EP1658392A1

EP1658392A1 - Colour conversion layers on metal surfaces

Info

Publication number: EP1658392A1
Application number: EP04764202A
Authority: EP
Inventors: Ulrich JÜPTNER; Jörg BECKER
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2003-08-26
Filing date: 2004-08-17
Publication date: 2006-05-24
Anticipated expiration: 2024-08-17
Also published as: US20060173099A1; ATE356895T1; DE10339165A1; DE502004003236D1; US8293029B2; EP1658392B1; WO2005021834A1

Abstract

Chromium-free conversion coating treatment solutions and processes for depositing a colored layer on zinc or galvanized steel, aluminum, magnesium or their alloys, are provided comprising: hexafluorotitanate and/or hexafluorozirconate ions; molybdate and/or tungstate ions; one or more chelating complex formers; and a copolymer of alkylene phosphonic or alkylene phosphinic acid and one or more unsaturated carboxylic acids.

Description

"Colored conversion layers on metal surfaces"

The invention is in the field of chemical surface treatment of zinc or galvanized steel, aluminum, magnesium or their alloys. It describes chrome-free conversion processes for such metal surfaces, i. H. chemical treatment processes that lead to the formation of a surface layer in which both cations of the treated metal surface and ions from the treatment solution are incorporated. The chrome-free coating is colored so that a simple visual check can be used to determine whether an adequate conversion layer has been formed. The task of this conversion layer is to reduce the tendency of the metal surface to corrode and to produce good adhesion between the metal surface and an organic coating applied to the conversion layer, such as, for example, a varnish or an adhesive.

There is extensive state of the art for the production of chrome-free conversion layers on the metal surfaces mentioned:

US-A-5 129 967 discloses treatment baths for a no-rinse treatment (referred to there as "dried in place conversion coating") containing aluminum

a) 10 to 16 g / l polyacrylic acid or its homopolymers, b) 12 to 19 g / l hexafluorozirconic acid, c) 0.17 to 0.3 g / l hydrofluoric acid and d) up to 0.6 g / l hexafluorotitanic acid.

EP-B-8 942 discloses treatment solutions containing, preferably for aluminum cans

a) 0.5 to 10 g / l polyacrylic acid or an ester thereof and b) 0.2 to 8 g / l of at least one of the compounds ^ ZrFg, ^ TiFg and H ₂ SiFß, the pH of the solution below 3.5 lies. Further polymers which can be used in similar treatment baths are listed in WO 02/20652.

US-A-4 992 116 describes treatment baths for the conversion treatment of aluminum with pH values between about 2.5 and 5, which contain at least three components:

a) phosphate ions in the concentration range between 1, 1x10 ^" ° to 5.3x10 ^" ^ mol / l corresponding to 1 to 500 mg / l, b) 1, 1x10 ^-5 to 1, 3x10 ^"3 mol / l of a fluoric acid of an element of the group Zr, Ti, Hf and Si (depending on the element 1, 6 to 380 mg / l) and c) 0.26 to 20 g / l of a polyphenol compound, obtainable by reacting poly (vinylphenol) with aldehydes and organic amines.

WO 92/07973 teaches a chromium-free treatment process for aluminum, which as essential components in acidic aqueous solution 0.01 to about 18 wt .-% ^ ZrFg and

0.01 to about 10% by weight of a 3- (N-C 1-4 alkyl-N-2-hydroxyethylaminomethyl) -4-hydroxystyrene polymer is used. Optional components are 0.05-10% by weight of dispersed SiO 2, 0.06-0.6% by weight of a solubilizer for the polymer and surfactant.

The polymer mentioned falls under the group of the "reaction products of poly (vinylphenol) with aldehydes and organic hydroxyl group-containing amines" which can be used in the context of the present invention.

WO 94/28193 describes a process for pretreating surfaces made of aluminum or its alloys before a second, permanently corrosion-protecting conversion treatment, the surfaces being brought into contact with acidic aqueous treatment solutions, the complex fluorides of the elements boron, silicon, titanium, zirconium or hafnium individually or in a mixture with one another in concentrations of the fluoro anions totaling between 100 and 4000, preferably 200 to 2000, mg / l and having a pH between 0.3 and 3.5, preferably between 1 and 3.

The treatment solutions can additionally contain polymers of the type of the polyacrylates and / or the reaction products of poly (vinylphenol) with aldehydes and organic hydroxyl-containing amines in concentrations below 500 mg / l, preferably below 200 mg / l. Other potential components of the treatment baths are Polyhydroxycarboxylic acids or their anions, especially gluconate ions, in concentrations up to 500 mg / l.

WO 95/04169 teaches the treatment of metal surfaces with a treatment solution which contains at least the following components: fluorocomplexes of titanium, zirconium, hafnium, silicon, aluminum and boron, metal ions selected from cobalt, magnesium, manganese, zinc, nickel, tin, copper , Zircon, iron and strontium, phosphates or phosphonates and water-soluble or water-dispersible organic film formers.

