DE102005004292A1 - Method for applying corrosion protection layer on metallic surfaces comprises treating the surface with a formulation having binding agent, pigment and/or filler and corrosion protecting agent, which is a thioamide group containing compound - Google Patents

Abstract

Method for applying corrosion protection layer on a metallic surface comprises treating the surface with a formulation containing at least one binding agent, a pigment and/or a filler and a corrosion protecting agent, which is at least one thioamide group containing compounds. Method for applying corrosion protection layer on a metallic surface comprises treating the surface with a formulation containing at least one binding agent, a pigment and/or a filler and a corrosion protecting agent, which is at least one thioamide group of formula -C(S)NR 1>R 2> containing compounds such as thioamide compound (D1) of formula R 4> n-R 3>-C(S)NR 1>R 2> or thioamide (D2) with at least two thioamide group. n : 1-5; R 1>, R 2>H or optionally substituted 1-20C alkyl; R 3>(n+1)-valenced 1-30C hydrocarbon; and R 4>functional group. Independent claims are included for: (1) a method for applying an integrated pretreating layer on metallic surface comprising treating the metallic surface with a crosslinkable preparation, containing a binding agent, a crosslinkable component, where the crosslinkable group is bounded with the binding agent and/or additionally a crosslinker is used, a pigment and/or filler, a corrosion protecting agent and optionally a solute, and crosslinking the applied layer, where the amount of the binding agent is 20-70 wt.%, filler contains 20-70 wt.% of at least one inorganic fine particulate fillers with an average particle size of less than 10 mu m, and the corrosion protecting agent contains 0.25-10 wt.% of thioamide group containing compounds, where the wt.% relate to the sum of all components except the solute; (2) a polymer comprising at least two terminally and/or laterally positioned thioamide group of formula -C(S)NR 1>R 2>; (3) integrated pretreating layer on a metallic surface of steel, zinc or its alloy or aluminum or its alloy obtained by the method; (4) metallic surface comprising the integrated pretreating layer; (5) a strip metal from steel containing a coating from zinc or its alloy comprising the surface; (6) a preparation, for applying corrosion protection layer on metallic surface, comprising at least one binding agent, a pigment and/or a filler and a corrosion protecting agent, which is at least one thioamide group of formula -C(S)NR 1>R 2> containing compounds such as thioamide compound (D1) of formula R 4> n-R 3>-C(S)NR 1>R 2> or thioamide (D2) with at least two thioamide group; and (7) a preparation, for applying an integrated pretreating layer on metallic surface, comprising a binding agent, a crosslinkable component, where the crosslinkable group is bounded with the binding agent and/or additionally a crosslinker is used, a pigment and/or filler, a corrosion protecting agent and optionally a solute, where the amount of the binding agent is 20-70 wt.%, filler contains 20-70 wt.% of at least one inorganic fine particulate fillers with an average particle size of less than 10 mu m, and the corrosion protecting agent contains 0.25-10 wt.% of thioamide group containing compounds, where the wt.% relate to the sum of all components except the solute.

Description

The The present invention relates to a method for applying integrated Pre-treatment layers on metallic surfaces, in particular the surfaces of Tape metals, by treatment with a composition which at least one binder, crosslinker, a finely divided inorganic filler as well as compounds with at least two thioamide groups or with a thioamide group and at least one functional group. she further relates to an integrated pretreatment layer which obtainable by the method is.

to Production of flat metallic workpieces such as automotive parts, body parts, equipment panels, Facade cladding, ceiling cladding or window profiles be suitable metal sheets by means of suitable techniques such as punching, Drilling, folding, profiling and / or thermoforming molded. Larger components, such as automobile bodies are optionally by welding several Single parts put together. The raw material for this is usually long metal bands, made by rolling the metal and storing and transporting to coils (so-called "coils") are wound up.

The As a rule, these metallic components must be protected against corrosion protected become. Especially in the automotive sector are the requirements very high on the corrosion protection. For newer car types will be nowadays up to 30 years warranty against rust through. modern Automobile bodies are manufactured in multi-stage processes and have a plurality of different layers.

While the Corrosion protection treatment in the past essentially on the finished metal workpiece, for example, a welded car body made In recent years, the anticorrosive treatment has been increasing Measurements on Band metal itself made by "coil coating".

By "coil coating" is meant continuous coating of metal strips with mostly liquid coating materials. It will be 0.2 to 2 mm thick and up to 2 m wide metal bands with a speed of up to 200 m / min through a coil coating plant transported and thereby coated. For this example, cold-rolled bands made of soft steels or structural steels, electrolytically galvanized sheet, hot-dip galvanized steel strip or bands made of aluminum or aluminum alloys are used. typical Plants include a feed station, a tape store, a cleaning and pre-treatment zone, a first painting station and baking oven and the following cooling zone, a second painting station with oven, laminating station and cooling as well a tape storage and rewinder.

• 1. Falls erforderlich: Reinigung des Metallbandes von Verschmutzungen, die sich während der Lagerung des Metallbandes angelagert haben sowie von temporären Korrosionsschutzölen mit Hilfe von Reinigungsbädern.
• 2. Auftragen einer dünnen Vorbehandlungsschicht (< 1 μm) im Tauch- oder Spritzverfahren oder im Rollenauftrag. Diese Schicht soll die Korrosionsbeständigkeit steigern und dient der Verbesserung der Haftung nachfolgender Lackschichten an der Metalloberfläche. Hierzu sind Cr(VI)-haltige wie chromatfreie Vorbehandlungsbäder bekannt.
• 3. Aufbringen einer Grundierung („Primer") im Rollenauftragsverfahren. Die Trockenschichtdicke liegt üblicherweise bei etwa 5–8 μm. Hier werden Lösungsmittel-basierte Lacksysteme eingesetzt.
• 4. Aufbringen einer oder mehrerer Decklackschichten („Topcoat") im Rollenauftragsverfahren. Die Trockenschichtdicke liegt hier bei etwa 15–25 μm. Hier werden ebenfalls Lösungsmittel-basierte Lacksysteme eingesetzt.

