| 摘要 |
Microporous sheet materials are produced by mixing a synthetic resin with a fine particulate water-soluble pore-forming material and a solvent incompatible with the pore-forming material but capable of forming a gel with the working material, mixing to form a dough, forming the dough to a sheet, heating the sheet to drive off the solvent, leaching in an aqueous bath to remove the pore-forming material and drying, a wetting agent either of the general formula <FORM:1107782/C3/1> wherein M represents an alkali metal and R an alkyl group, or comprising an ethoxylated fatty acid amine, the wetting agent being selected so as to make the finished microporous material hydrophilic. Specified resins are polyvinyl chloride and polyurethanes. The sulphosuccinate compounds are surface active at pH 6 to 9 and the ethoxylated fatty acid amines, e.g. of the formula Alk-N-[-(CH2CH2O)2H]2 at pH less than 3. The surface active agent may also control the cell size in the microporous sheet. |
