EP2989236A2 - Electrically conducting liquids based on metal-diphosphonate complexes - Google Patents

Abstract

The invention relates to electrically conducting liquids based on diphosphonate complexes and to the use thereof in methods for electrolytically modifying the surface of a flat metal workpiece. The invention further relates to the flat metal workpieces produced by said method and to the use of the metal workpieces as a substrate for forming permanent adhesive bonds with a plurality of materials and for accommodating liquid and solid materials.

Description

 ELECTRICALLY CONDUCTIVE LIQUIDS BASED ON METAL DI PHOSPHONATE COMPLEXES

The present invention relates to electrically conductive liquids based on diphosphonate complexes and their use in processes for the electrolytic surface modification of a flat metal workpiece. The invention further relates to the flat metal workpieces produced by this method and the use of the metal workpieces as a substrate for the formation of solid adhesive bonds with a variety of materials and for the absorption of liquid and solid materials.

A known method for the surface treatment of a metal workpiece, such as a metal strip or a sheet, represents the electrolytic

Coating a metal surface with a metal or a metal alloy is.

For example, in the electrolytic strip coating, the strip is passed through one or more electrolytic cells. In each electrolysis cell, the band is usually brought via so-called power rollers in a fixed-solid connection with the negative terminal of a rectifier. The band thus serves as a negative electrode, i. as a cathode. The positive electrode, i. the anode, is usually formed as a pair of electrodes, wherein the band passes between the two electrodes.

Disadvantages of this process are particularly evident in the transition from higher tape thicknesses to film thicknesses in that significant difficulties and limitations may arise in that (a) the film overheats and oxidizes due to the waste heat from the current transfer from the current roll, thereby eliminating the required currents (b) because of the low effective cross section of a film, the internal resistance becomes very high, which can lead to overheating of the film between the current roll and the electrolyte surface and to oxidation damage; (c) by contact of the film with the current roll removed particles and

Residuals local resistance peaks occur, which can lead to penetration or local discoloration of the film, and (d) due to the pre-treatment used and the subsequent film run in the coating system, the activation of the

Surface of the film is limited to the reduction and the annealing of the grain boundaries, so that there is no structurally optimized surface for the subsequent electrolytic metal deposition. Due to the electrolytic coating, the metal workpiece to be coated is uniformly provided on all sides with a substantially flat metal coating. Even with the use of metal workpieces with a relatively rough

Surface finish, the surface is leveled. However, for applications where good adhesion to another material is required, a smooth surface may be undesirable. Good adhesion between two materials is achieved when there is a chemical interaction and / or mechanical interlocking in topographical features of the adhesion partners. If this is not or not sufficiently the case, the adhesion deteriorates. So can a bad adhesion between one metal surface and the same or another

Material, such as a paint layer, a paint layer or an adhesive, lead to poor quality or even unusable products.

To improve the adhesion to metal surfaces, various technical solutions have been developed. As an electrolytic process for improving adhesion to metal surfaces, anodization is known. When anodizing is under

Use of an acidic electrolyte, e.g. Sulfuric, phosphoric or chromic acid, formed on the surface of a metal workpiece connected as an anode, a regularly structured, porous oxide layer. The pores allow the anodized metal workpiece to mechanically interlock with another material, such as a paint, varnish or adhesive layer. However, anodizing is limited to a few

Metal materials, such as aluminum, titanium and alloys, limited. Above all, the anodizing of aluminum (anodizing process, electrolytic oxidation of aluminum) is of industrial importance. Here, an aluminum oxide layer having a porous structure is formed on the surface of the aluminum material.

A solution to the problems arising in the described classical methods or the combination thereof is the center conductor principle (MLP), which is used in the electrolytic cleaning and in the electrolytic pickling of continuous material (strip, wire). In this process principle, a combined anodic and cathodic treatment is carried out. In the anodic treatment, a removal process is induced in which the smallest particles and residues or impurities present on the surface of the metal foil are removed and a bare surface is obtained. In the subsequent cathodic treatment is a

Deposition / coating process induced in which a metal from the Treatment liquid is deposited on the cleaned and bright surface. In the closed MLP is for the range of the cathodically polarized electrode and for the area of the anodic polarized electrode, ie for the Abtrag- and

Coating step, the same treatment liquid used. The open MLP (with separate baths) uses two different treatment liquids that are not in contact with each other.

The serious disadvantage of the closed center conductor principle compared to the classic solid-contact galvanic coating is that the removal from the surface of a substrate and the subsequent coating of the substrate with a foreign material with permanently consistent quality and

Composition of the treatment liquid are not feasible. In the open center conductor principle, this disadvantage is achieved by using different

Solved treatment liquids, the change of the treatment liquid, however, has other disadvantages in so far as the contact of the substrate with the liquid, for example in an intermediate sink, interrupted and exposed to the non-wetted areas of the substrate after the electrolytic removal of the atmosphere. By doing passivation and, where appropriate, corrosion of the freshly opened surface, the actual advantage of the central conductor principle is again limited or forfeited. Furthermore, the cooling of the substrate is interrupted by the treatment liquid.

Proposed solutions, for example by encapsulation of the electrode space of the removal zone with ion-specific membranes, as described for example in DE 199 51 324, in turn have disadvantages because (i) the carryover of the dissolved metal ions in the running direction of the continuous material is not prevented, (ii ) for the ion-specific membrane for a technically useful ion separation generally large differences in the properties or concentration of the ions to be separated must be present, (iii) in an ion exchange effect of these membranes redox processes between the ions are not suppressed and (iv) the continuity of

Entire process is no longer given by the exhaustion of the exchange capacity of the membrane.

As electrolytes for the deposition of metal surfaces in galvanic

Coating methods are used in addition to classic metal salt electrolytes Metal ions and simple anions, such as aqueous metal sulfate solutions, including metal complexes of metal ions and ligands or complexing agents from the family of polyhydroxycarboxylic acids, the polyamino, -imino or -nitriloessigsäuren, -methylenphosphonsäuren and -3-propionic acids and mixtures thereof used. The use of complexing agents serves to improve the deposition process and is essential for achieving sufficient solubility and stabilization of selected oxidation states of metal ions in certain pH ranges (typically 3.5 <pH <11.5). Polyhydroxycarboxylic acids, polyamino, -imino- and - nitriloacetic acids, methylenephosphonic acids and -3-propionic acids, and mixtures thereof are not sufficiently stable in the electrolytic process, since they undergo destruction in the electrocolysis reaction or in a secondary reaction after the oxidation of the methylene, Decompose amino, imino or nitrile function. Thus, carboxylates are oxidized at the anode to carboxyl radicals, which stabilize with elimination of carbon dioxide in a highly reactive alkyl radical. These radicals set more

Bonding fissions are in progress, and as a rule, this leads to the conversion of said ingredients into carbonate and poorly soluble decomposition products, which must be constantly removed from the process. Methylene phosphonates, which are virtually derivatives of formaldehyde, behave similarly. This methylene group is also easily oxidized to formate or carbonate, breaking the N-methylene bond and the P-methylene bond. In the electrolyte then accumulate the very difficult to remove decomposition products, which are usually amines, hydroxylamines and phosphates.

DE 3347593 describes electrolytes which comprise copper complexes of copper ions and a diphosphonate as complexing agent and a buffer for classical galvanic coatings. The diphosphonate-based electrolytes described therein are preferably prepared from copper (II) sulfate and used at elevated bath temperature for the deposition of a copper layer. For use in procedures for

Surface modification according to the central conductor principle prove the diphosphonate electrolytes of DE 3347593 due to their sulfate content as unsuitable. Hard anions such as sulfate or chloride are useful in breaking the passivation of the anode surface and in facilitating anodic erosion reaction in the process of US Pat

Center conductor principle, however, they prove especially in combination with the

Diphosphonation as detrimental, since it at the anode to the side reaction of the creeping Oxidation and destruction of diphosphonation or other organic

Tax additives lead.

There is thus a need for an improved electrolyte or for an improved process for the electrolytic surface modification of flat metal workpieces. It is therefore the object of the present invention to provide an improved treatment liquid for an improved method for modifying a

Metal surface of a sheet metal workpiece without the existing disadvantages of the prior art. Part of this requirement is the creation of an electrolyte family, which shows virtually the same surface activity regardless of the metal to be removed and the metal to be deposited and which is able to optimally prepare the surface in the removal step due to the familial similarity to the subsequent deposition. The family of electrolytes should have a narrowly varying density and a pH varying to narrow limits, and be composed of identical components other than the ablated metal ions, not acidic and of high ionic strength. Under these conditions, for example, the separation of the removal and deposition zone in the MLP by a non-miscible, non-conductive, heavy, inert separation liquid is realistic, and the substrate can be removed with continuous wetting and cooling in the MLP and coated with substrate-foreign elements.

With the aid of this improved treatment liquid or process, metal surfaces can be modified by applying uniformly distributed aggregates of one or more different metals to provide, for example, sheet metal workpieces with improved adhesion of coatings applied to the metal workpieces.

Another object of the present invention is to provide treatment liquids with which it is possible to work on flat metal workpieces

Coatings deposited with metal ions, which were not previously deposited in electrolytic processes as a treatment on metal surfaces. Brief description of the invention

To achieve the abovementioned objects, an electrically conductive liquid is provided according to the invention, comprising an aqueous solution of a

Metal complex, wherein the metal complex is a complex

(i) one or more metals selected from the group consisting of Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, Ti, Zr, Nb, Y, Nd, Sm, Gd, Tb , Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof, and

(Ii) one or more diphosphonate ligands of the general formula (I) 0 = P (OH) ₂ -X- (OH) ₂ P = 0 (I) wherein the OH groups in the general formula (I), the the two phosphorus atoms are bonded, independently protonated (OH) or deprotonated (0), wherein:

X = O, NR ¹ or CR ¹ R ² , in particular X = CR ¹ R ² , where

R ^{1 is} H, C ₁ -C ₆ -n-alkyl or C ₃ -C ₈ -isoalkyl, C ₅ -C ₆ -cycloalkyl, unsubstituted or substituted benzyl and substituted or unsubstituted phenyl,

R ² = R ¹ , -OR ³ or -NHR ³ , and

R ³ = H, C ₁ -C ₄ -n-alkyl or C ₃ -C ₄ -silkalkyl, and wherein the liquid further optionally comprises an additive of the general formula (II):

R ¹⁰ -CHR ⁸ -CHR ⁹ -Z- (CHR ⁴ -CHR ⁵ -Z) _n -CHR ⁶ -CHR ⁷ -R ¹⁰ (II) wherein:

 n = an integer from 1 to 1, in particular an integer from 1 to 3, Z = S or O, in particular S,

R ⁴ = H, C 1-4 -alkyl or phenyl,

R ⁵ = H, d-4-alkyl or phenyl, R ^{6 is} H, C 1-4 -alkyl or phenyl,

R ⁷ = H, d-4-alkyl or phenyl,

R ⁸ = H, d-4-alkyl or phenyl,

R ⁹ = H, C 1-4 -alkyl or phenyl,

R ¹⁰ = OH, COOH or COOR ¹¹ and

R ¹¹ = alkyl (in particular Ci- ₄ alkyl), Li, Na, or K.

When the metal is Cu, in the present invention, the additive is preferably contained in an amount of 0.05 to 0.5% by weight, more preferably in an amount of 0.1 to 0.2% by weight.

This electrically conductive liquid forms the treatment liquid (electrolyte) for a method according to the invention for the electrolytic surface modification of a flat metal work piece, in which at least one surface of the sheet metal

Metallic workpiece is anodically polarized in a treatment liquid and thereby anodic dissolution process is induced, and then the at least one

Surface of the sheet metal workpiece in a treatment liquid from the same group of treatment liquids is cathodically polarized and thereby a cathodic deposition process for depositing one or more metals on the at least one surface of the sheet metal workpiece is induced. The process of the invention enables the production of in the surface

modified sheet metal workpieces which, according to another aspect of the invention, can serve as a substrate for the formation of strong adhesive bonds with other materials.

Detailed description of the invention

The electroconductive liquid of the present invention, which is referred to as

Treatment liquid used in the method according to the invention for the electrolytic surface modification of a flat metal workpiece comprises an aqueous solution of a metal complex. Specifically, the metal complex is the complex of a metal with ligands of formula (I) wherein the metal may be either a single or two or more different metals. The metal or metals of the metal complex are selected from the group consisting of Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, Ti, Zr, Nb, Y, Ce, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof. Preferably, the metal is selected from Cu, Zn, Mn, In, Sn, Sb, Bi, Co, Ti, Zr, Nb and mixtures thereof.

