EP0166360B1 - Process for activating substrates for electroless plating - Google Patents

Abstract

Activation baths containing an organometallic compound based on elements of sub-group 1 or 8 of the periodic table with a "guest/host" interrelationship are outstandingly suitable for electroless metallization of preferably non-metallic substrates. Activators of palladium compounds and cyclic crown ethers are particularly suitable.

Description

It is known that solutions or dispersions of salts of the elements of group 1 B or 8 of the periodic table of the elements in polar organic solvents can be used for activation for the wet chemical metallization of non-metallic substrates (cf., for example, US Pat. No. 1,154,152 and DE -A 2 934 584).

• - ein vorheriges Beizen der zu metallisierenden Substratoberfläche erfordern,
• - nur für bestimmte Substrate, z.B. wie Acrylnitril-Butadien-Styrolcopolymerisate geeignet sind,
• - einen zusätzlichen Komplexierungs- bzw. Reduzierungsschritt erfordern,
• - nicht in schnell trocknenden aprotischen Lösemitteln durchführbar sind, da die Edelmetallsalze darin unlöslich sind.

The disadvantage of these methods is that they

• require prior pickling of the substrate surface to be metallized,
• are only suitable for certain substrates, such as acrylonitrile-butadiene-styrene copolymers,
• - require an additional complexation or reduction step,
• - cannot be carried out in fast-drying aprotic solvents, since the precious metal salts are insoluble in them.

It is also known that solutions of the dispersions of the Pd-O complexes of α, β-unsaturated ketones (cf. DE-A 2 451 217) or of the complexes of N-containing compounds (cf. DE-A 2 116 389 ) can be used to activate substrate surfaces. However, these processes also require an oxidative degradation treatment of the surfaces to be metallized, as a result of which their technical application is also restricted to certain substrates. In addition, they must also be post-treated with the aid of reducing agents or complexing agents so that they catalytically enable electroless metal deposition in the subsequent metallization step. In addition, the systems mentioned have the disadvantage that they are only sufficiently soluble in comparatively toxic aromatics and not in the commercially available solvents, such as 1,1-dichloroethane, trichlorethylene, ethanol and cyclohexane, and they show inadequate storage stability.

DE-A 2 934 584 also discloses water-containing activation baths which contain reaction products of noble metal-halogen complexes with polyglycol (ethers). These activation solutions have the disadvantage, among other things, that the substrates treated with them have to be annealed or treated with washing baths because of the high boiling points of the polyglycols, as a result of which part of the activator is lost.

Finally, elegant activation systems based on complex compounds of the elements of group 1B or 8 of the periodic table are known, which have an additional functional grouping to improve adhesion (cf. DE-A 3 148 280). With the help of functional groups matched to the respective substrate, different substrates such as glass, ceramics, polyester, polyamide and ABS plastics can be provided with an adhesive metal coating without prior pickling. However, these elegant activation systems also have the disadvantage that they are only limited under the conditions customary in the technology of plastic electroplating, in the best case they are stable in storage for a few months. This limited storage stability is only guaranteed if the activators are dissolved in specially cleaned solvents.

For this reason, technical solvents, which contain common impurities, stabilizers and foreign ions, have to be freed from these components at great expense, which additionally increases the process costs.

Another disadvantage of these systems is that they cannot be used in technically interesting solvents that are capable of forming complexes, such as dimethylformamide (DMF), dimethyl sulfoxide (DMSO), methyl ethyl ketone and pentanedione (2,4). They are stabilized in these media by additional complex formation in such a way that they no longer have a catalytic effect.

The object of the present invention is to develop activation systems based on organometallic compounds of the elements of groups 1 B and 8 of the periodic table that are readily soluble and have virtually unlimited storage stability for the pretreatment for the metallization of substrate surfaces, preferably in aprotic solvents are characterized by their excellent stability against moisture, atmospheric oxygen, common solvent stabilizers and impurities and their activation properties remain almost unaffected by the solvents which can form complexes.

This object is achieved according to the invention by the fact that those with a "We _t / guest" is used as the organometallic compounds -Wechselbeziehung.