WO 00/71626 discloses a chromium-free corrosion protection agent containing water and a.) 0.5 to 100 g / l hexafluoro anions of titanium (IV), silicon (IV) and / or zircon (IV) b.) 0 to 100 g / l Phosphoric acid c.) 0 to 100 g / l of one or more compounds of cobalt, nickel, vanadium, iron, manganese, molybdenum or tungsten, d.) 0.5 to 30% by weight of at least one water-soluble or water-dispersible film-forming organic polymer or copolymer (based on active substance), e.) 0.1 to 10% by weight of an organophosphonic acid f.) if necessary, other auxiliaries and additives.

In the above-mentioned documents, it is evident in many cases that the conversion layers produced are colorless and translucent, so that the treated metal surfaces appear shiny metallic. At least these documents do not disclose that colored layers would arise. However, from the many years of experience with the chromating of metal surfaces, the person skilled in the art is used to obtaining a colored layer as a result of the conversion treatment. He can then immediately visually recognize whether the treatment has brought the desired success. When producing colorless layers, however, this requires more complex surface analysis, for example the determination of the Ti content of the surface by means of an X-ray fluorescence measurement. There is therefore a need in practice for surface treatment processes which not only have good corrosion protection and paint adhesion properties like the conventional chromate coatings, but which are visible to the human eye in a similar way to chromate coatings.

There are approaches to solving this problem in the prior art. For example, WO 94/25640 discloses a method for producing blue-colored conversion layers on zinc / aluminum alloys. Here you bring the metal surfaces with a coating handling solution in contact, which has a pH between 3.5 and 6 and which has 0.2 to 3.0 wt .-% molybdenum and a fluoride content of 0.1 to 2.0 wt .-%. Molybdenum can be used as molybdate, as phosphomolybdic acid, as molybdenum chloride and the like. Fluoride can be used in the form of hydrofluoric acid, simple fluorides, but also complex fluoric acids such as fluorotitanic acid or fluorozirconic acid.

WO 95/14117 describes a similar treatment method, although the optical appearance of the conversion layers is not dealt with in more detail there. According to this document, the treatment solution contains heterooxo anions of molybdenum, tungsten or vanadium with one of the hetero ions phosphorus, aluminum, silicon, manganese, zirconium, titanium, tin, cerium or nickel. The treatment solution also contains an organic film former, which can be selected, for example, from acrylates. The heterooxo anions such as anions of heteropolyacids can be formed directly in the treatment solution by adding the starting products for this, for example molybdenum ions and phosphoric acid. In addition, the treatment solution should preferably contain an etchant for aluminum, for example fluoride, tetrafluoroborate or similarly acting etchants.

The teaching of WO 00/26437 goes the way of coloring the conversion layer using an organic dye (alizerin dye). The conversion layer itself is produced with a treatment solution which contains complex fluorides, for example of titanium and zirconium, in addition to other inorganic oxides, hydroxides or carbonates or their reaction products with the fluoric acids. In addition, a poly-4-hydroxystyrene (polyvinylphenol) substituted with amino groups can be present as the organic polymer.

In a first aspect, the present invention relates to an aqueous treatment solution for producing colored layers on surfaces of zinc, aluminum, magnesium or their alloys, which has a pH in the range from 1 to 6 and which a) a total of 4 to 4000 mg / l Hexafluorotitanate and / or Hexafluorozirkonationen, b) a total of 10 to 4000 mg / l molybdate and / or tungsten ions, calculated as dihydrate of the Na salt, c) a total of 1 to 2000 mg / l of one or more chelating complexing agents, d) 0, 04 to 40 mg / l of a copolymer of alkylenephosphonic or alkylenephosphinic acid and one or more unsaturated carboxylic acid (s) contains.

The metal surfaces can be surfaces of the metals mentioned or their alloys as such, but also surfaces of a substrate such as steel which is coated with the metals mentioned or their alloys. Examples of the latter are electrolytically galvanized or hot-dip galvanized steel, aluminized steel, or coated steels such as Galvalume ^® or Galfan ^® , which have a coating of zinc / aluminum alloys.

The treatment solution is preferably free of chromium. Furthermore, it preferably also contains no heavy metal ions other than those listed as components a) and b). This reduces the demands on the treatment of waste water.

The pH value of the treatment solution should not be significantly below a value of 1, since lower pH values lead to an increasingly stronger pickling attack on the metal surface. The pH is preferably not less than 2 and in particular not less than 2.5. At pH values above the stated limit of 6, the conversion layer is no longer formed to the desired extent. It is preferable to work at pH values which are not higher than 4 and in particular not higher than 3.5.

The essential components a) to d) mentioned are all protolytes, that is to say molecules or ions which can react with the release or absorption of protons in the sense of an acid-base reaction. It is therefore obvious to the person skilled in the art that these components undergo such reactions with one another and with the solvent water until the corresponding chemical equilibria have been reached. In the range of pH values mentioned it can be expected that all of these protolytes are in a partially protolyzed state, regardless of whether they have been introduced into the treatment solution in the form of their acids or their salts. The pH values mentioned, which are in the acidic range, are preferably set by introducing the hexafluorotitanate and / or hexafluorozirconate ions in the form of the free acids. An additional acid to adjust the acidic pH is then not necessary. However, one could also use these complex fluoride ions in the form of their salts and adjust the desired pH by adding another acid such as nitric acid. For economic reasons, the molybdate and / or tungsten ions are preferably used in the form of their salts, for example as sodium salts. The chelating complexing agents and the copolymer of group d) can also be used in the form of free acids or in the form of ammonium or alkali metal salts. This is primarily a question of commercial availability. If the desired pH value range is not reached automatically when the essential components are mixed with water, the pH value can be adjusted downwards by adding an acid such as nitric acid, and upwards by adding an alkali such as sodium hydroxide solution.

