Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
  • C23C18/18—Pretreatment of the material to be coated
  • C23C18/20—Pretreatment of the material to be coated of organic surfaces, e.g. resins
  • C23C18/28—Sensitising or activating

Definitions

• 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 heat-treated or treated with washing baths before the metallization because of the high boiling points of the polyglycols, as a result of which part of the activator is lost.
• Another disadvantage of these systems is that they cannot be used in technically interesting solvents which 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 so that they no longer have a catalytic effect.
• DMF dimethylformamide
• DMSO dimethyl sulfoxide
• methyl ethyl ketone methyl ethyl ketone
• pentanedione 2,4
• the object of the present invention is now to develop activation systems which are readily soluble in aprotic solvents and have virtually unlimited storage stability on the basis of organometallic compounds of the elements of the 1st and 8th subgroups of the periodic table, which are also distinguished by their excellent stability to moisture, Characterize atmospheric oxygen, common solvent stabilizers and impurities and their activation properties remain almost unaffected by the solvents which can form complexes.
• organometallic compounds used are those with a "host / guest" interrelation.
• 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.
• 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).
• All host complex ligands which contain heteroatoms (0, 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.
• 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.
• Such compounds are described in DE-A 2 842 862 and EP-A 10 615 and correspond e.g. the formulas
• R alkyl or aryl; eg methyl, ethyl, phenyl, biphenyl, phenylazophenyl and others
• 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).
• Precious metal compounds to be used with preference are those of the formula H 2 PdC1 4 , Na 2 (PdCl 2 Br 2 ), Na 2 PdCl 4 , Ca PdCl 4 , Na 4 (PtCl 6 ), AgNO 3 , HAuCl 4 and CuCl.
• the Pd compounds are preferred.
• Suitable colloidal noble metal systems are derived primarily from the metals Pd, Pt, Au and Ag and are, for example, in "plastic electroplating” by R. Weiner, Eugen G. Leuze Verlag, Saulgau / Württ. (1973), pages 180-209.
• 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 z - ], in due to the potential gradient the desired solvent phase is also transported.
• This phenomenon is basically for the Systems listed in points 2), 3) and 4) are relevant.
• 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 C1 2 , petroleum ether or chloroform and adding the noble metal system according to the principle already mentioned.
• a suitable aprotic solvent with a boiling point at 80 ° C. such as perchlorethylene, 1,1,1-trichloroethane, CH 2 C1 2 , petroleum ether or chloroform
• the said noble metals are initially introduced in an aqueous phase and, in accordance with the principle mentioned, they are diffused or complexed into an organic phase which contains the complex-forming host molecules, and the organic phase is separated from the aqueous phase , optionally neutral washed, freed from the solvent by recrystallization or evaporation and then used in a desired liquid medium for the activation.
• the activators to be used according to the invention diffuse in microscopic cavities (free volumes) of common polymers, with the result that additional adhesion of the activation nuclei or electrolessly deposited metal coatings is achieved.
• free volume theory can be found in the review J. Crank “The Mathematics of Diffusion” Oxford University Press, London (1975).
• the activators can be used in concentration ranges from 0.001 g / 1 (based on the noble metal) up to the respective solubility limit. It is preferable to work with 0.1 to 3.0 g / 1 of these substances.
• 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 , -NR 3 , -S0 3 H and -CN).
• the said host molecules can additionally be provided with a further functional group.
• 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 halide are particularly suitable for chemical anchoring of the activator on the substrate surface groups, sulfonic acid ester, halogen-containing heterocyclic radicals, such as chlorotriazinyl, -pyrazinyl-, -pyrimidinyl- or chloroquinoxalinyl, activated double bonds, such as relatively long-chain at vinylsulfonate or acrylic acid derivatives, amino groups, hydroxyl groups, isocyanate groups, olefinic groups and acetylenic groups and Hercapto weakness and epoxide groups, further Alkyl or alkenyl radicals from C 8 , in particular oleic, l
• 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.
• activators with, for example, additional carbonyl or sulfone groups are particularly favorable for metallizing 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.
• the new activation process is generally carried out by wetting the substrate surfaces to be metallized with a solution of the selective metal complex in a suitable organic solvent, removing the solvent and, if appropriate, sensitizing it with a suitable reducing agent.
