| 摘要 |
Articles made of ferrous metals are first coated with a metal or alloy electropositive to copper, e.g. zinc, lead, tin, aluminium, cadmium or lead-zinc alloys, then coated with copper or a copper alloy such as a brass or bronze by chemical deposition, and then coated with rubber by vulcanizing a rubber coating in contact with the copper surface. The coating of metal electropositive to copper may be applied by any suitable method such as hot dipping, electroplating, spraying, or cementation, the metal is then cleaned, e.g. in hot sodium carbonate solution, and then dipped in the copper-coating bath. The following examples of copper-coating baths are given:-(1) a solution of cuprous cyanide, sodium cyanide, sodium carbonate, and sodium thiosulphate; (2) a solution of copper sulphate and ammonium oxalate; (3) an acid solution containing copper sulphate and sulphuric acid particularly suitable for coating an article which has been coated with lead; (4) a solution of copper sulphate, potassium tartrate, and ammonia for articles which have been coated with cadmium. Salts of other metals such as silver, cobalt, tin, zinc &c. may be added to the copper baths to give alloy coatings. The process is particularly applicable to the preparation of wire for use as beads for pneumatic tyres.ALSO:Articles made of ferrous metals are first coated with a metal or alloy electropositive to copper, e.g. zinc, lead, tin, aluminium, cadmium, or lead-zinc alloys, then coated with copper or a copper alloy such as a brass or bronze by chemical deposition, and then coated with rubber by vulcanizing a rubber coating in contact with the copper surface. The coating of metal electropositive to copper may be applied by any suitable method such as hot dipping, electroplating, spraying, or cementation, the metal is then cleaned, e.g. in hot sodium carbonate solution, and then dipped in the copper-coating bath. The following examples of copper-coating baths are given:-(1) a solution of cuprous cyanide sodium cyanide, sodium carbonate, and sodium thiosulphate; (2) a solution of copper sulphate and ammonium oxalate; (3) an acid solution containing copper sulphate and sulphuric acid particularly suitable for coating an article which has been coated with lead; (4) a solution of copper sulphate, potassium tartrate, and ammonia for articles which have been coated with cadmium. Salts of other metals such as silver, cobalt, tin, zinc &c. may be added to the copper baths to give alloy coatings. The process is particularly applicable to the preparation of wire for use as beads for pneumatic tyres. |
