| 摘要 |
PURPOSE:To produce the title foam having a closed cell structure and an improved moldability. CONSTITUTION:A mixture of unexpanded spherical particles comprising shells made of a first thermoplastic resin and a blowing agent enclosed therein, an unbaked tetrafluoroethylene resin powder, and a powder of a second thermoplastic resin having an m.p. lower than that of the first thermoplastic resin is molded into a desired shape. The resulting molded article is heated to expand the particles, thereby converting the tetrafluoroethylene resin powder into a three-dimensional fibrous structure with the aid of the expansion pressure, simultaneously forming a closed cell structure based on the particles, and thereby integrally bonding the particles to the tetrafluoroethylene resin with the molten second thermoplastic resin. The prepd. foamed molded article, while having a closed cell structure with a high porosity, hardly exhibits the orientation of microfibers of the tetrafluoroethylene resin in any direction, allowing little anisotropy in mechanical strengths to occur. |