The coil coating process usually comprises the following process steps:

• 1. If necessary: Cleaning the metal strip of dirt accumulated during storage of the metal strip and of temporary anticorrosive oils with the aid of cleaning baths.
• 2. Application of a thin pretreatment layer (<1 μm) by dipping or spraying or by roller coating. This layer is intended to increase the corrosion resistance and serves to improve the adhesion of subsequent paint layers on the metal surface. For this purpose, Cr (VI) -containing and chromate-free pretreatment baths are known.
• 3. Application of a primer by roll application The dry film thickness is usually about 5-8 μm, where solvent-based coating systems are used.
• 4. Application of one or more top coats ("topcoat") using the roll application method The dry film thickness here is about 15-25 μm Here, solvent-based coating systems are likewise used.

The layer structure of a galvanized steel sheet coated in this manner is shown in FIG 1 shown. It shows a section through a steel band (1) , which with a zinc layer (2) and a conventional pretreatment layer (3) , a primer (4) and a topcoat (5) were applied.

So coated metal bands For example, for the production of housings for the so-called white goods (Refrigerators etc.), as facade panels for building or used in the automotive industry.

As shown above, the coating of the metal strips with the pretreatment layer (3) and a primer (4) very expensive. Furthermore, the demand for Cr (VI) -free systems for corrosion protection is increasing in the market. There has been no lack of attempts, instead of the separate application of a pretreatment layer (3) and the organic base coat (4) a single integrated pretreatment layer (3 ') to apply, which takes over the functions of both layers. Such a layer structure is exemplary and schematically in FIG 2 shown. The production of a coated metal strip is significantly simplified by such a single-step process.

US 5,322,870 discloses a composition for forming an integrated pretreatment layer, which comprises a polymeric coating agent, a crosslinker, and additionally alkyl- or arylphosphoric acid esters or alkyl- or arylphosphonic acid esters. Optionally, the composition may also comprise a pigment.

DE-A 199 23 084 discloses a chromium-free aqueous coating agent for one-step coating, which comprises at least hexafluoroanions of Ti (IV), Si (IV) and / or Zr (IV), a water-soluble or water-dispersible film-forming binder and an organophosphoric acid. The Composition may optionally also contain a pigment as well as crosslinking agent include.

DE-A 29 43 833 discloses the use of thiourea and thiourea derivatives as additives in an aqueous Conversion coating agent containing free sulfuric acid, hydrogen peroxide and silica.

EP-A 878 519 discloses preferably chromium-free, aqueous compositions for the preparation of anticorrosive coatings which contain 0.2 to 50 g / l of a thiocabonyl compound, 0.1 to 5 g / l of phosphates and water-soluble binders or binder dispersions. Optionally, 10 to 500 g / l of SiO ₂ may be present. The thiocarbonyl compounds may be, for example, thiourea, thioamides, thioaldehydes or thiocarboxylic acids. Thioamides with more than one thioamide group are not disclosed.

JP-A 2002-64856, JP-A 2002-241957, JP-A 297384 and JP-A 2003-73856 various watery Compositions for the production of anticorrosive coatings, which watery different aqueous Polymer dispersions, other components and thiocarbonyl compounds such as thiourea or ethanethioamide. thioamides with more than one thioamide group are not disclosed.

task The invention was an improved method for producing integrated Pre-treatment layers as well as improved integrated pretreatment layers provide.

• (1) Behandeln der metallischen Oberfläche mit einer vernetzbaren Zubereitung umfassend mindestens (A) ein Bindemittel, (B) vernetzbare Komponenten, wobei es sich dabei um vernetzbare Gruppen, die mit dem Bindemittel verbunden sind und/oder um mindestens einen zusätzlich eingesetzten Vernetzer handeln kann, (C) ein Pigment, (D) ein Korrosionsschutzmittel, sowie (E) optional ein Lösemittel, und
• (2) Vernetzen der aufgebrachten Schicht, wobei • die Menge des Bindemittels 20 bis 70 Gew. % beträgt, • es sich bei dem Füllstoff um 20 bis 70 Gew. % mindestens eines anorganischen feinteiligen Füllstoffes mit einer mittleren Partikelgröße von weniger als 10 μm handelt, • und es sich bei dem Korrosionsschutzmittel um 0,25 bis 10 Gew. % mindestens einer Thioamidgruppen (I) -C(S)NR¹R² aufweisenden Verbindung, ausgewählt aus der Gruppe von (D1) Thioamiden der allgemeinen Formel (II) R⁴ _n-R³-C(S)NR¹R², und (D2) Thioamiden mit mindestens 2 Thioamidgruppen handelt, und wobei n für eine natürliche Zahl von 1 bis 5 steht, und die Reste R¹, R², R³ und R⁴ das Folgende bedeuten: – R¹ und R² unabhängig voneinander H oder einen linearen oder verzweigten, optional substituierten Alkylrest mit 1 bis 20 C-Atomen, – R³ einen n-wertigen Kohlenwasserstoffrest mit 1 bis 30 C-Atomen, – R⁴ eine funktionelle Gruppe, und wobei sich die Gew. %-Angaben auf die Summe aller Komponenten mit Ausnahme des Lösemittels beziehen.

Accordingly, a method has been found for applying integrated pretreatment layers to metallic surfaces comprising at least the following steps:

• (1) treating the metallic surface with a crosslinkable preparation comprising at least (A) a binder, (B) crosslinkable components, which are crosslinkable groups which are connected to the binder and / or at least one additionally used crosslinker , (C) a pigment, (D) a corrosion inhibitor, and (E) optionally a solvent, and
• (2) crosslinking of the applied layer, wherein • the amount of the binder is 20 to 70% by weight, • the filler is 20 to 70% by weight of at least one inorganic fine-particle filler having an average particle size of less than 10 μm And the corrosion inhibitor is 0.25 to 10% by weight of at least one thioamide group (I) -C (S) NR ¹ R ^2- containing compound selected from the group of (D1) thioamides of the general formula (II) R ⁴ _{n is} -R ³ -C (S) NR ¹ R ² , and (D2) thioamides having at least 2 thioamide groups, and wherein n is a natural number from 1 to 5, and the radicals R ¹ , R ² , R ³ and R ⁴ the following R ¹ and R ² independently of one another are H or a linear or branched, optionally substituted alkyl radical having 1 to 20 C atoms, R ^{3 is} an n-valent hydrocarbon radical having 1 to 30 C atoms, R ^{4 is} a functional group , and wherein the wt.% data refer to the sum of all components except the solvent.

