| 摘要 |
<p>Expandable particles containing as a base resin a propylene polymer satisfying the following requirements (a) to (c); a resin composition; and an in-mold molding and an impact absorber each obtained by molding the expandable particles. The polymer comprises 100 to 85 mol% structural units derived from propylene and 0 to 15 mol% structural units derived from ethylene and/or a C4-20 α-olefin. In examination by 13C-NMR, the proportion of irregularly positioned propylene monomer units based on 2,1-insertion in all propylene units is 0.5 to 2.0% and the proportion of irregularly positioned propylene monomer units based on 1,3-insertion is 0.005 to 0.4%. The melting point, Tm [°C], and the water vapor permeability of a film of the polymer, Y [g/m2/24 hr], satisfy a specific relationship.</p> |
