Etching agent for aluminum or aluminum alloy

Abstract

A composition of an etching agent for aluminum or aluminum alloy and a treatment method thereof are provided. The etching agent does not contain a component not suitable for a wastewater treatment, such as boron and fluorine, and has stable etching performance even when performing an etching treatment continuously. The etching agent has excellent aging resistance providing good etching uniformity and corrosion resistance after etching. This etching agent is an etching agent for aluminum or aluminum alloy, including 50 parts by mass of an aminocarboxylic acid, 5 to 300 parts by mass of at least one selected from a hydroxycarboxylic acid, a dicarboxylic acid, a polycarboxylic acid, and salts thereof, and 10 to 800 parts by mass of at least one selected from a hydroxide, a carbonate, and a bicarbonate of an alkali metal, wherein an aqueous solution of the etching agent has a pH of 8 to 10.

Dependencies are inferred from the claim text.