ELECTROLYTIC ETCHANT COMPOSITION, ELECTROLYTIC ETCHING METHOD, ELECTROLYTICALLY ETCHED SUBSTRATE, ELECTRODE MATERIAL FOR ALUMINUM ELECTROLYTIC CAPACITORS, AND CAPACITOR

摘要

Provided is an electrolytic etchant composition which is capable of producing a substrate containing aluminum, said substrate having high electrostatic capacity and being suitable as an electrode material for aluminum electrolytic capacitors. The present invention is an electrolytic etchant composition which is used for the purpose of forming a pit in a substrate that contains aluminum by performing an electrochemical etching. This electrolytic etchant composition contains 10-70% by mass in total of at least one acid selected from the group consisting of acetic acid and lactic acid, 0.1-10% by mass of aluminum chloride, and water.