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

• polymeric materials must be pretreated before chemical and subsequent electroplating, e.g. by etching the polymer surface with polluting chrome sulfuric acids.
• EP-A 0 361 754 Pd-containing primers are proposed which require the additional use of chromosulfuric acid.
• the object of the present invention was therefore to develop an economical, universally applicable process for chemical metallization, with which material surfaces based on glasses, metals and in particular plastics can be provided with a well-adhering, wet-chemically deposited metal coating without prior etching with oxidants.
• substrate surfaces are coated with a special primer based on a polymeric organic film or matrix former which additionally contains an additive.
• the coating systems to be used at room temperature such as, for example, alkyd resins, unsaturated polyester resins, polyurethane resins, epoxy resins, modified fats and oils, polymers or copolymers based on vinyl chloride, vinyl ethers, vinyl esters, styrene, acrylic acid, acrylonitrile or Acrylic esters, cellulose derivatives, or the stoving enamels that crosslink at higher temperatures, such as polyurethanes made of hydroxyl-containing polyethers, polyesters or polyacrylates and capped polyisocyanates, Melamine resins from etherified melamine-formaldehyde resins and hydroxyl group-containing polyethers, polyesters or polyacrylates, epoxy resins from polyepoxides and polycarboxylic acids, carboxyl group-containing polyacrylates and carboxyl group-containing polyesters, stoving lacquers made from polyester, polyesterimides, polyesteramideimides, polyamideimides, polyamides, polyhydan
• auxiliaries and additives which may also be used, are described, for example, in DE-A 2 732 292, pages 21-24.
• the amount of film or matrix former used can be varied widely. As a rule, 3 to 30% by weight, preferably 4 to 20% by weight (based on the total formulation) are used.
• Additives b.) are organic and / or organometallic polymeric or prepolymeric compounds with a molecular weight of 100-1,000,000, preferably 500-20,000 with a total surface tension in the range of 45-65 mN / m, preferably 45-60 mN / m , particularly preferably 50-60 mN / m. Their amount can be varied widely between 0.1 and 15% by weight, based on the formulation, with 0.3-5% by weight being particularly preferred.
• polymers based on oxazolines such as polyethyloxazoline, which is produced, for example, by cationic polymerization from methyl tosylate and methyloxazoline, are suitable.
• Polymethyl, polypropyl and polybutyl oxazoline are also extremely suitable. Their amount can be varied widely between 0.1 and 15% by weight, based on the formulation, 0.3-5% by weight being particularly preferred.
• Examples include oligomeric polymethacrylic acid or its esters such as butyl, ethyl and methyl esters, polyamides based on adipic acid and hexamethylene diamine, polyethylene amines, amides, polyester types based on adipic acid, phthalic acid, butanediol, trimethylolpropane and polyacrylates such as polyethyl and polybutyl acrylate, polyalcohols such as polyvinyl alcohol or mixtures thereof. Polyester types and aliphatic polyamide types with a viscosity range of 10,000-35,000 cP at 20 ° C with a hydroxyl content of 5.5-0.15% or their isocyanate-modified derivatives are also suitable. Polyamines based on, for example, ethylene, propylene and butylene diamine are also suitable.
• organometallic compounds of the 1st or 8th subgroups of the periodic table in particular Pd, Pt, Au and Ag
• Organometallic compounds of palladium with olefins (dienes), with ⁇ , ⁇ -unsaturated carbonyl compounds, with crown ethers, with nitriles and with diketones such as pentadione-2,4 are particularly suitable.
• Butadiene palladium dichloride bisacetonitrile palladium dichloride, bisbenzonitrile palladium dichloride, 4-cyclohexene-1,2-dicarboxylic acid anhydride palladium dichloride, mesityl oxide palladium chloride, 3-heptene-2-one-palladium chloride, 5-methyl-3-hexadione chloride, 5-methyl-3-hexadiene chloride 4-palladium.
• O-valent complex compounds such as palladium (O) tetrakis (triphenylphosphine) are also suitable.
• Suitable ionic noble metals are salts such as halides, acetates, nitrates, carbonates, sulfates, sulfides and hydroxides, such as PdS, Na2PdCl4, Na2PdCN4, H2PtCl6, AgNO3, Ag2SO4, Ag2S.
• the amount of the noble metal can be varied widely in the range from 0.05 to 2.5% by weight, based on the overall formulation.
• the preferred amount of noble metal is 0.1-1.0% by weight.
• Suitable fillers d.) Are oxides of the elements Mn, Ti, Mg, Al, Bi, Cu, Ni, Sn, Zn and Si, as well as silicates, bentonites, talc and chalk. However, preference is given to using inorganic or organic fillers whose resistance is preferably between 0.01-10 ⁇ / cm.