Compounds consisting of selective complex ligands or host molecules and the guest ion or molecule to be complexed are generally known.

As selective complex ligands, cyclic or acyclic compounds come into question which, because of their chemical and / or physical nature, are a host molecule or, in the presence of ionogenic or neutral compounds to be complexed, assume the form required for complex or adduct formation, the polar regions being present in the presence of the to be directed towards the complexing medium.

As is known, the selectivity of the host molecule with respect to the guest ion or molecule to be complexed depends on its ring size, steric structure or chemical nature (whether polar or hydrophobic). There are numerous selective host molecules in the literature which are associated with the alkali or alkaline earth metal cations such as Li ⁺ , Na ⁺ , K ⁺ , Ca ²⁺ or NH ₄ ^* [cf. E. Weber, “Contacts” (Darmstadt) 1, (1984) and JG Schindler “Bioelectrochemical Membrane Electrodes” pp. 77-104, Walter de Gruyter Verlag, Berlin / New York (1983)] or with heavy metal ions such as Co ²⁺ , Ni2 ,, Fe ³⁺ , Cd2 and Ag as well as with anions such as CI- and S042- [cf. work cited above by JG Schindler, pp. 104-112] and with the neutral ligands or compounds can form a selective guest-host complex.

All host complex ligands which contain heteroatoms (O, N and S) in their chain are suitable for carrying out the novel process. Crown ethers, cryptands and podands or their derivatives and cyclic peptides are particularly suitable; furthermore, ester-linked macrolides containing tetrahydrofuran and analogous compounds based on heteroatoms such as S and N, which are known, for example, in biological systems as transport regulators.

A definition of the terms "Kronenether", "Cryptande" and "Podanden" can be found in the reviews F. Vögtle, "Contacts" (Darmstadt) (1977) and (1978), E. Weber, "Contacts" (Darmstadt) (1984) and Vögtle Chemikerzeitung 97, 600-610 (1973).

n = 0-4 R = Alkyl, Aryl oder Halogen

n = ₀-₄

n = ₀-₄ R' = Alkyl oder Aryl.Substituted or unsubstituted host ligands based on cyclic or acyclic crown ethers, which may additionally contain heteroatoms such as N and S in their ring system, are particularly preferably used to carry out the process according to the invention. Such compounds are described in DE-A 2 842 862 and EP-A 10 615 and correspond, for example, to the formulas

n = 0-4 R = alkyl, aryl or halogen

n = ₀ - _4.

n = ₀ - _4. R '= alkyl or aryl.

The cyclic compounds mentioned above are preferred.

Another variant of carrying out the process according to the invention is that the host molecules mentioned are covalently incorporated into polymeric or oligomeric compounds and then complexed with the desired activation media. Such oligomeric or polymeric systems are known and are described, for example, in “Novel Polyurethanes with Macroheterocyclic (Crown-Ether) Structures in the Polymer Backbone”, J.E. Herweh, J. of Polymer Science: Polymer Chemistry Edition, Vol. 21, 3101 (1983).

• 1) aus Verbindungen der Formel
  
  worin Me für Wasserstoff-, Alkali- oder Erdalkaliatome bzw. Schwermetallatome (Fe, Co, Ni oder Cu) oder für NH₄, Hal für Halogen (vorzugsweise Cl und Br) und E für ein Edelmetallatom der Gruppe 1 B oder 8 des Periodensystems, (vorzugsweise Pt, Pd und Au) mit der Wertigkeit m und der Koordinationszahl z steht, wobei z - m = n ist, oder
• 2) aus den Kationen, der besagten Elemente vorzugsweise Ag⁺, Cu²⁺ und Cu⁺ oder vorzugsweise
• 3) aus nichtkomplexen Salzen dieser Elemente der Formel
  
  oder
• 4) aus üblichen Kolloidal-Systemen dieser Edelmetalle gebildet.