The definition of the chelating complexing agent c) is to be understood as meaning that it represents a different compound than the copolymer mentioned under d), although this could also have chelating properties. Rather, the chelating complexing agents c) should preferably be non-polymeric molecules.

It generally applies to the concentrations of the active components a) to d) that the quality of the layer gradually decreases when the minimum concentration falls below the stated level. Exceeding the maximum concentration mentioned usually does no harm, but does not bring any significant advantages and is therefore uneconomical. The minimum concentration for component a) is preferably 30 mg / l and in particular 100 mg / l, for component b) 50 mg / l, in particular 100 mg / l, for component c) 5 mg / l, in particular 15 mg / l and for component d) 0.2 mg / l, in particular 0.5 mg / l. The preferred minimum concentrations of the individual components mentioned are independent of one another. However, preferably all 4 components are present at the same time with the minimum concentrations mentioned. This applies correspondingly to the preferred maximum concentrations of the individual components, which have the following values: component a) is preferably present in a maximum concentration of 1000 mg / l, in particular 500 mg / l, component b) in a maximum concentration of 2000 mg / l , in particular of 1000 mg / l, component c) in a maximum concentration of 1000 mg / l, preferably 300 mg / l and component d) in a maximum concentration of 10 mg / l, in particular 5 mg / l.

The treatment solution can additionally contain one or more further polymers which do not fall under group d) and which are known in the prior art for the treatment of the metal surfaces mentioned in connection with hexafluoro acids of titanium and / or zirconium. These additional polymers can be selected from: e) polyvinyl alcohol or water-soluble or water-dispersible partial esters thereof in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 20 mg / l and at most 1000 mg / l, preferably at most 500 mg / l, in particular at most 200 mg / l, f) polymers or copolymers of unsaturated mono- or dicarboxylic acids or their amides, in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / lg) esters from the polymers of groups e) and f) in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / l. h) 0.01 to 20 g / l of a polymer or co-polymer of vinylpyrrolidone, i) amine-substituted polymers of 4-hydroxystyrene in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / l, k) polymers of the diglycidyl ether of bisphenol A in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / l.

In the case of the polymer of group e), a “partial ester” is understood to mean that only a part of the alcohol groups is esterified, the ester formation taking place with non-polymeric carboxylic acids. In particular, the ester formation can take place with monobasic carboxylic acids with 1 to 4 carbon atoms.

The polymers or copolymers of group f) can be selected, for example, from homo- or copolymers of acrylic acid and / or methacrylic acid, the acid groups of which can be partially replaced by amide groups or esterified with alcohols, in particular with simple alcohols having 1 to 4 carbon atoms. Specific examples are homo- or copolymers of or with methyl methacrylate, n-butyl acrylate, hydroxyethyl acrylate and glycerol propoxitria acrylate. These specific examples are known for example from WO 95/14117. The polymers of group f) can also be selected from those which contain maleic acid monomers. A specific example of this is a maleic acid-methyl vinyl ether copolymer. The treatment solution preferably contains both polymers of group e) and those of group f). In this case it is particularly preferred that the polymer of group f) is a maleic acid-methyl vinyl ether copolymer.

Polymers of group e) generally contain free alcohol groups, those of group f) contain free carboxylic acid groups. These two polymers can therefore not only be used in a mixture with one another, but in a form in which ester formation has at least partially occurred between the alcohol groups of the polymer e) and the carboxylic acid groups of the polymer f). This is explained in more detail in WO 94/12570. The teaching described there can also be used in the context of the present invention.

The treatment solution can also contain polymers of group h). Such polymers and their use in treatment solutions for conversion treatment are described in more detail in DE-A-10005 113 and DE-A-101 31 723.

Furthermore, the additional polymers can be selected from those of group i), amine-substituted polymers of 4-hydroxystyrene, some of which are also referred to as polymers of polyvinylphenol. Examples of this can be found in WO 00/26437 and the literature cited therein, in particular US Pat. No. 5,281,282.

Furthermore, the additional polymers can be selected from those of group k), as is described in more detail in US-A-5356490.

In principle, the treatment solution according to the invention can be prepared by dissolving the individual components in the required concentration in water on site. In practice, however, the procedure is regularly such that aqueous concentrates of the treatment solution are made available, which the user dilutes on site with water to the required concentration or which he uses to supplement a used treatment solution with active ingredients. In the present case, a concentrate which can be used to prepare or supplement the treatment solution and which contains all essential and optional components is not very stable in storage. Rather, it proves to be advantageous to provide at least 2 separate concentrates, one of which is component b), c) and d) and, if appropriate, further optional components, the other is component a), likewise, if appropriate, together with optional components contains. Examples of concentrates of the latter type are known in the prior art, for example in the literature cited at the beginning. However, the invention encompasses one Another aspect is the first-mentioned concentrate, that is to say an aqueous concentrate for producing or supplementing an aqueous treatment solution according to one or more of claims 1 to 4, which b) a total of 2 to 200 g / l of molybdate and / or tungsten ions, calculated as dihydrate of sodium Salt, c) contains a total of 0.5 to 200 g / l of one or more chelating complexing agents, d) 0.02 to 5 g / l of a copolymer of alkylenephosphonic or alkylenephosphinic acid and one or more unsaturated carboxylic acid (s).

