PROBLEM TO BE SOLVED: To provide a warm-keeping agent for a polyolefin-based resin with which a polyolefin-based resin excellent in warm-keeping property can be obtained, and the polyolefin-based resin in which deterioration hardly occurs even if a pipe in contact with it is further heat-accumulated, can be obtained by adding it to the polyolefin-based resin as a warm-keeping property improver； and an agricultural film using it.SOLUTION: The warm-keeping agent for the polyolefin-based resin includes a perchlorate ion type hydrotalcite compound, and further, the polyolefin-based resin composition containing the warm-keeping agent is especially used for agricultural films.【課題】保温性改良剤としてポリオレフィン系樹脂に添加して、保温性に優れ、さらに接触しているパイプが蓄熱しても、劣化の起こりにくいポリオレフィン系樹脂が得られるポリオレフィン系樹脂用保温剤およびそれを用いた農業用フィルムの提供。【解決手段】過塩素酸イオン型ハイドロタルサイト類化合物を含有するポリオレフィン系樹脂用保温剤であり、また、上記保温剤を含有してなるポリオレフィン系樹脂組成物は、特に農業用フィルム用に用いられる。【選択図】なし