The metal is particularly preferably selected from Mn, Cu, Zn, Cd, In, Sn, Sb, Bi and mixtures thereof, in particular Cu, Zn, Sn, Bi and mixtures thereof. Specifically, the metal of the metal complex is Cu, Sn, Sb or a mixture thereof. If more than one metal is present, it is preferably a combination of Zn and Cu or Ni and Cu. In further preferred embodiments, the metal is selected from Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co and mixtures thereof, and is doped with one or more dopant metals. Suitable doping metals in the present invention are Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Nb and mixtures thereof. Preferred combinations of metal and dopant metal are combinations of Sn and Gd; Sn and Zr; Zn and Y, Dy, Zr or mixtures thereof, or combinations of Fe, Ni, Co or mixtures thereof with Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or

Mixtures thereof, such as Ni, Gd and Tb; Fe and Ln (Ln = Sm, Gd, Dy, Er); Co and Ln (Ln = Nd, Sm, Gd, Dy, Er).

Suitable diphosphonate ligands are compounds of the general formula (I)

0 = P (OH) ₂ -X- (OH) ₂ P = O (I) wherein:

X = 0, NR ¹ or CR ¹ R ² , where

R ¹ = H, C ₁ -C ₁₈ -n-alkyl or C ₃ -C ₁₈ -silkalkyl, C ₅ -C ₆ -cycloalkyl, unsubstituted or substituted benzyl and substituted or unsubstituted phenyl,

R ² = R ¹ , -OR ³ or -NHR ³ , and

R ³ = H, Ci-C ₄ -n-alkyl or C ₃ -C ₄ -lsoalkyl.

The bonded to the two phosphorus OH groups of the general formula (I) are independently protonated (OH) or deprotonated (0) before.

Preferably, in the general formula (I), X = CR ¹ R ² . Preferably, 2, 3 or 4 (all) of the bonded to the two phosphorus hydroxyl groups of the diphosphonate ligand of the general formula (I) are deprotonated. Such deprotonated diphosphonate ligands of the general formula (I) can be used in the pH range between about 6.5 and 11.0.

Depending on the particular combination of metal (s) and diphosphonate ligands, the molar ratio of metal: diphosphonate is preferably 1: 2 to 1: 4. The diphosphonate ligand can also form different chelates with the central ions, where it can usually attach as bidentate or tridentate. The size of the chelating ranges from 4 to 5 to 6.

For the production of electrically conductive liquids based on

Metal diphosphonate complexes are variously available in the complex depending on the metal or metals.

For example, oxides or carbonates of the desired metals are treated with the free diphosphonic acid. Subsequently, the neutralization is carried out, for example, with potassium hydroxide to set the optimum pH range, which is usually in the range of 8.5 to 10. By this method of preparation, the hard ion entry such as e.g. Halides or sulfates in the treatment liquid largely or completely avoided.

This process is preferably suitable for preparing the diphosphonate complexes of copper, zinc, manganese, indium, tin, antimony, bismuth, yttrium, lanthanum and lanthanides praseodymium, neodymium, samarium, europium, gadolinium, terbium, Dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Also diphosphonate complexes of cobalt are accessible in this way, although their stability is limited at pH values between 8.5 and 10. The cobalt diphosphonate complex is stable for up to 48 h in solution. However, to achieve longer shelf life, it must preferably be blended within 8 hours of recovery with the diphosphonate complex of a lanthanide (III) ion.

Another way to prepare Fremdänionenfreier metal diphosphonate liquids is the electrolytic Aufmetallisierung of Dikaliumdiphosphonats or a Diphosphonate complex of a so-called "inert" metal ion, ie, ions that can not be electrolytically deposited as metals from aqueous solution, with an excess of dipotassium diphosphonate in a particular electrolysis cell This cell operates at an anode to cathode current density ratio of at least 1:10, both Electrodes consist of the metal to be incorporated into the liquid, or the cathode deviates from titanium, stainless steel, gold or platinum The cathode can be provided with an electrode sack The diphosphonate base component is the dipotassium salt or the complexes or mixtures thereof

Diphosphonate complexes of the trivalent ions of Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu used, for example, from the corresponding metal oxides, 1 - hydroxyethane-1, 1-diphosphonic acid (HEDP) and potassium hydroxide simple are to produce.

By using the diphosphonate complexes of Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and / or Lu, it is also possible to obtain, for example, stable metal diphosphonates at pH values of 8.5 to 10 of cobalt, nickel or iron (as mixed metal diphosphonates). This is surprising since pure nickel or iron diphosphonate complexes in the range between pH = 8.5 and pH = 10 do not exist or pure cobalt diphosphonate complexes are not stable. Mixed metal diphosphonate complexes are accessible, for example, by co-treating suitable metal salts with free diphosphonic acid, by metallizing a Y and / or Ln diphosphonate or by blending metal diphosphonate complexes with Y and / or Ln diphosphonate complexes, the latter being often referred to as dilution complexes in this function. The individual diphosphonate-based solutions are usually miscible with each other in any ratio.

For example, electrolytic deposition of the unsaturated lanthanide diphosphonate with iron (II) ions is the optimal way to produce a ready-to-use for the production of the liquids containing iron diphosphonate

Treatment liquid.

The nickel diphosphonate electrolytes are best prepared by the co-dissolution of lanthanide (III) oxide and nickel (II) hydroxide or nickel (II) carbonate in HEDP followed by potassium hydroxide pH adjustment, the nickel content being compared to the sum of all complexing Ions must never be more than 20 mol%. Stable cobalt diphosphonates can also be prepared by co-dissolution of lanthanide (III) oxide and cobalt (II) carbonate in HEDP and subsequent pH adjustment with potassium hydroxide, the cobalt content may be up to 85 mol% of the sum of all complexing ions.

Titanium and zirconium are also referred to as inert ions in the present invention because they can not be electrodeposited from water as metals. In the form of their oxides, they have considerable potential in corrosion protection and in Cr (VI) -free passivation of metal surfaces. Your preparation and

Application is therefore not with the aim of depositing Ti or Zr as metallic layers, but instead of the metals which can be deposited (eg Zn, Cu, Ni, Co, Fe, In), or with the lanthanide complexes as additive to the diphosphonate complexes or stabilizers of diphosphonate complexes. Sn, Sb, Bi). The

corresponding diphosphonate complexes of these Ti (IV) or Zr (IV) ions are prepared via the solution of the acidic sulfates, since the HEDP is not acidic enough to dissolve the basic carbonates or even oxides of these elements. The stable complex solutions have a maximum of a metal (IV) diphosphonate ratio of 1: 3. The mixture of the acid sulphates and the HEDP solution precipitates the HEDP, which is reversed by the rapid, extremely exothermic adjustment by means of caustic potash. Immediately after the dissolution of the HEDP, the precipitation of well-crystallized potassium sulfate starts due to the high potassium excess in the solution. By cooling the complex solution to temperatures between 0 ° C and 5 ° C leads the solubility difference between the potassium sulfate and the remaining components to almost complete precipitation of the sulfate. The residual concentration of sulfate in these diphosphonate complexes of Ti (VI) and Zr (IV) is less than 1 g / l.

To further reduce the sulphate concentration, the solution obtained after separation of the precipitated sulphate is treated with a barium diphosphonate slurry with stirring (slurry: 1 part by mass 60% strength by weight solution of diphosphonic acid in water and 1.84 parts by mass of barium hydroxide octahydrate). The resulting

Precipitate is filtered off after 2 h. The sulphate concentration after this additional treatment method is about 1 mg / l.

The electrically conductive liquid according to the invention may comprise as an additional component an additive of the general formula (II): R ¹⁰ -CHR ⁸ -CHR ⁹ -Z- (CHR ⁴ -CHR ⁵ -Z) _n -CHR ⁶ -CHR ⁷ -R ¹⁰ (II) wherein:

 n = an integer from 1 to 1, in particular an integer from 1 to 3,

Z = S or O, in particular S,

R ⁴ = H, C 1-4 -alkyl or phenyl,

R ⁵ = H, d-alkyl or phenyl,

R ⁶ = H, d-alkyl or phenyl,

R ⁷ = H, d-alkyl or phenyl,

R ⁸ = H, d-alkyl or phenyl,

R ⁹ = H, d_ ₄ alkyl or phenyl,

R ¹⁰ = OH, COOH or COOR ¹¹ and

R ¹¹ = alkyl (in particular C _{1 4} -alkyl), Li, Na, or K.

When the compound of formula (II) comprises enantiomers or diastereomers, both the pure enantiomers or diastereomers and the corresponding mixtures can be used.

In particular, in the context of the present invention in CI_ ₄ alkyl methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl or sec-butyl, preferably methyl, ethyl, n-propyl, or n-butyl.

Preferably, in the additive of the formula (II): n = an integer from 1 to 3,

 Z = S,

R ⁴ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁵ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁶ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁷ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁸ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁹ = H, methyl, ethyl, n-propyl, or n-butyl,

R ¹⁰ = OH, COOH or COOR ¹¹ , and

R ¹¹ = K, methyl, ethyl, or n-propyl. Alternatively, the additive of formula (II) is a compound of formula

HO- (CHR ⁶ -CHR ⁷ -Z) _n -CHR ⁶ -CHR ⁷ -OH (III) wherein:

 n = an integer from 1 to 1 1,

 Z = S or O,

R ⁶ = H, methyl or phenyl, and

Ft ⁷ = H, methyl or phenyl, preferably n = 1 -3 and Z = S.

The additive is particularly preferably a compound of the formula (II) in which: n = 1 or 2, in particular 1,

 Z = S,

R ⁴ = R ⁵ = H or methyl,

R ⁶ = R ⁹ = H or methyl,

R ⁷ = R ⁸ = H or methyl,

R ¹⁰ = OH, COOH or COOR ¹¹ and

R ¹¹ = K, methyl, ethyl, or n-propyl.

More preferably, the additive is a compound of formula (IV):

10

'-CHR ⁸ -CHR ⁹ -S-CH ₂ -CH ₂ -S-CHR ⁶ -CHR ⁷ - (IV)

wherein

R ⁶ = R ⁹ = H or methyl,

R ⁷ = R ⁸ = H or methyl, and

R ¹⁰ = OH, COOH or COOK.

A particularly preferred additive of the general formula (II) is 1,8-dihydroxy-3,6-dithiaoctane (DTO). The additives of the formula (II) are commercially available or can be obtained by known chemical synthesis methods or analogously to these.

The additive is usually present in the liquid according to the invention in an amount of 0 to 1% by weight, preferably in an amount of 0.05 to 0.7% by weight, more preferably in an amount of 0.1 to 0.5 Wt .-%, based on the weight of the total solution before. If the electrically conductive liquid contains copper diphosphonate complex as the only metal diphosphonate complex, the additive is preferably present in an amount of from 0.05 to 0.2% by weight, based on the total solution. In one embodiment of the present invention, the metal of the metal diphosphonate complex is Cu, and 1, 8-dihydroxy-3,6-dithiaoctane is used as the additive.

Preferably, in this embodiment, the amount of additive is 0.05 to 0.2 wt .-% based on the total solution.

In a specific embodiment of the invention, the electrically conductive liquid is substantially free of sulfate and halide ions. The term "essentially free" in the sense of this invention means a residual concentration of these ions of less than 45 ppm (mass) in the case of halides and less than 120 ppm (mass) in the case of sulfate. In yet another specific embodiment, the metal of the metal complex is selected from the group consisting of Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, Nb and mixtures thereof, and the electrically conductive liquid is in the Essentially free of sulfate and halide ions.

In yet another embodiment of the invention, the liquid according to the invention contains, in addition to the diphosphonate of the formula (I), no additional buffer such as, for example, carbonates, borates, acetates or mixtures thereof.

The electroconductive liquid of the present invention has special properties which make it particularly suitable for use as a treating liquid in methods of electrolytic surface modification of metal substrates. Such processes require treatment liquids which are provided with components which, for example, are stable in a removal process of the surface modification process, ie are not or only slightly decomposed and in a deposition process of the surface modification process by the intervention of secondary equilibria in the processes in the intervene electric double layer and / or for growing of

Submicro-aggregates lead, which are small, crystalline compact in itself and evenly distributed over the surface.

Therefore, the present invention also provides a process for electrolytic

Surface modification of a sheet metal workpiece, in which at least one surface of the sheet metal workpiece is anodically poled in a treatment liquid, thereby inducing an anodic dissolution process, and

Subsequently, the at least one surface of the sheet metal workpiece is cathodically poled in a treatment liquid and thereby a cathodic

Deposition process for depositing one or more metals on the at least one surface of the sheet metal workpiece is induced, wherein

Treatment liquid one or more of the above-described electrically conductive liquids is used.

The use of the treatment liquids based on metal diphosphonate complexes in the inventive method for electrolytic

Surface modification can be done in a variety of embodiments.