In the treatment solution or the concentrates, the chelating complexing agent c) is preferably non-polymeric and is preferably selected from molecules with 2 or more phosphonic acid groups, in particular from geminal diphosphonic acids, and phosphonocarboxylic acids and their respective anions. (As explained above, the corresponding acid-base balance between the acid form and the salt form of the complexing agent will occur in the treatment solution and in the concentrate, regardless of the form in which it was introduced into the solution or the concentrate .)

Examples of such complexing agents are:

1-Hydroxy-1-phenylmethane-1, 1-diphosphonic acid

1-hydroxy-1-phenylmethane-1,1-diphosphonic acid ^■ 2 H ₂ O p-hydroxyphenyl-1-aminomethane-1,1-diphosphonic acid p-hydroxyphenyl-1-hydroxymethane-1,1-diphosphonic acid ^■ H ₂ O

1-Hydroxy-1-phenylmethane-1,1-diphosphonic acid ^• H ₂ O, Na ₂ - salt

1-hydroxyphenylmethane-1,1-diphosphonic acid ^■ H ₂ O

1-Amino-1 phenylmethane-1,1-diphosphonic acid

4-aminophenyl-1 hydroxymethane-1, 1-diphosphonic acid ^• H ₂ O p-aminophenyl-1-aminomethane-1,1-diphosphonic acid p-chlorophenylmethane -1,1-diphosphonic acid

1-Chloro-1-phenylmethane-1,1-diphosphonic acid ^■ 2 H ₂ O p-chlorophenyl-1-hydroxymethane-1,1-diphosphonic acid ^■ 2 H ₂ O

1-chlorophenylmethane -1,1- diphosphonic acid ^• H ₂ O p-chlorophenyl-1-chloromethane -1,1- diphosphonic acid

4-chlorophenyl-1-chloromethane diphosphonic acid ^■ 2 H ₂ O p-hydroxyphenylaminomethylene diphosphonic acid, disodium salt p-Hydroxyphenyl -1- aminomethane-1, 1-diphosphonic acid, containing methylol

3,4-dimethylphenyl-1-chloromethane diphosphonic acid

3,4-dimethylphenyl-1-hydroxymethane diphosphonic acid

3,4-Dimethylphenylaminomethandiphosphonsäure

3,4-dimethylphenyl-1-chloromethane -1,1- diphosphonic acid ^■ 2 H ₂ O,

4-dimethylaminophenyl-1-hydroxymethane diphosphonic acid

4- (N-benzyl-N, N-dimethylamino) phenyl-1-hydroxymethanediphosphonic

4-trimethylaminophenyl-1-hydroxymethane diphosphonic acid

3,4,5-trimethoxyphenyl-1-aminomethane-1,1-diphosphonic acid

1 -Bis- (N-hydroxymethyl) amino-1-phenylmethane -1,1- diphosphonic acid

3,5-dichloro-4-hydroxyphenyl-hydroxymethanediphosphonic

3,5-dibromo-4-hydroxyphenyl-aminomethane diphosphonic acid

1-amino-1-cyclohexylmethane-1,1-diphosphonic acid

1-hydroxy-1 -cyclohexylmethane-1, 1 -diphosphonic acid, sodium salt

1-hydroxy-1-cyclohexylmethane-1,1-diphosphonic acid, trisodium salt [4- (aminomethyl) cyclohexyl] -1-hydroxymethane-1, 1-diphosphonic acid

N - (hydroxymethyl) -1- aminoethane -1,1- diphosphonic acid

1,3-diaminopropane -1,1-diphosphonic acid

3-dimethylamino-1-aminopropane -1,1-diphosphonic acid

3- monomethylamino -1- aminopropane -1,1- diphosphonic acid

3- (N-dodecylamino) -1-aminopropane-1,1-diphosphonic acid

3- (N, N-Dodecylmethylamino) -1-aminopropane-1,1-diphosphonic acid

3- (N-dodecylamino) -1-aminopropane-1,1-diphosphonic acid ^■ HX (X = halogen)

3- (N-dimethyldodecylamino) -1-aminopropane-1,1-diphosphonic acid ^■ methyl iodide

2-amino-2-methyl-1-hydroxypropane-1,1-diphosphonic acid

3-amino-1-hydroxy-3-phenylpropane -1,1-diphosphonic acid

3-amino-3-phenyl-1-hydroxypropane-1, 1 -diphosphonic acid

3-diethylamino-1-hydroxypropane-1,1-diphosphonic acid

3-N, N-dimethylamino-1-hydroxypropane-1, 1 diphosphonic acid

3-N-bis (hydroxyethyl) amino-1-hydroxypropane-1, 1-diphosphonic acid

3- (N-dodecylamino) -1-hydroxypropane-1,1-diphosphonic acid

1,3-dihydroxy-3-phenylpropane-1,1-diphosphonic acid

3-dimethylamino-1-hydroxypropane-1,1-diphosphonic acid, sodium salt

1,3-dihydroxypropane-1,1-diphosphonic acid, disodium salt

1-hydroxy-3-diethylaminopropane -1,1- diphosphonic acid, sodium salt

1, 3-dihydroxy-3-phenylpropane-1, 1-diphosphonic acid, disodium salt 1,3-diaminobutane-1,1-diphosphonic acid

