Title:
ALUMINUM MATERIAL FOR ELECTROLYTIC CAPACITOR
Document Type and Number:
Japanese Patent JP3945597
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain aluminum foil in which pits are uniformly formed at high density by electrochemical etching to enlarge its surface area and capable of obtaining high capacitance by specifying the purity of an Al material and specifying the contents of Na, Mg and B.
SOLUTION: Relating to an Al material of ≥99.9 wt.%, preferably about ≥99.98%, furthermore, the content of Na is regulated to 0.01 to <10 ppm, the content of Mg is regulated to 0.1 to <10 ppm and the content of B is regulated to 0.01 to <10 ppm, and preferably the average concns. of Na, Mg and B in the layer to a depth of 1 μm from the surface are enriched to the ones higher than those in the layer inner than that. Relating to this Al material, by the synergic operation of optimum amounts of Na and Mg and the pit coarsening suppressing operation of Bi, fine capillary pits are uniformly formed at high density. This Al material is moreover incorporated with 1 to 100 ppm Si, 1 to 100 ppm Fe, 1 to 100 ppm Cu, 0.1 to 10 ppm Pb or the like as necessary, by which its characteristics can be improved.
Inventors:
Takeshi Itagaki
Application Number:
JP19023397A
Publication Date:
July 18, 2007
Filing Date:
July 15, 1997
Export Citation:
Assignee:
Mitsubishi Aluminum Co., Ltd.
International Classes:
C22C21/00; (IPC1-7): C22C21/00
Domestic Patent References:
| JP6065664A | ||||
| JP5315199A | ||||
| JP10140276A |
Attorney, Agent or Firm:
Katsumi Utaka
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