| 摘要 |
PURPOSE:To prevent aggregation of a nucleating agent, and to obtain thermoplastic resin foam having fine and uniform expanded texture, by introducing a gas, under pressure, into a molten resin that is premixed with the nucleating agent for expansion in a microcapsuled state, expanding it when it is extruded. CONSTITUTION:A nitrogen gas is introduced under pressure at 11kg/cm<2> into a thermoplastic resin, in a molten state, which is blended with a nucleating agent for expansion microcapsuled using liquid paraffin as a material, and dissolved in the molten resin. The resin is extruded at 240 deg.C, the gas is expanded by the pressure release in extrusion to form foam. Jamming of screen of breaker plate is prevented, stable expansion state is continued for a long period, and the uniform foam is obtained.
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