The inorganic part of the host / guest molecules is preferred

• 1) from compounds of the formula
  
  wherein Me for hydrogen, alkali or alkaline earth metal atoms or heavy metal atoms (Fe, Co, Ni or Cu) or for NH ₄ , Hal for halogen (preferably Cl and Br) and E for a noble metal atom from group 1 B or 8 of the periodic table, (preferably Pt, Pd and Au) with the valency m and the coordination number z, where z - m = n, or
• 2) from the cations, said elements preferably Ag ⁺ , Cu ²⁺ and Cu ⁺ or preferably
• 3) from non-complex salts of these elements of the formula
  
  or
• 4) formed from conventional colloidal systems of these precious metals.

Precious metal compounds to be used with preference are those of the formula H ₂ PdCl ₄ , Na ₂ (PdCI ₂ Br ₂ ), Na ₂ PdC1 ₄ , Ca PdC1 ₄ , Na ₄ (PtCl ₆ ), AgN0 ₃ , HAuC1 ₄ , and CuCI. The Pd compounds are preferred.

Suitable colloidal noble metal systems are derived primarily from the metals Pd, Pt, Au and Ag and are described, for example, in “Plastic Galvanization” by R. Weiner, Eugen G. Leuze Verlag, Saulgau / Württ. (1973), pages 180-209 .

in die gewünschte Lösungsmittelphase mittransportiert wird. Dieses Phänomen ist grundsätzlich auch für die Systeme, die in Punkten 2), 3) und 4) aufgeführt werden, relevant.For the case specified in point 1), the electrically neutral ligand takes up the cation M ^{n +} in its endohydrophilic cavity at the phase boundary and transports it into the organic solvent phase, the part [E ^{m +} Hal

is transported into the desired solvent phase. In principle, this phenomenon is also relevant for the systems listed in points 2), 3) and 4).

The activation solution can be prepared by dissolving the host molecule in a suitable aprotic solvent with a boiling point at 80 ° C. such as perchlorethylene, 1,1,1-trichloroethane, CH ₂ Cl ₂ , petroleum ether or chloroform and adding the noble metal system according to the principle already mentioned.

Another possibility for the production of the activation systems according to the invention is that the said noble metals are placed in an aqueous phase and they are again prepared according to the above-mentioned principle zip into an organic phase which contains, diffuses or complexes the host molecules capable of forming complexes, separates the organic phase from the aqueous phase, optionally neutralwashes it, frees it from the solvent by recrystallization or evaporation and then uses it in a desired liquid medium for the activation.

Although such systems have an unlimited shelf life in protic and aprotic solvents under conditions customary in the art of plastic electroplating, they surprisingly have good activation properties for electroless chemical metallization.

Since they diffuse extremely well both in microporous or macroporous membrane matrices and in inorganic porous solids, they are outstandingly suitable both for metal doping and for activation for the subsequent continuous electroless metallization of such porous systems.

The activators to be used according to the invention diffuse in microscopic cavities (free volumes) of common polymers, with which additional adhesion of the activation nuclei or electrolessly deposited metal coatings is achieved. The exact definition of “free volume theory” can be found in the review by J. Crank “The Mathematics of Diffusion” Oxford University Press, London (1975).

The activators can be used in concentration ranges from 0.001 g / l (based on the noble metal) up to the respective solubility limit. It is preferred to work with 0.1 to 3.0 g / l of these substances.

Thanks to their high storage stability (no clouding of the solutions - sometimes after weeks of storage) and their strong sorption in the ultraviolet and / or visible spectral range, they are ideal for continuous concentration monitoring with a photometer.

Otherwise, the sorption properties of the complex compounds to be used according to the invention can be increased further by introducing special substituents (in particular NO ₂ , -N ⁺ R ₃ , SO ₃ H and -CN).

The influence of electron-withdrawing or electron-donating substituents on the light absorption properties of carbon molecules is known and can be seen, for example, from D.H. Williams and J. Flemming "Spectroscopic methods in organic chemistry", Georg Thieme Verlag Stuttgart (1971).

To increase the pull-off strength of the activator or metal layer, the said host molecules can additionally be provided with a further functional group.

In certain cases a very good adhesive strength of the substrate surface is achieved with the further functional group, this adhesive strength being due to a chemical reaction with the substrate surface or to an adsorption or absorption.

