| abstract |
In the production of electrodes for aluminum electrolytic capacitors, in the hydration step, the aluminum electrode is brought into contact with pure water at a temperature of 70°C or higher to form a hydrated film with an appropriate film thickness on the aluminum electrode, and then, in the chemical conversion step, the temperature Chemical conversion is carried out at a chemical conversion voltage of 500V or more in a chemical conversion solution above 40°C. In the chemical conversion step, when the relative velocity of the chemical conversion liquid relative to the aluminum electrode is represented by the three-dimensional velocity vector BA, and the absolute value of the velocity vector BA is expressed as |B-A|, the absolute value of the velocity vector |B-A| satisfies the following conditional expression: 3cm/s≤|B-A|≤100cm/s. |