei nn tPRt ~_ Galvanised substrates: Coating adhesion after storage in salt water Aluminum Copper-accelerated salt spray test LASS
DIN 50021, 10 days Steel salt spray test SS DIN 50021, 21 days Results: Creepage along scribe (half scribe width):
U/2 in mm; Results of the stone-impact test for coating adhesion (K value, K = 1: best coating adhesion, K = 10:
worst coating adhesion) Example U/2 mm R R U/2 xmn With step 3, 4 0.7 8 9 0.8 Without step 3, 1.6 10 10 0.9 F_xan=y Conversion process with subsequent powder coating (galvanised steel) using copolymer mixtures Substrates: CRS, EG, HDG
Order of procedure (dipping application):
1. Cleaning: Ridoline~ 1570, 2%; Ridosol~ 1237, 0.3%; 5 minutes; 55~C (commercial metal cleaner manufactured by the Applicant) 2. Rinse deionised water 3. Conversion treatment: 180 seconds; 30~C, using one of the following bath formulations H2ZrF6 acid (45%; 1.38 g/1) vinylpyrrolidone/vinylcaprolactam copolymer (= Pa) +
vinylpyrrolidone/vinylimidazole copolymer (= Pb) (37 mg/1 solids content) 4. Rinse deionised water 5. Drying: compressed air 6. Coating: Polyester PES 5807/RAL 5009 GL (TIGC-f ree , product of the firm of Herbert ) ;
approx . 6 0 - 8 0 ~,m orro~ion Neutral salt spray test DIN 50021 SS, 21 days . CA 02453138 2003-12-12 Results: Creepage of paint along scribe, half scribe width;
coating adhesion by the cross-cut adhesion test Example Creepage Cross-cut (scale 0 to 5) CRS 1.7 mm 0 EG 2.5 mm 0 HDG 1.8 mm 0 5 The proportions of polymers can be varied, for example between homo- and/or copolymers Pa% = 100% - Pb%, with Pa>0.
,xa ~ Conversion process using copolymer mixtures (powder coating) Substrate: CRS
Order of procedure (dipping application):
1. Cleaning: Ridoline~ 1570, 2%; Ridosol~ 1237, 0.3%; 5 minutes; 55~C
2. Rinse deionised water 3. Conversion treatment:
180 s; 30~C, using one of the bath formulations according to the Table below H2ZrF6 acid (45%; 1.38 g/1) + vinylpyrrolidone/vinylcaprolactam copolymer (= Pb) +
vinylpyrrolidone/vinylimidazole copolymer (= Pa) (22 mg/1 solids content ) 4. Rinse deionised water 5. Drying: compressed air 6. Coating: Polyester PES 5807/RAL 5009 GL (TIGC-free, product of the firm of Herbert);
approx . 6 0 - 8 0 ~.m ~nrro~ion Neutral salt spray test DIN 50021 SS, 21 days Polymer Creepage 100% Pa 3.9 mm 70% Pa 2.3 mm
This invention relates to the field of corrosion protection treatment of metal surfaces. One aspect of the invention involves depositing an anticorrosive layer onto the bare metal surface. A second aspect of the invention involves enhancing the anticorrosive action of an anticorrosive layer already deposited onto the metal surface. A
particular feature of the invention is that no toxic heavy metals, such as chromium or nickel, have to be used.
There is extensive prior art relating to the deposition of anticorrosive layers onto bare metal surfaces and to the rinsing of already coated metal surfaces in order to increase corrosion protection. Some examples of documents which deal in particular with the chromium-free treatment of aluminum surfaces are given below. The term "conversion treatment" used in this connection indicates that components of the treatment solution react chemically with the metal surface, resulting in the formation of an anticorrosive layer into which both components of the treatment solution and metal atoms from the metal surface are incorporated.
The chromium-free conversion treatment of aluminum surfaces with fluorides of boron, silicon, titanium or zirconium, alone or in combination with organic polymers, in order to achieve a permanent corrosion protection and to produce a ' .. , CA 02453138 2003-12-12 v foundation for a subsequent coating is in principle known.
US-A-5 129 967 discloses treatment baths for a no-rinse treatment (therein referred to as "dried in place conversion coating") of aluminum, containing:
a) 10 to 16 g/1 polyacrylic acid or homopolymers thereof, b) 12 to 19 g/1 hexafluorozirconic acid, c) 0.17 to 0.3 g/1 hydrofluoric acid and d) up to 0.6 g/1 hexafluorotitanic acid.
