POROUS BODY AND METHOD FOR PRODUCING SAME

摘要

The present invention provides a porous body offering excellent heat resistance and having a fine cell structure and low relative permittivity, as well as a method for producing the same. The purpose of the present invention is to provide a heat-resistant porous body for which any decline in the upper temperature limit is minimized as well as a method for producing the same, by effectively removing residual additives that conventional methods of solvent extraction and the like have been unable to remove. This method for producing a porous body comprises: a step for applying to a substrate and drying a polymer composition comprising a polymer, a phase separation agent, and an organic solvent to prepare a polymer sheet having a microphase-separated structure; and a step for using a carbon dioxide fluid as an extraction solvent to extract and remove the phase separation agent from the polymer sheet while also raising the temperature of the carbon dioxide fluid, thus preparing a porous polymer sheet.