KR20180014018A - Pre-rinse containing a quaternary amine for conditioning prior to a conversion treatment - Google Patents

Abstract

The present invention relates to a multi-step method for corrosion prevention pretreatment of parts made of a metallic material. The part is applied to a conditioning wet-chemical treatment with an aqueous composition (A) containing a salt of a quaternary amine and then applied to an additional wet-chemical treatment based on a water-soluble compound of Zr, Ti and / or Si elements , A corresponding conversion of the surface of the metallic material takes place during this process, and this treatment provides an anti-corrosion primer for the additionally applied organic coating.

Description

PRE-RINSE CONTAINING A QUATERNARY AMINE FOR CONDITIONING PRIOR TO A CONVERSION TREATMENT FOR CONDITIONING WITH PRE-

The present invention relates to a multistage process for the corrosion inhibition pretreatment of parts made from metallic materials, characterized in that after the conditioning wet-chemical treatment using an aqueous composition (A) comprising a salt of a quaternary amine, the Zr, Ti and / Or a further wet-chemical treatment based on a water-soluble compound of the Si element, resulting in a corresponding conversion of the surface of the metallic material during this process, giving an anticorrosion primer for the additionally applied organic coating .

The conversion treatment of metallic surfaces to provide a coating, which provides protection against corrosion, based on aqueous compositions comprising water soluble compounds of Zr, Ti and / or Si elements, Field. Various variations of the metal pretreatment process as described above are known to improve the characteristic profile of such a conversion process and to provide sufficient paint adhesion since it is associated with corrosion protection, ≪ / RTI > or to an additional wet-chemical treatment step.

EP 1 455 002 A1, for example, discloses that if an aqueous rinse comprising an alkaline reactive compound follows the actual wet-chemical treatment or is followed by a downstream drying step, It is described that the conversion treatment with the composition described above which additionally comprises fluoride ion as a charge is advantageous in reducing the fluoride fraction in the conversion layer. Alternatively, the addition of certain cations selected from calcium, magnesium, zinc, copper, or silicon-containing compounds to compositions that cause surface conversion is used to reduce the fluoride content in the conversion layer.

With regard to the water-soluble compounds of the agents comprising Zr and / or Ti elements for the conversion treatment and the further adaptation of the procedure in the case of using fluoride ions, WO 2011012443 A1 describes a process for the preparation of one or more nitrogen heteroatom containing aromatic heterocycles Teaches a downstream aqueous rinse comprising an organic compound comprising a < RTI ID = 0.0 > click < / RTI > compound.

Compared with this prior art, the object is to provide a corrosion-resistant property of the conversion layer which can be obtained by a pre-treatment with a composition of a water-soluble compound of Zr, Ti and / or Si element more continuously on various metal substrates, , And to improve corrosion protection properties on steel surfaces. In particular, the average creep value in the caustic delamination after the paint coat structure is formed must be improved. In further sub-embodiments, the pretreatment should take place substantially without the presence of fluoride for environmental hygiene reasons. Thus, in order to be able to implement this sub-embodiment, the pretreatment method according to the invention is carried out in the presence of a so-called "free metal surface ", which is a degreased, cleaned metal surface comprising only the natural oxide layer, Homogeneous and complete conversion. Furthermore, under the same conditions, the dispersion in the conversion layer should be low, that is, from the viewpoint of process engineering, certain conversions must certainly be achieved. With regard to their use on various metal substrates, in particular, the optimum corrosion-inhibiting action by suitable wet-chemical pretreatment can be achieved in addition to the surface of iron and / or steel material and also of at least zinc, galvanized steel and / It is preferable for a composite structure comprising a single-layer surface.

This object is achieved by a multistage process for the pre-treatment of corrosion protection of parts made of metallic materials,

In the beginning

i) ("Conditioning") an aqueous composition (A) comprising a dissolved and / or dispersed salt of a quaternary organic amine, at least a portion of the surface of the component formed of a metallic material,

next

ii) (B) comprising at least one water-soluble compound of Zr, Ti and / or Si, with at least the same part of the surface of the part formed of a metallic material, irrespective of the rinsing step and / ("Transition layer formation")

Is accomplished by a multistage method.

