| 摘要 |
An electrolyte permeable diaphragm consisting essentially of asbestos is prepared by depositing asbestos and a porosity control agent selected from the group of cellulosic-type materials, e.g., starch, cellulose or rayon, infusible thermoset polymer materials, e.g., phenol-formaldehyde resin, urea-formaldehyde resin or melamine-formaldehyde resin, and inorganic materials, e.g., fiberglass, graphite, titania, silica, talc, vermiculite or potassium-containing mica from an aqueous slurry including alkali metal hydroxide onto a porous substrate, the porosity control agent being substantially stable and insoluble in the aqueous alkali metal hydroxide-containing slurry, followed by heating the deposited asbestos, porosity control agent and alkali metal hydroxide at temperatures between about 110 DEG C. and 280 DEG C. for a period of time sufficient to react the asbestos and alkali metal hydroxide whereby the porosity control agent provides the permeability for the diaphragm.
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