GASKET FOR FILTER PRESS-TYPE ELECTROLYTIC CELL, ITS PRODUCTION AND THE CELL PROVIDED WITH THE GASKET

摘要

PURPOSE:To provide the stabilized-quality gasket by graft-polymerizing a vinylidene monomer on the trunk polymer of a fluorine-contg. copolymer to obtain a soft fluororesin and specifying the modulus of shearing elasticity at a specified temp. CONSTITUTION:The gaskets 30 and 31 are interposed between the frames 5, 10 and 20 of the filter press-type electrolytic cell and an ion-exchange membrane 4. The gasket 30 is made of a soft fluororesin obtained by copolymerizing >=1 kinds of monomer contg. at least one kind of fluorine-contg. monomer and a monomer having a double bond and a peroxy bond in the molecule to produce a trunk polymer consisting of the fluorine-contg. polymer and graft- polymerizing a vinylidene monomer on the product. The modulus of shearing elasticity at 20 deg.C is controlled to 10<8>-4X10<9> dyne/cm<2> and that at 90 deg.C to >=10<8> dyne/cm<2>. Consequently, the electrolytic cell is stably operated for a long period.