The parts processed according to the present invention can be used in any arbitrarily shaped and arranged three-dimensional structure formed in the manufacturing process, especially semi-finished products such as ribbons, sheets, rods, tubes and the like, Lt; / RTI >

In the present invention, in the first step i) of the process according to the invention, the conditioning treatment is carried out using an aqueous composition (A) comprising a dissolved and / or dispersed salt of a quaternary organic amine (" ). As a result of this conditioning, a sufficient and homogeneous layer coating is achieved on the Zr, Ti and / or Si elements during the wet-chemical treatment with the aqueous composition (B), so that the transition of the metal surface of the component effectively takes place, Thereby providing a good paint primer. In particular, on the steel surface, a reproducible layer coating for the elements Zr, Ti and / or Si is achieved in the course of the process according to the invention, this layer coating additionally providing a corrosive creep for defects in the applied paint coating It represents the basis for effective suppression.

In the sense of the present invention, salts of quaternary organic amines dissolved or dispersed in water have an average particle diameter of less than 1 [mu] m in the aqueous phase. The average particle diameter can be measured according to ISO 13320: 2009 by laser diffraction from the cumulative particle size distribution, in a form known as the D50 value directly in aqueous composition (A) at 20 占 폚.

The presence of a fourth organic amine in the aqueous composition (A) in step i) increases the suitability of the conversion coating applied in step ii) to serve as a good paint primer. In the context of the present invention, the quaternary organic amine has a permanent positive charge because it contains at least one nitrogen atom exclusively having a covalent bond with the carbon atom.

It has a weight average molecular weight M _w in the context of the compounds of the present invention, quaternary organic amine is less than 5,000 g / mol are preferred.

Furthermore, since the heterocyclic compound comprising at least one nitrogen heteroatom, which exclusively has a covalent bond with a carbon atom exclusively, represents a suitable quaternary organic amine, this means that in the process according to the invention, It has been found to be a preferred component.

In a preferred embodiment, the quaternary organic amine present in the aqueous composition (A) is a heterocyclic compound comprising at least one nitrogen heteroatom of the formula (I)

≪ RTI ID = 0.0 > (I)

Functional groups R ^1, R ² and including R ^3, and are each hydrogen, C 6 branched or non-(非) branched aliphatic compounds of the following, or a functional group _{^{- (CR 4 R 4) x}} - [Z (R 4) _{(p-1) - (CR} 4 R 4) y] n -Z (R 4) p ( wherein Z is selected from oxygen or nitrogen, p is, in the case where Z is nitrogen, and takes a value of 2, or 1, x and y are each a natural number of 1 to 4, n is likewise a natural number of 0 to 4, and R ⁴ is selected from hydrogen or a branched or unbranched aliphatic compound having 6 or less carbon atoms, With the proviso that at least one of the functional groups R ² or R ³ is not selected from hydrogen;

A ring-constituting divalent functional group, Y comprising not more than 5 bridge atoms, wherein not more than one hetero-bridge atom different from a carbon atom selected from oxygen, nitrogen or sulfur may be a bridge atom, and carbon atoms Are eventually substituted independently of each other by a functional group which causes the ringing of the functional group R ¹ or the aromatic homocyclic compound of 6 or less carbon atoms to be achieved.

In general it has been found advantageous that the quaternary organic amine is represented by a heterocyclic compound comprising the skeleton of imidazole, imidazoline, pyrimidine, purine and / or quinazoline. Thus, in this context, the heterocyclic compound according to formula (I) is a ring-constituting divalent functional group Y which is selected from ethylene, ethanediyl, 1,3-propanediyl, -Butanediyl, 1,4-butenediyl, 1,4-butadiene diyl, -CH = N-, -CH ₂ -NH-, (N, N-dimethylene) amine, (N-methylene- Especially N-methylene-N-methylidene) amine, particularly preferably ethynediyl or -C = N- , And particularly preferably etendiyl, wherein in each case hydrogen in the covalent bond to the carbon atom is preferably replaced by the remaining representative of the functional group R ¹ according to general formula (I) .