Functional groups such as carboxylic acid groups, carboxylic acid halide groups, carboxylic acid anhydride groups, carbonic ester groups, carbonamide and carbonimide groups, aldehyde and ketone groups, ether groups, sulfonamide groups, sulfonic acid groups and sulfonate groups, sulfonic acid halideyl groups, halogenated acid groups, halogenated acid groups, halogenated acid groups, sulfonated acid groups, as chlorotriazinyl, -pyrazinyl-, -pyrimidinyl- or chloroquinoxalinyl, activated double bonds, further higher chain as vinylsulfonate or acrylic acid derivatives, amino groups, hydroxyl groups, isocyanate groups, olefinic groups and acetylenic groups and mercapto groups and epoxy groups, alkyl or alkenyl groups from C _s, in particular Olein, linoleic, stearin or palmiting groups.

If there is no anchoring by a chemical reaction, the adhesive strength can also be brought about by absorption of the organometallic activators on the substrate surface, the causes of the absorption being e.g. Hydrogen bonds or Waals forces.

It is expedient to match the functional groups which cause adsorption to the particular substrate. For example, long chain alkyl or alkenyl groups in the activator molecule the adhesive kit on substrates made of polyethylene or polypropylene. In contrast, activators with, for example, additional carbonyl or sulfone groups are particularly favorable for the metallization of objects based on polyamide or polyester.

Functional groups such as carboxylic acid groups and carboxylic acid anhydride groups are particularly suitable for anchoring the activator to the substrate surface by adsorption.

This is generally how the new activation procedure is carried out. that the substrate surfaces to be metallized are wetted with a solution of the selective metal complex in a suitable organic solvent, the solvent is removed and, if necessary, is sensitized with a suitable reducing agent. The substrate pretreated in this way is then metallized in a conventional metallization bath.

Suitable solvents are, in addition to the above-mentioned perchlorethylene, 1,1,1 trichloroethane. CH ₂ C1 ₂ , n-hexane, petroleum ether, cyclohexanone. Alcohols such as n-butanol, isopropanol, tert-butanol, ketones such as methyl ethyl ketone, aldehydes such as n-butanal-1, DMF and DMSO.

If the organometallic compound contains ligands that enable chemical fixation on the substrate surface, activation from the aqueous phase may also be possible.

Suitable reducing agents for sensitization are aminoboranes, alkali hypophosphites, alkali borohydrides, hydrazine hydrate and formalin. The substrates can be wetted by spraying. Printing, watering or impregnation.

In order to increase the adhesion of the metal coating to the carrier surface, those solvents or solvent mixtures which lead to dissolution or swelling of the plastic surface to be metallized are used to carry out the inventions method according to the invention used particularly preferably.

Through the action of the activator systems with their characteristic source effect on the substrates, a kind of «adhesion nucleation» is achieved, which can perhaps be imagined in such a way that there are gaps accessible to the activation nuclei on the substrate surface, to which the metals deposited during electroless metallization are anchored ,

The surface change caused by the "swelling adhesion nucleation" is noticeable through a change in light separation, cloudiness, light transmission (with transparent films and plates), change in layer thickness or with scanning electron microscope images in the form of cracks, caverns or vacuoles.

The swelling agent suitable for the particular polymer substrate to be metallized must be determined from case to case by means of appropriate preliminary tests. A swelling agent behaves optimally if it swells the surfaces of the substrates within reasonable times without completely dissolving the substrate or even negatively influencing its mechanical properties such as notch impact strength and without changing the organometallic activators.

Suitable swelling agents are the so-called o-solvents or their blends with precipitants, as described, for example, in the “Polymer Handbook” J. Brandrup et al, New York, IV, 157-175, (1974).

The solvents are removed from the wetted substrates simply by evaporation or, in the case of higher-boiling compounds, by extraction.

According to a preferred method variant, the activation baths are monitored with a photometer as a detector. The wavelength of the filter should correspond to the absorption maximum of the solution. The measurement signal is recorded with a compensation recorder and called up from a clock generator every 0.1 seconds to several minutes. With the help of a computer, the missing components (solvent, activator) can be added.