In In a second aspect of the invention, integrated pretreatment layers, preferably found with a thickness of 3 to 15 microns on metallic surfaces, which are obtainable by the process.

In In a third aspect of the invention, a preparation for carrying out the Method found which contains the above thioamides.

directory of the pictures

1 : Section through a galvanized steel strip in two-stage pretreatment

2 : Section through a galvanized steel strip with integrated, pre-treatment.

More specifically, the following is to be accomplished for the invention:
By means of the method according to the invention it is possible with particular advantage to provide planar metallic bodies such as metal sheets, foil, plates and in particular metal strips with an integrated pretreatment layer. Of course, however, it may in principle be arbitrarily shaped metallic surfaces.

at The type of metal can in principle be any metals act. In particular, however, it is such metals or Alloys, which are usually be used as metallic construction materials, and the protected against corrosion Need to become.

Especially are surfaces of iron, steel, Zn, Zn alloys, Al or Al alloys. It can be about the surfaces from completely from the said metals or alloys existing bodies act. The body can but also be coated only with these metals and even out different materials, such as other metals, Alloys, polymers or composites. In particular, can it is the surface of galvanized iron or steel. In a preferred embodiment of the method is the surface of a band metal, in particular around electrolytically galvanized or hot-dip galvanized steel. It can It is both one-sided and two-sided galvanized metal band act.

Zn or Al alloys are known in the art. Depending on the desired Application chooses the professional type and amount of alloy components. typical In particular, constituents of zinc alloys include Al, Pb, Si, Mg, Sn, Cu or Cd. Typical components of aluminum alloys In particular, Mg, Mn, Si, Zn, Cr, Zr, Cu or Ti are also Al / Zn alloys where Al and Zn are in nearly same amount are available. Coated with such alloys Steel is commercially available. The steel can be the usual, contain alloy components known to those skilled in the art.

Of the Term "integrated Pretreatment Layer "im Meaning of this invention means that the coating according to the invention directly on the metal surface is applied without a previously corrosion-inhibiting pretreatment like passivation or phosphating, especially no treatment carried out with Cr (VI) compounds becomes. The integrated pretreatment layer combines the passivation layer with the organic primer in a single layer. The term "direct upset "but concludes a thin layer on the metal surface, especially a thin one Oxide skin may be present during the usual handling of the metal inevitably forms in the presence of air.

On the integrated pretreatment layer can advantageously further paint layers, such as cathodic dip coating, applied directly without having any additional organic primer before must be applied. Of course, an extra organic primer but in special cases possible, although preferred is waived.

The used according to the invention Preparation for the treatment of metal surfaces comprises at least one Binder (A) and crosslinkable components (B). In the networkable Components may be at least one crosslinker, which in addition is used to a binder or it can be around Groups crosslinkable groups act, which with the binder are connected. Of course The binder can also have crosslinkable groups and additionally Crosslinkers are used.

in this connection are different combinations conceivable. For example, you can Binders and crosslinkers are used separately. The binder then comprises reactive functional groups which with complementary, react reactive functional groups in the crosslinkers. alternative they may also be self-crosslinking binders which Reactive functional groups include those with groups of their kind ("with oneself") or with complementary, reactive ones functional groups on the same polymer undergo crosslinking reactions can. Possible is that too exclusively the crosslinkers react with each other.

at the binders (A) may be those customary in the field of coil coating lacquers Act binders. Examples of suitable binders include (meth) acrylate (co) polymers, partially saponified polyvinyl esters, polyesters, alkyd resins, polylactones, Polycarbonates, polyethers, epoxy resin-amine adducts, polyureas, Polyamides, polyimides or polyurethanes. Of course you can too Mixtures of different polymers are used, provided There are no undesirable effects due to the mixture.

Prefers are used polyester or epoxy resin-amine adducts. The polyesters are particularly suitable for weldable Paints and the epoxy-amine adducts are preferred for paints that are not welded should be.

at suitable polyesters are in particular condensates low molecular weight dicarboxylic acids and dialcohols. Examples of suitable dicarboxylic acids include aliphatic dicarboxylic acids like adipic acid, azelaic acid, sebacic, dodecanedioic, aliphatic cycloaliphatic such as dimer fatty acids, i. reaction products unsaturated fatty acids cycloaliphatic dicarboxylic acids such as 1,4- or 1,3-cyclohexanedicarboxylic acid, tricyclodecanedicarboxylic acid and aromatic dicarboxylic acids like isophthalic acid, terephthalic acid or phthalic acid. It can Of course also derivatives of dicarboxylic acids be used. Particularly suitable are anhydrides such as phthalic anhydride, hexahydrophthalic or tetradehydrophthalic anhydride.

Examples suitable dihydric alcohols include aliphatic alcohols such as, for example Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-butanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1-methyl 1,3-propanediol, 2-butyl-2-ethylpropanediol, pentanediols, hexanediols, Octanediols, dodecanediol, hydroxypivalic acid neopentyl glycol esters, cycloaliphatic Alcohols such as 1,4- or 1,3-cyclohexanedimethanol, TCD-alcohol and Bis (4-hydroxycyclohexyl) methane or propane and dimer diols (hydrogenated Dimer fatty acids). It can Of course used in a known manner and derivatives of alcohols be, for example, esters, in particular the corresponding Methyl or ethyl ester.

Next linear binders can also branched binders are used. Suitable monomers for branching include tricarboxylic acids or their anhydrides such as trimellitic anhydride or trimesic acid and trialcohols such as trimethyolalkanes, for example trimethylolethane or trimethylolpropane.

Prefers can the polyesters by reaction with polyisocyanates in whole or in part be converted to isocyanate-terminated polyesters.

The OH number of the polyesters used is usually about 10 to about 200 mg KOH / g, preferably 15 to 120 mg KOH / g, more preferably 20 to 80 mg KOH / g and for example about 50 mg KOH / g. The molecular weights usually 400 to 10,000 g / mol, preferably 500 to 5000 g / mol and more preferably 1000 to 4000 g / mol.

Epoxy functional polymers can be prepared by the reaction of epoxy functional monomers such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether or hexanediol diglycidyl ether with phenols such as bisphenol A, bisphenol F and / or alcohols such as ethoxylated or propoxylated bisphenol A. Epoxy-functional polymers are commercially available, for example under the name of Epon ^® or Epiko te ^® .

