VIBRATION ENERGY ABSORBING MEMBER AND SOUND INSULATION MEMBER AND VIBRATION ABSORBING MEMBER INCLUDING THE SAME

PROBLEM TO BE SOLVED: To provide a vibration energy absorbing member having high vibration energy absorbing performance and excellent balance with rigidity.SOLUTION: A vibration energy absorbing member comprises 100 pts.wt. of polyolefin resin, 10 to 200 pts.wt. of a propylene-butene-1 copolymer and/or an ethylene-propylene-butene-1 terpolymer, and 10 to 500 pts.wt. of an organic fiber. In the propylene-butene-1 copolymer, the content of propylene is 50 to 99 mol% and the content of butene is 1 to 50 mol%. In the ethylene-propylene-butene-1 terpolymer, the content of propylene is 1 to 99 mol%, the content of butene is 1 to 50 mol%, and the content of ethylene is more than 0 mol% and not more than 80 mol%, (assuming 100 mol% of the total amount of the ethylene-propylene-butene-1 terpolymer). The weight-average fiber length of the organic fiber is 2 to 50 mm. 【課題】高い振動エネルギー吸収性能を有し、剛性とのバランスに優れる振動エネルギー吸収部材を提供する。【解決手段】ポリオレフィン樹脂１００重量部と、プロピレン−ブテン−１共重合体及び／又はエチレン−プロピレン−ブテン−１三元共重合体１０〜２００重量部と、有機繊維１０〜５００重量部とを含有する振動エネルギー吸収部材であって、前記プロピレン−ブテン−１共重合体中のプロピレン含有量は５０〜９９ｍｏｌ％、ブテン含有量は１〜５０ｍｏｌ％であり、前記エチレン−プロピレン−ブテン−１三元共重合体中のプロピレン含有量は１〜９９ｍｏｌ％、ブテン含有量は１〜５０ｍｏｌ％、エチレン含有量は０ｍｏｌ％を越え８０ｍｏｌ％以下であり、（但し、エチレン−プロピレン−ブテン−１三元共重合体の全体の量を１００ｍｏｌ％とする）、前記有機繊維の重量平均繊維長は２〜５０ｍｍである。【選択図】なし