Quaternary organic amines that have been found to be particularly advantageous include, but are not limited to, 1,2,3-trimethylimidazolium, 1-methyl-3-methylimidazolium, Imidazolium, 1-propyl-3-methylimidazolium, 1- (n-butyl) -3-methylimidazolium, 1- Methylimidazolium, 1-ethoxy-3-methylimidazolium, 1-propoxy-3-methylimidazolium, and particularly preferably 1,2,3-trimethylimidazolium .

The proportion of the fourth organic amine in the aqueous composition (A) is not less than 0.05 g / kg, preferably not less than 0.2 g / kg, and particularly preferably not less than 0.4 g / kg, but preferably not more than 5 g / Particularly preferably 10 g / kg or less, is generally advantageous in the present invention.

In the case of more than 10 g / kg, even if the rinsing step follows the conditioning in step i), since no inhibition of the corrosive delamination is observed after the paint structure is formed, Quaternary organic amines can be used economically in the process according to the invention.

In general, all anions, especially organic anions such as sulphates, nitrates, chlorides, carbonates, and alkyl sulphates, alkyl sulphonates, alkyl phosphates and / or alkyl phosphonates, Ions.

Surprisingly, it is surprising that monoalkyl sulfates, monoalkyl sulfonates, dialkyl phosphates and / or dialkyl phosphonates (preferably having up to 5 carbon atoms), preferably monoalkyl sulfates and / or monoalkyl sulfonates Is not more than 5 carbon atoms), and particularly preferably an anion (K) selected from methylsulfate has been found to be advantageous for the formation of a uniform conversion layer in step ii) of the process according to the invention, Additional presence is preferred.

As a result, since the anion K is preferably also an anion-generating component of the salt of the quaternary organic amine, the corresponding salt acts as both the source of the quaternary amine and the source of the anion (K) A) can be minimized. Thus, in addition to the salts of alkali metals and / or alkaline earth metals and the corresponding ammonium salts, a suitable source of anion (K) is in particular the corresponding salts of the quaternary organic amines described above.

In the present invention, the ratio of the anion (K) in the aqueous composition (A) is preferably not less than 0.05 g / kg, particularly preferably not less than 0.2 g / kg, and particularly preferably not less than 0.4 g / The ratio is preferably not more than 5 g / kg, and particularly preferably not more than 3 g / kg, which are calculated as equivalents of SO ₄ based on the aqueous composition (A), respectively. Above 5 g / kg, even if the rinsing step follows the conditioning in step i), since the conversion layer formation in step ii) does not increase further or more continuously, Can be used economically in the method according to the present invention.

The pH value of the aqueous composition (A) in step i) can be selected substantially freely and is usually in the range of 2 to 14, preferably more than 3.0, particularly preferably more than 4.0, and particularly preferably more than 5.0 , Preferably less than 12.0, particularly preferably less than 10.0, and particularly preferably less than 8.0.

Furthermore, this can be advantageous in the treatment of parts comprising the aqueous composition (A) additionally comprising a surface consisting of a zinc and / or zinc plated steel material containing a predetermined amount of iron ions, which upon contact with the zinc surface, Since it induces a thin iron-coat structure there, it additionally contributes to a more continuous provision of the corrosion protection available by the method according to the invention, especially for surfaces made of iron material. This type of ironizing is carried out in an acidic environment according to the teachings of WO 2008135478 A1, preferably in the presence of a reducing agent, or in an alkaline environment according to the teaching of WO 2011098322 A1, preferably in the presence of a complexing agent and a phosphate ion .

In the present invention, the aqueous composition (A) may contain additional components. In addition to the pH-regulating material, it may also comprise a surface-active substance, and its use is preferred for aqueous compositions (A) having a cleansing action.

