Patent ID: 8419920

Claim:
A method for preparing a sulfuric acid base copper electrolytic solution, comprising: preparing an initial aqueous solution containing 3-mercapto-1-propanesulfonic acid at a concentration of 2.8×10 −6 mol/L to 2.3 mol/L and cupric ions, wherein the relationship between the concentration of the 3-mercapto-1-propanesulfonic acid and the concentration of the cupric ions in the initial aqueous solution satisfies the Expression 1: [ Cupric ⁢ ⁢ ion ⁢ ⁢ concentration ⁢ ⁢ ( mol ⁢ / ⁢ L ) ] ⁢ [ 3 ⁢ - ⁢ mercapto ⁢ - ⁢ 1 ⁢ - ⁢ propanesulfonic acid ⁢ ⁢ concentration ⁡ ( mol ⁢ / ⁢ L ) ] ⁢ ≥ 0.005 ( Expression ⁢ ⁢ 1 ) forming a cuprous salt of the 3-mercapto-1-propanesulfonic acid and the cupric ions as shown in the following Formula 1: 4MPS+2Cu 2+ →2Cu(I)S(CH 2 ) 3 SO 3 +SPS+4H + (Formula 1); preparing a conversion solution by converting a part or all of the cuprous salt of the 3-mercapto-1-propanesulfonic acid into bis(3-sulfopropyl)disulfide by an oxidation reaction as shown in the following Formula 2: 2Cu(I)S(CH 2 ) 3 SO 3 +SPS+4H + +O 2 →2SPS+2H 2 O+2Cu 2+ (Formula 2) using air in the initial aqueous solution in the presence of sulfuric acid; and preparing a sulfuric acid base copper electrolytic solution by including the conversion solution in a copper sulfate-containing solution.