Epoxy resin-amine adducts can by reaction of said epoxy-functional components with phenols or aliphatic or cycloaliphatic dicarboxylic acids, acids Polyesters or alcohols, thiols and amines, in particular secondary amines such as diethanolamine or N-methylbutanolamine become.

Farther can also emulsion polymers are used. These are suitable especially for water-based formulations. Examples of suitable emulsion polymers or copolymers include acrylate dispersions, available in conventional Way of acrylic acid and / or acrylic acid derivatives, for example Acrylsäureestern and / or styrene. Also suitable are dispersions of polyurethanes, prepared from aromatic and / or aliphatic diisocyanates and polyesters or aliphatic soft segments.

The used formulation comprises 20 to 70 wt.% Of the binder. The quantities are based on the sum of all components the preparation with the exception of the solvent or the solvent mixture. Preferred is the amount of 30 to 60 wt.%, and particularly preferably 40 to 50 wt. %.

The crosslinking components (B) can thermally crosslinking groups or photochemically crosslinking groups exhibit.

suitable Thermal crosslinkers are, for example, crosslinkers based on Epoxides in which two or more epoxy groups by means of a linking Group are interconnected. Examples include low molecular weight Compounds with two epoxy groups such as hexanediol diglycidyl ether, phthalic or cycloaliphatic compounds such as 3,4-Epoxicyclohexancarbonsäure 3 ', 4'-epoxycyclohexylmethylester. Further examples of suitable crosslinkers include crosslinkers based on of melamine.

Especially blocked polyisocyanates are preferably used as crosslinkers. In blocking, the isocyanate group is reversible with a Blocking agent implemented. The blocking agent is heated on higher Temperatures split off again. Examples of suitable blocking agents are in DE-A 199 14 896, column 12, line 13 to column 13, line 2 discloses. Particular preference is given to polyisocyanates blocked with ε-caprolactam used.

suitable Crosslinkers for photochemical crosslinking are in particular compounds with several ethylenically unsaturated Groups, especially di- or polyfunctional acrylates such as Butanediol diacrylate, hexanediol diacrylate or trimethylolpropane triacrylate.

If a crosslinker is used separately, are usually 0.5 to 10 wt. %, preferably 1 to 8 wt.% and particularly preferably 2 to 6 wt. % used. Of course can also mixtures of different crosslinkers are used, provided that the properties of the layer are not adversely affected.

The for the inventive method used preparation further comprises at least one finely divided inorganic filler (C). The filler can also be an extra organic coating, for example for hydrophobing or Hydrophilization include. The filler should not exceed an average particle size of 10 μm. Preferably, the average Particle size 10 nm up to 9 μm and more preferably 100 nm to 5 μm. At round or approximately round Particles this indication refers to the diameter, with irregularly shaped, as for example in acicular Particles on the longest Axis. With the particle size is the Meant primary particle size. The skilled person is of course known that finely divided solids often agglomerate into larger particles, which must be dispersed intensively for use. The particle size is by the skilled person depending on the desired properties the layer chosen. It also depends, for example, on the desired one Layer thickness. As a rule, the expert is at a low Select layer thickness smaller particles.

Suitable fillers are on the one hand electrically conductive pigment or fillers in question. Such additives serve to improve the weldability and to improve a subsequent coating with electrodeposition paints. Examples of suitable electrically conductive fillers or pigments include phosphides, vanadium carbide, titanium nitride, molybdenum sulfide, graphite, carbon black or doped barium sulfate. Preference is given to using metal phosphides of Zn, Al, Si, Mn, Cr, Fe or Ni, in particular iron phosphides. Examples of preferred metal phosphides include CrP, MnP, Fe ₃ P, Fe ₂ P, Ni ₂ P, NiP or NiP _{2. 3}

It can also non-conductive pigments or fillers are used, such as finely divided amorphous silicon, aluminum or Titanium oxides, which may also be doped with other elements. For example can be used with calcium ions modified amorphous silica become.

Further Examples of pigments include anticorrosive pigments such as zinc phosphate, Zinc metaborate or barium metaborate monohydrate.

Of course you can too Mixtures of different pigments are used. The pigments become used in an amount of 20 to 70 wt.%. The exact amount is determined by the skilled person depending on the desired properties of the layer established. When using conductive pigments are the used quantities usually greater than when using non-conductive fillers. Preferred amounts for conductive Pigments and fillers 40 to 70 wt.%, Preferred amounts of non-conductive pigments 20 to 50% by weight.

The composition further comprises from 0.25 to 10% by weight of at least one thioamide group (I) -C (S) NR ¹ R ^2- containing compound.

R ¹ and R ² here are independently of one another H or a linear or branched, optionally substituted alkyl radical having 1 to 20 C atoms, preferably 1 to 10 C atoms and more preferably 1 to 6 C atoms. Additional substituents may in particular be oxygen- or nitrogen-containing substituents, for example OH groups or NH ₂ groups. Furthermore, in radicals with at least 3 C atoms, non-adjacent non-terminal C atoms can be replaced by O and / or N atoms. Examples of preferred radicals R ¹ and R ² include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, tert-butyl, n-pentyl and n-hexyl groups. It is preferable that at least one of R ¹ and R ² is H, and particularly preferably both are H.

The thioamides used according to the invention are compounds (D1) of the general formula (II) R ⁴ _n -R ³ -C (S) NR ¹ R ² , which have a thioamide group and one or more functional groups, or compounds (D1) D2) which have at least two thioamide groups.

In the compounds (D1), the thioamide group is linked via the (n + 1) -valent hydrocarbon radical R ³ with n functional groups R ⁴ , where n stands for a natural number from 1 to 5. Preferably n is 1 to 3 and more preferably 1 or 2.

R ³ is preferably an (n + 1) -valent aliphatic, cycloaliphatic, aromatic or araliphatic hydrocarbon radical having 1 to 30 C atoms, preferably 1 to 20 C atoms and particularly preferably 1 to 10 C atoms. It is obvious to the person skilled in the art that the values of n that are possible in principle also depend on the number of carbon atoms. As a rule, no more than one functional group per C atom of the hydrocarbon radical R ^{3 is} present on average.

On the one hand the thioamide group and n functional groups R ^{4 are} bonded to the radical R ³ . These may be the same or different functional groups.

