| 摘要 |
The production of approximately spherical polyolefin foam particles having a coarse cell structure and a narrow cell size distribution by dispersion foaming is achieved by a process in which the reactor contents, which essentially comprise polyolefin particles, a liquid dispersion medium and, if desired, a volatile blowing agent, are first treated at a first temperature above the crystallite melting point Tm of the polyolefin, and subsequently passed through a cooling device, in which the dispersion is brought to a second, lower temperature, and the polymer particles are then foamed at this temperature. The foamed particles can be converted into moldings by known methods.
|