EP-B-8 942 discloses treatment solutions, preferably for aluminum cans, containing:
a) 0.5 to 10 g/1 polyacrylic acid or an ester thereof, and b) 0.2 to 8 g/1 of at least one of the compounds H2ZrF6, HaTiFs and HzSiF6, wherein the pH of the solution is below 3.5, as well as an aqueous concentrate for replenishing the treatment solution, containing:
a) 25 to 100 g/1 polyacrylic acid or an ester thereof, b) 25 to 100 g/1 of at least one of the compounds H2ZrF6, HZTiFs and H2SiF6, and c) a source of free fluoride ions which provides 17 to 120 g/1 free fluoride.
DE-C-19 33 013 discloses treatment baths having a pH of above 3.5 which, besides complex fluorides of boron, titanium or zirconium in quantities of 0.1 to 15 g/1, based on the metals, contain in addition 0.5 to 30 g/1 oxidising agent, in particular sodium metanitrobenzenesulfonate.
DE-C-24 33 704 describes treatment baths for increasing the coating adhesion and the permanent corrosion protection on, inrP a~;a, aluminum; these baths may contain 0.1 to 5 g/1 polyacrylic acid or salts or esters thereof, as well as 0.1 .,_ , CA 02453138 2003-12-12 to 3.5 g/1 ammonium fluorozirconate, calculated as Zr02. The pH of these baths may vary over a wide range. The best results are generally obtained when the pH is from 6 to 8.
US-A-4 992 116 describes treatment baths for the conversion treatment of aluminum having a pH of between about 2.5 and 5, which contain at least three components:
a) phosphate ions within the concentration range of between 1.1 x 10'5 and 5.3 x 10'3 mol/1, corresponding to 1 to 500 mg/1, b) 1.1 x 10'5 to 1.3 x 10'' mol/1 of a fluoric acid of an element selected from Zr, Ti, Hf and Si (corresponding to 1.6 to 380 mg/1, depending on the element), and c) 0.26 to 20 g/1 of a polyphenol compound, obtainable by the reaction of poly(vinylphenol) with aldehydes and organic amines.
Here, a molar ratio of fluoric acid to phosphate of about 2.5:1 up to 1:10 is to be maintained.
DE-A-27 15 292 discloses treatment baths for the chromium-free preliminary treatment of aluminum cans. These baths contain at least 10 ppm titanium and/or zirconium, between 10 and 1000 ppm phosphate and a quantity~of fluoride sufficient for the formation of complex fluorides of the titanium and/or zirconium present, but at least 13 ppm, and have a pH of between 1.5 and 4.
WO 92/07973 discloses a chromium-free treatment process for aluminum which uses from 0.01 to about 18 wt.% H2ZrF6 and from 0.01 to about 10 wt.% of a 3-(N-Cl_,-alkyl-N-2-hydroxyethylaminomethyl)-4-hydroxystyrene polymer as essential components in acidic aqueous solution. Optional components are 0.05 to 10 wt.% dispersed Si02, 0.06 to 0.6 wt.% of a solubiliser for the polymer as well as a surfactant.
',~, , CA 02453138 2003-12-12 Notwithstanding this extensive prior art, of which only extracts are reported here, there is still a need for improved agents and processes for the corrosion protection treatment of metal surfaces.
The previously unpublished German Patent Application DE 100 05 113 is based on the finding that homo- or copolymers of vinylpyrrolidone have an excellent anticorrosive action. In a first aspect, that invention relates to a process for the corrosion protection treatment of a metal surface, which is characterised in that the metal surface is contacted with a homo- or copolymer of vinylpyrrolidone. Here, in a first embodiment of the invention, the metal surface may first of all be subjected to a conversion treatment according to prior art, for example, a phosphating using zinc or iron, a conversion treatment using fluoric acids of metals, for example, of titanium, zirconium or hafnium, or even of boron or silicon, or a treatment using a solution or suspension of an organic polymer which contains no vinylpyrrolidone units. Examples of such polymers are given in the literature cited in the introduction.
An alternative embodiment of the cited invention involves contacting the metal surface with a homo- or copolymer of vinylpyrrolidone at the same time that the metal surface is being subjected to a conversion treatment. In this case, the homo- or copolymer is therefore present in the treatment solution by means of which a conversion layer is produced on the metal surface. The treatment solution for the production of the conversion layer may contain, for example, phosphoric acid or anions thereof. Divalent cations, such as zinc and/or manganese, may also be present in the treatment solution. A particular example of such a treatment solution for the production of a conversion layer is a zinc phosphating solution, which produces a crystalline layer of zinc-containing metal phosphates on the metal surface. The treatment solution may, however, ", , CA 02453138 2003-12-12 also contain phosphoric acid and/or anions thereof, but no divalent metals. An example of this is an iron phosphating solution, which produces a substantially non-crystalline layer of metal phosphates and/or metal oxides on a metal 5 surface, in particular an iron-containing surface. The presence of homo- or copolymers of vinylpyrrolidone in such a treatment solution improves the corrosion protection achieved by the conversion layer. This also applies if the treatment solution, in addition to homo- or copolymers of vinylpyrrolidone, contains fluoric acids and/or complex fluorides of metals and semi-metals, such as boron, silicon, titanium, zirconium and/or hafnium, as components forming the conversion layer.