The functional groups R ⁴ may be, for example, -OH, -NH ₂ , -NHR ⁵ , -NR ⁵ R ^{5 '} , -COOH, -COOR ⁵ , -CONH ₂ , -CONHR ⁵ , -CONR ⁵ R ^5' , -NHCOR ⁵ , -NR ^{5 '} COR ⁵ , -NHCONHR ⁵ , -SH, -CN, -Si (OH) ₂ , -PO (OH) ₃ , -Si (OR ⁵ ) ₂ , -PO (OR ⁵ ) ₃ where R ⁵ and R ^{5 '} independently of one another are an alkyl radical, preferably a straight-chain or branched alkyl radical having 1 to 6 C atoms and particularly preferably -CH ₃ .

In a preferred embodiment of the invention, functional groups R ⁴ are those groups which have only N and / or O atoms as heteroatoms. Examples of such groups include -OH, -NH ₂ , -NHR ⁵ , -NR ⁵ R ^{5 '} , -COOH, -COOR ⁵ , -CONH ₂ , -CONHR ⁵ , -CONR ⁵ R ^5' , -NHCOR ⁵ , -NR ^{5 '} COR ⁵ , -NHCONHR ⁵ Preferably, the functional group is -OH and / or -NH ₂ .

In a preferred embodiment of the invention, the radical R ³ is a divalent hydrocarbon radical. Particularly noteworthy here are linear 1, ω-alkylene radicals of the general formula - (CH ₂ ) _k -, where k stands for a natural number of 1 to 30, preferably 1 to 20 and particularly preferably 1 to 10. It may also be divalent aromatic radicals, such as 1,4-phenylene, or substituted aromatic radicals of the general formula - (CH ₂ ) _{k '} - (C ₆ H ₄ ) - or - (CH ₂ ) _k' - (C ₆ H ₄ ) - (CH ₂ ) _{k "} -, where k 'and k" independently of one another represent a natural number from 1 to 10, preferably 1 to 3.

Examples of particularly preferred thioamides (D1) include ω-hydroxycarboxylic acid thioamides of the general formula HO- (CH ₂ ) _k -C (S) NR ¹ R ² , where the radicals and indices have the abovementioned meaning. k in these compounds is preferably 3 to 8. Examples of such compounds include 2-hydroxythioacetamide, 3-hydroxythiopropionamide, 4-hydroxythiobutanamide, 5-hydroxythiopentanamide, 7-hydroxythioheptanamide or 8-hydroxythiooctanamide, 9-hydroxythiononamide or 10-hydroxythiodecanamide.

The compounds (D2) containing at least two thioamide groups may in the simplest case be dithiooxamide R ¹ R ² N (S) CC (S) NR ¹ R ² .

Apart from these are compounds of the general formula R ⁶ (-C (S) NR ¹ R ² ) _m , in which m thioamido groups are linked together by a linking group R ⁶ , and m is a natural number of at least two acts. The compounds may be low molecular weight, oligomeric or polymeric compounds. The linking group R ⁶ is straight-chain or branched aliphatic, cycloaliphatic, aromatic and / or araliphatic hydrocarbon radicals in which non-adjacent C atoms can also be substituted by heteroatoms, in particular O and / or N atoms or functional groups , and which additionally may also have functional groups. Additional functional groups may in particular be the groups R ⁴ defined above.

In a preferred embodiment of the invention, D 2 is low molecular weight compounds. In this case, R ⁶ has 1 to 30 C atoms, preferably 2 to 20 C atoms and particularly preferably 2 to 10 C atoms, and in these compounds M has the value 2 to 6, preferably 2 to 4 and particularly preferably 2.

In a particularly preferred embodiment, (D2) is a thioamide of the general formula (III) R ¹ R ² N (S) CR ⁷ -C (S) NR ¹ R ² . R ⁷ here stands for a divalent, linking group which comprises 1 to 30 C atoms.

R ⁷ is, in particular, linear 1, ω-alkylene radicals of the general formula - (CH ₂ ) k-, where k is a natural number of 1 to 30, preferably 2 to 20 and particularly preferably 2 to 8. It may also be divalent aromatic radicals, such as 1,4-phenylene, or substituted aromatic radicals of the general formula - (CH ₂ ) _{k '} - (C ₆ H ₄ ) - or - (CH ₂ ) _k' - (C ₆ H ₄ ) - (CH ₂ ) _{k "} -, where k 'and k" independently of one another represent a natural number from 1 to 10, preferably 1 to 3.

Examples of such compounds D2 include malondithioamide, hexanedithioamides, 1,4-benzodithioamide or 1,2-benzodithioamide.

When R ⁷ may preferably radicals of the general formula further - _'- (CH _{2) k} -R _{^8' '-} (CH _{2) k,} act wherein R ⁸ represents a divalent functional group, in particular a P-containing functional Group. Examples of such groups include -OP (O) (OR ⁹ ) O-, -P (O) (OR ⁹ ) -, -P (S) (OR ⁹ ) -, -P (S) (SR ⁹ ) where R ⁹ is H, a monovalent metal ion or an alkyl radical, preferably a straight-chain or branched alkyl radical having 1 to 6 C atoms

The preparation of compounds with thioamide groups is known to the person skilled in the art. They can be prepared, for example, from the corresponding nitriles by reaction with H ₂ S.

In a further preferred embodiment of the invention, (D2) is a polymer which comprises at least two terminal and / or pendant thioamide groups. The term "polymer" includes oligomers and includes, in a known manner, high molecular weight compounds obtained from one or more monomers by polymerization, which may be substantially linear or branched polymers thioamide groups _n the polymers usually is 300 to 10 million g / mol, preferably from 500 to 1,000,000 g / mol and particularly preferably 1000 to 100,000 g / mol.

at the thioamide groups on the polymer may be end groups or it can be side-by-side Act groups. Permanent page Thioamidgruppen can be attached directly to the polymer main chain, or they can also have a Spacer be connected to the polymer backbone.

The polymers can be prepared by first preparing polymers containing nitrile groups and after polymerization the nitrile groups in a manner known in the art with H ₂ S to give thio amide groups.

Farther Is it possible, Use monomers for polymerization, which additional have reactive groups having with suitable thioamide groups Compounds can react. By way of example, mention may be made of polymers which contain maleic anhydride groups and reacted with, for example, ω-hydroxythioamides can be as shown below by way of example.

