POLYETHYLENE-BASED EXTRUSION FOAM

To provide a polyethylene-based extrusion foam which has a small average foam diameter, a high ratio of closed cells and less voids.SOLUTION: A polyethylene-based extrusion foam contains a polyethylene-based resin satisfying the following (a) and (b) in elongation viscosity measurement: (a) elongation viscosity at an elongational strain of 0.5 at solidification temperature +1°C of 2.0E+6 Pa s or more; and (b) a temperature range between a temperature at which elongation viscosity at an elongational strain of 0.5 is 4.0E+5 Pa s or more and solidification temperature +1°C of 4°C or higher and 9°C or lower.SELECTED DRAWING: None 【課題】 平均気泡径が小さく、独立気泡率が高く、かつ巣が少ない、ポリエチレン系押出発泡体を提供すること。【解決手段】 伸長粘度測定における次の（ａ）および（ｂ）を満たすポリエチレン系樹脂を含有するポリエチレン系押出発泡体；（ａ）固化温度＋１℃における伸長ひずみ０．５での伸長粘度が２．０Ｅ＋６Ｐａ・ｓ以上である、（ｂ）伸長ひずみ０．５での伸長粘度が４．０Ｅ＋５Ｐａ・ｓ以上となる温度から、固化温度＋１℃までの温度範囲が４℃以上、９℃以下である。【選択図】なし