To find out the difference between the adhesive property of electro-plating and of organic coating to metal surface, the acetyl cellulose films as organic are coated on the anodized aluminum plates under various anodizing conditions, and each adhesive strength is measured.
The results of the measurment are as follows.
1) The adhesive strength of the coating on aluminum plate anodized in phosphoric acid bath at room temperature is several times greater than the others. However, the strength falls with anodizing temperature rise.
2) The coatings on the aluminium plates anodized in sulphuric or oxalic acid bath and etched by sodium hydroxide have almost the same or slightly less adhesive strength as the above.
3) Such tendency of the adhesive property of organic coating is the same as that in the case of electro-plating of anodized aluminum.