In one embodiment of the deposition process of the invention

Method, which follows the principle of classical strip electroplating, the strip is connected as a substrate via a lying outside the treatment liquid solid-solid contact in the form of a current roller as a cathode. The anode is disposed parallel to the tape surface opposite one or both sides of the tape. The diphosphonate complexes provide a particular in this form of the deposition process

advantageous contribution, if otherwise only acidic, highly alkaline or cyanidic

Electrolytes of the metals to be deposited are available or if the

Diphosphonate complexes of several metals in a treatment liquid in this combination can not otherwise be obtained. These include u.a. the

Treatment solutions based on the diphosphonate complexes of the monometals Sn, Zn, Sb, In, Bi and Cu (in combination with DTO), as well as the bimetallic and tri metals: Sn-Gd-DTO, Sn-Zr, Zn-Zr, Fe-Ln , Co-Ln and Ni-Ln. The use of these treatment liquids remains limited only to low current densities (usually <8A / dm ² ), since the resolution of the layer in individual units under the application of higher current densities

Adhesive strength due to insufficiently prepared surface with increasing Current density is constantly decreasing.

In a further embodiment of the method according to the invention for

electrolytic surface modification of a flat metal workpiece according to the closed center conductor principle, the sheet metal workpiece is brought neither cathodically nor anodically in solid-fixed contact, but is polarized by at least one cathode anodic (positive) and then cathodically (negative) polarized by at least one anode. In this case, the current transfer to the flat metal workpiece is not effected by direct contacting of the flat metal workpiece via a contact element (such as, for example, a current roller) connected to a current source

Bandvanvanik), but through the treatment liquid through. In anodic polarization, an anodic dissolution process is induced on a surface of the sheet metal workpiece by removing minute particles and residues or impurities present on the surface of the metal foil, thereby obtaining a metallically bright surface. Furthermore, the

topographical features of the metal surface, in particular the roughness peaks, leveled. Furthermore, the anodic polarization or the anodic dissolution process induced thereby leads to an activated surface for the subsequent metal deposition. In particular, the surface obtained by the method according to the invention exhibits structural similarity or structural identity to the metal aggregates deposited on the surface of the flat metal workpiece in the subsequent deposition process (epitaxy or syntaxie).

The subsequent cathodic polarization becomes a cathodic

Deposition process in which a metal or metal alloy (i.e.

several different metals) is deposited on the surface of the sheet metal workpiece.

In a specific embodiment according to the open center conductor principle (MLP), removal and separation take place in separate cells, which are advantageously separated by a blow-off zone, a sink or both in combination, to carry over the treatment liquid of the removal reaction (anode) into the treatment liquid to prevent the deposition reaction (cathode).

For the removal reaction is then advantageously on a treatment liquid

Used diphosphonate base, which contains the same metal as the substrate and the only from a mixture of potassium dihydrogen and potassium hydrogen diphosphonate (K ₂ H ₂ Cb and K ₃ HCb) or from a diphosphonate complex of one or more inert

Metal ions, preferably the complexes of Y, Nd, Sm, Gd to Lu, Zr, with an excess of the potassium salts of the ligand, preferably K ₂ H ₂ Cb, K ₃ HCb and K ₄ Cb exists (where H ₄ Cb is the abbreviation the (tetravalent / four-protonated) diphosphonic acid). This embodiment can be transferred seamlessly to the treatment of a discrete, flat workpiece in the correspondingly timed method. This embodiment already allows the use of high current densities in order to deposit adherent individual units. It can be operated at current densities of up to 27A / dm ² . As the current density increases, the compactly deposited layer changes into individual units which are very adhesive. The classical electroplating can not display such individual aggregates with adherence.

This embodiment is so interesting because existing equipment can be used by the stain is rebuilt by installing the auxiliary cathodes in the Abtragszelle and get the classic deposition by replacing the power rollers against pulleys and maintaining the anodes as a deposition zone in the open center conductor principle remains.

The passivation of the freshly abraded surface by the atmosphere or the rinse water is by the diphosphonate itself or for example by DTO or by both (if DTO is included as an additive) as opposed to acidic

Treatment liquids visibly suppressed and the activity of the surface

sufficiently received.

The flat metal workpiece used in the present invention is preferably a metal workpiece having a thickness which is at least 100 times, more preferably at least 1000 times, and particularly preferably at least 10000 times smaller than the length and / or width of the metal workpiece. Consequently, the term "surface of the flat metal work piece" as a rule means the surface defined by the length and width, not the surface defined by the thickness and width or thickness and length

Metal foil. The term "metal strip" herein refers to a sheet metal workpiece having a given width and a thickness of 100 μm to 1 mm The term "metal foil" designates a flat metal workpiece with a given width and a thickness of less than 100 μm, usually with a thickness from 2 μηι to less than 100 μηι.

The flat metal workpiece is usually made entirely of a single metal, in particular copper, tin, zinc, aluminum, iron, nickel. However, it may also consist of a metal alloy, for example of at least two of the metals mentioned, preferably of a copper wrought alloy, iron alloy, silver alloy or tin alloy. Also, a flat metal workpiece made of steel can be used. The flat metal workpiece is particularly preferably a copper foil, a copper strip, a tinned foil or a tinned strip, in particular a tinned copper foil or a tinned copper strip.

Furthermore, the flat metal workpiece may also consist of two or more layers of a metal or a metal alloy, wherein the layers may be the same or different. Furthermore, the flat metal workpiece may be formed such that at least one and preferably both surfaces of the planar

Metal workpiece from a metal or a metal alloy and the remaining portion of the sheet metal workpiece may be any material, if this is suitable for use in the inventive method.

Before use in the method according to the invention, the areal

Metal workpiece usually pretreated. Corresponding pretreatment processes are known in the art and include, for example, degreasing, rinsing with water, aqueous surfactant solutions or solvents, and pickling with the solution of a mineral acid in water, preferably sulfuric acid.

The sheet metal workpiece is preferably passed through the treatment liquid and past the at least one cathode and the at least one anode during the electrolysis. This is done in a manner that results in the described anodic polarization and cathodic polarization and the induced anodic dissolution process and cathodic deposition process. In the case of endless metal foils or strips, they are usually passed through the treatment liquid using guide elements (eg deflection rollers). If a film conveyor system is used to carry out the process according to the invention, several electrolysis baths (electrolysis cells) can also be connected in series. In the context of the present invention, many arrangements of the at least one cathode and the at least one anode are conceivable. For example, 1, 2, 3, 4 or more cathodes and 1, 2, 3, 4 or more anodes per electrolysis cell or electrolyte bath can be used. These can be arranged differently (for example alternating cathode and anode, first all cathodes and then all anodes, a plurality of cathodes alternating with a plurality of anodes, cathodes and anodes arranged only on one side of the sheet metal workpiece or on both sides, etc.).

According to a preferred embodiment, preferably at least one cathode pair and at least one anode pair are used. The two cathodes of the cathode pair and the two anodes of the anode pair are arranged on opposite sides of the flat metal workpiece, so that the flat

Metal workpiece between the two anodes or between the two cathodes is located. Consequently, anodic or cathodic polarization occurs on both sides of the flat metal workpiece. Such a configuration allows the two-sided modification of the flat metal workpiece with deposited metal aggregates. According to another preferred embodiment, the sheet metal workpiece is first anodically polarized by two cathodes disposed on the same side of the sheet metal workpiece and then cathodically polarized by two anodes both located on the same side of the sheet metal workpiece as the cathodes.

Usually, the at least one surface of the flat metal workpiece is first anodically polarized by the at least one cathode and then cathodically polarized by the at least one anode. However, it is also envisaged that the "anodic polarization / cathodic polarization" cycle will be run through multiple times, and that the sheet metal workpiece may be poled anodically and cathodically one or more times in any order, typically first outweighing the anodic dissolution process and then the cathodic

Deposition process outweighs. It can be a phase with dominating

Dissolution process through a short phase with the deposition process to be interrupted (dominant dissolution process, interrupted by deposition process) and vice versa (dominant deposition process, interrupted by

Resolution process). The one or more anodic polarization and the one or more As already mentioned above, multiple cathodic polarization can be achieved by using a corresponding number of spatially separated anodes or cathodes. However, it is also possible to use electrodes which are selectively switched to positive or negative (contacted) and thus function both as a cathode and as an anode.

The cathodes and anodes are operated with direct current or a pulsed current, usually a pulsed direct current. For this purpose, rectifiers can be used. If the number of electrodes exceeds two (i.e., more than one cathode and / or more than one anode), the additional electrodes become

preferably operated by an additional rectifier. In the context of the present invention, it is also possible that in at least one working area (cathodic, anodic) each electrode is powered by a different rectifier, while in another work area, several rectifiers are switched to one electrode.

As anodes, insoluble or soluble anodes can be used in the process according to the invention. The insoluble anodes typically consist of an inert material (or oxides thereof) such as lead, graphite, titanium, platinum and / or iridium (and / or their oxides). Preferred insoluble anodes are titanium coated with platinum or iridium and / or ruthenium (and / or their oxides).

Particularly preferred is an iridium or iridium oxide coated titanium anode. In contrast, the soluble anodes consist of the metal to be coated or the metal alloys to be coated. Examples of suitable soluble anodes are anodes of copper or tin.

Suitable cathodes may be made of the same material as the material of the anodes. As a cathode, for example, a copper cathode can be used. In a preferred embodiment, copper electrodes are used both as an anode and as a cathode, in particular if copper is to be deposited on the surface of the flat metal workpiece.

As discussed in the description of the electrically conductive fluid of the invention, the treatment fluid may include an additive such as 1,8-dihydroxy-3,6-dithiaoctane (DTO). The intervention of the DTO in the anodic erosion and For example, in the case of zinc, copper, nickel, iron, tin and bismuth, cathodic deposition processes lead to the deposition of very adherent submicron and microcrystalline aggregates on the surfaces of the substrate to be modified. The possible addition of, for example, DTO - without this being decomposed in the electrolytic process - is therefore a decisive technical advantage of the metal and mixed metal Diphosphonatbehandlungsflüssigkeiten.

A significant advantage of the use of the diphosphonate metal complexes-containing treatment liquid in the process according to the invention is that the diphosphonate does not undergo creeping hydrolysis in continuous operation, such as the structurally related and similarly acting pyrophosphates. Further, the diphosphonate itself is an excellent buffer, it causes itself an excellent scattering of the deposited layer and needs no auxiliary buffer such as carbonate or the poisonous borate. In a preferred embodiment of the invention

The method is therefore limited to the use of additional buffers such as e.g. Carbonates, borates, acetates or mixtures thereof omitted in the treatment liquid. In addition, the diphosphonate treatment liquids have excellent scattering behavior in the structure of the deposition, so that the addition of scattering improvers such as gelatin or leveler can be dispensed with in the process according to the invention.

Further, it has surprisingly been found that the diphosphonate ion itself is capable of initiating the anodic erosion reaction, and thus, a diphosphonate complex-containing treatment liquid does not require hard anions such as sulfate or chloride to break the passivation of the anode surface. This is particularly advantageous because, as described above, the hard anions at the anode are u.a. lead to the side reaction of creeping oxidation and destruction of diphosphonation. Therefore, in a specific embodiment of the method according to the invention

Treatment fluids substantially free of sulfate and halide ions. The term "essentially free" in the context of this invention means a

Residual concentration of these ions below 45ppm (mass) for halides, below 120ppm (mass) for sulphate.

Without these hard the secondary anodic oxidation processes

Additional ions form diphosphonate-based, electrically conductive Treatment fluids also optimal conditions for use in the presence of oxidation-sensitive control additives. Thus, the treatment liquid used in the process according to the invention may contain additives which reduce the viscosity,

Thermal conductivity, electrical conductivity and / or the deposition of

Metal aggregates affect without being decomposed during the process.

Depending on the components used in the treatment liquids can be by the inventive method for electroytic

Surface modification of sheet metal workpieces various particularly advantageous effects in terms of the process itself or by means of

Achieve process generated modified surface.

For example, the layers deposited from the lanthanide-zirconium treatment liquids with zinc, copper, nickel, cobalt, iron, tin and / or bismuth also show extreme resistance to corrosion on copper. This is particularly noticeable and interesting with iron and tin. The drying rate of the iron layers on copper plays virtually no role in the deposition of the diphosphonates. In contrast, iron deposited from acidic treatment fluids already corrodes during rinsing after coating.

In the case of tin, a certain selectivity of the mixtures emerges: The mixed diphosphonate treatment liquids based on tin-gadolinium diphosphonate (75 mol% Sn, 25 mol% Gd) give with the addition of 0.1 to 0.5 mol -% DTO very stable, composed of strong columns tin layers on tin or copper. The surface is storage stable and shows good adhesion properties. Similar advantages can be seen in the tin layers, which consist of the

 Mixed diphosphonate treatment liquids with tin and zirconium (Sn at least 25 mol%, Zr (1: 4) at least 1 1 mol%). Although in the

Tin layer on steel or on copper only in the ppm range zirconium is detected, these layers tend under thermal stress near the melting point of the tin or significantly less yellowing or graying. This also applies to already melted tin layers from this deposit.

By combining the diphosphonates of, for example, Ni (II) (19 mol%), Gd (III) (76 mol%), Tb (III) (5 mol%) and the addition of DTO (0.1 to 0 , 5 mol%) is the nickel Surface structuring accessible. The small, grayish-black appearing

Nickel aggregates on the nickel surface are adherent and provide a clear

Increased adhesion to the pressed-on plastics and adhesive films.

