| 摘要 |
A resin foam having excellent dustproofness not only at ordinary temperatures but also particularly at high temperatures as well as having excellent flexibility. The resin foam has a thickness recovery ratio at high temperatures as defined below of not less than 25%, an average cell diameter of 10 to 200 μm, and a maximum cell diameter of not more than 300 μm, wherein the thickness recovery ratio at high temperatures is defined as follows: a resin foam in a sheet form is compressed, in an atmosphere of 80° C., for 22 hours in a thickness direction so as to have a thickness of 20% of the initial thickness; then, the compression state is released in an atmosphere of 23° C.; and a ratio of a thickness 24 hours after the release of the compression state to the initial thickness is defined as the thickness recovery ratio at high temperatures. |