A very particularly preferred embodiment of the method according to the invention consists in that the reduction in the metallization bath is carried out immediately with the reducing agent of the electroless metallization. This embodiment is particularly suitable for nickel baths containing amine borane or copper baths or silver baths containing formalin.

The metallization baths which can be used in the processes according to the invention are preferably baths with Ni, Co, Cu, Au, Ag salts or their mixtures with one another or with iron salts. Such baths are known in the art of electroless metallization of plastics.

Suitable substrates for the process according to the invention are: steels, titanium, glass, aluminum, textiles and fabrics based on natural and / or synthetic polymers, ceramics, carbon, paper, thermoplastics such as polyamide types, ABS (acrylonitrile butadiene styrene) polymers, polycarbonates, Polypropylene, polyester, polyethylene, polyhydantoin, thermosets such as epoxy resins, melamine resins, and their mixtures or copolymers.

• - Die eingesetzten Verbindungen zur Aktivierung von Substratoberflächen dürfen nicht zu einer irreversiblen Zerstörung des Metallisierungsbades führen.
• - Die lichtabsorbtionsfähigen Substituenten dürfen nicht eine Fixierung der Aktivatoren an die Substratoberfläche verhindern.
• - Die lichtabsorptionsfähigen Substituenten dürfen nicht eine Komplexierung des Trägermoleküls mit den Elementen der Gruppe 1B und 8 verhindern.
• - Die besagten Elemente dürften mit Wirtsliganden keine so starke Wechselwirkung eingehen, dass sie eine Katalyse zur chemischen Metallabscheidung verhindern.
• - Die verwendeten Lösungsmittel dürfen nicht im Absorptionsbereich des Aktivators Eigenabsorption aufweisen, müssen leicht entfernbarsein und dürfen nicht zu einem chemischen Abbau der metallorganischen Verbindung sowie zum völligen Auflösen der Substrate führen.
• - Um eine ausreichende Aktivierung zu erzielen, soll die Aktivierungszeit von einigen Sekunden bis zu einigen Minuten betragen.

Without restricting the scope of the method according to the invention, it is advisable to observe the following parameters when carrying out the method:

• - The connections used to activate substrate surfaces must not lead to irreversible destruction of the metallization bath.
• - The light-absorbing substituents must not prevent the activators from being fixed to the substrate surface.
• - The light-absorbing substituents must not prevent complexation of the carrier molecule with the elements of groups 1B and 8.
• - The said elements should not interact with host ligands so strongly that they prevent catalysis for chemical metal deposition.
• - The solvents used must not have self-absorption in the absorption area of the activator, must be easily removable and must not lead to chemical degradation of the organometallic compound or complete dissolution of the substrates.
• - To achieve sufficient activation, the activation time should be from a few seconds to a few minutes.

example 1

17.5 g aqueous Na ₂ PdCl ₄ solution (Pd content: 1.5% by weight) are mixed with 1 I CH ₂ C1 ₂ (technical), which additionally contains 2.5 g 1,4,7 Contains 10,13-pentaoxycylododecane, added at RT (room temperature). The mixture is stirred for 10 minutes before the aqueous phase is separated from the organic. You get a red-brown homogeneous activator solution. This solution is used to treat a plastic plate made of commercially available polyester with the dimensions 15 x 10 cm and 3 mm thick for 3 minutes. The substrate activated in this way is dried and then in an electroless nickel plating bath which contains 30 g / l NiSO ₄ -5H ₂ 0.15 g / l dimethylamine borane 2n solution, 11.5 g / l citric acid and 3.0 g / l boric acid and adjusted to pH 7.9 with ammonia, metallized. After 20 minutes, a uniform, shiny metallic nickel coating with an electrical conductivity is deposited on the substrate surface.

Comparative example

17.5 g of aqueous Na ₂ PdCl ₄ solution (Pd content: 1.5% by weight) are mixed with 1 1 CH ₂ CI ₂ (technically) and stirred for 120 minutes (no reaction!). The sodium tetrachloropalladinite remains in the aqueous phase. The colorless organic phase is tested according to Example 1, for its activity, for wet chemical metallization. Despite 120 minutes of treatment in the chemical metal Ni bath cannot be deposited on the substrate surface.

