| 摘要 |
PURPOSE:To obtain titled foam of outstanding shape memory effect with ready shape recovery even under decreased temperature, most suitable as insulating materials and/or cushioning ones for electrical equipment, etc., by crosslinking a noncrosslinked expanded material consisting mainly of high-molecular weight polycaprolactam followed by secondary processing. CONSTITUTION:A material consisting mainly of polycaprolactam with a molecular weight >=40,000 is incorporated with a foaming agent such as fron gas to make a string-shaped non-crosslinked expanded matter using, e.g., an extruder, followed by irradiating an ionizing radiation to the matter to effect crosslinking. The resultant crosslinked expanded material is heated, for example, to ca. 80 deg.C, being softened to change in shape and dimension, followed by cooling to solidify, thus obtaining the objective foam. In case said noncrosslinked expanded matter is thick bar or complex in shape, a chemical crosslinking will suitably be applied. |