• the particularly preferred filler is conductive carbon black. Mixtures of such inorganic or organic fillers are further preferred.
• the amount of the filler can be varied widely in the range from 0.5-35, but preferably 3-20, particularly preferably 5-15% by weight, based on the primer composition.
• Suitable solvents e.) In the primers according to the invention are substances known in printing or coating technology, such as aromatic and aliphatic hydrocarbons, for example toluene, xylene, gasoline, glycerol; Ketones, for example methyl ethyl ketone, cyclohexanone; Esters, for example butyl acetate, dioctyl phthalate, butyl glycolate; Glycol ethers, for example ethylene glycol monomethyl ether, diglyme, propylene glycol monomethyl ether; Esters of glycol ethers, for example ethylene glycol acetate, propylene glycol monomethyl ether acetate; Diacetone alcohol. Mixtures of these solvents and their blends with other solvents can of course also be used. The amounts used are 50-90% by weight, preferably 60-85% by weight.
• the primer according to the invention is generally prepared by mixing the constituents.
• the components can also be incorporated in separate steps.
• the primer can be applied to the plastic surfaces using the usual methods such as printing, stamping, dipping, brushing, knife coating and spraying.
• the layer thickness of the primer can be varied in the range of 0.1-200 ⁇ m, but preferably in the range of 5-30 ⁇ m.
• primers according to the invention does not require swelling adhesive treatment of the plastic. This prevents stress cracks from forming.
• Suitable substrates for the method according to the invention are workpieces based on inorganic glasses, metals and in particular plastics.
• Plastics such as those used in the electrical, electronics and household sectors are particularly preferred.
• ABS, PC (polycarbonate) or their mixtures and flame-retardant types such as Bayblend® FR-90, 1441, 1439 and 1448, polyamide, polyester types, PVC, polyethylene and polypropylene should be mentioned.
• Flameproofing of plastics is known.
• polybrominated bisphenols and halogenated benzylphosphonates are used.
• the surfaces modified in this way can then be sensitized by reduction.
• the reducing agents customary in electroplating such as hydrazine hydrate, formaldehyde, hypophosphite or boranes, can preferably be used for this purpose. Of course, other reducing agents are also possible.
• the reduction is preferably carried out in aqueous solution. However, other solvents such as alcohols, ethers, hydrocarbons can also be used. Of course, suspensions or slurries of the reducing agents can also be used.
• the surfaces activated in this way can be used directly for electroless metallization. However, it may also be necessary to clean the surfaces by rinsing off residual reducing agents.
• 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 version represents a simplification of the electroless metallization.
• This very simple embodiment only consists of the three work steps: immersing the substrate in the solution of the organic compound or applying or spraying on the primer, evaporating the solvent and immersing the surfaces activated in this way Metallization bath (reduction and metallization).
• This embodiment is particularly suitable for nickel baths containing amine borane or copper baths containing formalin.
• Metallization baths which can be used in the process according to the invention are preferably baths with nickel salts, cobalt salts, copper salts, gold and silver salts or mixtures thereof with one another or with iron salts. Such metallization baths are known in the electroless metallization art.
• the process according to the invention has the advantage that, even without previous oxidative etching and / or swelling or treatment with solvents widening the polymer chain of the substrate surface, an adherent metal deposition is made possible by the subsequent selective electroless metallization only with the aid of the primer surface.
• the new process thus enables material-saving and environmentally friendly, inexpensive, both full-surface and partial metal deposition on material surfaces.
• Materials metallized according to the new process are characterized by their excellent shielding against electromagnetic waves. These materials are used in the electrical, automotive, electronics and household sectors.
• the good mechanical properties of the polymeric base material are not adversely affected by the painting or metallization process.