Example 2

A 90 x 150 mm, 3 mm thick glass fiber reinforced (30 wt .-%) plastic plate made of polyamide-6 is in an activation bath, which

1,500 ml CH ₂ Cl ₂

2.5 g 1,4,7,10,13-pentaoxycyclododecane sodium tetrachloropalladinite

5 Minuten bei RT sensibilisiert, mit destilliertem Wasser gespült und dann in einem herkömmlichen hypophosphithaltigen Vernickelungsbad der Fa. Blasberg AG, Solingen, bei 30°C 25 Minuten vernickelt. Die Haftfestigkeit der Metallauflage, bestimmt durch die Abzugskraft nach DIN 53 494, beträgt 40 N/25 mm. Die galvanische Verstärkung von der o.a. Polyamid-Platte für die Bestimmung der Abzugskraft wurde wie folgt durchgeführt:

• a) eine halbe Minuten dekapieren in 10%iger H₂SO₄
• b) Spülen
• c) 5 Minuten im Halbglanznickelbad, Spannung 9 Volt, Badtemperatur 60°C
• d) Spülen
• e) eine halbe Minute dekapieren
• f) 90 Minuten im Kupferbad; Spannung 1,9 Volt, Badtemperatur 28°C
• g) Spülen.

contains, 5 minutes at RT activated at RT and dried. Then the plate in a bath consisting of

Sensitized for 5 minutes at RT, rinsed with distilled water and then nickel-plated in a conventional hypophosphite-containing nickel plating bath from Blasberg AG, Solingen, at 30 ° C. for 25 minutes. The adhesive strength of the metal pad, determined by the peel force according to DIN 53 494, is 40 N / 25 mm. The galvanic reinforcement of the above polyamide plate for the determination of the pull-off force was carried out as follows:

• a) Pick up half a minute in 10% H ₂ SO ₄
• b) rinsing
• c) 5 minutes in a semi-gloss nickel bath, voltage 9 volts, bath temperature 60 ° C
• d) rinse
• e) Pick up half a minute
• f) 90 minutes in a copper bath; Voltage 1.9 volts, bath temperature 28 ° C
• g) rinse.

The preparation of 1,4,7,10,13-pentaoxycyclododecane sodium tetrachloropalladinite

0.3 mol Na ₂ PdC1 ₄ in 1 IH ₂ O _dest . are mixed with 5 1 CH ₂ CI ₂ , which contains 0.9 mol 1,4,7,10,13-pentaoxycyclodecane at 40 ° C, stirred for 1.5 hours and then cooled. The organic phase is separated from the aqueous. After filtering, the solvent is removed from the organometallic compound in vacuo. The new compound is then recrystallized from toluene and CH ₂ Cl ₂ (1: 1% by volume). A red-brown crystalline compound with a decomposition point of - 225 ° C. is obtained. In CH ₂ Cl _{2 it has} an absorption maximum at 21 · 10 ³ cm ^-1 in the UV range.

Example 3

A 20 x 100 x 2 mm thick commercially available glass mat-reinforced epoxy resin plate is activated according to Example 1, sensitized according to Example 2 and then copper-coated for 20 minutes in a commercially available copper plating bath. A continuously copper-plated plastic plate is obtained.

Example 4

15 g of aqueous Li ₂ PtCl ₆ solution (Pt content: 1.6% by weight) are mixed with 11 petroleum ether (technical), which additionally contains 2.7 g of crown ether of the formula

enthält bei 30°C versetzt und 20 Minuten nachgerührt. Dann wird die wässrige Phase von der organischen abgetrennt.

contains mixed at 30 ° C and stirred for 20 minutes. Then the aqueous phase is separated from the organic one.

A dark-colored homogeneous activation solution is obtained. With this solution, an ABS plate with the dimensions 100 x 100 x 2 mm is treated for 5 minutes. The test specimen activated in this way is dried at RT, sensitized according to Example 2, and then nickel-plated according to Example 2. An electrically conductive metal pad is obtained.

