A process for producing a porous laminate having many micropores interconnected in the thickness direction, which comprises: a step in which a laminate is produced which comprises at least three layers comprising an interlayer made of a thermoplastic resin having a hard segment and a soft segment and two nonporous outer layers made of a filler-containing resin and located as outer layers respectively on both sides of the interlayer; a step in which the laminate obtained is impregnated with a supercritical or subcritical fluid and this state is relieved to vaporize the fluid and thereby make the interlayer porous; and a step in which the two nonporous outer layers located respectively on both sides are made porous by stretching.
一种生产在厚度方向上有许多微孔相互连接的多孔层压板的工艺,它包括第一步:生产一种层压板,该层压板至少由三层组成,其中包括一层由热塑性
树脂制成的中间层,该中间层具有硬段和软段;以及两层由含填料
树脂制成的无孔外层,这两层分别位于中间层的两侧;用超临界或亚临界流体浸渍所得到的层压板,并解除这种状态,使流体汽化,从而使夹层多孔;以及通过拉伸使分别位于两侧的两个无孔外层多孔的步骤。