• the substrate pretreated in this way can then be metallized in a conventional metallization bath.
• Suitable solvents are, in addition to the above-mentioned perchlorethylene, 1,1,1-trichloroethane, CH 2 ci 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.
• organometallic compound contains ligands which allow 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, impregnation or impregnation.
• solvents or solvent mixtures are used which lead to dissolution or swelling of the plastic surface to be metallized, particularly preferably used to carry out the method according to the invention.
• the surface change caused by the "swelling adhesion nucleation" is noticeable by a change in the light separation, cloudiness, light permeability (in the case of transparent films and plates), change in layer thickness or in 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 e-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.
• 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 at intervals of 0.1 seconds to several minutes.
• a compensation recorder and called up from a clock generator at intervals of 0.1 seconds to several minutes.
• 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 mixtures thereof 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, as well as their mixtures or copolymers.
• aqueous Na 2 PdC1 4 solution (Pd content: 1.5% by weight) are mixed with 1 1 CH 2 C1 2 (technical), which additionally contains 2.5 g of 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 phase. 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 ⁇ 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 containing 30 g / 1 NiS0 4 .
• 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 contains, 5 minutes at RT activated at RT and dried. The plate is then made up in a bath
• 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.
• aqueous Li 2 PtCl 6 solution (Pt content: 1.6% by weight) are mixed with 1 l of petroleum ether (technical), which additionally contains 2.7 g of crown ether of the formula contains mixed at 30 ° C and stirred for 20 minutes. Then the aqueous phase is separated from the organic.
• 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 specimen thus activated is dried at RT, sensitized according to Example 2, and then nickel-plated according to Example 2. An electrically conductive metal pad is obtained.
• 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
• a 200 x 100 x 2 mm thick, injection-molded plate made of an acrylonitrile / butadiene / syrene polymer is placed in an activation bath which consists of consists, activated in the course of 5 minutes, air-dried and then consisting of in a sensitization bath
• the activator adheres to the surface of the substrate so firmly that, despite subsequent treatment in a commercially available, concentrated NaOH solution ( ⁇ 45%), it is not possible to remove grease residues and mold release agents from the injection molded part.
• the specimen activated in this way can then be provided with a well-adhering chemogalvanic metal coating according to Example 2.
• a 200 x 100 x 3 mm thick, injection-molded, commercially available polyamide 6 plate is placed in an activation bath, which consists of 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.
• 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.
• 0.1 mol H 2 PtCl 6 are mixed with 8 1 CH 2 CC1 2 (post-cleaned), which contains 0.2 mol 1,4,7,10,13,16-hexaoxacyclooctadecane, stirred at 40 ° C for 30 minutes, concentrated in vacuo to dryness 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 C1 2 it has an absorption maximum at 42. 1 0 3 cm 1 .
• 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-hexaoxacyclooctadecane and 0.01 mol HAuCl 4 and 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.
• the yellow compound listed above has an unsharp melting point of 123 ° C.
• 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. 103 cm -1 .

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• Chemical & Material Sciences (AREA)
• Metallurgy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemically Coating (AREA)
• Control Of El Displays (AREA)
• Glass Compositions (AREA)
• Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
• Heterocyclic Compounds That Contain Two Or More Ring Oxygen Atoms (AREA)

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• 1984
  • 1984-06-29 DE DE19843424065 patent/DE3424065A1/de not_active Withdrawn
• 1985
  • 1985-06-18 AT AT85107522T patent/ATE38253T1/de not_active IP Right Cessation
  • 1985-06-18 EP EP85107522A patent/EP0166360B1/fr not_active Expired
  • 1985-06-18 DE DE8585107522T patent/DE3565862D1/de not_active Expired
  • 1985-06-20 US US06/746,913 patent/US4661384A/en not_active Expired - Fee Related
  • 1985-06-25 JP JP60137086A patent/JPS6115984A/ja active Granted
  • 1985-06-27 CA CA000485480A patent/CA1248414A/fr not_active Expired
  • 1985-06-27 FI FI852553A patent/FI852553L/fi not_active Application Discontinuation

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