ALUMINUM FOIL FOR ELECTROLYTIC CAPACITOR ELECTRODE AND ITS PRODUCTION

Japanese Patent JP3308456

B2

PROBLEM TO BE SOLVED: To produce an Al foil electrode for an electrolytic capacitor having large a capacitance by removing oxidized coating on the surface layer of the Al foil at the time of subjecting Al to hot rolling, process annealing and cold rolling to form into Al foil executing final annealing.
SOLUTION: An Al ingot having relatively low purity of 99.96 to 99.98% is subjected to hot rolling and cold rolling to work into a sheet material, which is thereafter subjected to process annealing at 200 to 500°C for ≥1hr and is successively rolled into Al foil having final thickness. Next, it is immersed in an aq. soln. of 2% NaOH heated at 55°C to dissolve away oxide in the surface of the Al foil exerting a bad influence to the subsequent etching treatment by 0.1μm ion the thickness direction, and after that, final annealing is executed. The Al foil as the electrode of an electrolytic capacitor for high voltage in which the crystal occupancy ratio of the (100) plane in the Miller Index is regulated to ≥92% in the inside structure is produced. This is subjected to electrolytic etching to increase the surface area and thus to form into the electrode for an electrolytic capacitor large in capacitance.

Masaharu Kurahashi
Kiyoshi Fukuoka

JP25539396A

July 29, 2002

September 05, 1996

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Sumitomo Light Metal Industry Co., Ltd.

B21B3/00; C22C21/00; C22F1/04; C23F1/00; C23F1/36; H01G9/055; (IPC1-7): C22F1/04; C23F1/00; H01G9/055

JP6212372A
JP2270928A
JP517856A
JP5239568A
JP83700A
JP5200405A

Fukuda Yasuo (1 person outside)

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