A Behavior of the Crystal Water of Zinc Phosphate and Its Relationship to Wet Adhesion of Paint on Electro-galvanized Steel
1986 Volume 72 Issue 8 Pages 1125-1132
Details
1986 Volume 72 Issue 8 Pages 1125-1132
A behavior of the crystal water of zinc phosphate and its relationship to wet adhesion of paint on electrogalvanized steel has been investigated. The conversion coating of Zn3(PO4)24H2O under the paint film entirely became dehydrated Zn3(PO4)22H2O by baking the film at the every content of Ni and Mn in the coating. In the case of low contents of Ni and Mn in the coating, Zn3(PO4)22H2O became rehydrated Zn3 (PO4)24H2O by immersion in water on wet adhesion test. However in the case of high contents Ni and Mn, Zn3(PO4)22H2O was not rehydrated.
The rehydration rate decreased with increasing the contents of Ni and Mn in the coating.
Therefore, it was found that the coating including high contents of Ni and Mn showed a very good wet adhesion. Moreover, the crystal of zinc phosphate coating including high contents of Ni and Mn was proved to be fine, dense and almost amorphous.