1-hydroxy-3-aminobutane -1,1- diphosphonic acid

3-monoethylamino-1-aminobutane-1,1-diphosphonic acid

4-amino -1-hydroxybutane -1,1- diphosphonic acid

4-N, N-dimethylamino -1-hydroxybutane -1,1- diphosphonic acid

6-amino -1-hydroxyhexane -1,1- diphosphonic acid

1, 6-dihydroxyhexane-1, 1-diphosphonic acid

1,6-dihydroxyhexane -1,1- diphosphonic acid, disodium salt

1.11 -dihydroxyundecane -1.1- diphosphonic acid

11-amino -1-hydroxyundecane -1,1- diphosphonic acid t- 1,2-diaminocyclohexane tetrakis (methylenephosphonic acid)

Glucamine - bis (methylenephosphonic acid)

Glucamine - bis (methylenephosphonic acid), sodium salt

1-ureidoethane -1,1- diphosphonic acid

Pyrimidyl-2-aminomethane diphosphonic acid

Pyridyl-2-aminomethylendiphosphonsäure

N, N '- dimethylureidomethane diphosphonic acid

N- (2-hydroxyethyl) ethylenediamine -N.N'.N'- trismethylenephosphonic acid

N- (2-hydroxyethyl) ethylenediamine -N.N'.N'- trismethylenephosphonic acid ^■ H ₂ O

Aminoacetic-N, N-dimethylenphosphonsäure

1,2-Diaminopropantetrakis (methyIenphosphonsäure)

2-hydroxypropane-1,3-diametetrakis (methylenephosphonic acid)

5-hydroxy-3-oxa -1- aminopentane-bis- (methylenephosphonic acid)

Imino-bis (methylenephosphonic acid)

Imino-bis (methylenephosphonic acid) nitrosamine

Nitrosamine of imino-bis- (methylenephosphonic acid), disodium salt γ, γ-diphosphono-N-methylbutyrolactam

Amidinomethylendiphosphonsäure

Formylaminomethandiphosphonsäure

2-lminopiperidone-6,6-diphosphonic acid ^■ H ₂ O

2-lminopyrrolidon-5,5-diphosphonic acid

N, N'-Dimethyliminopyrrolidon-5,5-diphosphonic acid

1-methyl-2-pyrrolidone-5,5-diphosphonic acid

Aminodiacetic-N-methylphosphonic

1,3-dihydroxy-2-methyl propane-N, N-dimethylenphosphonsäure

1,2-dihydroxy-3-amino-bis (methylene phosphonic acid) 2-hydroxypropane-1,3-diamintetrakis- (methylenephosphonic acid)

3,6-dioxa -1,8- diaminooctane - tetrakis (methylenephosphonic acid)

1,5-Diaminopentantetrakis (methylenephosphonic acid)

Methylamino - dimethylenephosphonic acid

N-hexylamino dimethylenphosphonsäure

Decylamino-dimethylenphosphonsäure

3-picolylaminodimethylenephosphonic acid ^• H ₂ O

methanediphosphonic

Methane diphosphonic acid ^■ H ₂ O, disodium salt

Dichloromethane diphosphonic acid ^• 5 H ₂ O, disodium salt

Dichloromethane diphosphonic acid-tetraisopropyl

1,1-diphosphonethane-2-carboxylic acid

Ethane -1,1- diphosphonic acid

Ethane -1,1- diphosphonic acid, tetrasodium salt

Ethane -1, 2-diphosphonic acid

Ethane -1, 1,2-triphosphonic acid

Ethylene diphosphonic acid, tetrasodium salt

1, 2-diphosphonethane -1,2- dicarboxylic acid

1, 2-diphosphonethane -1, 2-dicarboxylic acid ^• 2 H ₂ O

Ethane -1,1 - 2,2-tetraphosphonic acid ^• H ₂ O, hexaguanidine salt

Ethane -1,1,2,2-tetraphosphonic acid, hexaguanidine salt

Ethane -1,1,2,2-tetraphosphonic acid, guanidine salt

1 -phosphonoethane -1,2,2- tricarboxylic acid, potassium salt

Phosphonoacetic acid α-chloro -α- phosphonoacetic acid α-phosphonoacetic acid

1-phosphonopropane-2,3-dicarboxylic acid

1 -phosphonopropane-1,2,3-tricarboxylic acid, pentasodium salt

1 -phosphonopropane-1,2,3-tricarboxylic acid ^■ H ₂ O

Propane -1,1,3,3-tetraphosphonic acid, hexasodium salt

aminomethane diphosphonic acid

dimethylaminomethane

N-decylaminomethane -1,1- diphosphonic acid

N-decylaminomethane diphosphonic acid

N, N-dimethylaminomethane monohydrate

Dimethylaminomethane diphosphonic acid, disodium salt N-decylaminomethane diphosphonic acid, tetrasodium salt

