Matsushita Electric Industrial Co., Ltd.

Yuki Murata

Ichiro Yamashita

Tsuyoshi Yoshino

Kazuyo Saito

Yoshihiro Watanabe

Yukihiro Nitta

Hideki Masumi

Munehiro Morokuma

Takehiko Nakahara

Yoshiyuki Mori

The present invention relates to a solid electrolytic capacitor having a large capacitance and a higher resistance to heat and adapted as a surface-mount device and a method of producing the same. The invention may include the followings features: (1) a layer containing an electroconductive polymer and a less conductive polymer is provided on a dielectric oxide film on the positive electrode foil; (2) a separator of a polyester resin based unwoven fabric made by span bonding and/or wet processing a resin material is sandwiched between the positive electrode foil and the negative electrode foil and rolled together to form a capacitor element which also include a solid electrolyte; (3) a separator is sandwiched between the positive electrode foil and the negative electrode foil coated with a dielectric oxide film exhibiting a withstand voltage of 0.8 to 10 V and rolled together to form a capacitor element which also include a solid electrolyte of an electrically conductive polymer; (4) the negative electrode foil is coated with a layer made of at least a metallic material selected from titanium, zirconium, hafnium, and its compound or of a carbon material; (5) the capacitor element has its content of, water adjusted to not higher than 1% by weight and is enclosed in an outer case; (6-A) the solid electrolyte is a conductive polymer prepared by chemically polymerizing a heterocyclic monomer with the use of an oxidizing solution of which the weight ratio of bivalent iron to trivalent iron is not higher than 0.02; (6-B) the solid electrolyte is a conductive polymer prepared by chemically polymerizing a heterocyclic monomer with the use of an oxidizing solution of which the molar ratio of aliphatic and/or aromatic sulfonic acid to trivalent iron ranges from 3.0 to 3.5; and (7) the solid electrolyte is a conductive polymer prepared by chemically polymerizing a heterocyclic monomer in which the remaining of a basic organic solvent is not higher than 0.8%.

Solid electrolytic capacitor and production method thereof, and conductive polymer polymerizing oxidizing agent solution

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Yamaguchi, Japan

Yuki Murata