| 摘要 |
PURPOSE:To provide a particle which has high expansion performances and an ability to keep an excellent closed-cell content, can give a foamed molding of excellent quality when used in in-mold molding, can be expanded by using an inorganic gas when it is foamed or expanded during its production or during formation into a molding, and can clear the FC regulation. CONSTITUTION:Expanded polyolefin resin particles are kept in a gas atmosphere under elevated pressure below the critical pressure of carbon dioxide, and below 2 pts.wt., per 100 pts.wt. resin component, carbon dioxide gas is infiltrated into the resin to form expandable resin particles, which are foamed by heating to form expanded particles of an expansion ratio of 1.5-3.8cm<3>/g. Thus, new lowly expanded particles having an apparent film thickness per cell (as determined from cell diameters and the number of cells) in a range of 4-26mum and a closed-cell structure having a uniform cell diameter can be obtained. |
