| 摘要 |
PROBLEM TO BE SOLVED: To provide a fiber including thermally expandable resin particles obtained by a melt spinning method, which melts when heat is applied and can sufficiently expand the thermally expandable resin particles. SOLUTION: A method for producing a thermally expandable fiber comprises a step of mixing 1) a thermally expandable resin particles comprising an outer shell that includes a thermoplastic resin and a foaming agent that is included in the outer shell and is vaporized by heating and 2) a polyethylene-based base resin having a melting point Tm lower than an expansion start temperature of the thermally expandable resin particles and a melt flow rate (MFR) at 190°C of 6 g/10 min or more (load of 21.18 N (2.16 kgf), measured according to JIS K7210) to obtain a base mixture; and a step of spinning by a melt-spinning method at a temperature less than the expansion start temperature of the thermally expandable resin particles and equal to or greater than Tm+30°C so that at least one component constituting the fiber is a component that includes the base mixture. COPYRIGHT: (C)2012,JPO&INPIT |