Example 5

1 I CH₂C1₂ und 1,0 g salzsaurer KAuCl₄-Lösung (Au-Gehalt: 20 Gew.-%) durch 20 minütiges Rühren angesetzt wird, getaucht und danach in einem handelsüblichen Vernickelungsbad der Fa. Shipley AG, Stuttgart, stromlos vernickelt. Nach wenigen Sekunden beginnt sich die Oberfläche metallisch glänzend zu färben. Nach 20 Minuten haben sich - 20 g Me- tall/m² abgeschieden.A 10 x 10 cm square of a knitted fabric made of a polyester-cotton blend is at RT for 20 seconds in an activation bath, which consists of 2.9 g of crown ether of the formula

1 I CH ₂ C1 ₂ and 1.0 g of hydrochloric acid KAuCl ₄ solution (Au content: 20% by weight) are prepared by stirring for 20 minutes, immersed and then de-energized in a commercially available nickel plating bath from Shipley AG, Stuttgart nickel plated. After a few seconds, the surface begins to turn shiny metallic. After 20 minutes, - 20 g of metal / m ^{2 were} deposited.

Example 6

A 200 x 100 x 2 mm thick, injection-molded plate made of an acrylonitrile / butadiene / styrene polymer is placed in an activation bath which consists of

besteht, im Verlaufe von 5 Minuten haftaktiviert, an der Luft getrocknet und dann in einem Sensibilisierungsbad bestehend aus

consists, activated in the course of 5 minutes, air-dried and then consisting of in a sensitization bath

Treated for 5 minutes.

The activator adheres to the surface of the substrate so firmly that it cannot be removed from the injection molded part from grease residues and mold release agents despite subsequent treatment in a commercially available, concentrated NaOH solution (- 45%).

The specimen activated in this way can then be provided with a well-adhering chemogalvanic metal coating according to Example 2.

Preparation of 1,4,7,10,13,16-hexaoxacyclooctadecane sodium tetrachloropalladinite

0.1 mol of Na ₂ PdCl ₄ (anhydrous) are mixed with 5 l of pure CH ₂ Cl ₂ , which contains 0.2 mol of 1,4,7,10,13,16-hexaoxacyclooctadecane, and the mixture is subsequently stirred at the boiling temperature for 30 minutes and filtered off and then cooled. The solvent is removed from the organometallic compound under vacuum. The new compound is then recrystallized from purified 1,1,1-trichloroethane. A red-brown crystalline compound with a melting point of 223 ° C. is obtained. Your solution in CH ₂ Cl ₂ has an absorption maximum at 22 · 10 ³ cm ^-1 in the UV range.

Example 7

A 200 x 100 x 3 mm thick, injection-molded, commercially available polyamide 6 plate is placed in an activation bath, which consists of

besteht, 5 Minuten aktiviert, nach Beispiel 2 sensibilisiert und dann nach Beispiel 2 auf dem chemischen Wege vernickelt bzw. galvanisch verstärkt. Man bekommt einen Polymer-Metall-Verbundwerkstoff mit guter Metallhaftung.

exists, activated for 5 minutes, sensitized according to Example 2 and then nickel-plated or galvanically amplified according to Example 2. You get a polymer-metal composite with good metal adhesion.

Preparation of 1,4,7,10,13,16-hexaoxacyclooctadecane-hexachloroplatinic acid

0.1 mol H ₂ PtCl ₆ are mixed with 8 l CH ₂ Cl ₂ (post-cleaned), which contains 2 mol 1,4,7,10,13,16-hexaoxacyclooctadecane, stirred at 40 ° C for 30 minutes, filtered off and then the solvent is removed from the organometallic compound under vacuum. The new compound of CH ₂ CI ₂ and CCI ₂ = CCI ₂ (1: 1% by volume) is then recrystallized. An orange-yellow compound with a decomposition point of 133 ° C. is obtained. In CH ₂ Cl ₂ it has an absorption maximum at 37 · 10 ³ cm ^-1 in the UV range.

