| abstract |
PURPOSE:To prepare a porous body with excellent chemical resistance and uniform cell size, by dissolving polyolefin in a hot solvent, coating the obtained solution on a substrate, and removing the solvent. CONSTITUTION:A polyolefin such as polyethylene or polypropylene is dissolved in an aromatic hydrocarbon type solvent such as xylene or tetralin and, to this solution, a nonsolvent which does not dissolve said polyolefin but is compatible with the above-described solvent and of which b.p. is by at least 10 deg.C higher than that of the above-described solvent and the difference of solubility index is at least 0.3, such as cellosolve or dioctyl adipate, is added. Subsequently, the obtained solution is coated by impregnation into heat-resistance fabric or nonwoven fabric and, thereafter, the solvent and the nonsolvent are evaporated by heating. |