Have proven For example, copolymers of maleic anhydride and comonomers such as (meth) acrylic acid, acrylates and / or olefins as a starting material for modification.

to Preparation of the integrated pretreatment layers may include single thioamide or several different thioamides D1 and / or D2 are used. The expert meets among the principle potential Thioamides depending on the desired Properties of the integrated pretreatment layer a certain Selection. For the expert is of course that not all types of thioamides D1 and / or D2 for all species of binder systems, solvent systems or surfaces equally are well suited. By selecting specific functional groups or the linking one Group, the thioamides can be optimally adapted to specific systems. For example, it is more hydrophilic or rather hydrophobic Make connections D1 and / or D2 for targeted use in aqueous Produce paint systems or organic paint systems.

It is self-evident possible, the invention used Thioamides D1 and / or D2 mixed with others, from the above Definition of dissimilar thioamides, other thiocarbonyl compounds or generally other anticorrosion agents, provided that: There are no negative means to use, provided it is There are no negative properties. As a rule, the should Proportion of the invention used Thioamides at least 50 wt.%, Preferably at least 75 wt.% Regarding the Total amount of all organic corrosion inhibitors used be. Especially preferred are only thioamides D1 and / or D2 used.

The used according to the invention Thioamides are commonly used in an amount of 0.25 to 10 wt.%, Preferably 0.5 to 8 wt. % and more preferably 1 to 6 wt.% used.

When Component (E) comprises the preparation as a rule a suitable one Solvents in which the components are solved and / or dispersed to allow uniform application to the surface. But it is also possible in principle the preparation is solvent-free or substantially solvent-free to formulate as a powder coating. Preferably, the application of a Solvent.

suitable solvent are those which are capable of the compounds of the invention to solve, to disperse, suspend or emulsify. It may be to organic solvents or to trade water. Of course can also mixtures of various organic solvents or mixtures of organic solvent be used with water. The expert meets under the principle possible solvents depending on the desired Purpose and the nature of the compound of the invention used a suitable choice.

Examples of organic solvents include hydrocarbons such as toluene, xylene or mixtures such as are obtained in the refining of crude oil, such as hydrocarbon fractions of certain boiling ranges, ethers such as THF or polyethers such as polyethylene glycol, ether alcohols such as butyl glycol, ether glycol cetates such as butylglycol acetate, ketones such as acetone, alcohols such as methanol, ethanol or propanol.

Farther can Also preparations are used, the water or a predominantly aqueous Solvent mixture include. This should be understood as meaning mixtures which at least 50% by weight, preferably at least 65% by weight and especially preferably at least 80% by weight of water. Other components are water-miscible solvents. Examples include monoalcohols, such as methanol, ethanol or propanol, higher Alcohols such as ethylene glycol or polyether polyols and ether alcohols such Butyl glycol or methoxypropanol.

The Amount of solvents is determined by the skilled person depending on the desired properties of the preparation and the desired Application method selected. As a rule, amounts the weight ratio the layer components to the solvent 10: 1 to 1:10, preferably about 2: 1 without the invention on it limited should be. It goes without saying also possible, first to produce a concentrate and only on site to the desired concentration to dilute.

The Preparation is done by thoroughly mixing the components of the preparation made with the solvents. The person skilled in the art is familiar with suitable mixing or dispersing aggregates.

About the Components (A) to (D) and optionally (E) may be the preparation about that addition of one or more auxiliary substances and / or additives (F) include. Such auxiliaries and / or additives are used for fine control the properties of the layer. Their amount usually does not exceed 20% by weight with respect to the buzzer of all components except the solvents, preferably not 10%.

Examples of suitable additives are color and / or effect pigments, reactive diluents for thermal curing or curing with actinic radiation, rheology aids, UV absorbers, light stabilizers, radical scavengers, initiators for free-radical polymerization, catalysts for thermal crosslinking, photoinitiators and -coinitiators , Slip additives, polymerization inhibitors, defoamers, emulsifiers, degassing agents, wetting and dispersing agents, adhesion promoters, leveling agents, film-forming auxiliaries, rheology-controlling additives (thickeners), flame retardants, desiccants, skin-preventing agents, other corrosion inhibitors, waxes and matting agents, as described in the textbook »Lackadditive« by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, or the German patent application DE 199 14 896 A1 , Column 13, line 56, to column 15, line 54, are known.

preferred Additives are dibutyltin dilaurate as a catalyst for the thermal Networking.

to execution the method according to the invention becomes the metallic surface treated with the preparation.

optional becomes the surface cleaned before treatment. If the treatment according to the invention immediately after a metallic surface treatment, for example an electrolytic galvanizing or hot-dip galvanizing of steel strips, so can the bands as a rule without prior purification with the treatment solution according to the invention in Be brought in contact. Were the metal strips to be treated present? the coating of the invention however stored and / or transported, so are usually with Corrosion protection oils provided or at least so largely polluted that a cleaning before the coating according to the invention is required. The purification can be known to the person skilled in the art Methods with usual Cleaning agents take place.

at the method according to the invention For applying integrated pretreatment layers, the surface of the Metal treated with the preparation, for example by spraying, dipping or rolling up. After a dipping process you can remove the excess treatment solution workpiece Drain; in metal sheets, metal foils or the like, excess treatment solution can also be squeeze or squeegee. In the treatment at least parts of the polymer used as well as further components of the preparation from the surface chemisorbed the metal, leaving a strong bond between the surface and the components comes about. Treatment with the provocation usually takes place at room temperature without causing higher temperatures should be excluded in principle.

The treatment may be a so-called "no-rinse" process in which the treatment solution is dried directly in a drying oven immediately after application without rinsing, but it is also possible to replicate the surface after treatment with a cleaning liquid do the washing up.

at the most preferred coating of metal bands the coating can be made both on one side and on both sides. Most preferably, the coating is carried out by means of a continuous Process.

The strip coating can be carried out, for example, by means of a continuous strip coater, as described in Rompp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, page 55, "Bandbeschichtung", or in the German patent application DE 196 32 426 A1 is described. Of course, differently constructed systems can be used.

The Speed of the metal strip is determined by the expert the application and curing properties the preparation used. Generally proven have speeds of 10 to 200 m / min, preferably 12 up to 120 m / min, more preferably 14 to 100 m / min, especially preferably 16 to 80 and in particular 20 to 70 m / min.

