Abstract
The pigments, mixed with oils as described in the previous report, were painted on the polished iron plates, and after drying for 10 days, the painted plates were dipped for 24 hours in 0.5 % aqueous solution of Copper Sulphate.
When the iron plate touches with Copper Sulphate through the paint film, brownish metallic copper may precipitate on the film, therefore we can jade the grade of permeability of the film from the amount and the magnitude of copper precipitates.
Between the impermeability of the film and the result of the scratch test of the film, no special relation was found.
While almost all the pigments, which had given the impermeable film as the paint, have had rust inhibitive property by themselves.
Impermeable film was given by the following pigmets: Zinc Oxide, Litharge, Red Lead, Chrome Yellow, Zinc Yellow, Three new pigments made by the author on trial, Ultramaline, Carbon Black.
The pigments, which have shown good results in the inhibitive property by themselves, the scratch test and the impermeability of the film as the paint, were as follows : Litharge, Red Lead, White Lead, Chrome Oxide, One of the new pigments prepared by the author.
