Abstract: A cation exchange membrane is installed to an electrolytic cell to be used in a form of a cation exchange membrane of a fluorinated polymer having ion exchange groups having the formula--(COO).sub.m Xwherein X represents an alkali metal atom or --NRR' and R and R' respectively represent hydrogen atom or a lower alkyl group; and m represents a valence of m, by covering a membrane of a fluorinated polymer having ion exchange groups having the formula--COOLwherein L represents hydrogen atom or a C.sub.1 -C.sub.20 alkyl group on said electrode in the installation.

Abstract: An electrolytic cation exchange membrane which comprises a first film made of a fluorinated polymer having cation exchange groups and containing a fibrillated tetrafluoroethylene polymer and a second film laminated thereon, made of a fluorinated polymer having carboxylic acid groups as its ion exchange groups, said first film having a greater thickness and smaller specific electric resistance than said second film.

Abstract: An electrolytic cell comprises intercalated finger-shaped electrodes each disposed through a cation exchange membrane, in which said cation exchange membrane constitutes a cylinder or envelope enclosing a finger-shaped anode or cathode A flare is formed at one end or each end of the cylinder or at the open end of the envelope. The flare is joined with a flange to form a unitary cation exchange membrane-flange structure which liquid-tightly divides an anode compartment and a cathode compartment.

Abstract: An ion exchange membrane of a fluorinated polymer is bonded to a synthetic resin with a binder selected from the group consisting of fluorinated polymers, polyolefins and polyaryl ethers. The binder is in a form of a net, a cloth or a porous sheet so as to form an uneven interlayer.

Abstract: A fluorinated cation exchange membrane is formed using a copolymer of a fluorovinyl ether (I) having the formulaCF.sub.2 .dbd.CF--O--CF.sub.2 --CFXOCF.sub.2).sub.l (CFX').sub.m (CF OCFX").sub.n Awherein l is 0 to 3; m is 2 to 6; n is 0 to 4 and one of l and n is not zero and l+m+n.gtoreq.3; X, X' and X" are the same or different and each respectively represent --F or --CF.sub.3 ; A represents --CN,--COF, --COOH, --COOR,--COOM or --CONR.sub.2 R.sub.3 ; R.sub.1 represents a C.sub.1-10 alkyl group; and M represents an alkali metal or a quaternary ammonium salt; and a fluorinated olefin (II), or a hydrolyzed copolymer thereof. The fluorinated cation exchange membrane is used for production of a halogen and an alkali metal hydroxide by electrolysis of an alkali metal hydride.

Abstract: An organic solution of a fluorinated copolymer having carboxylic acid groups comprises the copolymer of fluorinated ethylenically unsaturated monomer and a functional monomer having carboxylic acid group (--COOH group) dissolved in a hydrophilic organic solvent with a small amount of water.

Abstract: An organic dispersion is prepared of an acid type fluorinated polymer comprises copolymerizing a fluorinated ethylenically unsaturated monomer and a functional monomer having an acid type functional group in an aqueous medium under an action of a polymerization initiator source to obtain an aqueous dispersion of an acid type fluorinated polymer having the functional monomer unit content of 5 to 40 mol %; and replacing an aqueous medium of the aqueous dispersion to a hydrophilic organic medium under maintaining the dispersion.

Abstract: A cation exchange membrane of a fluorinated polymer for an electrolysis comprises a structure of a copolymer of a fluorinated olefin and a fluorovinyl compound having the formulaCF.sub.2 .dbd.CX--(OCF.sub.2 CFY).sub.l (O).sub.m (CFY').sub.n COOMwherein X represents --F or --CF.sub.3 ; Y and Y' respectively represents --F or a C.sub.1 -C.sub.10 perfluoroalkyl group; l is 0 to 3; m is 0 or 1; n is 0 to 12 and M represents hydrogen atom or an alkali metal atom; and a modified surface layer of said cation exchange membrane in an anode side which has --SO.sub.3 M groups formed by converting --COOM groups.

Abstract: A modified polytetrafluoroethylene is produced by polymerizing tetrafluoroethylene in an aqueous medium containing a dispersing agent with a polymerization initiator source and then, copolymerizing tetrafluoroethylene and a fluorinated monomer having an acid type functional group as a copolymerizable modifier in the presence of the resulting polytetrafluoroethylene to obtain a modified polytetrafluoroethylene having the modifier component of 0.001 to 10 mol %.

Abstract: A fluorinated copolymer having ion-exchange group is produced by copolymerizing a fluorinated ethylenic unsaturated monomer and a functional monomer having a functional group of carboxylic acid group or a group which can be converted to carboxylic acid group in an aqueous medium in the presence of a polymerization initiator source and in the presence of a specific molecular weight regulator. The specific molecular weight regulator is selected from the group consisting of aliphatic alkanes alicyclic alkanes and water soluble organic solvents and controls the molecular weight without lowering the copolymerization velocity and without lowering the stability of the aqueous latex.