Example 8

besteht, 5 Minuten aktiviert, nach Beispiel 2 sensibilisiert und dann nach Beispiel 2 auf dem chemischen Wege vernickelt bzw. galvanisch verstärkt. Man erhält einen Polymer-Metall-Verbundwerkstoff mit guter Metallhaftung.A 200 x 100 x 3 mm thick polyamide-6,6 plate is placed in an activation bath

exists, activated for 5 minutes, sensitized according to Example 2 and then nickel-plated or galvanically amplified according to Example 2. A polymer-metal composite material with good metal adhesion is obtained.

Preparation of 1,4,7,10,13-pentaoxocyclododecane hexachloroplatinic acid

0.1 mol of H ₂ PtCl ₆ are mixed with 8 l of CH ₂ -CCl ₂ (post-cleaned), which contains 0.2 mol of 1,4,7,10,13,16-hexaoxacyclooctadecane, and the mixture is stirred at 40 ° C. for 30 minutes , concentrated to dryness in vacuo and then recrystallized from CH ₂ C1 ₂ and toluene (1: 0.25% by volume). An orange compound with a decomposition point of 163 ° C. is obtained. In CH ₂ Cl _{2 it has} an absorption maximum at 42 · 10 ³ cm ^-1 .

Example 9

A 10 x 10 cm knitted fabric made of a polyester-cotton blend is placed at RT for 60 seconds in an activation bath which consists of 0.01 mol guest-host molecule based on 0.01 mol 1,4, 7,10,13 , 16-Hexaoxacyclooctadecan and 0.01 mol HAuCl ₄ and has an absorption maximum at 31 · 10 ³ cm ^-1 in the UV range, dipped and then nickel-plated according to Example 5. After a few minutes, the surface begins to turn shiny metallic. After 18 to 20 minutes, 20 g of metal / m ^{2 have} deposited. The yellow compound listed above has an unsharp melting point of 123 ° C.

Example 10

A 10 cm x 10 cm knitted fabric from a cotton fabric is at RT for 45 seconds in an activation bath, which consists of a guest / host molecule based on 0.005 mol 1,4,7,10,13-pentaoxacyclododecane and 0.005 mol HAuCl ₄ in CH ₃ CC1 ₃ consists, activated, dried and then copper-plated in a commercially available copper plating bath. In the course of approx. 15 minutes, a shiny, well-adhering and electrically conductive copper layer is deposited on the sample surface.

The complex compound used has an unsharp melting point at 97 ° C and a UV absorption maximum at 51 · 10 ³ cm ^-1 .

Claims (8)

1. Process for the electroless wet chemical metallisation of substrate surfaces, these being activated before metallisation with the aid of solutions of organometallic compounds based on elements from group 1 B or 8 of the periodic system in, preferably, aprotic solvents, characterised in that the organometallic compounds used are those with a «host/guest» interrelationship. 2. Process according to Claim 1, characterised in that the host molecules which are capable of complex formation in the organometallic compounds are crown ethers, cryptands or podands.

3. Process according to Claim 1, characterised in that the selective complex ligand or the host molecule in the organometallic compound is a cyclic compound which, in the presence of the medium to be complexed, assumes the structure required for complex formation or host/guest interaction.

4. Process according to Claim 1, characterised in that the host molecules contain cyclic crown ethers of the formulae

wherein n = 0-4 R = alkyl, aryl or halogen

wherein
n = 0-4

wherein n = ₀-₄ R' = alkyl or aryl.

5. Process according to Claim 1, characterised in that the selective complex ligand and the host molecule in the organometallic compounds have a pure hydrocarbon structure.

6. Process according to Claim 1, characterised in that the host molecules of the organometallic compounds contain additional functional groups.

7. Process according to Claim 1, characterised in that the medium to be complexed in the host/guest molecules is a compound of the formula

wherein Me represents hydrogen, alkali metal, alkaline earth metal or heavy metal atoms or represents NH₄, Hal represents halogen and E represents a noble metal atom of the groups 1 B and 8 of the periodic system with the valency m and the coordination number z, wherein z - m = n.

8. Process according to Claim 1, characterised in that the guest molecule to be complexed is a compound from the series H₂PdCI₄, Na₂(PdCI₂Br₂), Na₂PdCI₄, Ca PdC1₄, Na₄ (PtCl₆), AgN0₃ and CuCI.