The Application of the paints of the invention can in any way, for. B. by spraying, pouring or Roll painting, done. Of these application methods that is Roll coating particularly advantageous and is therefore preferred according to the invention used.

Everyone Application step of roller painting can with multiple rolls carried out become. Preferably, two to four and especially two Rollers applied.

At the Roll painting dips the rotating pickup roller (pick-up roller) in a supply of the paint according to the invention and takes over so the paint to be applied. This one is from the pickup roller directly or via at least one transfer roller transferred to the rotating application roller. From this will be the paint transferred by rectified or reverse stripping on the tape.

Of the paint according to the invention but can also be pumped directly into a gap between two rollers be what is called by the experts as a nip feed.

This is according to the invention opposing Stripping or the reverse roller coating process is beneficial and therefore preferably applied.

At the the roller painting can the rotational speeds of the pickup roller and the application roller from coating process to Coating process very much vary greatly. Preferably, the application roller has a circulation speed, which is 110 to 125% of the tape speed, and the pickup roller one Rotational speed, which is 20 to 40% of the belt speed.

in the Connection to the application of the preparation used according to the invention any solvent present in the layer is removed and the layer networked. This can be done in two separate steps though also be done simultaneously. To remove the solvent, the layer preferably heated by means of a suitable device. The Drying can also be done by contacting with a gas stream. Both methods can be combined.

The curing method depends on the nature of the crosslinker and takes place in all Usually thermally. The curing however, can also be combined with actinic radiation or thermal and with actinic radiation. Joint hardening with Heat and actinic radiation is also called dual-cure by experts designated. Under actinic radiation is here and below electromagnetic radiation, such as near infrared, visible light, UV radiation or X-radiation, in particular UV radiation, or corpuscular radiation, such as electron radiation Understood.

The for curing required temperature depends in particular on the used Crosslinkers. Very reactive crosslinkers can be used at lower temperatures hardened are considered less reactive crosslinkers. The temperature of the layer is usually for curing between 120 and 250 ° C.

The Heating the lacquer layers according to the invention during thermal curing preferably by convection heat transfer, irradiation with near or far infrared and / or bands based on iron done by electrical induction.

The Heating time, i. the duration of thermal curing varies dependent on of the inventive paint used. Preferably lies at 10 s to 2 min. Is essentially the convection heat transfer applied at the preferred tape speeds convection ovens a length from 30 to 50, especially 35 to 45 m needed. The circulating air temperature is naturally higher than the temperature of the layer and can be up to 350 ° C.

The thermal curing the paint layers of the invention can still be supported by the irradiation with actinic radiation.

However, the curing can also take place with actinic radiation alone, as described for example in the German patent application DE 198 35 206 A1 is described.

By the inventive method is an integrated pretreatment layer on a metallic Surface, especially the surface of iron, steel, zinc or zinc alloys, aluminum or aluminum alloys available. The exact structure and composition of the integrated pretreatment layer we do not know. It includes besides the reaction products the polymer as well as the crosslinker the fillers, thioamide and optional other components. In addition, you can even from the metal surface leached and re-deposited components, such as conventional amorphous oxides of aluminum or Zinc and possibly other metals may be present. The composition the passivation layer does not seem to be homogeneous but Show concentration gradients.

The Thickness of the integrated pretreatment layer will ever be appreciated by the skilled person according to the desired Properties of the layer set. As a rule, has a Thickness from 3 to 15 μm, even if in special cases the thicknesses even outside these areas may lie. Preferred is a thickness of 4 to 10 microns and more preferably 5 to 8 microns. The fat results from the amount of each applied composition.

On the metallic surface with an integrated pretreatment layer can still further paint layers be applied.

This can be done in the same coil coating line at the multiple application and possibly curing stations in a row are switched. Alternatively, however, after the application and the hardening the integrated pretreatment the coated tape again and again additional layers are applied in other systems. After Production of coated tapes can Wrapped coils are coated and then moved to another location be processed further; you can but also, directly from the coil coating, further processed become. So can laminated with plastics or with removable protective films be provided.

The but with the integrated pretreatment layer provided bands can but without further painting first crushed and processed into moldings. Various Moldings can also by welding together become. Examples of suitable shaping processing methods are Pressing and deep drawing.

The resulting profile elements and moldings, as are scratch-resistant, corrosion-resistant, weather-stable and chemically stable and can be used without problems be painted over with a variety of paints.

Of the Lack without conductive Pigments can be used as a KTL replacement if it is in a layer thickness about 10-15 μm applied becomes.

The The following examples are intended to explain the invention in more detail.

base formula

For the formulation for the preparation of an integrated pretreatment layer, the following components were used:

The Components were placed in a suitable stirred vessel in the order listed mixed and predispersed with a dissolver for ten minutes. The resulting mixture was transferred to a bead mill with cooling jacket and 1.8-2.2 mm SAZ glass beads mixed. The regrind was during 1 milled for 30 minutes. Subsequently the millbase was separated from the glass beads.

The millbase was added with stirring in the order given, with 5.9 parts by weight of a commercial self-crosslinking urethane resin (Desmodur ^® VPLS 2253 from Bayer AG) and 0.4 parts by weight of a commercial cross-linking catalyst (Borchi ^® VP0245 from Bayer AG).

Examples 1 to 3, Comparative Examples 1 to 3

Of the Base recipe were each additional in each case 3 parts by weight of one of the thioamides to be used according to the invention added with at least two thioamide groups. The used thioamides Table 1 is compiled.

To For comparison purposes, a base formulation was left without additives, Furthermore were linked to a thioamide group but without functional Group as well as a dithiocarbamate tested.

Tabelle 1: Für die Versuche eingesetzte Thioamide

Table 1: Thioamides used for the experiments

Applying the integrated invention pretreatment layers

The compositions were coated on steel plates of grade Z (OEHDG 2 Fir ma Chemetall) and applied to aluminum plates AlMgSi (AA6016 company Chemetall) in a wet film thickness that after curing in a continuous dryer at a convection temperature of 185 ° C and an object temperature of 171 ° C coatings resulted in a dry film thickness of 6 microns.

Test of the coatings

Test of steel sheets:

With Steel plates became a standardized 10-week climate change test carried out (VDA climate change test, VDA test sheet 621-415 Feb82).

