Conductive polymer dispersion liquid, electrolytic capacitor, and method for producing electrolytic capacitor

Patent metadata

Field	Value
Publication number	US-2024191046-A1
Application number	US-202418583599-A
Country	US
Kind code	A1
Filing date	Feb 21, 2024
Priority date	Jan 31, 2019
Publication date	Jun 13, 2024
Grant date	—

Abstract

Disclosed is a method for producing an electrolytic capacitor, the method including the steps of: preparing an anode foil that includes a dielectric layer, a cathode foil, and a fiber structure; preparing a conductive polymer dispersion liquid that contains a conductive polymer component and a dispersion medium; producing a separator by applying the conductive polymer dispersion liquid to the fiber structure and then removing at least a portion of the dispersion medium; and producing a capacitor element by sequentially stacking the anode foil, the separator, and the cathode foil. The dispersion medium contains water. The fiber structure contains a synthetic fiber in an amount of 50 mass % or more. The fiber structure has a density of 0.2 g/cm 3 or more and less than 0.45 g/cm 3 .

First claim

1 . A method for producing an electrolytic capacitor, the method comprising the steps of:
preparing an anode foil that includes a dielectric layer, a cathode foil, and a fiber structure; preparing a conductive polymer dispersion liquid that contains a conductive polymer component and a dispersion medium; producing a separator by applying the conductive polymer dispersion liquid to the fiber structure and then removing at least a portion of the dispersion medium; and producing a capacitor element by sequentially stacking the anode foil, the separator, and the cathode foil, wherein the dispersion medium contains water, the fiber structure contains a synthetic fiber in an amount of 50 mass % or more, and a cellulose fiber in an amount of 10 mass % or more and less than 50 mass %, the synthetic fiber includes at least one selected from the group consisting of a nylon fiber, an aramid fiber, an acrylic fiber, and a polyester fiber, the fiber structure has a density of 0.2 g/cm 3 or more and less than 0.45 g/cm 3 , and a mass of the conductive polymer component per unit area of the separator is 0.02 mg/cm 2 or more.

2 . A method for producing an electrolytic capacitor, the method comprising the steps of:
preparing an anode foil that includes a dielectric layer, a cathode foil, and a fiber structure; preparing a conductive polymer dispersion liquid that contains a conductive polymer component and a dispersion medium; producing a separator by applying the conductive polymer dispersion liquid to the fiber structure and then removing at least a portion of the dispersion medium; and producing a capacitor element by sequentially stacking the anode foil, the separator, and the cathode foil, wherein the dispersion medium contains water, the fiber structure contains a cellulose fiber in an amount of 40 mass % or more, a synthetic fiber and a paper strengthening agent, the synthetic fiber includes at least one selected from the group consisting of a nylon fiber, an aramid fiber, an acrylic fiber, and a polyester fiber, the fiber structure has a density of 0.2 g/cm 3 or more and less than 0.45 g/cm 3 , and a mass of the conductive polymer component per unit area of the separator is 0.02 mg/cm 2 or more.

3 . The method for producing an electrolytic capacitor in accordance with claim 2 ,
wherein the paper strengthening agent comprises at least one selected from the group consisting of a urea formaldehyde resin, a melamine formaldehyde resin, a polyamide polyamine epichlorohydrin, and a polyvinylamine.

4 . The method for producing an electrolytic capacitor in accordance with claim 2 ,
wherein the paper strengthening agent comprises at least one selected from the group consisting of a polyacrylamide, a polyvinyl alcohol, a starch, and a carboxymethyl cellulose.

5 . The method for producing an electrolytic capacitor in accordance with claim 2 ,
wherein the fiber structure contains the synthetic fiber in an amount of 10 mass % or more.

6 . The method for producing an electrolytic capacitor in accordance with claim 1 ,
wherein, in the step of producing the separator, the conductive polymer dispersion liquid is applied to the fiber structure by using a coating method.

7 . The method for producing an electrolytic capacitor in accordance with claim 1 ,
wherein the conductive polymer component is contained in the conductive polymer dispersion liquid in an amount of 1 mass % or more and 15 mass % or less, and the conductive polymer dispersion liquid has a viscosity of 10 mPa's or more, the viscosity being measured at room temperature by using a vibration viscometer.

8 . An electrolytic capacitor comprising:
an anode foil that includes a dielectric layer; a cathode foil; and a separator that is interposed between the anode foil and the cathode foil, wherein the separator contains a fiber structure and a conductive polymer component that is attached to the fiber structure, the fiber structure contains a synthetic fiber in an amount of 50 mass % or more, a cellulose fiber in an amount of 10 mass % or more and less than 50 mass %, the synthetic fiber includes at least one selected from the group consisting of a nylon fiber, an aramid fiber, an acrylic fiber, and a polyester fiber, the fiber structure has a density of 0.2 g/cm 3 or more and less than 0.45 g/cm 3 , and a mass of the conductive polymer component per unit area of the separator is 0.02 mg/cm 2 or more.

9 . An electrolytic capacitor comprising:
an anode foil that includes a dielectric layer; a cathode foil; and a separator that is interposed between the anode foil and the cathode foil, wherein the separator contains a fiber structure and a conductive polymer component that is attached to the fiber structure, the fiber structure contains a cellulose fiber in an amount of 40 mass % or more, a synthetic fiber, and a paper strengthening agent, the synthetic fiber includes at least one selected from the group consisting of a nylon fiber, an aramid fiber, an acrylic fiber, and a polyester fiber, the fiber structure has a density of 0.2 g/cm 3 or more and less than 0.45 g/cm 3 , and a mass of the conductive polymer component per unit area of the separator is 0.02 mg/cm 2 or more.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Kubo Daisuke
• Arima Hiroyuki
• Tashiro Tomoyuki
• Takatani Kazuhiro
• CHASHIRO Kenta
• Matsushita Shumpei

Classifications

• H01G9/02 Primary

  Diaphragms; Separators · CPC title

• H01G9/0032

  formation of the dielectric layer · CPC title

• C08J2477/00

  Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers · CPC title

• C08J2467/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08J2467/06 takes precedence) · CPC title

• C08J2433/26

  Homopolymers or copolymers of acrylamide or methacrylamide · CPC title