Electrolytic capacitor

Abstract

An electrolytic capacitor having a low impedance characteristic, having a high withstand voltage characteristic of 100V class, wherein the electrolytic capacitor provides an excellent high temperature life characteristic and an excellent leakage characteristic. The electrolyte solution containing the aluminum tetrafluoride salt is used. Moreover, the ceramics coating layer or the insulating synthetic resin layer is formed at a contact portion with the sealing component of the rivet or the cathode leading means. Alternatively, a partial cross-linking peroxide butyl rubber that added peroxide as cross-linking agent to a butyl rubber polymer comprised of isobutylene, isoprene, and divinylbenzene copolymer is used as the sealing member. The electrolytic capacitor of the present invention has a low impedance characteristic, a high withstand voltage characteristic, and an excellent high temperature life characteristic.

1 . An electrolytic capacitor having a capacitor element fabricated by winding an anode electrode foil provided with anode leading means and a cathode electrode foil provided with cathode leading means via a separator and impregnating it with electrolyte solution, an outer case for housing the capacitor element, and a sealing member for sealing an open part of the outer case, characterized in that a electrolyte solution containing aluminum tetrafluoride salt is used as said electrolyte solution, and that a ceramics coating layer is formed at a contact portion with the sealing member and the cathode leading means.  
   
   
       2 . An electrolytic capacitor according to  claim 1 , wherein the cathode leading means includes an aluminum conductor comprised of a rod member and a flat member, wherein the ceramics coating layer is formed on the rod member prior to capacitor production process.  
   
   
       3 . An electrolytic capacitor according to  claim 1 , wherein the ceramics coating layer is formed by using a coating agent comprised of metal alcoxide ceramics one kind or two kinds or more selected from Al 2 O 3 , SiO 2 , and ZrO 2 .  
   
   
       4 . An electrolytic capacitor having a capacitor element fabricated by winding an anode electrode foil provided with anode leading means and a cathode electrode foil provided with cathode leading means via a separator and impregnating it with electrolyte solution, an outer case for housing the capacitor element, and a sealing member for sealing an open part of the outer case, characterized in that a electrolyte solution containing aluminum tetrafluoride salt is used as said electrolyte solution, and that an insulating synthetic resin layer is formed at a contact portion of the cathode leading means with the sealing member.  
   
   
       5 . An electrolytic capacitor according to  claim 4 , wherein the cathode leading means includes an aluminum conductor comprised of a rod member and a flat member, wherein the insulating synthetic resin layer is formed on the rod member prior to capacitor production process.  
   
   
       6 . An electrolytic capacitor having a capacitor element fabricated by winding an anode electrode foil, a cathode electrode foil and a separator and impregnating it with electrolyte solution, an outer case for housing the capacitor element, and a sealing member for sealing an open part of the outer case, wherein that a electrolyte solution containing aluminum tetrafluoride salt is used as said electrolyte solution, wherein a partial cross-linking peroxide butyl rubber that peroxide is added as cross-linking agent to a butyl rubber polymer comprising a copolymer of isobutylene, isoprene, and divinylbenzene is used as said sealing member.  
   
   
       7 . An electrolytic capacitor obtained by impregnating a capacitor element with electrolyte solution containing an aluminum tetrafluoride salt, wherein the capacitor element is formed by wounding an anode electrode foil with a anode leading terminal and a cathode electrode foil with a cathode leading terminal together with intervening separator, housing the capacitor element in an cylindrical outer case with a bottom, and a sealing an open end of the case by a sealing member with a rivet connecting said cathode leading terminal to said outside terminal, characterized in that a ceramics coating layer is formed at a contact portion of the rivet with the sealing component.  
   
   
       8 . An electrolytic capacitor obtained by impregnating a capacitor element with electrolyte solution containing an aluminum tetrafluoride salt, wherein the capacitor element is formed by wounding an anode electrode foil with a anode leading terminal and a cathode electrode foil with a cathode leading terminal together with intervening separator, housing the capacitor element in an cylindrical outer case with a bottom, and a sealing an open end of the case by a sealing member with a rivet connecting said cathode leading terminal to said outside terminal, characterized in that a ceramics coating layer is formed on said cathode leading terminal.  
   
   
       9 . An electrolytic capacitor obtained by impregnating a capacitor element with electrolyte solution containing an aluminum tetrafluoride salt, wherein the capacitor element is formed by wounding an anode electrode foil with a anode leading terminal and a cathode electrode foil with a cathode leading terminal together with intervening separator, housing the capacitor element in an cylindrical outer case with a bottom, and a sealing an open end of the case by a sealing member with a rivet connecting said cathode leading terminal to said outside terminal, characterized in that an insulating synthetic resin is formed at a contact portion of the rivet with the sealing component.  
   
   
       10 . An electrolytic capacitor obtained by impregnating a capacitor element with electrolyte solution containing an aluminum tetrafluoride salt, wherein the capacitor element is formed by wounding an anode electrode foil with a anode leading terminal and a cathode electrode foil with a cathode leading terminal together with intervening separator, housing the capacitor element in an cylindrical outer case with a bottom, and a sealing an open end of the case by a sealing member with a rivet connecting said cathode leading terminal to said outside terminal, characterized in that an insulating synthetic resin layer is formed on said cathode leading terminal.  
   
   
       11 . An electrolytic capacitor according to  claims 1  to  10 , wherein an electrode foil subjected to a phosphate treatment is used as the cathode electrode foil or the anode electrode foil.