Method for manufacturing electrolytic capacitor

Abstract

A method for manufacturing an electrolytic capacitor of the present disclosure includes first to third steps. In the first step, a capacitor element is prepared that includes an anode body on which a dielectric layer is formed. In the second step, the capacitor element is impregnated with a first treatment solution containing at least a conductive polymer and a first solvent. In the third step, the capacitor element is, after the second step, impregnated with a second treatment solution that contains a polyol compound having 3 or more hydroxyl groups per molecule.

What is claimed is: 
     
         1 . A method for manufacturing an electrolytic capacitor, the method comprising:
 a first step of preparing a capacitor element that includes an anode body on which a dielectric layer is formed;   a second step of impregnating the capacitor element with a first treatment solution containing at least a conductive polymer and a first solvent; and   a third step of impregnating, after the second step, the capacitor element with a second treatment solution that contains a polyol compound having 3 or more hydroxyl groups per molecule.   
     
     
         2 . The method for manufacturing an electrolytic capacitor according to  claim 1 ,
 wherein the polyol compound is at least one selected from the group consisting of glycerin, polyglycerin, trimethylolpropane, erythritol, pentaerythritol, xylitol, and mannitol.   
     
     
         3 . The method for manufacturing an electrolytic capacitor according to  claim 1 ,
 wherein the second treatment solution contains a second solvent that dissolves the polyol compound.   
     
     
         4 . The method for manufacturing an electrolytic capacitor according to  claim 3 , the method comprising a fourth step of removing at least a part of the first solvent and/or the second solvent after the third step. 
     
     
         5 . The method for manufacturing an electrolytic capacitor according to  claim 3 ,
 wherein the second solvent is at least one selected from the group consisting of water, a monohydric alcohol, a dihydric alcohol, and an aprotic solvent.   
     
     
         6 . The method for manufacturing an electrolytic capacitor according to  claim 1 ,
 wherein a content of the polyol compound in the second treatment solution is 2% by mass or more.   
     
     
         7 . The method for manufacturing an electrolytic capacitor according to  claim 1 ,
 wherein a mass of the polyol compound with which the capacitor element is impregnated in the third step is twice to 100 times a mass of the conductive polymer with which the capacitor element is impregnated.   
     
     
         8 . The method for manufacturing an electrolytic capacitor according to  claim 1 ,
 wherein the first solvent is water, and   the capacitor element in which at least water remains is impregnated with the second treatment solution in the third step.   
     
     
         9 . The method for manufacturing an electrolytic capacitor according to  claim 1 , the method comprising a fifth step of impregnating the capacitor element with an electrolyte solution after the third step.