However, in a preferred embodiment, the aqueous composition (A) has a surface activity not less than 0.05 g / kg, preferably less than 0.01 g / kg, and particularly preferably less than 0.001 g / kg, Compound, the interaction of the surface active compound with the surface of the metallic material of the component does not compete with the interaction with the quaternary organic amine, thus corresponding to each desired technical effect.

In the sense of the present invention, the surface-active compound has an HLB (Hydrophilic-Lipophilic Balance) value of less than 5 or greater than 10. The HLB value is calculated according to the following formula and can take on a value from 0 to 20, on an arbitrary scale:

HLB = 20 占 (1- _Ml / M)

(Wherein, M _l: ratio (非) of lyophilic ionic groups of the surfactant molecular weight; M: molecular weight of the nonionic surfactant).

Further, it is preferred that the aqueous composition (A) in step i) of the process according to the invention has a total of less than 0.5 g / kg, particularly preferably less than 0.1 g / kg, and particularly preferably less than 0.05 g / It is preferable to include a dissolvable and / or dispersed organic polymer which does not exhibit a quaternary organic amine. Thus, as described above with respect to the presence of a surface-active compound, the interaction of the surface of the metallic material of the component with such a polymer, as described above, can be enhanced by the use of a conditioner, or a quaternary organic amine additionally present in the preferred embodiment of the invention And thus is guaranteed to respond to each desired technical effect. Organic polymers dissolved or dispersed in the context of the present invention have a weight average molecular weight M _w of at least 5,000 g / mol and have an average particle diameter of less than 1 μm in the aqueous phase. The average particle diameter can be measured according to ISO 13320: 2009 by laser diffraction from the cumulative particle size distribution, in a form known as the D50 value directly in aqueous composition (A) at 20 占 폚.

In a preferred method according to the invention, no transition layer is produced on the surface of the metallic part in step i). Thus, the aqueous composition (A) does not contain any components in an amount that may enable the formation of a conversion layer on the surface of the metallic material of the part during the period provided for conditioning in step i). If on each surface of the metallic material a cover layer is produced by a wet-chemical process, there is a transition layer during the conditioning process in step i) of the process according to the invention, which is in the coat structure, in the titanium group, And / or a phosphate of an element of the group of chromium and / or chromium, or a phosphate of an element of calcium, iron and / or zinc, in an amount of not less than 5 mg / m ² based on the respective transition metals, Gt; mg / m < ² > The corresponding transition metal can be determined quantitatively by X-ray fluorescence (XRF) analysis, but the coat structure for the phosphorus element is determined by acid pickling of the surface of the metallic material in aqueous 5 wt.% CrO ₃ and subsequent atomic emission Can be measured by spectroscopy (ICP-AES).

In order to prevent the formation of a conversion layer on the surface of the metallic part of the part, the method according to the invention preferably comprises the step of applying the aqueous composition (A) in step i) in an amount of 0.005 g / water and less than 1 g / kg of Zn, Mn and Ca elements based on water-soluble compounds of Zr, Ti and / or Si elements, preferably less than 0.001 g / kg and particularly preferably less than 0.001 g / Compound and / or free fluoride, preferably less than 0.05 g / kg, and particularly preferably less than 0.01 g / kg, as measured using a fluoride-sensitive electrode at 20 ° C. In a further preferred embodiment, the total proportion of fluoride in the aqueous composition (A) is less than 0.05 g / kg, particularly preferably less than 0.02 g / kg, and particularly preferably less than 0.01 g / kg. The total proportion of fluoride (total fluoride) is measured in a TISAB buffered aliquot of aqueous composition (A) using a fluoride-sensitive electrode at 20 ° C (TISAB: total ionic strength adjustment buffer ), Wherein the volume-based mixing ratio of the buffer solution to the aqueous composition (A) aliquot is 1: 1. TISAB was prepared by dissolving 58 g NaCl, 1 g sodium citrate and 50 ml glacial acetic acid in 500 ml deionized water (kappa <1 μScm ^-1 ), setting the pH to 5.3 with 5 N NaOH, (&Lt; ¹ &lt; / RTI &gt;&lt; RTI ID = 0.0 &gt; uScm- ¹ ) &lt; / RTI &gt;

In method step ii), a sufficient amount of the active ingredient (s) must be present in the acidic aqueous composition (B) to form the conversion layer. In this connection, the aqueous composition (B) in step ii) is preferably at least 0.01 g / kg, particularly preferably at least 0.05 g / kg, based on the elements of Zr, Ti or Si, Is advantageously comprised of a water-soluble compound of Zr, Ti or Si element of at least 0.1 g / kg. In this context, it should be noted that such compounds according to the invention are considered water-soluble if their solubility in deionized water (? <1 μScm ^-1 ) at 20 ° C is 1 g / L or more.

