Method for treating plastic surface

Abstract

Treatment equipment has a treatment tank provided with a thermostatic heater on its outer periphery and a supply tank connected through a pipe and a pump. The treatment tank and the supply tank are filled with persulfate solutions S and S1 having predetermined sulfuric acid concentrations and persulfuric acid concentrations respectively. In the treatment tank, a plastic plate is vertically hung as plastic to be treated. The sulfuric acid concentrations of the persulfate solutions S and S1 are each 50 to 92 wt %. The persulfuric acid concentrations of the solutions S and S1 are each 3 to 20 g/L after the persulfate is dissolved. According to a Cr-free method for treating a plastic surface using such treatment equipment, it becomes possible to form a plating film that sufficiently adheres to the plastic surface.

Dependencies are inferred from the claim text.