The use of diphosphonate mixed treatment liquids from the

To be deposited metal ions such as Zn, Cu, Ni, Co, Fe, Sn, Bi and the diphosphonate solutions of Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Yb and Lu allows the specifically adjustable deposition of the lanthanide metals doped layers of said host metals, which can also be deposited from aqueous solution alone. The can

Depending on the system, concentrations of Ln dopants can reach from percentage fractions (Gd-Sn) up to 20 mol% (Sm-Co).

In one embodiment of the method according to the invention, layers of Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, or mixtures thereof as host metals and Ti, Zr, Nb, Y, Nd, Sm, Gd, Tb , Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof as doping metals deposited on the sheet metal workpieces. The doping metals are preferably deposited in a concentration in the range from 1 ppm to 20,000 ppm, based on the host metals. The relative amount of doping metal can be determined by varying the average current density of the deposition and variation of the

Adjust the concentration ratio (preferably in the range of 1: 5 to 150: 1) between the dopant metal and the host metal in the treatment liquid.

In a further embodiment of the method according to the invention are potentially strong ferromagnetic, closed layers with a circulation in the range of 10 nm to 1 μηι with Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof doped metals Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, or mixtures thereof, which have a greater layer thickness of tipping between the in-plane and the out-of-plane orientation of the Have domains as in vacuum technically deposited, ferromagnetic, pure metal layers.

The inventive method is particularly suitable for the deposition of corrosion-stable iron and / or tin surfaces and of recrystallization-inhibited tin surfaces.

The following are some examples of devices for performing the inventive method illustrated.

The devices comprise at least one container for receiving a

Treatment liquid, at least one arranged in the container cathode and at least one arranged in the container anode, wherein the at least one

Cathode and the at least one anode are connected to a power source and wherein the flat metal workpiece is not connected to a power source.

Preferably, at least one cathode and / or at least one anode is the

Device designed as a flow electrode, comprising an electrode housing with a metal grid through which the treatment liquid (hereinafter also referred to as

Electrolyte designated) may enter the housing, wherein the electrode housing is at least partially filled with metal balls, which are in contact with each other and with the metal grid. The electrode housing further includes an electrolyte supply for introducing an electrolyte and a flow opening from which the electrolyte that has flowed from the electrolyte supply between the metal balls to the flow opening exits. The flow opening is arranged so that sufficient flow of the working zone, i. of the space between electrode and planar

Metal workpiece, done. For this purpose, the flow opening is usually arranged so that the exiting electrolyte flows past the metal grid. Preferably, the flow past substantially parallel to the metal grid. In operation, this results in a substantially laminar flow in the space between the electrode and the flat metal workpiece, which is preferably a continuous metal strip or a continuous metal foil.

Usually, the electrode housing also includes a lid to prevent falling out of the metal balls and a defined flow through the

Ensure flow electrode with electrolyte. For example, the lid may be releasably connected to the electrode housing with thumbscrews and may further include contacts for connection to a power source. In operation, the flow electrode is connected anodically or cathodically to a current source, wherein usually the metal grid is contacted anodically or cathodically.

The electrolyte which has passed through the metal balls is preferably collected in an electrolyte channel and then supplied to the flow port. Of the Electrolyte channel and the flow opening are preferably in the bottom of the electrode housing. The flow opening is preferably designed as a flow lip, which preferably extends over the entire length of the metal grid in the bottom of the electrode housing. If a filter fleece arranged in front of the metal grid is used as anode bag, the flow opening is arranged such that the electrolyte emerges in front of the filter fleece and flows along it, substantially laminar.

The electrode housing may for example consist of a plastic, such as polypropylene. The metal balls may consist of the metals mentioned above for the anode and cathode. Preferably, at least one anode is in the form of the above

designed flow electrode designed. In the case of the anode, the metal balls are preferably made of the metal or metals to be deposited on the sheet metal workpiece. Preferably, the

Metal balls copper balls. The metal grid is preferably an expanded metal grid (expanded metal blend surface), in particular a titanium expanded metal.

FIG. 1 shows schematically an embodiment of a dissolving / separating cell 30 for carrying out the method according to the invention for the surface treatment of a flat metal workpiece 32, in this case a metal foil. The dissolving / separating cell 30 has a trough-like, upwardly open container 31, in which treatment liquid 36 is located. The dissolving / depositing cell 30 further includes first, second and third diverting pulleys 34a, 34b and 34c and a first working electrode consisting of two cathodes 40a and 40b arranged in parallel, and a second working electrode consisting of two parallel arranged anodes 44a and 44b insists on. The cathodes 40 a and 40 b and the anodes 44 a and 44 b are connected to a current source 45. The first and third deflection rollers 34a, 34c are arranged above the container 31 outside the treatment liquid 36 and above the first and second working electrodes, while the second deflection roller is located at the bottom of the container 31 within the treatment liquid and below the working electrodes. Furthermore, the dissolution / deposition cell 30 has a separator 48 for reducing reactive currents.

The flat metal workpiece 32 passes over the first guide roller 34a in the

Treatment liquid 36 and between the two cathodes 40a, 40b, so that they on each one of the two sides of the continuous flat Metal workpiece 32 are located. Neither the flat metal workpiece 32 nor the first deflection roller 34a is connected to a power source. The region 38a of the flat metal workpiece 32 located between the two cathodes 40a, 40b is positively (anodically) polarized by the two cathodes 40a, 40b. The two cathodes 40a, 40b define a resolution region 42. In the enlarged and schematically illustrated section of the dissolution region 42, impurities present on the surface of the sheet metal workpiece 32 and any foreign metals present and / or certain (eg uneven) metal structures are largely eliminated. As a result, a contaminant-free, homogeneous and defined surface of the sheet metal workpiece 32 is obtained, which is suitable for obtaining defined metal structures in the subsequent deposition step.

After passing through the cathodes 40a, 40b, i. of the dissolution region 42, the flat metal workpiece 32 is passed through the second deflection roller 34b, which is likewise not connected to a power source, between the two anodes 44a, 44b, which are located in each case on one of the two sides of the flat metal workpiece 32 and form the second working electrode. Through the two anodes 44a, 44b, a region 38b of the flat metal workpiece 32 is negatively (cathodically) polarized. The two anodes define a deposition region 46. In the enlarged and schematic

shown section of the deposition region 46 migrate the positively charged metal ions of the treatment liquid 36 to the negatively polarized surface of the sheet metal workpiece 32 and divorced in a defined manner on the surface of the sheet metal workpiece 32 from. After passing through the deposition region 46, the sheet metal workpiece 32 runs out of the treatment liquid 36 and over the third deflection roller 34c, which is not connected to a power source.

The flat metal workpiece 32 electrolytically treated in this way with a treatment liquid according to the invention has sub-micron-sized metal aggregates defined on its surface and shows surprisingly good adhesion and adhesive properties.

As an alternative to the embodiment described in FIG. 1, according to the closed center conductor principle (MLP), different treatment liquids can be used in the dissolution area 42 and in the deposition area 46, which are separated by a dense, nonconductive, processable separating liquid, which also makes contact with the has flat workpiece. In this way, the closed MLP of Figure 1 becomes an open MLP with separate ablation and deposition zones, and the substrate can be ablated with continuous wetting and cooling in the dissolution area and coated in the deposition area with non-substrate elements.

FIG. 2 describes by way of example such an apparatus for carrying out a method according to the open center conductor principle using the example of tin plating of copper foil. As a dissolution / separation cell, a trough-type, upwardly open container (BW) made of polypropylene with a container wall thickness of 20 mm is used, which is divided by a 15 mm thick polypropylene partition (TW) into a dissolving and a separation zone, the Partition does not reach all the way to the bottom of the container. At the bottom of the container is a dense, non-conductive, prozessinerte

Separating liquid, which extends over the lower edge of the partition and a

Release agent zone (TM) forms in the container. Above this separating agent zone, a copper diphosphonate DTO electrolyte (CuE) is located in the dissolution zone, the liquid level of which reaches up to an overflow opening (ÜL-Cu) in the dissolving zone of the container. In the deposition zone is above the release agent zone, a tin-gadolinium diphosphonate DTO electrolyte (SnGdE), the liquid level extends to an overflow opening (ÜL-Sn) in the deposition zone of the container. In the copper diphosphonate DTO electrolyte emerges an auxiliary cathode (HK), which contains copper balls (Cu) surrounded by a titanium expanded metal window (TiF). In the tin-gadolinium diphosphonate DTO electrolyte, an auxiliary anode (HA) emerges, which is surrounded by a titanium expanded metal window (TiF)

Tin granules (Sn) contains. The inflow of the copper diphosphonate DTO electrolyte (ES-Cu) takes place in the dissolution zone via the auxiliary cathode, that of the tin-gadolinium diphosphonate DTO electrolyte (ES-Sn) in the deposition zone via the auxiliary anode, as in FIG shown. The scraper nozzles AD-Cu and AD-TM serve the complete

Replacement of the previous medium from the film surface, also referred to as turbulent stripping. The cleaning cycle (RKL-TM) is the extractive washing / care of the release agent of entrained electrolyte residues. The dissolving / separating zones furthermore each have two deflection rollers (UW), one being arranged above the electrolyte and one each in the separating agent zone. The flat copper workpiece runs in the strip or film running direction (BLR) over the first deflection roller into the copper diphosphonate DTO electrolyte-containing treatment liquid and past the auxiliary cathode in the dissolution zone, whereby the flat metal workpiece positive (Anodic) polarized and a removal of impurities and uneven metal structures present on the surface of the sheet copper workpiece takes place. As a result, a contaminant-free, homogeneous and defined surface is obtained on the copper workpiece that is suitable for obtaining defined metal structures in the subsequent deposition step. The copper workpiece then enters the release agent zone and is transported from there by means of the deflection rollers therein under constant fluid contact in the deposition zone. Here, the copper workpiece is negatively (cathodically) polarized when passing through the auxiliary anode and positively charged tin ions from the tin-gadolinium diphosphonate DTO treatment liquid are deposited in a defined manner on the negatively charged copper surface of the copper workpiece. Likewise, gadolinium can be deposited in the ppm range together with the tin. After passing through the deposition zone, the tinned copper workpiece runs out of the treatment liquid SnGdE.

It has been found that the metal or metals, which according to the

according to the invention are deposited, the surface of the sheet metal workpiece does not consistently cover, but rather in the form of evenly distributed, discrete metal aggregates. The present invention therefore also relates to the flat metal workpieces produced by this method, the surfaces of which are provided with metal aggregates. These metal aggregates are

Metal growths on the surface of the sheet metal workpiece, produced by the electrolytic deposition of one or more metals. The metal aggregates are usually uniformly distributed on the surface and may have a different appearance. Typical are compact aggregates on a crystalline basis with different habit. The size of the metal aggregates is usually in

Submicrometer range (<1 μηι). Typically, 90% or more (more preferably 95% or more, especially 99% or more) of the metal aggregates have a size in the range of 0.05 to 1μηι, preferably in the range of 0.3 to 0.7μηι and especially in the range between 0.35 and 0.65 μηι. The size refers to the mean diameter of the deposited metal aggregates, determined by

electron micrographs.

FIG. 3 shows an SEM image of a copper foil treated in the closed MLP with the electrolytically obtained Cu-DTO diphosphonate electrolyte. The surface (very small black pyramids), also referred to as vsbp, looks depending on the aggregate density brown to black off. Blackening is thought to be a physical process of extinguishing the light by surface interference. The depicted smallest aggregates have grown with their lattice plane base on the previously removed foil and show flat crystal surfaces. They consist (in terms of measurement accuracy) of copper only. The layer thickness is less than 0.5 μm. The extension in the plane of the film is in the range of 30 nm to 300 nm.

The roughness of the metal surface increases slightly due to the deposition of the metal aggregates. After deposition of the metal aggregates, in particular of copper aggregates, on a flat metal workpiece, in particular on a copper foil or strip, the mean roughness values Ra and Rz, determined in accordance with DIN EN ISO 4288: 1998, preferably in the range from 0.22 to 0, 32 μηι for Ra and in particular in the range of 0.24 to 0.28 μηι for Ra, and preferably in the range of 1, 4 to 2.1 μηι for Rz and in particular in the range of 1, 6 to 1, 9 μηι for Rz , In contrast, for example, has a copper foil before deposition roughness values of about 0.20 μηι for Ra and 1, 3 μηι for Rz on.