Further, in economic considerations, it is advantageous if the total proportion of these compounds, based on the Zr, Ti and Si elements, is preferably not more than 0.5 g / kg, since these higher contents are usually the corrosion inhibiting Further improving the properties and making it more difficult to control the coat structure for these elements due to higher deposition kinetics.

Due to the conditioning in step i) of the process according to the invention, the non-fluorine water soluble compound of the Zr, Ti or Si element is also added to the aqueous composition (B) in order to cause a sufficient conversion of the surface of the metallic material of the part, And is therefore preferred. (NH ₄ ) ₂ Zr (OH) ₂ (CO ₃ ) ₂ , ZrO (NO ₃ ) ₂ or TiO (SO ₄ ), or silanes containing at least one Si-C covalent bond are particularly preferred representatives.

As described above, the use of the composite fluoride, and also the glass fluoride, in step ii) resulting in the conversion of the surface of the metallic material of the part, is achieved by the conditioning in step i) Can be omitted. Thus, a preferred method according to the invention is characterized in that the proportion of free fluoride in the aqueous composition (B) is less than 0.05 g / kg, 0.01 g / kg, 0.001 g / kg and 0.0001 g / kg, Particularly preferably, free fluoride is not present. Further, in a preferred embodiment of the process according to the invention, the total proportion of fluoride (aqueous fluoride) in the aqueous composition (B) is 0.05 g / kg, 0.02 g / kg, 0.01 g / kg, 0.001 g / kg and less than 0.0001 g / kg, with very particular preference being given to the absence of fluoride. The proportion of free fluoride and the total proportion of fluoride can be ascertained similar to the procedure used to measure the same parameters in aqueous composition (A).

In combination with the conditioning in step i), when copper ions are present in the aqueous composition (B) in step ii), the best results for corrosion protection are achieved. Thus, in a particularly preferred embodiment of the process according to the invention, the aqueous composition (B) is added in the form of a water-soluble salt, preferably copper sulfate, copper nitrate and copper acetate, As well. In this context, it should be noted that such compounds according to the invention are considered water-soluble if their solubility in deionized water (? <1 μScm ^-1 ) at 20 ° C is 1 g / L or more.

The content of copper from the water-soluble compound in the aqueous composition (B) is preferably 0.001 g / kg or more, and particularly preferably 0.005 g / kg or more. However, the content of copper ions preferably does not exceed 0.1 g / kg, particularly preferably does not exceed 0.05 g / kg, since otherwise the deposition of the copper element is predominantly associated with the conversion layer formation It starts to become.

The pH value of the aqueous composition (B) is preferably in the acidic range, particularly preferably in the range of 2.0 to 5.0, and particularly preferably in the range of 2.5 to 3.5.

Furthermore, it is preferable that the aqueous composition (B) contains nitrate ions as an accelerator for the conversion layer formation, wherein the ratio of the nitrate ions is preferably not less than 0.5 g / kg, but preferably not more than 4 g / kg &lt; / RTI &gt;

Surprisingly, successes according to the present invention occur substantially independently of the performance of the rinsing and / or drying step immediately after conditioning in step i). Differences in the performance of the method caused by the intermediate rinsing step can be compensated periodically by suitably increasing the concentration of the quaternary organic amine and anion (K) present in the aqueous composition (A). In any case, the general suitability of the method for achieving the object of the present invention is not affected by the execution of the rinsing and / or drying step between method steps i) and ii). However, in view of process engineering, in order to separate the active component from the individual treatment steps, it is preferred that the rinsing step follows immediately after step i) in the method according to the invention, wherein preferably before step ii) Is not performed.

