| 摘要 |
<p>An adherent metallic coating, having sufficient ductility to provide at least 5% elongation before rupture, tensile strength of at least 20,000 p.s.i. and compressive stress of between 1,000 and the tensile strength in p.s.i., is electro-deposited on the surface of a plastic, e.g. an oxymethylene or acrylonitrile-butadiene-styrene polymer, a cellulose ester, an olefine or acrylic polymer, an epoxy or alkyd resin, a polyamide, polycarbonate or polystyrene or a phenolic resin. The plastic surface may be rendered conductive by sensitizing with SnCl2 solution, then simultaneously spraying with two solutions, one containing AgNO3 and NH4OH, the other glyoxal and triethanol-amine, firing in an oven after water rinsing and dipping in an alkyl benzene sulphonate detergent, then H2SO4 solution followed by water rinsing, prior to electro-plating, e.g. with copper using a plating bath containing copper and alkali metal (e.g. K) pyrophosphate and NH4OH with dimercapto thiodiazole; the copper plate, after H2SO4 rinsing, may be nickel coated using a bath containing nickel sulphate and chloride or sulphamate with H3BO3, then after a further H2SO4 rinse, Cr plated using a CrO3-H2SO4 bath. Alternatively the plastic surface may be roughened with Al2O3 particles, cleaned with HCl and/or NaOH solution, sensitized with SnCl2 solution, activated with a solution of PdCl2 and HCl, oven dried, then immersed in a solution containing basic nickel carbonate, sodium hypophosphite, HF and HNO3 to coat nickel, prior to electro-plating.</p> |