These special metal aggregates are responsible for ensuring that the surface obtained has excellent adhesion properties (adhesion properties) and

Excellent as a substrate for the formation of solid adhesives with a variety of materials. The increase in adhesion is primarily explained by the fact that the metal aggregates protrude from the surface of the flat metal workpiece and serve as "anchor points" for the adhesion partner, in particular the metal aggregates on the surface of the flat metal workpiece during the pressing or rolling (roll cladding). with the same or a different material, when painting with or without subsequent curing / crosslinking, or when gluing to form a strong adhesive bond A large number of materials are suitable as adhesion partners for the metal workpiece according to the invention, for example thermoplastics such as PA 66, PI and PET, Synthetic resins (epoxies), adhesives, varnishes and pastes, such as graphite pastes.

The present invention therefore also relates to the use of the according to the

According to the invention produced metal workpieces as a substrate for the formation of solid adhesives with other materials such as thermoplastics, resins, adhesives, paints and pastes.

With the aid of the method according to the invention can be using

corresponding treatment liquids based on metal diphosphonate complexes furthermore also apply structured layers of one or more different metals over the surface, including as dopants in the layer also those which are normally not electrolytically depositable from aqueous solution. It is also possible to apply laminar layers which have a high potential for use in the field of magnetic field sensors and the absorption / conversion into catalytically active centers in the layer. The present invention therefore also relates to the use of the metal workpieces produced by the method according to the invention as

Base materials for the production of GMR sensors or Hall sensors (detection of magnetic fields), as well as base materials whose surface can be converted by oxidation into catalytically active mixed oxides and thinnest oxide ceramics, analogous LNO layers.

Other examples of the variety of applications for which the after

According to the invention produced sheet metal workpieces can be used, u.a. Laminates of copper with PET for the shielding of cables and plug and device housings against electromagnetic interference, in particular in signal transmission. Furthermore, the use as an electrical conductor in the production of MID (Molded Interconnect Devices) circuits should be mentioned. These are circuits based on hot stamping of metallic foils on thermoplastic substrates. Another application is as a substrate for electrode material in battery technology. In particular, the

flat metal workpieces according to the invention also in the production of stable, needed in printed circuit board technology for the production of copper laminates

Connections are used. Especially in the production of printed circuit boards, the adhesive strength of the metallic conductor on the substrate (eg FR-4) is of central importance. This is due, on the one hand, to the process steps required in the production (etching, drilling, pressing) and, on the other hand, to the stress on the printed circuit board in the final product itself. EXAMPLES

PREPARATION OF DIPHOSPHONATE ELECTROLYTES Manufacture from metal oxides and diphosphonic acid

Synthesis Example 1: Electrolyte A - Copper Diphosphonate DTO Electrolyte

In a 2000 ml beaker, 327.5 g of deionized water and 466.7 g of a 60% aqueous solution of 1-hydroxyethane-1, 1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany) mixed by stirring. Within 30 minutes 54.5 g of finely powdered, blue-black copper (II) oxide are added at 60 ° C with stirring. The oxide initially dissolves, then forms a deep blue mud. After the addition is complete, place the beaker in a room temperature water bath. After 10 minutes, 45% (D = 1, 46 g / cm ³ ) is cautiously begun with vigorous stirring / kneading with the slow, continuous addition of 461.3 g of potassium hydroxide solution. Upon addition, the temperature is controlled. The reaction temperature is always maintained at <90 ° C. After 20 minutes, the addition of the potassium hydroxide solution is complete. The resulting solution is kept for 2 h at 90 ° C, whereby the evaporation loss is constantly compensated by the addition of further demineralized water. It is then cooled to 25 ° C, the pH to 8.5 to 10 with

Adjusted potassium hydroxide. The resulting deep blue solution is filtered at room temperature over a filter with activated carbon (<50 μηι), and after filtration is made up to 1000 ml with demineralized water.

The obtained copper diphosphonate electrolyte A is a colorless liquid having a pH of 9.2 ± 0.5 and a density of 1.31 g / cm ³ at 25 ° C. The molar ratio of Cu: P: K is 1: 4.0 ± 0.2: 5.4 ± 0.4 (determined by optical

Inductively Coupled Plasma (ICP-OES) Emission Spectrometry, 6%

Nitric acid).

The above solution was then heated to 60 ° C and with good stirring in stages with a total of 0.1 wt .-%, based on the total weight of the electrolyte, (1, 31 g) of 1, 8-dihydroxy-3,6-dithiaoctane (DTO) to obtain the copper diphosphonate DTA electrolyte. The DTO dissolves completely within 2 minutes. Synthetic Example 2: Electrolyte B - bismuth diphosphonate electrolyte

In a 2000 ml beaker, 344.6 g of deionized water and 438.1 g of a 60% aqueous solution of 1-hydroxyethane-1, 1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany) mixed by stirring. Within 30 minutes 95.6 g of finely powdered, yellow bismuth (III) oxide are added with stirring. The oxide initially dissolves, then forms a white mud and a yellow sediment. After the addition is complete, place the beaker in a room temperature water bath. A titanium sonotrode is positioned in the center of the beaker and switched on. After 10 minutes, gently start with the slow, continuous addition of 476.7 g potassium hydroxide solution 45% (D = 1.46 g / cm ³ ). During the addition the sonication and the addition are interrupted for the purpose of temperature control. The reaction temperature is always maintained at <85 ° C. After 30 minutes, the addition of the potassium hydroxide solution and the sonication is complete. The resulting solution is kept at 90 ° C for 6 h, whereby the evaporation loss is constantly compensated. It is then cooled to 25 ° C, the pH adjusted to 8.5 to 9.5 with potassium hydroxide.

The resulting colorless solution may still have a slight fog which is lost by storage for 24 hours. If the fog remains, it is filtered through a filter (<50 μm) filled with activated charcoal, and after filtration, it is made up to 1000 ml with demineralized water.

The obtained bismuth diphosphonate electrolyte B is a colorless liquid having a pH of 8.8 ± 0.3 and a density of 1.355 g / cm ³ at 25 ° C. The molar ratio of Bi: K: P is 1: 7.6 ± 0.4: 6.4 ± 0.3 (determined by ICP-OES, 6%

Nitric acid).

Synthetic Example 3: Electrolyte C - cobalt diphosphonate electrolyte

In a 2000 ml beaker, 360 g of deionized water and 466 g of a 60% aqueous solution of 1-hydroxyethane-1, 1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany) are mixed by stirring. Within 60 minutes with stirring 81, 3 g of finely powdered, pinkish cobalt (ll) carbonate registered. The carbonate dissolves quickly at first, then forms a pale pinkish mud. In particular, after the onset of sludge formation must be added carefully to a foaming of the

Avoid reaction vessel (escaping reaction gas carbon dioxide). Immediately after the end of the addition and the gas evolution, the beaker is in a

Water bath set from room temperature. Without a break and under strong

Stirring / kneading is started carefully with the slow, continuous addition of 412.4 g potassium hydroxide solution 45% (D = 1, 46 g / cm ³ ). When adding the

Temperature constantly controlled, the reaction temperature is always maintained at <85 ° C. After 15 minutes, the addition of the potassium hydroxide solution is complete. The resulting solution is then kept at 90 ° C for 1 h, whereby the evaporation loss is constantly balanced. It is then cooled to 25 ° C, the pH adjusted to 9.0 to 10 with potassium hydroxide. The rich pink solution is filtered through a filter (<50 μηι) with activated carbon, and after filtration is made up to 1000 ml with demineralized water. The obtained cobalt diphosphonate electrolyte C is a pinkish liquid with a pH of 9.5 ± 0.5 and a density of 1.32 g / cm ³ at 25 ° C. The molar ratio of Co: P: K is 1: 4.0 ± 0.2: 4.9 ± 0.3 (determined by ICP-OES, 6%

Nitric acid).

Synthetic Example 4: Electrolyte D - Tin Diphosphonate Electrolyte

In a 2000 ml beaker, 325.6 g of demineralized water and 464 g of a 60% aqueous solution of 1-hydroxyethane-1,1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany) are stirred mixed. Within 60 minutes 91.8 g of finely chipped, black tin (II) oxide are added with stirring. The oxide initially dissolves slowly, then forms a white mud and a gray sediment. After the end of the addition is stirred for 4 h. The beaker is then placed in a room temperature water bath. After 10 minutes, while stirring / kneading, the slow, continuous addition of 458.5 g of potassium hydroxide solution 45% (D = 1.46 g / cm ³ ) is started carefully. Upon addition, the reaction temperature is controlled. The

Reaction temperature is always maintained at <80 ° C. After 30 minutes, the addition of the potassium hydroxide solution is complete. The resulting solution is kept at 80 ° C for 6 h, whereby the evaporation loss is constantly compensated. It is then cooled to 25 ° C and stored for a further 48 h. The pH is adjusted to 9.0 to 10 with potassium hydroxide. The resulting colorless solution still has a colorless veil and an oily top film and is filtered through a filter with activated carbon (<50 μηι). After filtration, make up to 1000 ml with demineralized water.

The obtained tin diphosphonate electrolyte D is a colorless liquid having a pH of 9.4 ± 0.3 and a density of 1.34 g / cm ³ at 25 ° C. The molar ratio of Sn: P: K is 1: 4.9 ± 0.3: 8.5 ± 0.5 at a variable Sn (II): Sn (IV) ratio (determined by ICP-OES, 6% Nitric acid).

Synthesis Example 5: Electrolyte E - erbium diphosphonate electrolvt

In a 2000 ml beaker, 377 g of deionized water and 504.6 g of a 60% aqueous solution of 1-hydroxyethane-1, 1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany) by stirring mixed. 141, 6 g of finely powdered, red erbium (III) oxide are added with stirring within 20 minutes. The oxide initially dissolves, then forms a red mud and red sediment. After the addition is complete, place the beaker in a room temperature water bath. A titanium sonotrode is positioned in the center of the beaker and switched on. After 10 minutes, the slow, continuous addition of 446.7 g potassium hydroxide solution 45% (D = 1.46 g / cm ³ ) is started carefully. During the addition, the sonication and the addition are interrupted for temperature control. The reaction temperature is always maintained at <90 ° C. After 30 minutes, the addition of the potassium hydroxide solution and the sonication is complete. The resulting solution is kept for 2 h at 90 ° C, whereby the evaporation loss is constantly compensated. It is then cooled to 25 ° C, the pH adjusted to 8.5 to 9.5 with potassium hydroxide.

The resulting red solution must not have a haze. If a fog remains, it is filtered through a filter (<50 μm) filled with activated charcoal and, after filtration, the volume is made up to 1000 ml with demineralized water.

The resulting erbium diphosphonate electrolyte E is a raspberry red liquid having a pH of 9.0 ± 0.5 and a density of 1.43 g / cm ³ at 25 ° C. The molar Ratio of Er: P: K is 1: 4.0 ± 0.2: 4.8 ± 0.3 (determined by ICP-OES, 6% nitric acid).

Synthetic Example 6: Electrolyte F - terbium diphosphonate electrolyte

Following the procedure of Synthesis Example 5 but substituting erbium (III) oxide for 138.4 g of terbium (III / IV) oxide, terbium diphosphonate electrolyte F was found to be a pale green liquid having a pH of 9.0 ± 0.5, a density of 1.43 g / cm ³ and a molar ratio of Tb: P: K of 1: 4.0 ± 0.2: 4.8 ± 0.3.

Synthetic Example 7: Electrolyte G - Gadolinium Diphosphonate Electrolyte

In a 2000 ml beaker, 318 g of deionized water and 465.8 g of a 60% aqueous solution of 1-hydroxyethane-1, 1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany) by stirring mixed. Within 30 minutes 123.8 g of finely powdered, colorless gadolinium (III) oxide are added with stirring. The oxide initially dissolves exothermally, then forms a white slurry and a colorless sediment. After the addition is complete, place the beaker in a room temperature water bath. After 10 minutes, 45% (D = 1, 46 g / cm ³ ) is cautiously begun with vigorous stirring / kneading with the slow, continuous addition of 412.4 g of potassium hydroxide solution. When adding the temperature of the reaction mixture is always controlled. The

Reaction temperature is always maintained at <90 ° C. After 20 minutes, the addition of the potassium hydroxide solution is complete. The resulting solution is kept for 2 h at 90 ° C, whereby the evaporation loss is constantly compensated. It is then cooled to 25 ° C and the pH adjusted to 8.5 to 9.5 with potassium hydroxide.

The resulting colorless solution still has a slight fog, which can be lost by storage for 24 hours. If the fog remains, it is filtered through a filter (<50 μm) filled with activated charcoal. After filtration, make up to 1000 ml with demineralized water.

The obtained gadolinium diphosphonate electrolyte G is a colorless liquid having a pH of 9.0 ± 0.5 and a density of 1.32 g / cm ³ at 25 ° C. The molar Ratio of Gd: P: K is 1: 4.0 ± 0.2: 4.8 ± 0.3 (determined by ICP-OES, 6% nitric acid).

