| 摘要 |
PURPOSE: To obtain products with independent blowhole structure and a high compression strength by supplying a specific resin composition in extruder wherein melted/mixed, and then by introducing and mixing blowing agent that is insoluble in this resin at room temperature but soluble in the melt. CONSTITUTION: An engineering thermoplastic resin, alone or as a resin composition comprising this and alkenyl aromatic polymer, is supplied to extruder 2, followed by melting and mixing. By introducing blowing agent that is almost insoluble in this resin at room temperature but soluble at a high temperature into the extruder, the blowing agent and resin are mixed. This mixture is cooled in the second extruder 12 and foamed through a die. By the way, polyphenylene ether/crystalline polystyrene(PPE/PS) resin is preferable as the thermoplastic composition, and hydrocarbon, chloro-fluorocarbon and the like are preferable as the blowing agent. Foam structure can be obtained for more than 95%, by relatively small-sized independent blowhole structure. |