According to DE 100 05 113 cited above, the ready-to-use solution for treating metal surfaces preferably contains between 0.05 and 200 g/1 of a homo- or copolymer of vinylpyrrolidone. The set object of the present invention is to improve on the subject matter of DE 100 05 113 with regard to the efficiency of the chemicals used.
The present invention relates to an agent for treating metal surfaces, which contains phosphoric acid and/or at least one fluoric acid of one or more elements selected from Zr, Ti, Hf and Si or the respective anions thereof, as well as a homo- or copolymer of vinylpyrrolidone, characterised in that it is in the form of a ready-to-use solution for application, containing a) 0.02 to 20 g/1 phosphoric acid and/or at least one fluoric acid of one or more elements selected from Zr, Ti, Hf and Si or the respective anions thereof, as well as b) 10 to 49.9 mg/1 of a homo- or copolymer of vinylpyrrolidone.
Where phosphoric acid is present, the agent for treating metal surfaces is a phosphating solution. If this does not contain ions of divalent metals, such as zinc and/or manganese, it is a so-called "non-layer-forming"
..., , CA 02453138 2003-12-12 phosphating solution, for example, it may be in the form of an iron phosphating solution. Phosphating solutions containing zinc and/or manganese, which contain, for example, 0.3 to 2 g/1 zinc ions and, if desired, in addition to or instead of this about the same concentration of manganese ions, are referred to as so-called "layer-forming" phosphating solutions in the field of conversion treatment. The treatment solution may also contain one or more fluoric acids of one or more elements selected from Zr, Ti, Hf and Si, together with or instead of phosphoric acid. Depending on the adjusted pH of the solution, both phosphoric acid and the above-mentioned fluoric acids are present partly in the form of singly or multiply negatively charged anions. The ratio of acidic anions to undissociated acid depends on the protolysis constant of the respective acid and on the pH actually established. This phenomenon is generally known as the acid-base equilibrium. In addition to the above-mentioned essential components, the agents contain water and, if desired, other active components or auxiliary substances in order to adjust the pH, increase the anticorrosive action, improve the ease of application and possibly for other purposes.
If the agents according to the invention contain copolymers of vinylpyrrolidone, these copolymers may contain one or more other monomers in addition to vinylpyrrolidone. They may therefore be, for example, copolymers comprising 2 components or copolymers comprising 3 components (= terpolymers). Mixtures of homopolymers and two-component copolymers, of homopolymers and terpolymers or of two-component polymers and terpolymers, may also be used.
The ready-to-use agent can be obtained by diluting a concentrate; this is the subject matter of the previously unpublished German Patent Application DE 100 05 113.
Depending on the specific composition, it may be that concentrates which already contain all the active components are not sufficiently stable in storage for long ., CA 02453138 2003-12-12 periods. In these cases, it is preferable to divide the concentrates up into at least two components, each containing selected components of the ready-to-use anticorrosive agent. For example, it may be advisable that one component of the concentrate contain at least predominantly the inorganic constituents of the agent, while at least one other component of the concentrate contains the organic polymers. The two components of the concentrate may then have different pH values, thus enabling the stability of the concentrate components in storage to be enhanced. In order to prepare or to replenish the agent in its ready-to-use form, the individual components of the concentrate are diluted with water to the extent that the active components are present in the required concentration range. Here, it may be necessary to adjust the pH to within the required range by adding an acid or a lye.
Preferred concentration ranges for the active components a) and b) in the solution for application, in the case of phosphoric acid or phosphate ions, are 5 to 20 g/1, in particular 8 to 16 g/1 phosphate ions, and in the case of the fluoric acids are a quantity such that Zr, Ti, Hf and/or Si, based on these elements, are present in a concentration within the range of between 20 and 1000 mg/1, in particular 50 to 400 mg/1. The concentration of the homo- or copolymers of vinylpyrrolidone in the solution for application is preferably within the range of 20 to 45 mg/1.