1-aminoethane-1,1-diphosphonic acid

1-Amino-2-chloroethane -1,1- diphosphonic acid

1-amino-2-phenylethane -1,1- diphosphonic acid

1-Monomethylaminoethane-1,1-diphosphonic acid

N-monohydroxymethylaminoethane-1,1-diphosphonic acid

1-aminopropane -1,1- diphosphonic acid

1-aminopropane-1, 1, 3-triphosphonic acid

1-aminobutane-1,1-diphosphonic acid

1-aminohexane-1,1-diphosphonic acid

1-aminodecane-1,1-diphosphonic acid

1-aminohexadecane -1,1- diphosphonic acid

1-hydroxy-3,6,9-trioxadecane -1,1-diphosphonic acid, trisodium salt

Cocosalkylaminobis (methylenephosphonic acid)

4- ethyl -4- methyl -3- oxo -1- aminohexane -1,1- diphosphonic acid

1-hydroxy-3-oxo -4-ethyl -4-methylhexane -1,1- diphosphonic acid

1-Amino -4- ethyl -4- methyl-3-oxohexane -1,1- diphosphonic acid

1-hydroxy-3-oxo -4- ethyl -Λ- methylhexane -1,1- diphosphonic acid ^■ 1 H ₂ O, Na salt

4-ethyl -4-methyl-3-oxohex-1-ene -1,1- diphosphonic acid

4-methyl -4-ethyl-3-oxohex-1-ene -1,1- diphosphonic acid, Na ₄ salt

1-Amino -3- oxo -4,4- dimethylheptane -1,1- diphosphonic acid

1-Hydroxy -3- oxo -4,4- dimethylheptane -1,1- diphosphonic acid ^• H ₂ O, Na salt

4,4-dimethyl-3-oxo-hept -1- en -1,1- diphosphonic acid

4,4-Dimethyl-3-oxo-hept -1- en -1,1- diphosphonic acid, Na salt

1 -Amino -3- oxo -4,4- dimethyldecane -1,1- diphosphonic acid

1-hydroxyethane-1,1-diphosphonic acid (HEDP)

2- [benzimidazolyl (2.2) -] - ethandiphosphonsäure monohydrate

2- [benzimidazolyl (2.2) -] - ethandiphosphonsäure

N-carboxymethane -1 - aminoethane -1,1- diphosphonic acid

1, 5-diaminopentane -1, 1, 5,5-tetraphosphonic acid trihydrate α-octadecyl-phosphonosuccinic acid ß-trifluoromethyl-ß-phosphonobutyric acid

1 -decylpyrrolidone -2,2- diphosphonic acid

Pyrrolidone -5,5- diphosphonic acid

2,2-diphosphono -N-decylpyrrolidone γ, γ-diphosphono -N-methylbutyrolactam 1,4-thiazine dioxide -N-methane diphosphonic acid p- (1,4-thiazine dioxide) -N-phenylene-hydroxymethane diphosphonic acid α- (1,4-thiazine dioxide) -N-ethane -α, α-diphosphonic acid

3- (1,4-thiazine dioxide) -N-1-hydroxypropane -1,1-diphosphonic acid

6- (1,4-thiazine dioxide) -N-1-hydroxyhexane -1,1-diphosphonic acid

11- (1,4-thiazine dioxide) -N- 1-hydroxyundecane -1,1-diphosphonic acid

Azacyclopentane -2,2- diphosphonic acid

N-methyl azacyclopentane -2,2-diphosphonic acid

N-decylazacyclopentane -2,2-diphosphonic acid

N-tetradecylazacyclopentane -2,2- diphosphonic acid

Azacyclohexane -2,2- diphosphonic acid

1 - (4,5-Dihydro -3H-pyrrol-2-yl -) - pyrrolidinylidene -2,2-diphosphonic acid

Hydroxymethane diphosphonic acid, disodium salt

1 -Oxaethane -1, 2-diphosphonic acid undecane hydrate, tetrasodium salt

1-hydroxypropane -1,1- diphosphonic acid

1-hydroxypropane -1,1- diphosphonic acid, tetrasodium salt

1-Hydroxybutane -1,1- diphosphonic acid heptadecane hydrate

1-hydroxybutane -1,1- diphosphonic acid, trisodium salt

1-hydroxypentane -1,1- diphosphonic acid, tetrasodium salt

1 -hydroxyoctane -1,1- diphosphonic acid, tetrasodium salt.

In the treatment solution and the corresponding concentrate, the copolymer d) is preferably selected from copolymers of vinylphosphonic acid and one or more unsaturated carboxylic acids selected from acrylic acid, methacrylic acid and maleic acid, the acid groups of which may be at least partially esterified with alcohols having 1 to 4 carbon atoms. A specific example is a vinylphosphonic acid-acrylic acid copolymer, which is available under CAS no. 27936-88-5 is known. The molecular weight is in the range from 30,000 to 90,000. This polymer is commercially available, for example, as a 20% strength aqueous solution which has a total phosphorus content of 2.0 ± 0.2% by weight.

