| 摘要 |
<p>In a process for producing polyolefin prefoam particles with the use of water as an expanding agent, it is intended to provide polyolefin prefoam particles exhibiting high expansion ratio whose dispersion is low. Polyolefin prefoam particles are produced by a process effectively utilizing water used in a dispersion medium as an expanding agent, comprising dispersing, in an aqueous dispersion medium in a sealed container, polyolefin resin particles whose capability of water impregnation has been increased by causing the same to contain a hydroxyalkylethanolamine being a special cationic surfactant and a compound having triazine skeleton whose molecular weight per triazine skeleton is 300 or less; heating the dispersion to a temperature not lower than the softening temperature of the polyolefin resin particles and increasing the internal pressure of the sealed container by introduction of air or nitrogen; and releasing them to an atmosphere of pressure lower than the internal pressure to thereby effect expansion.</p> |