In the present invention, the rinsing step is to remove the water-soluble residues, which are chemical compounds that are not always firmly adhered, and to remove the wet film adhering to the parts together with the solid particles drawn in the previous wet- To be loosened from the aqueous liquid medium. The aqueous liquid medium does not include any chemical components that cause the surface of the component made of the metallic material to significantly cover the transition metal, metalloid or polymeric organic compound. However, such a significant surface cover does not allow for the liquid medium of the rinse to be in contact with each other, without taking into account the amount obtained as a result of the residue and the amount lost by drag-out by the wet film attached to the component On these components, on the basis of the element or the respective polymeric organic compound, at least 10 mg / m ^{2 of the} rinsed surface, and preferably at least 1 mg / m ² of the rinsed surface.

In the present invention, the drying step is any method step in which the drying of the aqueous liquid film attached to the surface of the component is intended as a result of the provision and use of technical means, in particular by the application of heat energy or the application of air flow .

The parts processed in the method according to the invention are at least partly made of a metallic material. The preferred metallic materials which clearly demonstrate the improvement of the properties of the conversion layer as paint primers are iron and iron alloys, and in particular steel. In this context, iron alloys are understood to mean materials in which at least 50% of each material is formed of iron atoms. On the surface made of iron and its alloys, a significant improvement in corrosion protection occurs in connection with the corrosive creep to the defect, which means that irrespective of whether the rinsing and / or drying step follows immediately after conditioning in step i) It occurs substantially independently.

In the process according to the invention, step ii) is followed preferably by application of an organic coating, in particular a powder coating or a dip coating, which is preferably an electrical dip coating. The electrical dip coating is preferably carried out in the rinsing step, but is particularly preferably not carried out in the drying step.

In a preferred embodiment of the method according to the invention the part comprises a surface at least partly made of iron and / or steel material, preferably at least 50% of the surface of the part representing the surface made of metallic material, Preferably, at least 80% is formed of a surface of iron and / or steel material.

However, basically, in addition to the surface made of iron and / or steel material, a composite structure including a surface made of zinc and / or zinc plated steel and an aluminum material (if necessary, additionally in phosphate form) And in particular the parts, are processed in a method according to the invention.

Further, when the part comprises a surface made of zinc and / or zinc plated steel material, a thin amorphous layer containing iron is applied to such surface, and as is typically found on surfaces made of iron and / or steel material , It is generally preferred that effective conditioning is imparted to the surface of such material in step i) of the method according to the invention as well. Particularly effective ironing of surfaces made of zinc and / or galvanized steel in this connection is described in documents WO 2011098322 A1 and WO 2008135478 A1 in the form of wet-chemical processes in each case, May be applied in an equivalent manner just prior to performing step i). In this connection, in the method according to the invention, the part is a zinc and / or zinc-coated and at least in part, preferably consists of the steel material to 20 mg / m ² over the surface of the part produced from such a material, but preferably Is covered with iron by 150 mg / m ² or less.

Example Implementation:

Hereinafter, a steel sheet (CRS) is applied to a multi-step process for the corrosion prevention pretreatment. The suitability of the metal sheet provided with a paint coat to serve as a pretreated and good paint primer is tested in accordance with DIN EN ISO 4628-8 for corrosive delamination.

General methods for pretreatment and coating include the following individual essential and optional steps (A) to (E):

(A) Alkaline cleaning and degreasing:

Dipping the sheet in an alkaline detergent composed of 4 wt.% Ridoline® 2011 (Henkel) and 0.4 wt.% Ridosol® 1270 (Henkel) with stirring at 56 ° C for 5 minutes;

(B) rinsing at 20 < ⁰ &gt; C, respectively, with process water and then with deionized water (kappa <1 [mu] Scm &lt; ^-1 &gt;);

(C) The sheet was conditioned in a composition comprising a predetermined amount of "conditioner" in deionized water (K <1 μScm ^-1 ) at 35 ° C for 1 min without adding additional pH- step;

(D) if necessary, rinsing with deionized water at 20 占 폚 (? <1 μScm ^-1 );

(E) sheet in an aqueous composition having a pH value of about 2.6, containing 1.6 g / kg ZrO (NO ₃ ) ₂ , at 35 ° C for 3 minutes.