The treatment solution preferably contains an additional polymer or copolymer from group f), which is selected in particular from maleic acid-methyl vinyl ether copolymers and from polymers or copolymers of acrylic acid and / or methacrylic acid, the carboxyl groups of which are at least partially replaced by amide groups. Instead of such a polymer, it is also possible to use its ester with polyvinyl alcohol, which was described above as a polymer of group g). In a further aspect, the invention relates to a method for producing colored layers on surfaces of zinc, aluminum, magnesium or their alloys, the surfaces being sprayed or dipped with an aqueous treatment solution after or for a period in the range from 2 seconds to 10 minutes brings in contact several of claims 1 to 4 or 6 to 8, which has a temperature in the range of 10 to 70 ° C.

The explanations given above for the explanation of claim 1 apply to the metal surfaces. With regard to the preferred duration of treatment, there is a connection between the concentration of the individual active substances and the time: the shorter the duration of treatment, the more concentrated the treatment solution is preferably chosen. Treatment times at the lower end of the specified interval, for example in the range from 2 to about 10 seconds, can be used in the treatment of running metal strips. Treatment times in the range from 0.5 to 3 minutes are preferably selected for the parts treatment. The temperature of the treatment solution is preferably set to at least 20 ° C. A maximum temperature of 60 ° C is usually sufficient.

The treatment step according to the invention is generally part of a treatment sequence, as is customary in the case of conversion treatment of the metal surfaces mentioned before a subsequent coating or adhesive bonding. Such a sequence of processes usually begins with a cleaning / degreasing of the metal surfaces, for which an alkaline cleaner can be used, for example. This is followed by one or more rinsing steps with water. This can be followed by an acidic treatment step to remove superficial oxides that are not removed during alkaline cleaning. This step is also referred to as "deoxidizing" or "pickling" and is used in particular on surfaces of aluminum and its alloys. After an intermediate rinse with water and preferably an additional rinse with demineralized water, this is followed by the treatment step according to the invention with the treatment solution according to the invention. Then you can rinse again with water. However, the method can also be carried out as a "no-rinse" method, ie rinsing with water after the treatment step according to the invention can also be dispensed with. The result of this treatment sequence is a yellowish, corrosion-protected metal surface which has good adhesion to a subsequently applied layer based on organic polymers, for example a paint or an adhesive. This surface usually contains 1 to 70 mg titanium and / or zircon per m ² , in particular 3 to 30 mg / m ² . The molybdenum and / or tungsten layer is usually between 2 and 500 mg / m ² . These values can be measured using standard surface analysis methods, for example with X-ray fluorescence methods. Therefore, the present invention also includes metal strips, metal sheets or metal parts which - as explained in more detail above - have surfaces of zinc, aluminum, magnesium or their alloys and have colored layers on these surfaces which were produced by the method according to the invention. The metal strips, metal sheets or metal parts can be coated with a layer based on organic polymers such as, for example, a lacquer or an adhesive. The invention accordingly also encompasses metal strips, metal sheets or metal parts with the surfaces mentioned, which have been treated with the method according to the invention and which were subsequently coated with a lacquer or glued to further components. For example, these metal strips, metal sheets or metal parts can have a powder coating.

The process according to the invention therefore provides metal surfaces which have good corrosion protection and good paint adhesion, as the person skilled in the art knows as a result of the technically very advantageous chromating processes which are undesirable for ecological and health reasons. On account of the color of the surface, the person skilled in the art immediately sees whether an adequate conversion layer has formed during the treatment, as is usual with chromating. The process according to the invention thus has the technical advantage over the production of colorless conversion layers that the result of the treatment is immediately visually recognizable without the need for special surface analysis.

embodiments

Sample sheets made of aluminum of the alloys AA 5005 and AA 6060 were pretreated as is technically customary before the treatment step according to the invention:

Cleaning: spray with an alkaline cleaner (Ridoline ^® 124N 1.5%, Ridoline® 120WX, each commercial product from the applicant) 0.05%, 60 ° C, 1 min Rinse: city water, room temperature, 0.5 minutes

Rinse: Demineralized water, room temperature, 0.5 minutes.

This was followed by the treatment step according to the invention in the spraying process according to Table 1, comparative examples V1 to V3 and exemplary embodiments B1 to B8.

Before the immersion process according to Example B9, the following was pretreated:

Cleaning: alkaline cleaner (P3-almeco ^® 18, a commercial product of the applicant) 3%, 60 ° C, 3 minutes

Rinse: city water, room temperature, 0.5 minutes

Pickling: Deoxidizer ^® 4902 (a commercial product of the applicant), 2%, room temperature, 3 minutes

Rinse: city water, room temperature, 0.5 minutes

Rinse: Demineralized water, room temperature, 0.5 minutes

After the conversion treatment step according to Table 1, the sheets were rinsed with demineralized water and dried and then coated with a commercially available polyester paint (facade quality, white, TGlC-free). A practical paint adhesion test was then carried out: The test sheets were cross-cut, stored in boiling demineralized water for 2 hours and then at room temperature for one hour. Then an adhesive tape was stuck over the cross-cut area and peeled off again. The amount of paint removed from the sample plate was assessed and characterized by cross-cut marks: Gt 0: no paint loss, Gt 5: extensive paint loss. Compositions of the treatment solutions and treatment results are summarized in the table.