Synthesis Example 8: Electrolyte H - neodymium diphosphonate electrolvt

In a 2000 ml beaker, 275.6 g of demineralized water and 472.9 g of a 60% aqueous solution of 1-hydroxyethane-1, 1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany) mixed by stirring. Within 30 minutes 77.2 g of finely powdered, blue neodymium (III) oxide are added with stirring. The oxide dissolves initially exothermic, then forms a purple mud. After the addition is complete, place the beaker in a room temperature water bath. After 10 minutes will be under good

Stirring / kneading was started carefully with the slow, continuous addition of 514.3 g potassium hydroxide solution 45% (D = 1, 46 g / cm ³ ). When adding the

Temperature of the reaction mixture always monitored. The reaction temperature is always maintained at <90 ° C. After 20 minutes, the addition of the potassium hydroxide solution is complete. The resulting solution is kept for 1 h at 90 ° C, wherein constantly the

Evaporation loss is compensated. It is then cooled to 25 ° C and the pH adjusted to 9.0 to 9.8 with potassium hydroxide. At the end, make up to 1000 ml with demineralized water.

The obtained neodymium diphosphonate electrolyte H is a red-violet liquid having a pH of 9.4 ± 0.4 and a density of 1.34 g / cm ³ at 25 ° C. The molar ratio of Nd: P: K is 1: 6.0 ± 0.4: 9.0 ± 0.5 (determined by ICP-OES, 6% nitric acid).

Synthetic Example 9: Electrolyte I - nickel-gadolinium diphosphonate electrolyte

In a 2000 ml beaker, 324.8 g of demineralized water and 465.8 g of a 60% aqueous solution of 1-hydroxyethane-1,1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany). mixed by stirring. Within 30 minutes with stirring first 12.7 g of finely powdered, apple green nickel (II) hydroxide and immediately thereafter 99.0 g feinpulvriges

Gadolinium (III) oxide. The oxides initially dissolve, then forming a pale yellow mud and an almost colorless sediment that does not contain green matter may contain. After the end of the addition of the oxides, the beaker is in a

Water bath set from room temperature. Without pause, with vigorous stirring / kneading, the slow, continuous addition of 417.6 g of potassium hydroxide solution 45% (D = 1.46 g / cm ³ ) is started carefully. Upon addition, the reaction temperature is controlled and always kept at <90 ° C. After 20 minutes, the addition of the potassium hydroxide solution is complete. The resulting solution is kept for 2 h at 90 ° C, whereby the evaporation loss is constantly compensated. It is then cooled to 25 ° C and the pH adjusted to 8.5 to 9.5 with potassium hydroxide. The resulting green-yellow solution may still have a slight fog, which is lost by storage for 24 hours. If the fog remains, it is filtered through a filter (<50 μm) filled with activated charcoal and, after filtration, made up to 1000 ml with demineralized water.

The resulting nickel-gadolinium diphosphonate electrolyte I is a green-yellow liquid having a pH of 9.0 ± 0.5 and a density of 1.32 g / cm ³ at 25 ° C. The molar ratio of [Gd + Ni]: P: K is 1: 4.1 ± 0.3: 4.4 ± 0.3 with a Ni: Gd ratio of 1: 3.9 (determined by ICP-OES , 6% nitric acid).

Synthetic Example 10: Electrolyte J - nickel-gadolinium-terbium diphosphonate electrolv with 0.5 M% DTO additization

1000 ml of this electrolyte are prepared by blending 950 ml (1254 g) of the nickel-gadolinium diphosphonate electrolyte I of Synthesis Example 9 with 50 ml (70.5 g) of the terbium (III) diphosphonate electrolyte F of Synthesis Example 6.

The resulting nickel-gadolinium-terbium diphosphonate solution is then heated to 60 ° C and with good stirring in stages with a total of 0.5 wt .-%, based on the total weight of the electrolyte, (5.5 g) 1, 8 Dihydroxy-3,6-dithiaoctane (DTO) to give the electrolyte J as a green-yellow liquid with a pH of 9.0 ± 0.5, a density of 1.32 g / cm ³ at 25 ° C, a molar ratio [Gd + Tb + Ni]: P: K of 1: 4.0 ± 0.3: 4.5 ± 0.3 and a Ni: Gd: Tb ratio of 1: 3.9: 0, 2 (ICP-OES, 6% nitric acid). Production by surface metallization

Synthesis Examples 1 1 - 14: Electrolytes K, L, M and N - Copper diphosphonate DTO electrolvts

In a 2000 ml beaker, 336.4 g of demineralized water and 451.7 g of a 60% aqueous solution of 1-hydroxyethane-1, 1-diphosphonic acid (Cublen K60, available from Zschimmer & Schwarz, 09217 Burgstädt, Germany). mixed by stirring. The beaker is placed in a room temperature water bath. Then, with good stirring, the slow, continuous addition of 491.9 g of potassium hydroxide solution 45% (D = 1.46 g / cm ³ ) is started carefully. At the time of addition, temperature is controlled. The reaction temperature is always maintained at <80 ° C. After 20 minutes, the addition of the potassium hydroxide solution is complete. It is then cooled to 25 ° C, the pH adjusted to 6.5 to 8.5 with potassium hydroxide or diphosphonate.

The resulting colorless solution is clear and is made up to 1000 ml with demineralized water. The colorless liquid has a pH of 8.8 ± 0.3, a density of 1.27 ± 0.02 g / cm ³ at 25 ° C, and a K: P molar ratio of 1.5: 1 ( ICP-OES, 6% nitric acid).

In a separate 1000-ml beaker, two 8-mm copper anodes are introduced, in the middle of a copper cathode made of 0.5 mm copper sheet. The electrodes will be

Faced against each other with two 0.3 mm HDPE plates. The ratio of

immersed anode surface opposite to the cathode surface is 10: 1. The cathode is wrapped with a bag of PP fiber to keep away unwanted separating and partially peeling copper from the solution. Subsequently, 860 ml (= 1100 g) of the colorless solution obtained above are charged. The apparatus is fitted with a magnetic stir bar and positioned on a magnetic stirrer in a water bath. The apparatus is stirred at 600 rpm, becomes a rectifier

connected and the maximum possible current (23 A) applied. to

Power supply is a power supply of the type Statron type 3254.1 with preselected

Amperage and display of the corresponding voltage used. Between the power supply and the electrolytic cell is a Polwendeschalter, whereby the polarity of the film and the electrodes during the experiment in any order and in any time can be turned (replaced). Due to the electrolysis, the temperature rises to 60 ° C within 24 minutes, whereby the maximum current density is reached at approx. 48 ° C. During plating, the copper content is controlled at 60 minute intervals. This increases rapidly at the beginning and only slowly changes above 13.5 g / l copper. After 3 x 6 h = 18 h Aufmetallisierung the electrolysis is stopped, the electrodes are removed, the apparatus removed from the water bath and cooled to room temperature.

The pH of the solution is then adjusted to about 9.5 with potassium hydroxide (45%) and the apparatus is made up to 860 ml with demineralized water. The resulting copper diphosphonate solution is a deep blue liquid with a pH of 9.5 ± 0.3 and a density of 1.31 ± 0.02 g / cm ³ at 25 ° C. The Cu concentration is 15.3 g / l, the molar ratio of Cu: P: K is about 1: 1 1: 14.8 (determined by ICP-OES, 6% nitric acid)

The above solution was then heated to 60 ° C and with good stirring in stages with a total of 0.05 wt .-%, based on the total weight of the electrolyte, (0.56 g) of 1, 8-dihydroxy-3,6-dithiaoctane (DTO) to obtain the copper diphosphonate DTO electrolyte K. The DTO dissolves completely within 2 minutes. The deep blue color of the solution remains unchanged.

Similarly, but with the addition of a total of 1.13 g (0.1% by weight), 2.26 g (0.2% by weight) and 5.5 g (0.5% by weight). ) DTO, the electrolytes L, M and N were prepared.

Examples 15-18: Electric K1, L1, M1 and N1 - copper diphosphonate-DTDA electrolvts

4,7-Dithiadecanedioic acid (DTDA) was prepared as described in US Pat. No. 2,602,816 and recrystallised from boiling water (mp 163-164 ° C.).

Analogous to Synthesis Examples 1 1 - 14, a copper diphosphonate solution was prepared by Aufmetallisierung. The solution was then added at room temperature while stirring with 1.44 g of 4,7-dithiadecanedioic acid (DTDA) (0.1% by weight, based on the total weight of the electrolyte, of 1000 ml) to give the copper diphosphonate DTDA -Electrolyte K1 obtain. The DTDA dissolves completely within 20 seconds. The deep blue color of the solution remains unchanged. The pH of the electrolyte is readjusted to the range around 9 by the addition of potassium hydroxide solution (50%).

Similarly, but with the addition of a total of 2.75 g (0.21% by weight), 5.23 g (0.40% by weight) and 14.4 g (1.10% by weight, respectively). ) DTDA, the electrolytes L1, M1 and N1 were prepared.

Synthetic Example 19: Electrolyte K2 - copper diphosphonate DMDTK electrolv

Dipotassium 2,9-dimethyl-4,7-dithiadecanedioate (DMDTK) was prepared analogously to D.M. Haddleton, et. al, Polymer Chemistry, 2010, Vol. 1, p. 1 196 to 2040, as follows. Ethanedithiol was reacted with ethyl methacrylate (1: 2.2) in acetone catalysed by triethylamine. About 80% of the acetone was distilled off, triethylamine and unreacted ethyl methacrylate then extracted from the distillation residue with ice-cold dilute hydrochloric acid from the aqueous-acid, the crude product then extracted with toluene, the toluene extract over sodium sulfate / soda = 3: 1 (both anhydrous) dried , The toluene extract was saponified with ethanolic potassium hydroxide in ethanol at 78 ° C, the potassium salt of 2,9-dimethyl-4,7-dithia-decanedioic acid (dipotassium-2,9-dimethyl-4,7-dithiadecanedioate, DMDTK) in pure Form (as a mixture of diastereomers) precipitated on cooling the reaction solution.

Analogous to Synthesis Examples 1 1 - 14, a copper diphosphonate solution was prepared by Aufmetallisierung. The solution was then stirred at room temperature with 4.06 g of dipotassium 2,9-dimethyl-4,7-dithiadecanedioate (DMDTK).

(0.31 wt% based on the total weight of the electrolyte of 1000 ml) to obtain the copper diphosphonate DMDTK electrolyte K2. The DMDTK dissolves completely within 10 seconds. The deep blue color of the solution remains unchanged.

Synthetic Examples 20 - 23: Electrolytes K3. L3, M3 and N3 - copper diphosphonate DMDTDA electrolvts

2,9-Dimethyl-4,7-dithiadecanedioic acid (DMDTDA) was obtained as follows: from the toluene extract obtained in the preparation of dipotassium 2,9-dimethyl-4,7-dithiadecanedioate (DMDTK) in vacuo (50 torr). the toluene and smallest remnants of the Ethyl methacrylate distilled off. The resulting honey-colored oil was saponified in aqueous 10% sodium hydroxide solution and the acid precipitated by slow pouring into stirred dilute hydrochloric acid at room temperature. The crude product was washed with ice water and then recrystallized from boiling water (mp 152-156 ° C). The 2,9-dimethyl-4,7-dithiadecanedioic acid (DMDTDA) was obtained as a mixture of the diastereomers.

Analogous to Synthesis Examples 1 1 - 14, a copper diphosphonate solution was prepared by Aufmetallisierung. The solution was then heated to 60 ° C and treated with stirring with 1, 57 g of 2,9-dimethyl-4,7-diethiadecanedioic acid (DMDTDA) (0.12 wt .-% based on the total weight of the electrolyte of 1000 ml) to obtain the copper diphosphonate DMDTDA electrolyte K3. The DMDTDA dissolves completely within 20 seconds. The deep blue color of the solution remains unchanged. The pH of the electrolyte is readjusted to the range around 9 by the addition of potassium hydroxide solution (50%).

Similarly, but with the addition of 3.15 g (0.24 wt%), 6.29 g (0.48 wt%) and 15.7 g (1.20 wt%) DMDTDA, the electrolytes L3, M3 and N3 were produced.

SURFACE MODIFICATION OF FLAT METALWORK PIECES

Example 1 Modification of a Tinned Copper Foil by Deposition of

Zinnaqqreqaten on the film surface according to the closed center conductor principle

electrolysis arrangement

For the surface modification of a tinned copper foil, the following static electrolysis arrangement was used to simulate the closed center conductor principle:

The static electrolytic cell comprises a 1000 ml beaker filled with an electrolyte (900 ml). The beaker stands on a stirrer. The stirrer is used to heat the electrolyte, the temperature is constantly through a

Thermocouple with stainless steel sheath is tested and within ± 2 ° C constant is held. Stirring speed is maintained at 1000 rpm and agitation is transferred to the electrolyte solution through a 40xd6 round magnetic stir bar (PTFE).