Following the conversion treatment in method step (E), each sheet was first rinsed with deionized water (? <1 μScm ^-1 ) at 20 ° C, then coated with electrophoretic paint and dried at 180 ° C : 18 to 20 占 퐉; CathoGuard (R) 800 from BASF Coatings).

Table 1 below shows the different organic compounds used in the conditioning in step (C).

[Table 1]

In an experiment to perform a conversion treatment based on a single non-fluoride composition (No. 1) on a steel sheet, the coat structure in the range of 0 to 20 mg / m ² zirconium was reproduced in step (D) It is clear that it can not possibly be implemented. Conditioning based on pretreatment using an aqueous solution containing polyvinylpyrrolidone (No. 2) is likewise a failure because the conversion layer formation does not occur at an increased level or reproducibly at all. Significant conversion of the steel surface is achieved only when an imidazolium salt is added, resulting in coating weights in the range of 15 to 60 m ² , which are usually sufficient to serve as good corrosion protection and good paint primers (No. 3 And 4). When methyl sulfate anion is additionally present, stronger promotion of conversion layer formation is observed (No. 5).

The corrosion results and the respective associated process sequences are provided in Table 2.

[Table 2]

¹ Corrosion under cutting in accordance with DIN EN ISO 4628-8, after aging in the VW alternating climate test according to PV 12103.

^The mean values and standard deviations over the ^two 25 sheets are used here for the individual coat sheet structures of the individual sheets, and the mean values from 6 individual measurements on the same sheet are used for the measurements, using an analysis surface of 50 mm ² Performed with an X-ray fluorescence analyzer Niton® XL3t 900 (Thermo Fisher Scientific).

# Mean values and standard deviations across the 62 sheets

Claims (15)

A multistage process for corrosion protection pretreatment of a component made at least in part from a metallic material,
In the beginning
(i) contacting at least a portion of the surface of the component formed of a metallic material with an aqueous composition (A) comprising a dissolved and / or dispersed salt of a quaternary organic amine,
next
ii) bringing at least the same part of the surface of the part made of a metallic material into contact with an aqueous composition (B) comprising at least one water-soluble compound of Zr, Ti and / or Si elements
A multi - step method for pretreatment of corrosion protection. The multi-step process of claim 1, wherein the quaternary organic amine is selected from heterocyclic compounds comprising at least one quaternary nitrogen heteroatom. 3. The method of claim 2, wherein the heterocyclic compound comprising at least one quaternary nitrogen heteroatom corresponds to the formula (I)

