PROBLEM TO BE SOLVED: To provide a repellent which has excellent sustained releasability while having biodegradability and can be used for a long period of time.SOLUTION: The repellent is obtained by impregnating a base material composed of a polylactic acid copolymer obtained by polymerizing a predetermined amount of L-lactide with a resin essence oil having &alpha-pinene as the major component. Since even the inner part of the base material is impregnated with &alpha-pinene, the amount of the &alpha-pinene released per unit time with the decomposition of the polylactic acid copolymer can be maintained constant.COPYRIGHT: (C)2011,JPO&INPIT【課題】生分解性を有しつつ、優れた徐放能を有し、長期間使用が可能な忌避剤を提供する。【解決手段】L-ラクチドが所定の割合で重合されたポリ乳酸共重合体からなる基材に、α-ピネンを主成分とする樹脂精油を含浸させる。α-ピネンが基材の内部まで含浸するため、ポリ乳酸共重合体の分解に伴う単位時間当たりのα-ピネンの放出量をほぼ一定に保つことができる。【選択図】図2
