| 摘要 |
Diaphragms for use in electrolytic and ion-exchange processes are produced by incorporating in a thermoplastic polymer fine granules of an ion-exchange resin with the aid of a solvent which gels the thermoplastic polymer to produce a dough, shaping the latter as by extrusion, sheeting or calendering into diaphragm form, and removing the solvent by evaporation. The polymer may be polyvinyl chloride, a copolymer of vinyl chloride and vinyl acetate or vinylidene chloride or polyethylene, and the solvent may be dimethyl cyclohexanone, butyl acetate or xylene, which may contain a diluent such as white spirit. Polypropylene sebacate may be incorporated as plasticizer. The mixture from which the dough is made may contain a leachable ingredient such as sodium chloride which may be removed after evaporation of the solvent so that the diaphragm contains pores through which liquids may diffuse. The ion-exchange resin may be a cation exchange resin of the phenolic type containing nuclear sulphonic hydroxyl groups or an anion exchange resin of the phenolic type containing amino and phenolic hydroxyl groups. Reference has been directed by the Comptroller to Specifications 719,315 and 721,161.
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