Suitable homo- or copolymers of vinylpyrrolidone are, for example, the polymers listed in Table 1 or polymers of the monomers named therein.
Tab1_e 1: Examples of homo- or copolymers of vinylpyrrolidone '... , CA 02453138 2003-12-12 Name Trade name and manufacturer Vinylpyrrolidone, homopolymer Luviskol~, BASF/
ISP
Vinylpyrrolidone/Vinyl acetate Luviskol~, BASF/
ISP
Vinylpyrrolidone/Vinylcaprolactam Luvitec~, BASF
Vinylpyrrolidone/Vinylimidazole Luvitec~, BASF
Vinylpyrrolidone/Vinylimidazolium methyl sulfateLuvitec~, BASF
Vinylpyrrolidone/Na methacrylate Luvitec~, BASF
Vinylpyrrolidonelolefins ISP~, Antaron Vinylpyrrolidone/Dimethylaminoethyl methacrylateISP~
Vinylpyrrolidone/DimethylaminopropylmethacrylamideISP~, Styleze Vinylpyrrolidone/Dimethylaminoethyl methacrylate,ISP~, Gafquat ammonium salt Vinylpyrrolidone/Vinylcaprolactam/DimethylaminoethylISP~
methacrylate VinylpyrrolidonelMethacrylamidopropyltrimethyl-ISP~, Gafquat ammonium chloride Vinylpyrrolidone/Vinylcaprolactam/DimethylaminoethylISP~, Advantage methacrylate Vinylpyrrolidone/Styrene ISP~, Antara In order to increase the corrosion protection, the agents according to the invention may contain other transition metal ions, such as ions of the elements zinc, manganese, cerium or vanadium, also hydrofluoric acid or free fluorides. The presence of chromium ions or nickel ions may in principle also have advantages. However, for reasons of industrial safety and environmental protection, the addition of chromium ions or nickel ions is preferably .. CA 02453138 2003-12-12 avoided. Consequently, in a preferred embodiment of the invention, the agent is free from nickel and chromium. This means that these metals or compounds thereof are not intentionally added to the agent. The possibility cannot be ruled out, however, that ions of nickel and/or chromium, originating from the material of the tank or from the surfaces to be treated, such as steel alloys, will enter the agent (the treatment solution) in low concentrations.
However, in practice, it is anticipated that the concentrations of nickel and/or chromium in the ready-to-use treatment solution will not be more than about 10 ppm.
The ready-to-use agent according to the invention has a pH
preferably in the range of 1 to 6 and in particular in the range of 2 to 5.5. This means that the fluoric acids of the elements Zr, Ti, Hf or Si, depending on pH and protolysis constants, are partly in the form of the free acids, but partly in the form of the acidic anions thereof. It is therefore irrelevant whether these fluoric acids are used as such or in the form of the salts. Furthermore, acid-soluble compounds of Zr, Ti, Hf or Si, as well as hydrofluoric acid or soluble fluorides may be added separately, as the fluoro anions of the above-mentioned elements can be formed from these. Depending on the method of use, the pH has to be adjusted to the desired range by addition of acid, such as the free fluoric acids of the above-mentioned elements, but even, for example, hydrofluoric acid, sulfuric acid, nitric acid or phosphoric acid or by addition of a base, such as alkali metal carbonate solution, alkali metal hydroxide solution or ammonia.
By reason of the especially good anticorrosive action of homo- or copolymers of vinylpyrrolidone which contain caprolactam groups, in a particular embodiment the agent according to the invention contains homo- or copolymers of vinylpyrrolidone containing caprolactam groups.
.- CA 02453138 2003-12-12 A further aspect of the invention is a process for treating metal surfaces, wherein the metal surfaces which, if desired, may already carry an anticorrosive layer, are 5 contacted with the above-mentioned agent. The metal surfaces may be selected, for example, from surfaces made of steel, zinc-plated steel (electroplated or hot-dip galvanised), steel coated with zinc alloy, or of aluminum or magnesium. Here, the metals aluminum and magnesium are 10 generally not in pure form, but in the form of alloys with other elements, such as lithium, zinc, copper, silicon, magnesium (in the case of aluminum alloys) or aluminum (in the case of magnesium alloys). The process is envisaged in particular for the treatment of surfaces made of those metals which are used in the construction of vehicles, in the household appliance industry, or in the field of architecture or furnishings.