Above the beaker there is a cover plate made of PP, which is placed over the beaker and has an inert electrode made of Ti / lr0 ₂ on each side at a distance of 30 mm. These electrodes are flat sheets that dive parallel to each other and each perpendicular to the electrolyte solution. The single-sided, immersed surface is between 60 mm x 80 mm and 60 mm x 100 mm per electrode. In the middle, the plastic plate was provided parallel to the inert electrodes with an opening of 20 mm x 80 mm, through which the flexible film holder can be inserted into the cell. This film holder was therefore designed to be flexible so that the film, once clamped, then the entire process including the pre and

Aftertreatment steps (eg cleaning / sink / sink, pickling / pickling / sink / sink, electrolysis / sink / sink, passivation / sink / VE-sink) can pass through in the same holder and must be taken out of the holder only after the last rinse for drying , The film holder consists of two PP frames with a window of 80 mm x 60 mm, in which the film is clamped. The clamping screws are made of PA6 plastic. The lower clamping screws serve only to tension the film, the upper clamping screws additionally serve to produce a releasable press contact to a TiPt expanded metal grid. This contact point dips into the solution, so that the film is completely immersed in the electrolyte and the contact point is blinded by the frame of the film holder relative to the field of the cell. The expanded metal used for contacting protrudes at the top of the cell and is over a

Alligator clip powered. For the power supply a power supply of the type Statron with preselectable current strength and indication of the corresponding voltage is used. Between the power supply and the electrolysis cell is a

Polwendeschalter, whereby the polarity of the film and the electrodes during the experiment in any order and in any time can be turned (exchanged).

surface modification

A tinned copper foil with pure tin deposit of about 2 μηι, a copper layer thickness of 35 μηι, a length of 8.5 cm (effective) and a width of 5.0 cm was initially subjected to a pretreatment comprising the following steps in the order given:

- Pre-cleaning: Purax 6029PUS, 40 g / l, 60 ° C, de-energized, 10s.

 - sink: water

 - Fine cleaning: Velocit 1 127M, 25 g / l, 60 ° C, de-energized, 10s.

 - sink: water

 - Pickling / pickling: sulfuric acid (7% in water), 25 ° C - 35 ° C.

 - sink: water

The thus pretreated copper foil was then surface-modified in the described static electrolysis device using the electrolyte D of Synthetic Example 4 at 60 ° C. The current densities used were varied between 0.52 A dm ² and 10.4 A / dm ² . The anodic current efficiency is up to a current density of 1.2 A / dm ² or a charge density of 23.7 C / dm ² at 100%. When these limit values are exceeded, the removal from the film remains constant at 7.5 ± 0.6 mg / dm ² , ie the anodic current efficiency drops continuously above the limit values. The deposition / deposition reaction was immediately following the ablation reaction

carried out. Again, the current densities between 0.52 A / dm ² and 10.4 A / dm ^{2 were} varied.

The inert electrodes were before the first energization in the electrolyte with a

Anodensack provided to keep in the Polwendung these electrodes from cathodic to anodically peeled tin particles from the electrolyte.

After passing through the electrolysis apparatus, the surface-modified film was subjected to a post-treatment comprising the following steps in the order given:

- sink: water

 - Passivation: Dissolve 6 g potassium dichromate in water at room temperature.

 - sink: water

- Drying with warm air between 90 ° C and 120 ° C. Table 1 Results of the electrolytic treatment of tin-diphosphonate tinned copper foil: The theoretical values of the deposition performance for tin are listed to classify the results: Tin (II) -> Tin (0) = 0.615 mg / As; Tin (IV) -> Tin (0) = 0.308 mg / As.

The deposited tin layer shows highly branched aggregates and reaches at a charge density of 208 C / dm ² a growth height of> 5 μηι on the film. at Charge densities from 90 C / dm ² and constantly at> 1 16 C / dm ² , the deposited tin aggregates are brittle and the color of the resulting surface changes from light gray to matt dark gray. After completion of the experiments, the electrolyte was analyzed for the content of tin (II) (iodatometric), total tin and additionally for the entry of copper from the film core (Sn, Cu - ICP-OES, nitric acid):

The concentration of tin in the electrolyte dropped from 64.7g / l to 59.3g / l.

 The tin (II) content dropped from originally 14.7 g / L (22.7%) to 1.6 g / L (2.7%).

 In the electrolyte solution no copper could be detected at the beginning, according to the

At the end of the tinned copper foil treatment, 20 ± 5 mg Cu / I electrolyte solution was measured.

The causes of tin loss are the carryover into the sink and the asymmetry of the process between removal and deposition on this film. In addition, tin was found in the anode bags of the inert electrodes. The regeneration of tin (II) from tin (IV) at the inert cathode is incomplete. Here this process and the deposition of metallic tin are found. In contrast to acidic tin electrolytes of the prior art, the ratio between tin (II) and tin (IV) in the electrolyte does not affect the quality of the deposited tin layer. The electrolyte shows excellent micro-scattering even without additives, similar to stannate (IV) electrolytes. Acidic tin (II) electrolytes are virtually unusable without the micro-scattering enhancing additives.

Example 2: Modification of a copper foil by deposition of Kupferqqqqq on the film surface according to the closed center conductor principle

electrolysis arrangement

For the surface modification of a copper foil using copper diphosphonate electrolytes, a closed-center foil conveyor system was used, which was designed for foils or strips up to a width of 330 mm. The plant essentially corresponds to the plant shown in FIG. 1 and has a chute and a reel with electronic tension control. The control options include amperage of each

Electrode segments, strip tension, belt speed and temperature of the electrolyte. The rectifiers used are from the company plating electronic type pe86CW-6 424-960-4 with 4 outputs. The maximum pulse current is 960 A, the maximum continuous current is 424 A. The temporal course of the current can be defined as a pulse sequence via the associated software.

The electrolytic cell of the film conveyor system used comprises a cathode and an anode for one-sided electrolytic deposition. The cathode and the anode are positioned parallel to the film run and arranged so that during the film run the same side or surface of the metal foil is opposite first to the cathode and then to the anode. Furthermore, the cathode and the anode are completely surrounded by electrolyte. Although only one cathode and one anode are used in the experiments described herein, in principle a variety of different configurations may be used, for example, a dual cathode and a double anode for double-sided electrodeposition, or two sequentially arranged cathodes and anodes.

As electrodes (anode and cathode) flow electrodes were used in this experiment, which comprise a polypropylene electrode housing and a high-current titanium contact frame with a titanium expanded metal blend surface backfilled with copper balls. The electrode is located in an anode bag made of PP fabric. The flow rate is possible up to 20 l / min. The electrolyte is introduced into the flow electrode via an electrolyte feed, flows past the metal balls in the direction of the housing bottom of the electrode housing and is received by an electrolyte channel in the bottom of the electrode housing. The electrolyte then exits the electrolyte channel via a flow opening in the form of a flow lip and flows upwards past the metal grid. In this alternative form of the film passage system, the electrolyte, after passing through the flow electrode, passes into the electrolytic bath and from there via an overflow into a reservoir, from which the electrolyte is then pumped again into the flow electrode.

As an alternative to the flow electrode described above, a three-part copper sheet convection electrode can also be used. The individual electrode segments can be controlled separately via a rectifier or switched Gleichpolig. The electrode is located in an anodic bag made of polypropylene fabric. The necessary flow is generated by means of a B2-rod pump from Lutz

(a total of 40 l / min distributed over 2 electrodes).

surface modification

With the electrolytes K, L and M

A hard-rolled copper foil having a thickness of 0.035 mm and a width of 300 mm was first subjected to a pretreatment comprising the following steps in the order given:

- degreasing: immersion pass with electrolytic support, 45 ° C, alkaline cleaner

- Sink: water, dipping, 45 ° C

 - Pickling: Sulfuric acid 4% in water, dip run, 30 - 35 ° C.

 - Sink: water, immersion run, room temperature

 - Sink: water, immersion run, room temperature

The pretreated copper foil was then in the described

Film flow system using the electrolytes K, L or M (Synthesis Examples 1 1, 12 and 13) and another electrolyte, which was prepared analogously to Synthesis Example 1 1, but to which no DTO had been added, surface-modified. The process parameters were as follows:

Film speed: 2 m / min

Average current: 66 A (= 27.5 A / dm ² )

Pulse sequence: 10 ms at 132 A, 10 ms pause

Electrolyte temperature: 50 ± 2 ° C

Electrode distance: 30 mm

After passing through the electrolysis apparatus, the surface-modified copper foils were subjected to a post-treatment comprising the following steps in the order given:

- Sink: water, immersion run, room temperature

- Sink: water, immersion run, room temperature - Passivation: Chromium (VI) -containing solution, dip run, room temperature

 - Sink: water, immersion run, room temperature

 - Sink: demineralized water, misting, room temperature

 - Drying with warm air 90 ° C

With the electrolytes K1. L1 and M1

A hard-rolled copper foil having a thickness of 0.035 mm and a width of 300 mm was first subjected to a pretreatment comprising the following steps in the order given:

- degreasing: immersion pass with electrolytic support, 45 ° C, alkaline cleaner

- Sink: water, dipping, 45 ° C

 - Pickling: Sulfuric acid 4% in water, dip run, 30 - 35 ° C.

 - Sink: water, immersion run, room temperature

 - Sink: water, immersion run, room temperature

The pretreated copper foil was then in the described

Film passage system using electrolytes K1, L1 or M1

(Synthesis Examples 15, 16 and 17) surface-modified. The process parameters were as follows:

Film speed: 2 m / min

Average current: 66 A (= 27.5 A / dm ² )

Pulse sequence: 10 ms at 132 A, 10 ms pause

Electrolyte temperature: 50 ± 2 ° C

Electrode distance: 30 mm

After passing through the electrolysis apparatus, the surface-modified copper foils were subjected to a post-treatment comprising the following steps in the order given:

- Sink: water, immersion run, room temperature

 - Sink: water, immersion run, room temperature

- Sink: demineralized water, misting, room temperature - Drying with warm air 90 ° C

With the electrolytes K2. K3. L3 and M3

As described above for the surface modification with the electrolyte K1, a copper foil after appropriate pretreatment using the electrolytes K2, K3, L3 or M3 (Synthesis Examples 19, 20, 21 and 22, respectively) in the described

Treated film conveyor system and then subjected to the aftertreatment.

Those obtained with the electrolytes K, L, M, K1, L1, M1, K2, K3, L3 and M3

surface-modified copper foils showed in scanning electron microscopy

Images of the surface (REM external, FEI XL 30, 45 ° tilt angle, 15 kV AcT

(Acceleration voltage), SE-detector, magnification of 10000 times) distinct and uniform depositions of copper aggregates on the copper surface, regardless of whether DTO (electrolytes K, L, M) or a compound of 4,7-dithiadecanedioic acid (electrolytes K1, L1 , M1, K2, K3, L3, M3) was used. In a copper foil treated with the copper electrolyte without additive addition, no such deposits could be observed.

Example 3: Modification of a Copper Foil by Separation of Zinnaqqreqaten on the Folienobefläche on the open center conductor principle

For modifying a copper foil by depositing a tin layer in the open center conductor method, an apparatus as shown in Figure 2 is used as discussed above. As a copper foil substrate is a 40-meter-long and 200 mm wide copper foil with a thickness of about 35 μηι. The separating liquid used is 2-methoxy-1-iodobenzene. As a container for the continuous apparatus is a polypropylene container with a side wall thickness of 20 mm and a

Capacity of about 12 I used. As a treatment liquid for the removal of 30 l of copper diphosphonate DTO electrolyte M (of Synthesis Example 13) having a copper content of 17.1 g / l, a density of 1, 32 g / cm ³ at 25 ° C and pH = 9.2 at 60 ° C used. The auxiliary cathode for the removal is a frame electrode

Polypropylene (PP) with a Ti expanded metal window (270 mm wide and 1 10 mm long in the film direction), which is backfilled with copper balls. The PP frame is designed so that the inflow of the circulated treatment liquid through the electrode frame so This ensures that the copper balls, the potential-forming window and the space between the auxiliary electrode window and the film to be treated are washed around in a targeted manner. As the treating liquid for the deposition, a total of 30 l of a blend of the tin diphosphonate electrolyte D (of Synthesis Example 4) and the gadolinium diphosphonate electrolyte G (of Synthesis Example 7) is used in a ratio of 80% Sn and 20% Gd. 5.1 g / l of 1,8-dihydroxy-3,6-dithiaoctane are added. As auxiliary anode, the same type of electrode is used as in the removal zone, but as a backfill of the Ti expanded metal window instead of the copper balls tin granules are used with a maximum diameter up to 12 mm. This treatment liquid is used at 60 ° C, pH = 9.2. Both treatment liquids are in separate storage tanks and are completely circulated within 15 minutes. The separating liquid is used as a static phase at the bottom of the treatment cell and is present in an amount of 4 l (= 7.3 kg). The film is passed past the electrodes at a speed of 0.4 m / min. The

Electrode length in film direction is 1 10 mm. The current density used is applied in different pulses and is 6.82 A / dm ² . The applied charge density is 1 12 C / dm ² .