Abstract: A fluorinated copolymer having ion-exchange group is produced by copolymerizing a fluorinated ethylenic unsaturated monomer and a functional monomer having a functional group of carboxylic acid group or a group which can be converted to carboxylic acid group in an aqueous medium in the presence of a polymerization initiator source. The fluorinated copolymer obtained by the copolymerization is treated with an alcohol at higher than 20.degree. C. in the form of particles before a molding. The melt flowability of the fluorinated copolymer is improved.

Abstract: A cation exchange membrane of a fluorinated polymer is formed by incorporating fibrils of polytetrafluoroethylene into a cation exchange resin of a fluorinated polymer having carboxylic acid groups or functional groups which can be converted to carboxylic acid groups.

Abstract: A cation exchange membrane of a fluorinated polymer is formed by incorporating fibrils of polytetrafluoroethylene in a cation exchange resin of a fluorinated polymer having sulfonic acid type ion exchange groups which has high chemical resistances such as chlorine resistance, oxidation resistance and alkaline resistance, in an electrolysis.

Abstract: A fluorinated copolymer having 1 to 50 mole % of a component having functional group of carboxylic acid group or a group which can be converted to carboxylic acid group, is produced by copolymerizing a fluorinated ethylenic unsaturated monomer and a functional monomer having the functional group in the presence of a polymerization initiator source in an aqueous medium under the pressure of higher than 7 kg/cm.sup.2 whereby the copolymer having high molecular weight (T.sub.Q of higher than 150.degree. C.) and an ion exchange capacity of 0.5 to 4 meq/g dry polymer is produced.

Abstract: A fluorinated cation exchange membrane is made of three component copolymer produced by copolymerizing a fluorovinylpolyether having the formula Icf.sub.2 .dbd. cf--o-cf.sub.2 --(cfxocf.sub.2).sub..alpha. --(cfx').sub..beta. --(cf.sub.2 ocfx").sub..gamma. --awherein .alpha. is 0 to 3; .beta. is 0 to 6; .gamma. is 0 to 4 and either .alpha. or .gamma. is not 0; X, X' and X" respectively represent --F or a C.sub.1-5 perfluoroalkyl group; A represents --CN--, --COF, --COOH, --COOR.sub.1, --COOM or --CONR.sub.2 R.sub.3 ; R.sub.1 represents a C.sub.1-10 alkyl group preferably a C.sub.1-3 alkyl group, R.sub.2 and R.sub.3 respectively represents hydrogen atom or a C.sub.1-10 alkyl group; and M represents an alkali metal atom or a quaternary ammonium group, a fluorovinyl compound having the formula IIcf.sub.2 .dbd. cf--(o).sub..delta. --(cfy).sub..gamma. --a'wherein .delta. is 0 to 1; .gamma. is 1 to 6; Y represents --F or a C.sub.

Abstract: A fluorinated copolymer having 1 to 50 mole % of a component having functional group of carboxylic acid group or a group which can be converted to carboxylic acid group, is produced by copolymerizing a fluorinated ethylenic unsaturated monomer and a functional monomer having the functional group in the presence of a polymerization initiator source in 0 to 10 mole of an inert organic solvent per 1 mole of the functional monomer under the pressure of higher than 6 kg/cm.sup.2 whereby the copolymer having high molecular weight (T.sub.Q of higher than 150.degree. C) and an ion exchange capacity of 0.5 to 4 meq/g dry polymer is produced.

Abstract: Electrochemical properties of a cation exchange membrane of a carboxylic acid type fluorinated polymer which is used for an electrolysis of an aqueous solution of an alkali metal chloride is recovered by converting ion exchange groups of --COO).sub.m M; wherein M represents an alkali metal or an alkaline earth metal; and m represents a valence of M; to the corresponding acid or ester groups of --COOR wherein R represents hydrogen or a C.sub.1 - C.sub.5 alkyl group and heat-treating the fluorinated polymer having the groups of --COOR.

Abstract: An acid diffusion-dialysis membrane, which can be used for separating an acid from a mixture of an acid and a salt, or a mixture of an acid and a water-soluble organic compound, e.g., glucose, by non-electrolytic dialysis, is prepared by forming a film from the combination of (I) a vinyl group containing benzene monomer or a vinyl group containing pyridine monomer, (II) a non-conjugated divinyl-containing monomer, and (III) a thermoplastic polymer which is swellable or soluble in the monomer mixture, polymerizing said monomer mixture in the film, and then introducing anion exchange groups into the resulting polymerized product. The acid diffusion-dialysis membrane is characterized by a high acid diffusion-dialysis coefficient and a high acid-salt selectivity ratio, and further by a relatively high mechanical strength.