SEALING BODY FOR CAPACITOR, AND CAPACITOR

PROBLEM TO BE SOLVED: To obtain a sealing body excellent in adhesiveness between a base plate and rubber using technology for bonding a hard base plate to rubber by chemical bond.SOLUTION: The shapes of opening part of a metal case 1 and a sealing body for sealing it are formed into non-circular shapes such as an oval, an ellipse, or a compressed circular shape. Terminal insertion holes 5,5 larger than the outer diameters of lead terminals 4, 4 are formed in the base plate 2. Insertion hole inner surface parts 3c of rubber 3 bonded to the surface of the base plate are formed on the insides of the terminal insertion holes 5, 5, and airtightness between the lead terminals 4, 4 and the insertion holes 5, 5 is secured by this insertion hole inner surface parts 3c. Producing an OH group on the surface of the hard base plate such as a metal plate or a resin plate and using a dually functional organic compound having a reactive functional group to the OH group of the hard base plate and the rubber in the same molecule, the hard base plate is bonded to the rubber by chemical bond. In this case, the OH group is formed on the surface of the base plate 2, and 3-acryloxy-propyl-trimethoxysilane is reacted to the OH group. The base plate 2 is fixed in a die and the rubber 3 is charged in it to integrate both of them.