| 摘要 |
PURPOSE:To form phosphoric acid salt film excellent in anticorrosive property, by adding naphthoquinone derivatives to treating liquid and also, contacting with air or air and oxygen, at the time of forming phosphoric acid salt chemical treating film on the surface of metal. CONSTITUTION:Anticorrosive phosphoric acid chemical treating film is formed on the surface of metal parts to be treated in the chemical treating vessel 4 after removing fat in the vessel 1 and washing by water in the vessel 2, 3. Zinc phosphate solution is put in the vessel 4 and naphthoquinone derivatives are added as cathode depolarizing agent. The above metal parts are dipped in the vessel 4 and air or mixed gas of air and oxygen, is blown in the vessel 4 from the pipe 5 and then, oxygen potential necessary for phosphoric acid salt film forming reaction, is given to the liquid. Lowering of zinc concentration in the treating liquid is prevented by circulating a part of the liquid through the small room 7 filling up the zinc carbonate 9 by the pump 6 and supplying it. Or, zinc is supplied by eluting metallic zinc by anode electrolysis. Also, phosphoric acid salt film forming is accelerated by irradiating ultra violet rays or electron beam in the vessel 4 or treating liquid circulating system. |