In this connection, those metal surfaces which as yet have no anticorrosive layer may be treated. The treatment process according to the invention then produces an anticorrosive coating, which at the same time improves the adhesion of an organic coating, such as a lacquer, optionally to be applied subsequently. However, those metal surfaces which already have a previously formed anticorrosive layer may also be treated by the process according to the invention. In this case, the anticorrosive action of this previously applied anticorrosive layer is further improved. For example, the process according to the invention is suitable for the aftertreatment of metal surfaces which have an X-ray-amorphous or crystalline coating, such as are produced, for example, by a non-layer-forming or a layer-forming phosphating, for instance, a layer-forming zinc phosphating. The treatment according to the invention of such pretreated metal surfaces results in the closure of the pores remaining in the initial anticorrosive layer after the pretreatment.
' CA 02453138 2003-12-12 ZZ
In the treatment process according to the invention, the metal surfaces may be contacted with the treatment solution, for example, by spraying or dipping. In this case, it is preferable to arrange that the treatment solution be rinsed off with water after a contact time, which may range, for example, from 30 seconds to 5 minutes.
Alternatively, the treatment solution may be contacted with the metal surface in the so-called no-rinse process. Here, the treatment solution is either sprayed onto the metal surface or transferred onto the surface by spreading rollers. After a contact time, which may range, for example, from 2 to 20 seconds, the treatment solution is then dried without further intermediate rinsing. This may take place, for example, in a heated furnace.
For the treatment process according to the invention, the treatment solution has a pH preferably in the range of 1 to 6. However, narrower pH ranges may be preferred, depending on the substrate and method of application and the contact time. For example, the pH is adjusted preferably to within the range of 2 to 6 for the treatment of bare metal surfaces; in particular to within the range of 2 to 4 for the treatment of aluminum surfaces and in particular to within the range of 3 to 5 for the treatment of steel, zinc or zinc-plated steel. Already pretreated metal surfaces having, for example, a phosphate layer, are preferably contacted with a treatment solution having a pH in the range of 3.5 to 5. The temperature of the treatment solution in the course of the process according to the invention may generally be between the freezing point and the boiling point of the treatment solution, temperatures in the region of room temperature or above being preferred for practical reasons. For example, the temperature of the treatment solution may be within the range of 15~C to 60~C
and in particular from 20~C to 45~C.
The treatment process according to the invention is one step in an otherwise conventional sequence of steps in the field concerned. For example, the metal surfaces to be treated are usually cleaned using a conventional cleaning solution prior to the treatment according to the invention.
However, the cleaning step may be omitted if, immediately before the treatment according to the invention, the metal surfaces to be treated are coated, for example, zinc-plated, or are subjected to a conversion treatment, for example, a phosphating. After the treatment step according to the invention, the metal surfaces are conventionally coated with an organic coating, for instance, a lacquer.
This may be a powder coating, for example, or an electrolytically, especially cathodically, precipitable electrophoretic coating.
A particularly preferred procedure in carrying out the process according to the invention involves treating the metal surface with an aqueous solution of an acid prior to its being contacted with the above-mentioned agent in order to produce a conversion layer, i.e. during a conversion treatment. The inserted processing step, involving the treatment of the metal surface with an aqueous solution of an acid prior to the conversion treatment, is also referred to in the industry as "acid pickling" or "pickle passivation'. Acids which are conventionally used for acid pickling or pickle passivation can be employed for this purpose in the procedure according to the invention. An example of these is phosphoric acid.