• a 100 x 100 mm test plate made from a blend consisting of 60% of a polyester made of 4,4'-dihydroxydiphenyl-2,2-propane and carbonic acid and 40% acrylonitrile-butadiene-styrene copolymer with a Vicat temperature of approx. 90 ° C , was provided on one side with a 10 ⁇ m thick primer and dried at 80 ° C. in the course of 45 minutes.
• the primer consisted of 53.7 Parts by weight of polyurethane resin, 198 Parts by weight of solvent mixture consisting of toluene, diacetone alcohol and isopropanol (1: 1: 1); 14.7 Parts by weight of titanium dioxide; 5.4 Parts by weight of talc; 5.4 Parts by weight of chalk; 7.2 Parts by weight of carbon black; 20% in butyl acetate; 6.6 Parts by weight of polyester with 4.3% OH groups with a surface tension> 45 mN / m, 20% solution in MEK (methyl ethyl ketone) and DAA (diacetone alcohol) (1: 1); 9 Parts by weight of suspended silicate, 10% digestion in xylene and 0.35 Parts by weight of bisbenzonitrile palladium II dichloride.
• test plate was then treated in a reduction bath consisting of 10 g of dimethylamine borane and 1.0 g of NaOH in 1 liter of water at 30 ° C. and then at Room temperature copper-plated in a chemical copper bath for 30 minutes, washed with distilled water and then annealed at 80 ° C for 30 minutes. A 1.5 ⁇ m thick copper layer was formed.
• the metal coating also had a peel strength according to DIN 53 494 of 25 N / 25 mm.
• a polyphenylene oxide / polystyrene plate was made up with a primer 53.7 parts by weight Polyurethane resin 200 parts by weight Solvent mixture consisting of toluene, diacetone alcohol and isopropanol (1: 1: 1) 15 parts by weight Titanium dioxide 6 parts by weight talc 8 parts by weight Carbon black, 20% in butyl acetate 7 parts by weight Poly-2-ethyl-2-oxazoline, 20% solution in MEK 8 parts by weight Silica-based suspension agent, 10% digestion in xylene, 0.5 parts by weight 3-hexen-2-one palladium chloride, provided on one side and dried at 80 ° C for 45 minutes.
• Solvent mixture consisting of toluene, diacetone alcohol and isopropanol (1: 1: 1) 15 parts by weight Titanium dioxide 6 parts by weight talc 8 parts by weight Carbon black, 20% in butyl acetate 7 parts by weight Poly-2-ethyl-2-oxazoline, 20% solution in MEK 8 parts by weight
• the plate coated in this way was provided with a 2 ⁇ m thick copper layer in a chemical copper plating bath over the course of 45 minutes.
• This plate was well shielded from electromagnetic waves.
• a 100 x 100 mm ABS plate was made with a primer consisting of 50 parts by weight of a polyol component. 88.76 parts by weight a polyester polyol of molecular weight 2000 made from adipic acid, ethylene glycol and 1,4-dihydroxybutane (molar ratio of the diols 70:30) 8.0 parts by weight Ethylene glycol 0.5 parts by weight water 0.5 parts by weight Triethylenediamine 0.55 parts by weight a commercially available polysiloxane stabilizer 1.25 parts by weight Na2PdCl4 and 1.0 part by weight Tetrabutylammonium chloride, and 50 parts by weight of a polyisocyanate component 90.0 parts by weight an NCO prepolymer of 65.0 parts by weight of 4,4'-diisocyanate diphenylmethane and 38.0 parts by weight of the polyester polyol used in the polyol component 250.0 parts by weight Solvent mixture consisting of toluene, diacetone alcohol and isopropan
• a 100 x 150 mm test plate made of a polycarbonate was provided with an approximately 15 ⁇ m thick primer layer and dried at 65 ° C. in the course of 30 minutes.
• test plate was copper plated in a chemical copper plating bath over 30 minutes, washed with water and then dried at room temperature.
• a 2 ⁇ m thick copper layer had formed, which had a peel strength according to DIN 53 494 of 15 N / 25 mm.
• This metallized plate had excellent shielding against electromagnetic waves.

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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)
• Paints Or Removers (AREA)
• Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)
• Chemically Coating (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Laminated Bodies (AREA)
• Details Of Measuring And Other Instruments (AREA)
• Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)

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• 1990
  • 1990-11-16 DE DE4036591A patent/DE4036591A1/de not_active Withdrawn
• 1991
  • 1991-11-04 DE DE59104146T patent/DE59104146D1/de not_active Expired - Fee Related
  • 1991-11-04 EP EP91118731A patent/EP0485839B1/fr not_active Expired - Lifetime
  • 1991-11-07 US US07/788,957 patent/US5378268A/en not_active Expired - Lifetime
  • 1991-11-12 JP JP3322376A patent/JPH04365872A/ja active Pending
  • 1991-11-13 CA CA002055352A patent/CA2055352C/fr not_active Expired - Fee Related

Patent Citations (5)

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