To After completion of the corrosion load, the sheets were visually evaluated. It was both the formation of corrosion products on the undamaged paint surface as also the tendency to infiltrate edge and Ritz judged.

0

= Korrosionschäden wie bei der Nullprobe

+

= weniger Korrosionsschäden als bei der Nullprobe

++

= wesentlich weniger Korrosionsschäden als bei der Nullprobe

The following grades were awarded

0

= Corrosion damage as in the blank sample

+

= less corrosion damage than the blank sample

++

= significantly less corrosion damage than the blank sample

Test of aluminum sheets:

At Aluminum plates became the acidic salt spray test ESS (DIN 50021 June 88) carried out. To After completion of the corrosion load, the sheets were visually evaluated. Here were the circular Deletions on the entire paint surface rated.

0

= Korrosionschäden wie bei der Nullprobe

+

= weniger Korrosionsschäden als bei der Nullprobe

++

= wesentlich weniger Korrosionsschäden als bei der Nullprobe

The following grades were awarded

0

= Corrosion damage as in the blank sample

+

= less corrosion damage than the blank sample

++

= significantly less corrosion damage than the blank sample

Tabelle 2: Zusammenstellung der Ergebnisse der Korrosionsschutztests The results of the tests are summarized in Table 2:

Table 2: Compilation of the results of the corrosion protection tests

The Examples and Comparative Example show that the invention used Thioamides D1 and / or D2 give better results in integrated pretreatment layers deliver as other thioamides and other thiocarbonyl compounds

Claims (19)

Method for applying integrated pretreatment layers to metallic surfaces, at least comprising the steps of (1) treating the metallic surface with a crosslinkable preparation comprising at least (A) a binder, (B) crosslinkable components, which are crosslinkable groups which are connected to the binder and / or may be at least one additionally used crosslinker, (C) a pigment, (D) a corrosion inhibitor, and (E) optionally Solvent, and (2) crosslinking of the applied layer, characterized in that • the amount of the binder is 20 to 70 wt.%, • the filler is 20 to 70 wt.% Of at least one inorganic finely divided filler having an average particle size is less than 10 μm, and • the corrosion inhibitor is from 0.25 to 10% by weight of at least one thioamide group (I) -C (S) NR ¹ R ^2- containing compound selected from the group of (D1) thioamides of the general formula (II) R ⁴ _n -R ³ -C (S) NR ¹ R ² , and (D2) thioamides having at least 2 thioamide groups, and wherein n is a natural number from 1 to 5, and the radicals R ¹ , R ² , R ³ and R ^{4 are} the following e are: R ¹ and R ² independently of one another are H or a linear or branched, optionally substituted alkyl radical having 1 to 20 C atoms, R ^{3 is} an (n + 1) -valued hydrocarbon radical having 1 to 30 C atoms, R ^{4 is} a functional group, with the proviso that the wt.% Data refer to the sum of all components except the solvent. Process according to claim 1, characterized in that R ¹ and R ² are H. A method according to claim 1 or 2, characterized in that it is the functional group R ⁴ is an O and / or N-containing group. Process according to Claim 1 or 2, characterized in that (D2) is a thioamide of the general formula (III) R ¹ R ² N (S) CR ⁷ -C (S) NR ¹ R ² , where R ⁷ is a divalent, linking group having 1 to 30 carbon atoms, which may also include other functional groups. A method according to claim 1 or 2, characterized in that (D2) is a polymer which comprises at least two terminal and / or pendant thioamide groups -C (S) NR ¹ R ² . Polymer comprising at least two terminal and / or pendant thioamide groups -C (S) NR ¹ R ² . Method according to one the claims 1 to 5, characterized in that the metallic surface before treating with the preparation in an additional purification step (0) is cleaned. Method according to one the claims 1 to 5, 7, characterized in that it is in the metallic surface around the surface of steel, zinc or zinc alloys, aluminum or aluminum alloys is. Method according to one the claims 1 to 5, 7, 8, characterized in that the integrated pretreatment layer a thickness of 3 to 15 microns having. Method according to one the claims 1 to 5 and 7 to 9, characterized in that the treatment by means of rolling, spraying or dipping process. Method according to claim one of the claims 1 to 5 and 7 to 10 characterized in that it is in the metal surface around the surface of a strip metal. Method according to claim 11, characterized in that the band metal is electrolytic galvanized or hot-dip galvanized Steel acts. Method according to claim 11 or 12, characterized in that the treatment by means of a continuous process. Integrated pretreatment layer on a metallic surface made of steel, zinc or zinc alloys, aluminum or aluminum alloys available by a method according to the claims 1 to 5. Integrated pretreatment layer according to claim 14, characterized in that the thickness of the layer is 3 to 15 microns. Metallic surface comprising an integrated Pre-treatment layer according to claim 14 or 15. Metallic surface according to claim 16, characterized that on the integrated pretreatment layer one or more several on top of each other attached lacquer layers are located. Steel strip metal comprising a coating Zn or a Zn alloy, which is a surface according to claim 16 or 17. A composition for applying integrated pretreatment layers to metallic surfaces comprising at least the following components: (A) a binder, (B) crosslinkable components, which are crosslinkable groups which are bonded to the binder and / or at least one additionally used crosslinker can, (C) a pigment, (D) a corrosion inhibitor, and (E) optionally a solvent, characterized in that • the amount of the binder 20 to 70 wt.%, • It is the filler by 20 to 70 wt .% of at least one inorganic finely divided filler having an average particle size of less than 10 microns, and • it is the corrosion inhibitor by 0.25 to 10 wt.% Of at least one thioamide groups (I) -C (S) NR ¹ R ² having A compound selected from the group of (D1) thioamides of the general formula (II) R ⁴ _n -R ³ -C (S) NR ¹ R ² , and (D2) thioamides having at least 2 thioamide groups and wherein n is a natural number from 1 to 5, and the radicals R ¹ , R ² , R ³ and R ^{4 are} the following: - R ¹ and R ^{2 are} independently H or a linear or branched, optionally substituted Alkyl radical having 1 to 20 C atoms, - R ^{3 is} an (n + 1) -valent hydrocarbon radical having 1 to 30 carbon atoms, - R ^{4 is} a functional group, wherein the wt.% Data on the sum of all components with Refer to the exception of the solvent.