After the treatment of the copper foil, the deposited layer weight of tin / Gd on the copper foil, the proportion of Gd versus tin in the layer, the

Metal contents of the treatment liquids and the introduction of the copper from the removal zone into the deposition zone determines:

Average layer weight:

Molar ratio Gd / Sn in the layer:

Content of copper in erosion electrolytes:

Content of tin in the deposition electrolyte:

Content of gadolinium in the deposition electrolyte

Introduced soluble copper in the deposition electrolyte: <0.02 g / l

The probe elements of the treatment liquids or of the release agent potassium, phosphorus, sulfur and iodine are not detected in the deposited layer (<5 ppm). INVESTIGATION OF THE LIABILITY CHARACTERISTICS TEST PROCEDURE 1 - Adhesion test

An adhesive tape (Tesafilm® Transparent 57404-00002) was deposited over the electrolytically treated, dry, cold and at least 15 minutes

Lay metal foil surface and pressed with a soft roller firmly on the surface. Care was taken to ensure that no air bubbles formed between the adhesive tape and the film surface. After a period of 30 seconds after the adhesive strip was pressed on, it was caught on its projection and peeled off from the retained metal foil. In this case, a pulling rate of 2 to 3 seconds was observed for a length of 8 cm.

The peeled tape was then glued to a piece of white paper and the color change caused by metal aggregates released from the paper

Foil surface are demolished and stick to the tape. Furthermore, it was judged whether the adhesive layer of the Tesafilms after peeling completely or partially remained on the surface of the metal foil.

Test Method 2 - Peel Adhesion Test

The peel strength was determined according to DIN EN 60249 on a Zwick BZ2 / TN1 S peeling tool with Xforce HP 500 N load cell and software testXpert 12.3. For this purpose, the samples were cut from a pressed composite panel and peeled or peeled the film at an angle of 180 °. The pressed composite panel was produced by pressing the film with a plastic substrate at a temperature of 160 ± 10 ° C and a compression pressure of 120 ± 5 bar over a period of 60 ± 5 min. The results of the peel test are given in N / mm.

Example 4: Adhesion on tin-diphosphonate electrolvt treated tinned copper foil

The non-brittle tin growth films (Examples Nos. 1 to 14, see Table 1) obtained in Example 1 were subjected to the above-described adhesion test. To the Comparison served classically produced, unpassivated and non-oiled

Tinplate surfaces in the original (dendritic) deposition state and in the de-melted state (overlay 8.2 g Sn / m ² surface, 0.32 mm core band, unstructured (gable KWW GmbH Iserlohn)). All samples showed a significantly improved adhesive strength of the adhesive strip on the tin-coated metal surface compared to the tinplate surface, which manifested as graying of the film adhesive layer by torn-off tin aggregates. Samples 4-14 no longer permit easy peeling off of the adhesive strip; the adhesive layer remains adhered to the surface of the film, and in some cases, the film tears when peeled off. On the other hand, the tinplate surfaces used for comparison allow in every case a complete removal of the adhesive strip. The removal of the adhesive strip from the surface of the tinplate in the molten state is carried out to 80%, without leaving any visible traces on the surface.

Example 5: Adhesion to copper diphosphonate additive electrolvt

surface-modified copper foil

The adhesion test described above and in Example 4 was repeated with the copper foils obtained in Example 2 and surface-modified with the electrolytes K1, L1, M1 (additive = DTDA), K2 (additive = DMDTK) or K3, L3, M3 (additive = DMDTDA) , The tests showed excellent adhesion of the adhesive film to the copper layer. In all tests, the adhesive film adhered to the entire surface, and when removing the adhesive film, the adhesive layer of the film remained on the copper layer.

The surface modification of copper foils using copper diphosphonate electrolyte with the addition of additive, for example in the closed center conductor principle thus provides adherent surfaces, the u.a. have excellent adhesion to adhesive tape.

Example 6: Adhesion to tin-diphosphonate electrolvt treated copper foil

The adhesion test described above and in Example 4 was repeated with the copper foil obtained in Example 3 in the open center conductor method Sn-modified method. The test showed excellent adhesion of the adhesive film on the Tin layer. The adhesive layer of the film remained on the tin layer, or the film strip was destroyed in the attempt to peel off the tin surface.

The use of tin diphosphonate electrolytes for the deposition of Sn layers thus provides both in the closed and in the open center conductor principle in the

Deposition process microstructured, adherent surfaces, which i.a. have excellent adhesion to adhesive tape.

Example 7: Peel Strengths of Pressed Composite Panels of Copper DTO Electrolyte Modified Copper Foils and Various Plastics

Composite panels were made by pressing with the electrolyte L

surface-modified copper foil of Example 2 and the following plastic substrates: a) Ultramid® A3X2 G5, b) Grivory® HT2V-3H, c) FR-4 epoxy resin and d) FR-4 polyimide. For comparison, a composite plate was used, which was electrolytically modified with the electrolyte without DTO additive (electrolyte 0: copper content 7.0 g / l, sulfate content 69.4 g / l, density 1, 07 g / cm ³ ) copper foil (analog Example 2) and FR-4 epoxy resin. The peel strengths of the respective composite panels were tested according to the peel strength test described above and are as follows:

Electrolyte L / Ultramid® A3X2 G5 1, 7 N / mm

 Electrolyte L / Grivory® HT2V-3H 1, 3 N / mm

 Electrolyte L / FR-4 epoxy resin 2.0 N / mm

 Electrolyte L / FR-4 polyimide 1, 7 N / mm

 Electrolyte 0 / FR-4 epoxy 1, 2 N / mm

In Figure 4, the peel strengths are shown graphically for ease of illustration. As can be seen from these data, the peel strength of a composite of FR-4 epoxy resin and electrolyte L modified copper foil significantly increased as compared with that of a composite of FR-4 epoxy resin and electrolyte-modified copper foil. The peel tests with the plastic sub-strates also prove the outstanding adhesive potential of the surfaces modified according to the invention.

Claims

1 . Electrically conductive liquid comprising an aqueous solution of a

Metal complex, wherein the metal complex is a complex

(i) one or more metals selected from the group consisting of Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, Ti, Zr, Nb, Y, Ce, Nd, Sm, Gd , Tb, Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof, and

(Ii) one or more diphosphonate ligands of the general formula (I) 0 = P (OH) ₂ -X- (OH) ₂ P = 0 (I) wherein the OH groups in the general formula (I), the the two phosphorus atoms are bonded, independently protonated (OH) or deprotonated (0), wherein:

X = O, NR ¹ or CR ¹ R ² , in particular X = CR ¹ R ² ,

R ^{1 is} H, C ₁ -C ₆ -n-alkyl or C ₃ -C ₈ -isoalkyl, C ₅ -C ₆ -cycloalkyl, unsubstituted or substituted benzyl and substituted or unsubstituted phenyl,

R ² = R ¹ , -OR ³ or -NHR ³ , and

R ³ = H, -C ₄ n-alkyl or C ₃ -C ₄ -lsoalkyl, and wherein

 the OH groups of the general formula (I) bonded to the two phosphorus atoms are each independently protonated (OH) or deprotonated (0), the liquid also optionally comprising an additive of the general formula (II):

R ¹⁰ -CHR ⁸ -CHR ⁹ -Z- (CHR ⁴ -CHR ⁵ -Z) _n -CHR ⁶ -CHR ⁷ -R ¹⁰ (II) wherein:

n = an integer from 1 to 1, in particular an integer from 1 to 3, Z = S or O, in particular S,

R ⁴ = H, C 1-4 -alkyl or phenyl,

R ⁵ = H, d-4-alkyl or phenyl,

R ^{6 is} H, C 1-4 -alkyl or phenyl,

R ⁷ = H, d-4-alkyl or phenyl,

R ⁸ = H, d-4-alkyl or phenyl,

R ⁹ = H, d_ ₄ alkyl or phenyl,

R ¹⁰ = OH, COOH or COOR ^{1 1} and

R ^{1 1} = alkyl, Li, Na, or K.

2. The liquid of claim 1, wherein the metal is selected from Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, Ti, Zr, Nb and mixtures thereof, optionally doped with Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof,

3. The liquid of claim 2, wherein the metal is selected from Cu, Sn, Sb or mixtures thereof, and is preferably Cu.

4. The liquid of claim 2, wherein the metal is selected from Fe, Ni, Co or mixtures thereof doped with Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof, preferably with Sm, Gd, Dy, Er or mixtures thereof.

5. The liquid according to any one of claims 1 to 4, wherein the additive in an amount of 0 to 1 wt .-%, preferably in an amount of 0.05 to 0.7 wt .-%, particularly preferably in an amount of 0, 1 of 0.5 wt .-%, based on the mass of the total solution, is included.

The fluid of any one of claims 1 to 5, wherein the fluid comprises an additive of formula (I I) wherein: n = an integer from 1 to 3,

 Z = S,

R ⁴ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁵ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁶ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁷ = H, methyl, ethyl, n-propyl, or n-butyl, R ⁸ = H, methyl, ethyl, n-propyl, or n-butyl,

R ⁹ = H, methyl, ethyl, n-propyl, or n-butyl,

R ¹⁰ = OH, COOH or COOR ¹¹ , and

R ¹¹ = K, methyl, ethyl or n-propyl.

The fluid of claim 6, wherein the additive is 1, 8-dihydroxy-3,6-dithiaoctane.

The fluid of claim 1, wherein the metal is Cu and the additive

1, 8-dihydroxy-3,6-dithiaoctane.

9. The liquid according to any one of claims 1 to 8, wherein the liquid in

Essentially free of sulfate, nitrate, halogenate and halide ions.

10. The liquid according to any one of claims 1 to 9, wherein the liquid in addition to the ligand of formula (I) contains no additional buffer.

1 1. Process for the electrolytic surface modification of a planar

Metal workpiece, in which

 at least one surface of the sheet metal workpiece in one

Treatment fluid is poled anodically and thereby anodic

Dissolution process is induced, and then

 the at least one surface of the sheet metal workpiece in one

Treatment fluid is poled cathodically and thereby a cathodic

Deposition process for depositing one or more metals on the at least one surface of the sheet metal workpiece is induced,

 characterized in that

 the treatment liquid is a liquid according to any one of claims 1 to 10.

12. The method of claim 1 1, wherein the sheet metal workpiece for inducing the dissolution process is anodically polarized by at least one cathode without direct contact, the flat metal workpiece for inducing the

Deposition process is cathodically polarized by at least one anode without direct contact, and the cathode and the anode are arranged so that between anode and metal workpiece and between the cathode and metal workpiece Treatment liquid is located.

13. The method according to any one of claims 1 1 and 12, wherein the treatment liquid in the anodic dissolution process and the treatment liquid in the cathodic deposition process are different treatment liquids and the

Treatment liquid in the anodic dissolution process and the

Treatment liquid in the cathodic deposition process by a non-conductive separating liquid, which has contact with the flat workpiece, are separated.

14. The method of claim 1, wherein by varying the mean current density of the deposit and varying the concentration ratio between dopant metal (s) and host metal (s) between 1: 5 and 150: 1 in the

Treated metal doped layers of host metals are deposited, wherein the host metals are selected from Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co and mixtures thereof, the doping metals are selected from Y, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Nb and mixtures thereof, and the

Doping metals in an amount ranging from 1 ppm to 20,000 ppm in the layer.

15. The method according to any one of claims 1 1 to 14, wherein ferromagnetic closed layers of the metals Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, Nb or mixtures thereof, with Y, Nd, Sm , Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof are deposited in a thickness of 10 nm to 1 μηι, which preferably has a greater layer thickness of the tipping between the in-plane and the out- of-plane orientation of the domains have as in vacuum technology

deposited, ferromagnetic, pure metal layers.

16. The method according to any one of claims 1 1 to 14 for the production of

corrosion-resistant iron and / or tin surfaces and of recrystallization-inhibited tin surfaces.

17. Sheet metal workpiece obtained by the method of any one of

Claims 1 1 to 16.

18, sheet metal workpiece according to claim 17, wherein the surface of the sheet metal workpiece has metal aggregates, preferably 90% or more, more preferably 95% or more, in particular 99% or more of the metal aggregates a size in the range of 0.05 to 1 μηι, preferably in the range of 0.3 to 0.7 μηι and in particular in the range between 0.35 and 0.65 μηι have.

19. A sheet metal workpiece according to claim 18, wherein the metal aggregates Cu, Zn, Mn, In, Sn, Sb, Bi, Fe, Ni, Co, Nb or mixtures thereof, and preferably one or more dopant (s) selected from Y, Nd , Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr and mixtures thereof, and preferably containing the doping metal (s) in an amount ranging from 1 ppm to 20,000 ppm Metal aggregate is present (available).

20. Use of the sheet metal workpiece according to any one of claims 17, 18 or 19 as a substrate for the formation of solid adhesive bonds with other materials.

21. Use according to claim 20, wherein the other materials are selected from thermoplastics, synthetic resins, adhesives, paints and pastes.