Table: treatment solutions, treatment parameters and treatment results (V: comparative solutions not according to the invention, B: examples according to the invention); Concentrations in mg / l in water; Treatment duration: 1 minute; V1 to V3 and B1 to B8: treatment in

Syringes, B9: treatment in diving.

Continued table

Claims

claims

1. Aqueous treatment solution for producing colored layers on surfaces of zinc, aluminum, magnesium or their alloys, which has a pH in the range from 1 to 6 and which a) a total of 4 to 4000 mg / l hexafluorotitanate and / or hexafluorozirconate ions, b) a total of 10 to 4000 mg / l of molybdate and / or tungsten ions, calculated as the dihydrate of the Na salt, c) a total of 1 to 2000 mg / l of one or more chelating complexing agents, d) 0.04 to 40 mg / l of one Contains copolymers of alkylenephosphonic or alkylenephosphinic acid and one or more unsaturated carboxylic acid (s).

2. Aqueous treatment solution according to claim 1, characterized in that the concentration of the hexafluorotitanate and / or hexafluorozirconate a) calculates a total of at least 30 mg / l, preferably at least 100 mg / l and / or the concentration of the molybdate and / or tungsten ions as dihydrate of Na salt b) a total of at least 50 mg / l, preferably at least 100 mg / l and / or, the total concentration of the one or more chelating complexing agents c) a total of at least 5 mg / l, preferably at least 15 mg / l and / or the concentration of the copolymer of alkylenephosphonic or alkylenephosphinic acid and one or more unsaturated carboxylic acid (s) d) is at least 0.2 mg / l, preferably at least 0.5 mg / l.

3. Aqueous treatment solution according to one or both of claims 1 and 2, characterized in that the concentration of the hexafluorotitanate and / or hexafluorozirconate ions a) a total of at most 1000 mg / l, preferably at most 500 mg / l and / or the concentration of the molybdate and / or tungsten ions, calculated as the dihydrate of the sodium salt b) in total at most 2000 mg / l, preferably at most 1000 mg / l and / or, the total concentration of the one or more chelating complexing agents c) a total of at most 1000 mg / l, preferably at most 300 mg / l and / or the concentration of the copolymer of alkylenephosphonic or alkylenephosphinic acid and one or more unsaturated carboxylic acid (n ) d) is at most 10 mg / l, preferably at most 5 mg / l.

4. Aqueous treatment solution according to one or more of claims 1 to 3, characterized in that it additionally contains one or more further polymers which do not fall under group d) and which are selected from: e) polyvinyl alcohol or water-soluble or water-dispersible partial esters thereof in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 20 mg / l and at most 1000 mg / l, preferably at most 500 mg / l, in particular at most 200 mg / l, f) polymers or copolymers of unsaturated mono- or dicarboxylic acids or their amides, in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / lg) esters from the polymers of groups e) and f) in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and Höc at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / l. h) 0.01 to 20 g / l of a polymer or co-polymer of vinylpyrrolidone, i) amine-substituted polymers of 4-hydroxystyrene in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / l, k) polymers of the diglycidyl ether of bisphenol A in a concentration of at least 1 mg / l, preferably at least 10 mg / l, in particular at least 30 mg / l and at most 2000 mg / l, preferably at most 500 mg / l, in particular at most 300 mg / l.

5. Aqueous concentrate for producing or supplementing an aqueous treatment solution according to one or more of claims 1 to 4, which b) a total of 2 to 200 g / l of molybdate and / or tungsten ions, calculated as dihydrate of the Na salt, c) a total of 0 , 5 to 200 g / l of one or more chelating complexing agents, d) 0.02 to 5 g / l of a copolymer of alkylenephosphonic or alkylenephosphinic acid and one or more unsaturated carboxylic acid (s).

6. Aqueous treatment solution according to one or more of claims 1 to 4 or concentrate according to claim 5, characterized in that the chelating complexing agent c) is selected from molecules with 2 or more phosphonic acid groups, preferably from geminal diphosphonic acids, and phosphonocarboxylic acids and their respective anions

7. Aqueous treatment solution according to one or more of claims 1 to 4 or concentrate according to claim 5, characterized in that the copolymer d) is selected from copolymers of vinylphosphonic acid and one or more unsaturated carboxylic acids selected from acrylic acid, methacrylic acid and maleic acid.

8. Aqueous treatment solution according to claim 4, characterized in that it contains at least one polymer or copolymer f) which is selected from maleic acid-methyl vinyl ether copolymers and from polymers or copolymers of acrylic acid and / or methacrylic acid, the carboxyl groups of which are at least partially replaced by amide groups are, or its esters with polyvinyl alcohol as polymer g).

9. A method for producing colored layers on surfaces of zinc, aluminum, magnesium or their alloys, the surfaces being sprayed or immersed for a period of time in the range from 2 seconds to 10 minutes using an aqueous treatment solution according to one or more of claims 1 to 4 or 6 to 8 in contact, which has a temperature in the range of 10 to 70 ° C.

0. Metal strips, metal sheets or metal parts which have surfaces of zinc, aluminum, magnesium or their alloys and which have colored layers on these surfaces which were produced by a method according to claim 9.