&Lt; RTI ID = 0.0 &gt; (I)
Functional groups R ^1, R ² and including R ^3, and are each hydrogen, C 6 branched or non-(非) branched aliphatic compounds of the following, or a functional group _{^{- (CR 4 R 4) x}} - [Z (R 4) _{(p-1) - (CR} 4 R 4) y] n -Z (R 4) p ( wherein Z is selected from oxygen or nitrogen, p is, in the case where Z is nitrogen, and takes a value of 2, or 1, x and y are each a natural number of 1 to 4, n is likewise a natural number of 0 to 4, and R ⁴ is selected from hydrogen or a branched or unbranched aliphatic compound having 6 or less carbon atoms, With the proviso that at least one of the functional groups R ² or R ³ is not selected from hydrogen;
A ring-constituting divalent functional group, Y comprising not more than 5 bridge atoms, wherein not more than one hetero-bridge atom different from a carbon atom selected from oxygen, nitrogen or sulfur may be a bridge atom, and carbon atoms Are eventually substituted independently of each other by a functional group which causes the ringing of the functional group R ¹ or the aromatic homocyclic compound of 6 or less carbon atoms to be achieved. The process of claim 3, wherein the ring-constituent 2 functional group Y is selected from the group consisting of ethylene, ethynediyl, 1,3-propanediyl, 1,3-propanediyl, 1,4-butanediyl, (N, N-dimethylene) amine, (N-methylene-N-methyllylidene) amine, preferably ethynediyl, 1,4-butadienediyl, -CH = N-, -CH ₂ -NH-, -Butadiene diyl, -C = N- or (N-methylene-N-methyllylidene) amine, particularly preferably ethynediyl or -C = N- and especially preferably etendiyl, Wherein the hydrogen covalently bonded to the carbon atom can be replaced by the remaining representative of the functional group R &lt; ^{1 &} gt ;. The process according to any one of claims 1 to 4, wherein the quaternary organic amine is selected from the group consisting of 1,2,3-trimethylimidazolium, 1-methyl-3-methylimidazolium, 3-methylimidazolium, 1- (n-butyl) -3-methylimidazolium, 1- (isobutyl) -3-methyl Imidazolium, 1-methoxy-3-methylimidazolium, 1-ethoxy-3-methylimidazolium and 1-propoxy-3-methylimidazolium, preferably 1,2,3-trimethyl &Lt; / RTI &gt; imidazolium &lt; RTI ID = 0.0 &gt;. &Lt; / RTI &gt; 6. Process according to any one of claims 1 to 5, wherein the composition (A) in step i) is selected from the group consisting of monoalkyl sulfates, monoalkyl sulfonates, dialkyl phosphates and / or dialkyl phosphonates (Preferably no more than 5 carbon atoms), preferably a monoalkyl sulfate and / or a monoalkyl sulfonate (preferably no more than 5 carbon atoms), particularly preferably an anion selected from methyl sulfate A multi-step method for corrosion prevention pretreatment. The composition according to any one of claims 1 to 6, wherein the proportion of the fourth organic amine in the composition (A) is 0.05 g / kg or more, preferably 0.2 g / kg or more, particularly preferably 0.4 g / kg or more , But preferably not more than 20 g / kg, particularly preferably not more than 10 g / kg. 8. A multi-step process for corrosion inhibition pretreatment according to any one of claims 1 to 7, characterized in that no transition layer is formed on the surface of the metallic part in step i). A composition according to one or more of claims 1 to 8, wherein the composition (A) is less than 0.05 g / kg, preferably less than 0.01 g / kg, particularly preferably less than 0.001 g / A multi-step process for anticorrosive pretreatment, characterized by comprising an unconfined surface active compound. The composition according to any one of claims 1 to 9, wherein the composition (B) in step ii) is present in an amount of 0.01 g / kg or more, preferably 0.05 g / kg or more, Characterized in that it comprises water-soluble compounds of elements of Zr, Ti or Si in an amount of 0.1 g / kg or more. 11. Composition according to one or more of the preceding claims, characterized in that the composition (B) in step ii) contains less than 0.05 g / kg, preferably less than 0.01 g / kg, particularly preferably less than 0.001 g / A multi-step process for corrosion inhibition pretreatment, characterized in that it comprises free fluoride. A composition according to any one of the preceding claims wherein the total proportion of fluoride in the composition (B) in step ii) is less than 0.05 g / kg, preferably less than 0.01 g / kg, particularly preferably 0.001 g / kg, and particularly preferably less than 0.0001 g / kg. &lt; RTI ID = 0.0 &gt; 8. &lt; / RTI &gt; Process according to one or more of the preceding claims, characterized in that the cleaning and degreasing step of the part is carried out before step i), preferably by contacting it with an aqueous composition comprising a surface-active compound. Multi - step method for preprocessing. Process according to one or more of the preceding claims, characterized in that a rinsing step is carried out between process steps i) and ii) and preferably no drying step is carried out. . A method as claimed in any one of the preceding claims wherein the part at least partially comprises a surface of iron and / or steel material and preferably comprises at least 50% of the surface of the metallic material of the part, more preferably at least 80 % Or more of the surface of the steel is formed of a surface of iron and / or steel material.