Examples: Use as a conversion treatment Conversion process with previous pickle passivation Substrates: Hot-dip galvanised steel (HDG), electrolytically galvanised steel (EG), aluminum (AC120), cold-rolled steel (CRS) Order of procedure (spray application):
1. Cleaning: Ridolinem 1570, 3%; 82 seconds, 55~C
Ridosol~ 1270, 0.3% (commercial metal cleaner manufactured by the Applicant) 2. Rinse deionised water 3. Pickle passivation: phosphoric acid, 0.23%, 82 seconds 4. Rinse deionised water 5. Conversion treatment: 108 seconds; 30~C, using an aqueous solution containing H2ZrF6 acid (45%; 1.38 g/1) vinylpyrrolidone/vinylcaprolactam polymer (37 mg/1 solids content) 6. Rinse deionised water 7. Drying: compressed air 8. Coating: lead-free cathodic electrophoretic coating (BASF CG 310) Thickness of coating: 20-23 ~.m ~~-xamOrder of procedure as above, but without steps 3 and 4 ('nrrnei nn tPRt ~_ Galvanised substrates: Coating adhesion after storage in salt water Aluminum Copper-accelerated salt spray test LASS
DIN 50021, 10 days Steel salt spray test SS DIN 50021, 21 days Results: Creepage along scribe (half scribe width):
U/2 in mm; Results of the stone-impact test for coating adhesion (K value, K = 1: best coating adhesion, K = 10:
worst coating adhesion) Example U/2 mm R R U/2 xmn With step 3, 4 0.7 8 9 0.8 Without step 3, 1.6 10 10 0.9 F_xan=y Conversion process with subsequent powder coating (galvanised steel) using copolymer mixtures Substrates: CRS, EG, HDG
Order of procedure (dipping application):
1. Cleaning: Ridoline~ 1570, 2%; Ridosol~ 1237, 0.3%; 5 minutes; 55~C (commercial metal cleaner manufactured by the Applicant) 2. Rinse deionised water 3. Conversion treatment: 180 seconds; 30~C, using one of the following bath formulations H2ZrF6 acid (45%; 1.38 g/1) vinylpyrrolidone/vinylcaprolactam copolymer (= Pa) +
vinylpyrrolidone/vinylimidazole copolymer (= Pb) (37 mg/1 solids content) 4. Rinse deionised water 5. Drying: compressed air 6. Coating: Polyester PES 5807/RAL 5009 GL (TIGC-f ree , product of the firm of Herbert ) ;
approx . 6 0 - 8 0 ~,m orro~ion Neutral salt spray test DIN 50021 SS, 21 days . CA 02453138 2003-12-12 Results: Creepage of paint along scribe, half scribe width;
coating adhesion by the cross-cut adhesion test Example Creepage Cross-cut (scale 0 to 5) CRS 1.7 mm 0 EG 2.5 mm 0 HDG 1.8 mm 0 5 The proportions of polymers can be varied, for example between homo- and/or copolymers Pa% = 100% - Pb%, with Pa>0.
,xa ~ Conversion process using copolymer mixtures (powder coating) Substrate: CRS
Order of procedure (dipping application):
1. Cleaning: Ridoline~ 1570, 2%; Ridosol~ 1237, 0.3%; 5 minutes; 55~C
2. Rinse deionised water 3. Conversion treatment:
180 s; 30~C, using one of the bath formulations according to the Table below H2ZrF6 acid (45%; 1.38 g/1) + vinylpyrrolidone/vinylcaprolactam copolymer (= Pb) +
vinylpyrrolidone/vinylimidazole copolymer (= Pa) (22 mg/1 solids content ) 4. Rinse deionised water 5. Drying: compressed air 6. Coating: Polyester PES 5807/RAL 5009 GL (TIGC-free, product of the firm of Herbert);
approx . 6 0 - 8 0 ~.m ~nrro~ion Neutral salt spray test DIN 50021 SS, 21 days Polymer Creepage 100% Pa 3.9 mm 70% Pa 2.3 mm
Claims (4)
1. A process for treating metal surfaces, characterized in that the metal surfaces are contacted during a conversion treatment with a preparation containing phosphoric acid and/or at least one fluoro acid of one or more elements from the group consisting of Zr, Ti, Hf and Si or anions thereof and a homo- or copolymer of vinyl pyrrolidone, the preparation being present as a ready-to-use application solution which contains a) 0.02 to 20 g/l phosphoric acid and/or at least one fluoro acid of one or more elements from the group consisting of Zr, Ti, Hf and Si or anions thereof and b) 10 to 49.9 mg/l of a homo- or copolymer of vinyl pyrrolidone, and the preparation being free from divalent metals where it contains phosphoric acid and/or anions thereof as component a).
2. A process as claimed in claim 1, characterized in that the preparation is free from nickel and chromium.
3. A process as claimed in one or both of claims 1 and 2, characterized in that the homo- or copolymer of vinyl pyrrolidone contains caprolactam groups.
