Metallizing plastics surfaces

摘要

1,149,033. Coating with metals. BADISCHE ANILIN - & SODA-FABRIK A. G. No. 31866/66. Headings C7B and C7F. In an electroless process for coating a plastics sheet with copper or silver in which the plastics surface is first coated with iron powder in a binder, the binder contains at least 20% by weight of a polyisocyanate. The binder may also include vinyl copolymers, polyvinyl chloride, acetal, formal or butyral or soluble polyamide. The coating may be applied through a stencil, and the powdered iron coating may be annealed at a temperature up to 60 ‹C. prior to deposition. A bath for depositing copper may comprise (g./l.) 150 copper sulphate, 40 triethanolamine, and 27 sulphuric acid. A silver layer may be deposited on the copper using a bath comprising 1À5 silver nitrate, 3 E.D.T.A., 3 sodium thiosulphate, and 2 tartaric acid. The copper surface may be electro-plated with a further layer of copper, using the same bath as for the electroless-plating, and then with Cr, Ni, Co or Rh, and the copper or silver surfaces may be electro-plated with Fe, Ni or Co or mixtures thereof.