4. A process as claimed in one or more of claims 1 to 3, characterized in that the metal surface is treated with an aqueous solution of an acid before being contacted with the preparation claimed in one or more of claims 1 to 3.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10131723.9 | 2001-06-30 | ||
| DE10131723A DE10131723A1 (en) | 2001-06-30 | 2001-06-30 | Corrosion protection agents and corrosion protection processes for metal surfaces |
| PCT/EP2002/006888 WO2003002781A1 (en) | 2001-06-30 | 2002-06-21 | Corrosion protection agent and corrosion protection method for metal surfaces |
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| Publication Number | Publication Date |
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| CA2453138A1 true CA2453138A1 (en) | 2003-01-09 |
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| CA002453138A Abandoned CA2453138A1 (en) | 2001-06-30 | 2002-06-21 | Corrosion protection agent and corrosion protection method for metal surfaces |
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|---|---|
| US (1) | US20040151619A1 (en) |
| EP (1) | EP1402083B1 (en) |
| JP (1) | JP2004533542A (en) |
| KR (1) | KR20040043135A (en) |
| CN (1) | CN1527889A (en) |
| AT (1) | ATE294259T1 (en) |
| BR (1) | BR0210725A (en) |
| CA (1) | CA2453138A1 (en) |
| CZ (1) | CZ20033572A3 (en) |
| DE (2) | DE10131723A1 (en) |
| ES (1) | ES2240824T3 (en) |
| MX (1) | MXPA03011369A (en) |
| RU (1) | RU2004102694A (en) |
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| WO (1) | WO2003002781A1 (en) |
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| DE102004011544A1 (en) * | 2003-03-31 | 2004-10-14 | Behr Gmbh & Co. Kg | Heat exchanger for a vehicle comprises a hydrophilic surface coating consisting of a gel produced by a sol-gel method |
| DE10339165A1 (en) | 2003-08-26 | 2005-03-24 | Henkel Kgaa | Colored conversion coatings on metal surfaces |
| DE10353149A1 (en) * | 2003-11-14 | 2005-06-16 | Henkel Kgaa | Supplementary corrosion protection for components made of pre-coated metal sheets |
| DE10358309A1 (en) * | 2003-12-11 | 2005-07-21 | Henkel Kgaa | Functionalized phenol-aldehyde resin and process for treating metal surfaces |
| DE10358310A1 (en) * | 2003-12-11 | 2005-07-21 | Henkel Kgaa | Two-stage conversion treatment |
| DE102004022565A1 (en) * | 2004-05-07 | 2005-12-22 | Henkel Kgaa | Colored conversion coatings on metal surfaces |
| US7351295B2 (en) * | 2006-03-23 | 2008-04-01 | Pp6 Industries Ohio, Inc. | Cleaning and polishing rusted iron-containing surfaces |
| DE102006039633A1 (en) * | 2006-08-24 | 2008-03-13 | Henkel Kgaa | Chrome-free, thermally curable corrosion inhibitor |
| DE102007005943A1 (en) | 2007-02-01 | 2008-08-07 | Henkel Ag & Co. Kgaa | Metal pretreatment with luminescent pigments |
| ES2391870T3 (en) * | 2007-02-12 | 2012-11-30 | Henkel Ag & Co. Kgaa | Procedure to treat metal surfaces |
| DE102007057185A1 (en) | 2007-11-26 | 2009-05-28 | Henkel Ag & Co. Kgaa | Zirconium phosphating of metallic components, in particular iron |
| CN101748002A (en) * | 2008-11-28 | 2010-06-23 | 安集微电子（上海）有限公司 | Fluorine-containing composition and application thereof |
| CN101928650B (en) * | 2009-06-23 | 2016-02-17 | 安集微电子（上海）有限公司 | A kind of fluoro-containing composition and application thereof |
| EP2405031A1 (en) * | 2010-07-07 | 2012-01-11 | Mattthias Koch | Method for coating shaped bodies and coated shaped body |
| KR101263086B1 (en) * | 2010-12-28 | 2013-05-09 | 주식회사 포스코 | Plate type zirconium phosphate and preparation method thereof |
| KR101645063B1 (en) * | 2013-03-27 | 2016-08-03 | 주식회사 포스코 | Plate type zirconium phosphate and preparation method thereof |
| DE102015206812A1 (en) | 2015-04-15 | 2016-10-20 | Henkel Ag & Co. Kgaa | Polymer-containing pre-rinse before a conversion treatment |
| EP3502311A1 (en) * | 2017-12-20 | 2019-06-26 | Henkel AG & Co. KGaA | Method for the corrosion protection and cleaning pretreatment of metallic components |
| MX2022010366A (en) * | 2020-02-25 | 2022-09-21 | Chemetall Gmbh | One-step pretreatment method of metallic substrates for metal cold forming. |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1933013C3 (en) * | 1969-06-28 | 1978-09-21 | Gerhard Collardin Gmbh, 5000 Koeln | Process for the production of protective layers on aluminum, iron and zinc by means of solutions containing complex fluorides |
| US3912548A (en) * | 1973-07-13 | 1975-10-14 | Amchem Prod | Method for treating metal surfaces with compositions comprising zirconium and a polymer |
| US4148670A (en) * | 1976-04-05 | 1979-04-10 | Amchem Products, Inc. | Coating solution for metal surface |
| JPS6267181A (en) * | 1985-09-19 | 1987-03-26 | Nippon Parkerizing Co Ltd | Aqueous solution for chemical conversion of titanium or alloy thereof |
| US5129967A (en) * | 1988-05-03 | 1992-07-14 | Betz Laboratories, Inc. | Composition and method for non-chromate coating of aluminum |
| US4992116A (en) * | 1989-04-21 | 1991-02-12 | Henkel Corporation | Method and composition for coating aluminum |
| US5239002A (en) * | 1990-08-16 | 1993-08-24 | Phillips Petroleum Company | Polymeric adhesive and anti-corrosion agents |
| BR9607325A (en) * | 1995-02-28 | 1997-12-30 | Henkel Corp | Process of forming a protective coating on a metallic surface |
| DE19621184A1 (en) * | 1996-05-28 | 1997-12-04 | Henkel Kgaa | Zinc phosphating with integrated post-passivation |
| JPH10182916A (en) * | 1996-10-21 | 1998-07-07 | Nippon Paint Co Ltd | Metal surface-treating composition containing acrylic resin and containing n-heterocycle, treatment by using the same and treated metal material |
| DE69831351T2 (en) * | 1997-10-14 | 2006-06-29 | Henkel Kgaa | Composition and method for multi-purpose treatment of metal surfaces |
| DE10005113A1 (en) * | 2000-02-07 | 2001-08-09 | Henkel Kgaa | Corrosion inhibitor and corrosion protection method for metal surfaces |
| DE10010758A1 (en) * | 2000-03-04 | 2001-09-06 | Henkel Kgaa | Corrosion protection of zinc, aluminum and/or magnesium surfaces such as motor vehicle bodies, comprises passivation using complex fluorides of Ti, Zr, Hf, Si and/or B and organic polymers |
| DE10010355A1 (en) * | 2000-03-07 | 2001-09-13 | Chemetall Gmbh | Applying phosphate coatings to metallic surfaces comprises wetting with an aqueous acidic phosphatizing solution containing zinc ions, manganese ions and phosphate ions, and drying the solution |
| DE10030462A1 (en) * | 2000-06-21 | 2002-01-03 | Henkel Kgaa | Adhesion promoter in conversion solutions |
-
2001
- 2001-06-30 DE DE10131723A patent/DE10131723A1/en not_active Withdrawn
-
2002
- 2002-06-21 MX MXPA03011369A patent/MXPA03011369A/en unknown
- 2002-06-21 BR BR0210725-2A patent/BR0210725A/en not_active IP Right Cessation
- 2002-06-21 EP EP02780906A patent/EP1402083B1/en not_active Expired - Lifetime
- 2002-06-21 AT AT02780906T patent/ATE294259T1/en not_active IP Right Cessation
- 2002-06-21 SK SK1619-2003A patent/SK16192003A3/en unknown
- 2002-06-21 WO PCT/EP2002/006888 patent/WO2003002781A1/en active IP Right Grant
- 2002-06-21 CN CNA028132149A patent/CN1527889A/en active Pending
- 2002-06-21 RU RU2004102694/02A patent/RU2004102694A/en not_active Application Discontinuation
- 2002-06-21 JP JP2003508743A patent/JP2004533542A/en active Pending
- 2002-06-21 DE DE50202924T patent/DE50202924D1/en not_active Expired - Fee Related
- 2002-06-21 CZ CZ20033572A patent/CZ20033572A3/en unknown
- 2002-06-21 CA CA002453138A patent/CA2453138A1/en not_active Abandoned
- 2002-06-21 ES ES02780906T patent/ES2240824T3/en not_active Expired - Lifetime
- 2002-06-21 KR KR10-2003-7017270A patent/KR20040043135A/en not_active Application Discontinuation
-
2003
- 2003-12-11 US US10/734,815 patent/US20040151619A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| SK16192003A3 (en) | 2004-05-04 |
| EP1402083A1 (en) | 2004-03-31 |
| ATE294259T1 (en) | 2005-05-15 |
| DE10131723A1 (en) | 2003-01-16 |
| RU2004102694A (en) | 2005-06-10 |
| CN1527889A (en) | 2004-09-08 |
| JP2004533542A (en) | 2004-11-04 |
| CZ20033572A3 (en) | 2004-11-10 |
| MXPA03011369A (en) | 2004-07-01 |
| US20040151619A1 (en) | 2004-08-05 |
| BR0210725A (en) | 2004-07-20 |
| DE50202924D1 (en) | 2005-06-02 |
| EP1402083B1 (en) | 2005-04-27 |
| WO2003002781A1 (en) | 2003-01-09 |
| ES2240824T3 (en) | 2005-10-16 |
| KR20040043135A (en) | 2004-05-22 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued |